CHANGSTAR: Audiophile Headphone Reviews and Early 90s Style BBS
Lobby => Speakers => Topic started by: Marvey on February 09, 2014, 07:40:46 PM
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Donald North (for those who do not know, he's made some awesome DNA speakers) advised me that I needed to make some open baffle speakers; and that once I did, I would never go back to box speakers. He was right.
(http://www.changstar.com/index.php?action=dlattach;topic=1436.0;attach=5550;image)
More later...
- BTW, I'm hauling this project up to the Bay Area Meet. There will be a dedicated speaker room set away from the headphone rooms.
- Yes, those are the 8" Moth Cicada drivers up top. Those drivers, based on their TS parameters, were practically designed for OB.
- Based on the sound quality, my wife approves of the mess - most of which scattered around the house and not seen in the photo.
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Those look fun. Also they look easier to make. I might think about trying a pair if we can get specs/plans.
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That's the idea. To eventually come up an easy plan(s).
They are supremely easy to make. I probably made things much more difficult by first building a frame and then detachable pieces so I could experiment. Just cutting a 4x8 sheet in half would get you almost right there.
I'm integrating the woofers right now. They are the Eminence Betas. The extremely high Qts of the Alphas scared me away. A suitable replacement for the 8" wide band driver could be found with Fostex. An alternative would be a separate 8" mid + tweeter.
So far I've only heard the Cicada drivers augmented by the subs. Surprisingly / scary good. OB speakers are like the equivalent of open headphones. All box speakers sound like closed headphones. That's a pretty big difference. I was also surprised at the speed and resolution of the Moth driver. My wife said this was the best sounding speaker I've ever made, and I hadn't integrated the woofers yet. There's a slight recess in the mid-bass with only the Moth drivers.
This is probably the easiest speaker I've ever made too. The OB woofers will be run through the cheapy Behringer DCX2496 for X-over and EQ below ~200Hz. The Moth driver will use only one capacitor in the signal path for high pass x-over.
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(http://www.changstar.com/index.php?action=dlattach;topic=1436.0;attach=5550;image)
(http://matthewmeyer.net/wordpress/wp-content/uploads/2013/10/pans-labyrinth-pale-man.jpg)
Couldn't help it.
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LOL @ Kirosia
Don't take any of the nice looking food from Purrin's table, or his speakers will wake up and eat you.
But yeah... speakers are awesome. I'm getting into speakers this year, myself.
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Looks good. Is the size of these speakers an indication of their range?
The speakers look large enough to fill a decent sized living room for music and movies.
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Ive heard Vintage open Baffle Altecs and they were pretty nice already
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Damn damn damn! Purrin beats me to it again! If I hadn't been swamped with classes this quarter I would have had my own OB built by now. At this point I'm looking at first order filters + software PEQ to touch things up, similar to what you have I imagine. Still going to use that Alpha 15A driver myself.
Give me a few more weeks and it'll be ready. I promise it'll be even dirtier and cheaper than yours :)p1
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(http://www.changstar.com/index.php?action=dlattach;topic=1436.0;attach=5550;image)
(http://matthewmeyer.net/wordpress/wp-content/uploads/2013/10/pans-labyrinth-pale-man.jpg)
Couldn't help it.
Dang, don't give me any ideas. I could might draw something like that on the boards.
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Looks good. Is the size of these speakers an indication of their range?
The speakers look large enough to fill a decent sized living room for music and movies.
Pretty much. The problem with OB speakers is bass roll off depending upon the drivers used. The wide baffles help to extend that. The 15" Betas have a Fs of 35Hz and fairly high Qts. I think I'm getting extension down to 40Hz. Everything, x-overs, EQ, etc. so far has been done by ear, so I'm not totally sure about that. I'm hoping not to have to resort to a sub. I do know that I have quite a lot of headroom to probably squeeze another 5-10Hz of bass extension using EQ.
Regardless of OB design or not, I'm a huge advocate of BIG drivers for bass, even mid or high bass. There's nothing like 15" or 18" woofers producing bass. Just an effortless, very refined, and fast explosive quality to it. And likewise 8" drivers producing mids. It's nice not seeing the drivers move or just barely move. Lower distortion. Probably also has something to do with keeping the magnetic field on the voice coil in the most linear range of its motion. Or maybe it's something like that old adage for car engines: there's no replacement for displacement. This is why most $50,000 "audiophile" speakers at events like THE SHOW suck. Many of these designs have been compromised by the WAF - thin skinny "attractive" things.
Just do the math. How many 8 inch "woofers" does it take to equal the cone area of one 15 inch woofer used here.
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Damn damn damn! Purrin beats me to it again! If I hadn't been swamped with classes this quarter I would have had my own OB built by now. At this point I'm looking at first order filters + software PEQ to touch things up, similar to what you have I imagine. Still going to use that Alpha 15A driver myself.
Give me a few more weeks and it'll be ready. I promise it'll be even dirtier and cheaper than yours :)p1
Just wait a bit and you can have my Betas. The woofers I have, at less than $80 each, are definitely the weakest link. I already plan on replacing them with maybe 18" drivers of quality closer to the Cicada drivers.
If you have enough room for an OB setup, you will never go back. The OB sound is really open. Practically removes the walls from the room.
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Interesting. I've never heard OB speakers. Might help solve my problem with speakers.
Do you think you can get to a point where no sub is needed and reach down to say 30hz cleanly. I'm guessing at least a 15" would be necessary.
Is that any particular baffle material that is better for this implementation? How much are we looking at for a full project cost?
edit: Also, any particular amping needs? It seems inefficient, so will something like a Ragnarok not be able to handle this?
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Funny tidbit when I found out originally that Craig wasn't going to bring the 445 or mk4 amp to the Bay Area meet:
ME:
Craig, those Cicada drivers are awesome. I can't believe the extension in treble for an 8" driver - no supertweeter needed; and also in bass on an open baffle.
CRAIG:
Yeah, their Fs is about 50Hz, but Qts is around 0.7. I've never heard them on an OB, but I've heard of others getting good results. I saw on picture of a guy putting the driver on a glass (acrylic) board once.
ME:
I'll bring them to the meet so you can hear them. These drivers were always meant to be used on OB.
CRAIG:
The old Cicada enclosures didn't use the modern bracing techniques. So what you are going to use as a amp?
ME:
Well, I was hoping that I could use one of YOUR amps since I am using a MOTH driver, but since you are not bringing anything, I'm going to use one of Schiit's. I mean, I would prefer not to use a Schiit amp because I am using your MOTH driver, and that just wouldn't be right to you.
CRAIG:
Oh, in that case, I'll try to bring either a 445 or one of the mk4 amps to the meet.
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Two speakers set into a stand...finally a DIY speaker that I could build!
What would happen if you shrunk the width of the baffle on the top half with the Moth driver? I am wondering if I could shrink it down into a smaller size and make an open baffle bookshelf size speaker with one of the full range drivers like the fostex. I guess I would loose bass extension unless I implemented a separate sub. Might be worth trying if I could trade off more openness vs increased bass response from a ported bookshelf speaker (which isn't going to be that great anyway from something the size I am considering).
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I always drive by this place that makes marble countertops and keep thinking I should get some slabs to mount speakers onto.
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I guess I would loose bass extension
Pretty much. Baffle needs to be large with respect to wavelength or else you have an acoustic short circuit. How wide are those baffles purrin?
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You could probably reduce the width of the top half where the Moth drivers are mounted. I kept them wide on purpose to allow for a variety of mounting locations even though I decided on mounting in the middle. The baffles are 24" wide. The other reason was to provide for a lot of latitude (I really didn't know what the TS parameters of the Moth driver were and to this day, I do not trust the published specs.) as I used them solely by themselves with a sub but no woofers.
The consideration for the Moth driver was to run them from a 3-6 watt tube amp (guess which ones) using one capacitor only. I hate passive x-over components. All they do is destroy the sound. But in this case, I was willing to make a compromise - a very small one. Because I was only using one cap, the best I was going to get was a 1st order 6db electrical roll-off. That's not very much roll-off at all to protect the Moth driver from over-excursion (always an issue with OB), so I wanted to make sure I could run the Moth driver as low as possible before crossing over to the woofers.
I haven't done the calculations for this scenario, but I suspect I could have gotten away with no baffle or just a 1-2" lip around the Moth driver if I wanted to crossover at 200-300Hz.
In terms of OB bookshelf - the serious downside to OB is that you need a lot of room - and that means several feet behind the speaker to the wall.
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Interesting. I've never heard OB speakers. Might help solve my problem with speakers.
Do you think you can get to a point where no sub is needed and reach down to say 30hz cleanly. I'm guessing at least a 15" would be necessary.
Is that any particular baffle material that is better for this implementation? How much are we looking at for a full project cost?
edit: Also, any particular amping needs? It seems inefficient, so will something like a Ragnarok not be able to handle this?
We'll see how low it gets after some tuning tonight. I haven't run the measuring tools yet. I think an 15" woofer with the right parameters can do 30Hz or very close to it at reasonable SPL. SPL, cone excursion, and digital headroom are the limitations.
LOL, I'm using cheapass oak plywood 5/8". Will add rib supports in the back. I plan on using some more attractive wood pieces, probably CNC'd for a final version. Unlike a box speaker, heroic construction methods are not as crucial to OB speakers.
In terms of amps, 3 watts for the wide-bander. 100+ watts for the woofers. Recommend the highest quality amp you can fine for the wide-bander. Something from Emotiva should do for the woofers.
DCX2496 is a few hundred bucks.
Woofers were well less than $200 shipped.
Suitable wide-banders could be $600 if you want really really good ones.
How much is an Emotiva power amp?
Outside of the quality amp, we are talking less then the cost of a new HD800. This includes drivers, wood, OB woofer processor, and woofer amp.
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Very cool build, I bet they sound great. I prefer boxless as well (half the reason I prefer stats), but I would worry a little about the panels resonating a bit - especially the woofer panel. It looks like you'll have this covered soon. What kind of support is temporarily in place?
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Pic from side and back plz!
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Pretty much. The problem with OB speakers is bass roll off depending upon the drivers used. The wide baffles help to extend that. The 15" Betas have a Fs of 35Hz and fairly high Qts. I think I'm getting extension down to 40Hz. Everything, x-overs, EQ, etc. so far has been done by ear, so I'm not totally sure about that. I'm hoping not to have to resort to a sub. I do know that I have quite a lot of headroom to probably squeeze another 5-10Hz of bass extension using EQ.
What do you think of doing a half open speaker ala something like the NOLA Viper? To me, having an open baffle design go well below 100Hz just seems unnecessary, being that all bass is omni directional, and most of what you're hearing is actually reflections as opposed to direct sound. A sealed or ported box would give you a lot more extension than not, and there are considerable advantages to a bipolar design of two opposing woofers in phase with each other.
As for size, I generally (very generally) prefer 12" woofers to anything else, I think they are the best middle ground between fast 8" or 10" woofers that struggle with deep bass extension and SPL without considerable xmax that makes them start to go out of control, or huge woofers that can often sound too slow without servo control, or otherwise sacrifice deep extension in order to not move too much and keep up. Two 12" woofers in a box are hard to beat. It's what Eggleston uses in the Andra, and they get 18Hz at -3dB, and that puppy can keep up with anything you throw at it.
The Lotus Granada is one of the more interesting full open designs that I've seen, but when I've heard it at shows it wasn't perfect, particularly in the treble region. It costs TOTL Venture money, and the Ventures definitely have it beat. Looks cool though.
(http://www.stereotimes.com/images/zzzzzRMAF09-127.gif)
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wtfbbq rack are you using? Looks like a bunch of ikea lacks cut down and stuck together.
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wtfbbq rack are you using? Looks like a bunch of ikea lacks cut down and stuck together.
Lol, good eye.
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Congrats Purrin for building a dipole speaker system! I'm really glad you tried the concept and are enjoying the performance.
@DaveBSC: In my opinion the most benefit from dipole (OB) speakers is in the bass because you get a lot less room mode excitation. Dipoles have a directivity index of 4.8dB, which means for the same on-axis SPL as a box speaker, you're radiating 4.8dB less power into the room. With proper room placement you attain a much smoother frequency response in room at the listening position without the need for room EQ.
With dipole woofers, it's all about air volume displacement. Multiple 10 or 12 inch woofers are good. So is a pistonic 15 or 18 inch woofer.
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Really cool! Looking forward to more details, design, etc.
Dang, don't give me any ideas. I could might draw something like that on the boards.
Let me know if you need any help.
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The consideration for the Moth driver was to run them from a 3-6 watt tube amp (guess which ones) using one capacitor only. I hate passive x-over components. All they do is destroy the sound. But in this case, I was willing to make a compromise - a very small one. Because I was only using one cap, the best I was going to get was a 1st order 6db electrical roll-off. That's not very much roll-off at all to protect the Moth driver from over-excursion (always an issue with OB), so I wanted to make sure I could run the Moth driver as low as possible before crossing over to the woofers.
I haven't done the calculations for this scenario, but I suspect I could have gotten away with no baffle or just a 1-2" lip around the Moth driver if I wanted to crossover at 200-300Hz.
You'll need a much larger baffle than a 2" lip around the Moth driver to go down to 200-300Hz without roll-off. The size in your photos looks good.
For high-pass filter on the full-range driver, try using a series cap on the input of the amp powering it. You'll need to calculate the value depending on desired corner frequency and amplifier input impedance. In my experience this will provide a more predictable and desirable filter with the added benefit of more dynamic range from the amp itself.
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Marv, you seen Bryan's work on the DCX 2496?
http://www.head-fi.org/t/693497/official-2014-bay-area-meet-sunday-feb-16th-2014/300#post_10256047
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Oh that looks fantastic! I seem to recall reading that was a direction they were considering with Ti Kan's CBT36.
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What do you think of doing a half open speaker ala something like the NOLA Viper? To me, having an open baffle design go well below 100Hz just seems unnecessary, being that all bass is omni directional, and most of what you're hearing is actually reflections as opposed to direct sound.
I know... lots of old schoolers think OB bass is a waste of power - and indeed it is. To follow up on what Donald said on OB bass, the directionality of OB bass is actually not omni-directional, but rather in a figure eight pattern with the rear facing radiation in opposite phase to the front. In theory, we are actually reducing some of the initial side reflections from the wall.
I'll post of pic of the behinds. You'll see that I've actually implemented a partial U-frame with irregular patterns in the back. This should provide a slight hypercardioid radiation pattern. From other speakers, I know the significant room nodes (27, 44, 66, and 88), and I found out with OB that the magnitude of the 44 and 88 nodes were halved. (For some reason, the node at 66Hz wasn't mitigated.) In addition, I found that two nulls around 60 and 74, which I could never really fill before regardless of how much +EQ I applied were easily correctable.
Finally, despite the massive power waste, I like sharp and fast setting impulse response of OB. Everything in box (or even stuffed U frame) seems to have its impulse response dampened or settling time extended.
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@DaveBSC: In my opinion the most benefit from dipole (OB) speakers is in the bass because you get a lot less room mode excitation. Dipoles have a directivity index of 4.8dB, which means for the same on-axis SPL as a box speaker, you're radiating 4.8dB less power into the room. With proper room placement you attain a much smoother frequency response in room at the listening position without the need for room EQ.
With dipole woofers, it's all about air volume displacement. Multiple 10 or 12 inch woofers are good. So is a pistonic 15 or 18 inch woofer.
Interesting, though it's worth noting that the majority of commercial fully OB designs (as far as I'm aware) use some form of active EQ, so you end up with room EQ anyway. There's also arguably more of a need for room treatments with dipoles and OB designs in particular than with traditional box speakers, and especially compared to FR enclosures or constant directivity horn types. FR enclosures for example should need little more than bass traps.
The typical treatments I see with traditional dipoles like ESLs or planars or OBs is to try to "black hole" the wall behind the speakers with absorption, though I've found that diffusers can actually be more effective, though trickier, as you want some reflection, just not right away. Linkwitz argues for >6ms IIRC, but I've heard other designers recommend >10ms. The other option is to pull your dipoles 6+ feet away from the wall, but of course that's often not practical.
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Very quick EQ from last night - didn't want to annoy family to much with pink noise or sweeps.
I was really surprised that the predictive models worked out well. A +3 rise around 400Hz from the OB was corrected for. The Moth driver has some ringing at 10kHz and shoutyness at 1.5kHz which were pushed down (-6db and -3db). Again, I don't believe in overly aggressive EQ. Another bump at 80Hz (actually think of it as a rolloff somewhere lower) was also pushed down on the woofers.
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Don't laugh at the ratshack 'lytic cap, the CAT5 speaker cable, and the Obligato taped to the back of the board.
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How does it compare to the Fostex BLH once EQed? I'm betting the lack of weird horn coloration in the upper bass is the biggest difference.
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I've seen much worse.
By the way, try one of those Linkwitz' designs, they really take names once fitted with proper speakers.
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Speaking of Linkwitz an acquaintance of mine built a pair of lx521'es. I'm dying to hear them.
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I've seen much worse.
By the way, try one of those Linkwitz' designs, they really take names once fitted with proper speakers.
I'm going into a totally different direction from Linkwitz. He's into active x-over and EQ with op-amps, inefficient poorly behaved, but very precise sounding metal drivers, 88 high powered solid-state amplifiers (one for each driver), etc.
I'm into tubes (namely SET) + efficient drivers (at least from bass on up); and I won't touch op-amps for x-over or EQ in the critical regions (been there, done that.) I'm also done with inefficient poorly behaved metal drivers which require 8-order x-overs so they don't end up sounding like aluminum pots and pans banging on each other.
Just opposite philosophies and tastes.
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How does it compare to the Fostex BLH once EQed? I'm betting the lack of weird horn coloration in the upper bass is the biggest difference.
There's really no comparison. First off, the 6" driver of the BK-16 is no way going to compete with a 15" for bass and 8" for mids. The 6" driver actually sounds muddy and strained in comparison. Not only is there lack of horn coloration, but the room just opens up with OB. The Moth driver is also far superior in terms of resolution, speed, and extension compared to the fe166 of the BK-16. (Note no supertweeter.) The downside is the ringing at 10k, which isn't a bad spot and can always be EQ'd down. Also the big baffles tend to create less precise more diffuse imaging. I may put some diffusor type stuff like strips or foam on the baffle to improve this.
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Interesting, though it's worth noting that the majority of commercial fully OB designs (as far as I'm aware) use some form of active EQ, so you end up with room EQ anyway. There's also arguably more of a need for room treatments with dipoles and OB designs in particular than with traditional box speakers, and especially compared to FR enclosures or constant directivity horn types. FR enclosures for example should need little more than bass traps.
The typical treatments I see with traditional dipoles like ESLs or planars or OBs is to try to "black hole" the wall behind the speakers with absorption, though I've found that diffusers can actually be more effective, though trickier, as you want some reflection, just not right away. Linkwitz argues for >6ms IIRC, but I've heard other designers recommend >10ms. The other option is to pull your dipoles 6+ feet away from the wall, but of course that's often not practical.
Jamo made a passively-EQ'd dipole, the R909. My preference is bi-amping with active equalization. With dipole woofers you can use a simple 6dB/oct lowpass filter with gain to do the EQ and the gain can be performed through opamps, transistors, or my preference triodes. The same can't be said for room EQ which needs parametric EQs and preferably done in the digital domain to minimize signal degradation.
In the bass region I would say dipoles need less room treatment than box speakers, which need bass traps and more. In the midrange and treble, both dipole and traditional moving coil speakers have similar front radiation into the room with attention needed for first reflection points, etc. Dipoles do have the extra radiation from the rear which some people prefer to leave untouched. Linkwitz talks about illuminating the room evenly across the frequency spectrum and I see his points. Others use mild room damping.
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Also the big baffles tend to create less precise more diffuse imaging. I may put some diffusor type stuff like strips or foam on the baffle to improve this.
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Are you sure the somewhat diffuse imaging is due to the big baffle and not the rear radiation into the room? My experience says it falls to the latter category. One way to investigate is listen to the speakers outdoors, where you won't hear the rear radiation.
I, too, notice dipole midrange and treble being a little more diffuse imaging than I like, which can be refined with some rear wave damping. I took a different approach and made the midrange-treble portion of my Sequence speakers as a sealed box.
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LOL, I've been moving the speakers up 1" per day from the back wall in hopes my wife won't notice. You are probably right, it's the back wall reflections.
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I, too, notice dipole midrange and treble being a little more diffuse imaging than I like, which can be refined with some rear wave damping. I took a different approach and made the midrange-treble portion of my Sequence speakers as a sealed box.
Now THAT is interesting. A NOLA in reverse. I don't think I've ever seen that done by anyone else.
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LOL, I've been moving the speakers up 1" per day from the back wall in hopes my wife won't notice. You are probably right, it's the back wall reflections.
Yep, hence the typical arrangement of loading up the wall behind dipoles with panels and traps - most people with dipoles just try to knock out the rear wave. If you can, try using diffusion there instead. If you get it right in terms of of the delayed reflection, the space will sound MUCH larger than it actually is, without the imaging issues caused by early reflections from the wall behind (and possibly the side walls depending on what you have there.)
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Now THAT is interesting. A NOLA in reverse. I don't think I've ever seen that done by anyone else.
I'm not the first to do it. I believe that honor goes to Celestion with their System 6000 in the 80s. I built my own dipole woofers in the early 90s to go with their SL700SE and later continued this configuration with the Sequence
(http://i39.tinypic.com/16auu8h.jpg)
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For a diffusor, a bit of rough concrete in a with an U shape is pretty good. Or better yet, chunk of pumice - both absorbs and diffuses.
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The fireplace and bricks behind actually work well as good diffusor at 1-4kHz.
To be clear, I wouldn't say the imaging is bad, it's just not totally spot on like the BK-16 kit I had before. Minor adjustments tend to help a lot. Toe-in speakers, moving a few inches forward, moving a few inches closer, etc.
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I'm not the first to do it. I believe that honor goes to Celestion with their System 6000 in the 80s. I built my own dipole woofers in the early 90s to go with their SL700SE and later continued this configuration with the Sequence
(http://i39.tinypic.com/16auu8h.jpg)
Very cool. Couldn't you get to the same goal with monitors and dipole subwoofers though? That would open up more options in terms of being able to use dedicated amplifiers and PEQ etc without affecting the main speakers at all, for those of us that like a "less is more" approach.
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Very cool. Couldn't you get to the same goal with monitors and dipole subwoofers though? That would open up more options in terms of being able to use dedicated amplifiers and PEQ etc without affecting the main speakers at all, for those of us that like a "less is more" approach.
I don't clearly understand your question. Can you elaborate please?
Yes, you can use monitors with dipole subwoofers which is what the Celestion speaker was (SL600 monitors with System 6000 dipole subwoofers & active crossover). Dipole woofers provide their benefit below 200Hz where the room modes dominate, so in my experience it's best to highpass the main speakers/monitors. This can be done as simply as a strategic capacitor in series with the amp powering the monitors. For my personal setup I built the highpass filter into the 2A3 PSE amps powering the 95dB efficient midrange-tweeter array.
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[quote author=Donald North link=topic=1436.msg37892#msg37892
I don't clearly understand your question. Can you elaborate please?
Yes, you can use monitors with dipole subwoofers which is what the Celestion speaker was (SL600 monitors with System 6000 dipole subwoofers & active crossover). Dipole woofers provide their benefit below 200Hz where the room modes dominate, so in my experience it's best to highpass the main speakers/monitors. This can be done as simply as a strategic capacitor in series with the amp powering the monitors. For my personal setup I built the highpass filter into the 2A3 PSE amps powering the 95dB efficient midrange-tweeter array.
[/quote]
What I mean is, run the subwoofers from the pre-outs of the linestage to high-powered SS A/B or even Class D if you want amps with whatever type of EQ you like, and then the main outs to Class A monos powering the monitors. The subwoofers could be placed where ever they are most effective in the room, there's no need for them to be attached to the monitors in any way.
Basically, the same idea as a typical monitor/sub setup, just with dipole subwoofers instead of traditional woofer in a box types.
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Thanks for the clarification. Yes you can do this as you describe and it will sound good. However in my opinion you'll attain improved sound by highpass filtering the monitors.
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Your Sequence speakers are at the top of my list of things I want to hear most, Donald. Do you take them to shows?
I'm pretty much set on making the jump to speakers. It's mostly just a question of when now....
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Your Sequence speakers are at the top of my list of things I want to hear most, Donald. Do you take them to shows?
I'm pretty much set on making the jump to speakers. It's mostly just a question of when now....
I haven't exhibited the Sequences at a show in years. I have them nicely setup at my home and you're welcome to come to Los Angeles and hear them here.
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I'm still due over one of these days...
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Did you try to chamfer the baffle cutouts? Or was it beyond your abilities/worries? I can't tell from the pics.
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I chamfered (badly) one cutout of the 8" driver ... until I realized the construction of the frames in the back of both the 15" and 8" drivers did not necessitate such.
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Was visually bored while listening to music tonight and did some perfunctory searches about DIY open baffle and came up with several results I skimmed through but then came across an AVS thread that had a good discussion and read it in full. I didn't want to get into the nuts and bolts of open baffle, but wanted to see what happened when opinions clashed, as that is a good opportunity to learn from both sides. Take a look:
http://www.avsforum.com/t/1470169/open-baffle-speakers
One person mentions a proper OB setup is 4 drivers, dipole tweeters, a mid, and bass woofer a la Linkwitz Orion. I know Donald's Sequence is dipole on the bass woofer only so it's interesting to see how both of those setups can sound good. Something I also noticed on Linkwitz site was magnet mounting the mids driver to make it more nimble. Basically the cone side is not mechanically connected to the baffle, just a strip of foam type material to seal it, and the rear is magnetically attached to a metal plate that is secured into a wooden support. Something like this could be done on your setup, Marv, to make the full range driver more precise, if that is in fact what effect magnetic mounting has.
It's interesting to see all these OB designs. They seem more varied than sealed speakers or horns.
Something else mentioned in the AVS thread is that, contrary to what I imagined, OB speakers tend to have a smaller sweetspot, but that sweetspot is much sweeter than more traditional speakers due to the timed reflections more accurately imitating instruments that, of course, don't just radiate forward, but backward as well. This last point makes me even more curious about OB speakers as it seems box speakers killing or dramatically reducing backwave defeats the purpose of trying to sound real. Even ported designs don't do enough. Horns (of reasonable size/cost) try to use this effect, but the reflection comes from mostly the speaker's footprint, not the surrounding walls as it would with live musicians. I think this point has a lot to do with why I like my speakers I have now, but find them to be too cannon like in delivery and thus not all that realistic.
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Something else mentioned in the AVS thread is that, contrary to what I imagined, OB speakers tend to have a smaller sweetspot, but that sweetspot is much sweeter than more traditional speakers due to the timed reflections more accurately imitating instruments that, of course, don't just radiate forward, but backward as well. This last point makes me even more curious about OB speakers as it seems box speakers killing or dramatically reducing backwave defeats the purpose of trying to sound real. Even ported designs don't do enough. Horns (of reasonable size/cost) try to use this effect, but the reflection comes from mostly the speaker's footprint, not the surrounding walls as it would with live musicians. I think this point has a lot to do with why I like my speakers I have now, but find them to be too cannon like in delivery and thus not all that realistic.
Keep in mind that many people with dipoles like OBs or ESLs try to essentially neutralize the back wave by lining the front wall with absorption. The idea that dipole = real and monopole = not real is just not accurate. The helpfulness of reflections, both from the front wall and side walls, is very dependent on when they arrive. If you place dipoles too close to untreated walls, the sound will be considerably worse than monopoles. Forward radiators are also capable of very wide, very stable sweetspots, particularly those with extremely narrow cabinets like the Dynaudio Confidence series. In terms of the sound absolutely filling the room and extending far beyond the speakers themselves, the Confidence C4 easily outperforms the VAST majority of dipolar panel speakers that I've heard.
True omnis like Duevels or MBLs more closely approximate how instruments behave than dipoles do, but there's usually a trade off there in terms of imaging. There really is no magic bullet.
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Here it is finally. Going to evaluate the woofer before adding the mid/tweeter:
(http://i.imgur.com/K9KSR0W.jpg)
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Haha nice!
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Bet those sound just like LCD-2s as is.
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LMAO! You really crack me up sometimes.
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Lol! There's a surprising amount of music up to 1k. Some nasty cone breakup after that though.
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So I ran across this, which helped quite a lot, but doesn't get into enough detail, IMO.
http://www.enjoythemusic.com/diy/0709/open_baffle.htm
He talks about the baffle size being a tone shaper, but you guys talk in this thread about certain drivers needing certain baffle distances. How do you know whether to leave 5 inches on each side of a 15" woofer or 8 inches or another dimension? Do tweeters and midrange/fullrange need smaller baffles due to the frequencies they radiate?
Anyone got links to beginner friendly guides to speaker design? Specifically OB would be nice, but general info is great as well.
I think I can get my head around the acoustics part as I work with acoustic amplifiers daily, I just need some guidance when it comes to speakers. The hard part will be the crossovers, at least to understand, since I have zero experience with building electronics.
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This is what I use. Definitely not for noobs. One issue is that TS parameters provided by driver manufacturers are sometimes wrong - usually with the less expensive drivers - or the off brands. The Chinese stuff tends to be all over the place. The Qts which Craig quoted me on the Cicada drivers were too low. Sometimes you end up resorting to use of the "Force" after handling /test a driver to guesstimate the right TS numbers. But I did found the models in the program below scary accurate.
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(http://i.imgur.com/eSN7uq9.jpg)
(http://i.imgur.com/6tx6a36.jpg)
Yep...I listened to this bastardization tonight. Go ahead and laugh it up. Cheap electrolytic, cheap solid core inductor, connections twisted together. First order filter at 200Hz. It actually doesn't sound terrible. Poor but not terrible.
- Imaging is wonky, midrange weirdness too
- Surprisingly decent tonal balance. I think it's on the bassy side of things though. But not that muddy
- I'm getting fairly good bass extension. Good impact down to 40Hz based on my warble tones
- I do not seem to get any better/more bass by placing the woofer baffles together, as opposed to pulling them apart. Not intuitive, knowing what I know about OBs. Perhaps something to do with their acoustics centers still being close to the end of the baffle?
- Might be worth it to look into structural upgrades. I don't think I'm hearing any resonances, but you can feel 'em when you touch the cabinet. Still has some peaks and nulls I feel. Might just be room modes, although I don't think my space is too mode-y.
- Not that easy to listen to. This was less of a problem with the BK12 unadulterated. No joke, I think my Marantz is giving out on me sonically. I need a new amp(s)
I'll measure tomorrow.
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Try with the baffles on the outside of the Fostex kits. Might help with imaging.
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Will do.
So I was talking to the Exit Level Audio guy (forgot his name) and open baffles came up. He recommended I look into some Alpair driver (forgot the name again). Any opinions on that? I'm still weighing my options on what I want to use. Transplanting the Fostex makes the most sense. But I know once I cut the baffle it's going to be a PITA to try to make a larger cutout for a larger driver. So it better not suck.
He also recommended I check out the Open Baffle forum on AudioCircle. I'm flipping through there right now to see what's up.
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That setup certainly is... interesting, lol. Agree about putting the woofers on the outside. You're likely running into some of the same problems as when you have a big flat panel TV between the speakers.
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I skipped Alpair because of their low efficiency and low impedance. Also they lie big time on their published FR graphs, and that doesn't gel well with me (what else are they lying about?)
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Their published FR graphs definitely seem too smooth.
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Pulled 'em apart. Big time improvement.
- Imaging is quite a bit better; Separation is better; easier on the ears
- Just noticed a MAJOR null in bass response around 80Hz. Using the Aphex Twin track called "Ageispolis", which BTW is a great track for detecting mid-bass and upper-bass smoothness/quality
- Other than the above point, I'm really starting to like the open baffle bass
- These still tend to fall apart during complex passages. I think it's the FE126's fault actually. Funny how even humble headphone systems can be better than speakers in this regard
- Good representation of space and reverberant qualties. I bet this would be even better with tubes :)p17
- Vocal shoutiness/harshness might be back a a little
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On 80Hz null. Typical of many rooms is USA type houses. Very hard to get rid of that in some rooms.
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Well...this explains it.
Here's the OB response w/o crossover and w/o the Fostex. In-room and at the listening position:
(http://i.imgur.com/4hgf3Bs.png)
Here's the response of each w/ just the first-order filters in place:
(http://i.imgur.com/C7EvXVO.png)
Things worth noting:
- Low pass is ineffective at reaching the ideal curve because of the rising impedance of woofer (inductive load). See here http://www.parts-express.com/pedocs/specs/290-407-eminence-alpha-15a-specifications-44604.pdf (http://www.parts-express.com/pedocs/specs/290-407-eminence-alpha-15a-specifications-44604.pdf). Fortunately, I accounted for this and cooked up an impedance flattening circuit, which should shunt away the extra HF above 200Hz, similar to a second order filter. Will be added once I actually solder the xover :)p13
- The high pass also sucks at achieving its curve because it's still stuck in the horn. The summed response is elevated in the upper bass because of this. This shouldn't be a problem once it's out of the horn, so I'm not worried about it. The FE126 has a 10dB/octave roll off starting at 200Hz that will be working with me instead of against me
- Woofer still contributing at 1k and 2k is probably what was making vocals sound nasty
- Great bass extension. Better than I imagined. This system is able to excite the lowest mode at 38Hz, unlike the BK12 or OSMT
Now the big question is WTF is going on at 500Hz. I seem to be getting nulls at every odd multiple of that. And the weirdness still showed up in the high-pass response even when the woofer was unplugged. My best guess is that the presence of this big ass baffle in the room has to do with it. Any ideas? Possibly relevant information:
Distance from baffle to front wall: 112" -> 2.84m -> Half wave resonance at 60Hz
Distance from baffle to back wall: 70" -> 1.77m -> Half wave resonance at 100Hz
Baffle width: 24" -> .6m -> Half wave resonance at 286Hz
Baffle height: 48" -> 1.21m -> Half wave resonance at 142Hz
Perhaps a more structurally sound baffle will eliminate those nulls. Or perhaps this is par for the course with dipoles/OBs.
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Also, here is the room simulation according to REW. And my xover simulation in LTspice.
(http://i.imgur.com/3qOm0rN.jpg)
(http://i.imgur.com/b5f0Qsy.jpg)
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- Still incapable of heavy bass; seems uncontrolled. I'm starting to think first-order filter on the FE126En is not enough and it's contributing weird things. Or perhaps my baffle is still resonant but I've added a second leg and used dynamat at the junctions which seems to help
- A bit of sibilance/sharpness is there when I listen on axis (horizontal)
- Not bassy anymore, bit brighter tonal balance
- I'm noticing the image placed behind the baffles is very good; great soundstage depth
- I really like these at low volumes, tonal balance seems better, dynamics seem cleaner; they fall apart when loud/complex (I'm talking 85dB+)
- Really dig the vocals right now; nastiness seems gone
- 10x coherence than before
(http://i.imgur.com/lxVEc4o.jpg)
(http://i.imgur.com/lqtpbcI.jpg)
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What size cap you using?
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100u.
(http://i.imgur.com/XIhRQw8.png)
Again, I still have no idea what's going on at 500Hz and its odd harmonics. Some sort of weird comb filtering or whatever. Also, it seems the break-up nodes from the woofer still aren't being suppressed as well as they should be. More on this in a bit.
(http://i.imgur.com/v8JTKqe.png)
Fortunately, EQ is very good at curing these. Takes away the plasticky, artificial timbre from guitars which is painfully obvious on A/B. The coloration is much less noticeable with vocals actually, but the EQ still helps there too. Pushed down the 6k spike which smooths things out in the treble. Should mention that the PN seems much more indicative of what I'm hearing, so bugger the sweeps. Still think I'm noticing some weirdness with male vocals. I'm going to listen more for the next few days and compare to the my HD600 rig. I'll have them side-by-side for direct comparison.
Lessons learned:
- Trying to work first order slopes in this design was a major mistake. I originally planned with 2nd order but I figured I could be a cheap ass and get away first order (less component cost). In the end, being a cheap bastard is going to cost me more because this configuration is not up to snuff and I'm going to need to change things
- Breakup nodes from woofer still shine through. Low pass slope is not steep enough and this driver is poorly behaved
- Bass handling: the Fostex is much better behaved throughout, but lacks the ability (or rather, sounds bad) when trying to produce bass at the same time. It's just the limited excursion that's killing it. I am unable to boost subbass to compensate for dipole roll-off because it would drive the 4.5" driver crazy. Only fix for this is separate channels (bi-amping)
- Dynamat is very useful for building loudspeakers
- I seem to have placed the FE126En in just the right spot. Knowing it's got a bit of rising response on top, I put it higher on the baffle so that I would be just enough off-axis vertically. Results are good to my ears.
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The jaggy up and down thing: normal for rooms / from reflections.
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Don't think I was seeing it that bad before with the BK12. I'm going to haul them into my backyard and try.
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(http://i.imgur.com/luHq2eA.png)
First EQ was kinda by ear, this one is the result of doing it real-time with PN:
1k: -10dB Q=1
2k: -5dB Q=3
7k: -6dB Q=6
Not touching the bass right now, but it's really good. The more I listen the more I like these
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Without having completely finished this thread, I already want to give big ass sucking thumbs up for this. Very nice.
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Recent comments about flat screen tvs interfering with OB have me concerned as my listening space does include a 52" TV between the speakers and it is on a stand, not mounted on the wall, making it even worse. Still worth pursuing or don't bother?
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Max, I think Dave was referring to the fact that when the baffles are pushed together, they could act like a big flat-screen. So long as your TV is back against your front wall, and you are able to pull the OBs out and away from each other, you should be dandy. I find my OBs to have quite good center imaging/coherence when the positioning is right.
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Was dicking around with my mic today and thought I'd share this:
(http://i.imgur.com/NRQfioU.png)
Should note:
- Taken in room at listening position, no EQ applied
- Total Slices: 100
- Time Range: 4ms
- Window: 5ms
- Rise Time: .1ms
- 1/48 octave smoothing in CSD mode
A bit of ringing near 7k definitely stands out, but noting the time axis it isn't terrible. And you should consider all the other excess energy the room is storing, (windowing makes the rest of that disappear).
I might try to piece together the ETCs next week.
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I think my favorite part about OBs is listening behind them. 8)
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Recent comments about flat screen tvs interfering with OB have me concerned as my listening space does include a 52" TV between the speakers and it is on a stand, not mounted on the wall, making it even worse. Still worth pursuing or don't bother?
I wasn't referring to OBs specifically, a big TV between the speakers really messes with the center image, regardless of the radiation pattern. I don't even use a multi-shelf equipment rack for that reason, all of my stuff is on amp stands a few inches off the floor.
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Update:
After tweaking the crossover a bit more here's where I'm at. This is in-room response with PN. No EQ applied.
No smoothing
(http://i.imgur.com/dUxAOPm.png)
1/2 Octave smoothing
(http://i.imgur.com/zRwG7oR.png)
Sounds excellent in just about all aspects. Tonally neutral and non-fatiguing which is always my #1 priority. Great bass that isn't peaky like with traditional cabinets. I do hear some bass distortion at higher (90dB+) levels. But it's incredibly articulate and detailed when rendering the low-end. Stand-up bass on recordings is palpably real and placed perfectly in the mix, something subwoofers can't hope to do.
Imaging isn't pinpoint like you get with a traditional mini-monitor or slim cabinet. You kind of trade spacious-ness for pinpoint-ness. Instead of instruments being confined to little blobs in space, they're expansive and in the room with you. Cliche, I know, but these loudspeakers are good at doing just that. Some might not like the effect, but it's all relative.
Am going to listen more and enjoy. I have the Jantzen caps in but I haven't installed them yet. That might be a fun comparison if I can figure out a way to A/B them. Other than that, I'm going to start saving up for a pair of these guys:
http://www.madisoundspeakerstore.com/ribbon-tweeters/raal-dipole-140-15d-ribbon-driver/
Yeah, I know. More immediate step is better amplification and possibly active xover.
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Any opinions on these? Look they could be just what I need in terms of the right crossover slope.
http://www.hawthorneaudio.us/catalogs/index.php?main_page=product_info&cPath=3&products_id=62
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Notice how they keep inching closer to the listening position... ;D
(http://i.imgur.com/a8hbrtu.jpg)
I've got a good grip on their sound at this point. Measurements to follow.
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Awaiting. I'm assuming not as much extension as the smaller drivers. I have supertweeters for you BTW.
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These drivers are actually much better behaved which is a surprise for me. The FE126En had a pair of peaks at 5k and 7k. These seem to have a pair at 3.5k and 5k, which is further from that critical harshness zone. These drivers are easier to listen to without EQ.
(http://i.imgur.com/l3SyK6o.jpg)
- Red is on-axis, 2ft from driver.
- Green is listening position, baffles ~6ft from my front wall, ~20degree of axis
- Blue is listening position, baffles ~4.5ft from my front wall, <20degree of axis
Both green and blue have non-ideal amounts of toe-in which make it look more rolled than it is. I definitely miss a bit of that last octave in this position. Only reason I measured this way was because the FE126En sounded best in that position as it smoothed out those peaks a wee bit. FE166En sounds best directly on axis, as the red plot indicates. And it's less peaky (in perceived terms) so it's not a problem. As you move the baffles forward, you get bassier. You also get more spacious and involving soundstage. It's a funny trick that OBs pull off. And I feel the 166 is a better candidate for OB duty than the 126
Here's an ARTA plot that's probably most representative of what I'm hearing:
(http://i.imgur.com/JvDxlQ8.png)
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Wow, those are spectacular results. You can try a parallel LCR notch filter at 900-1k, but it may be better to leave it.
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Yep, it's good. Best system I've ever had in my space I can tell you that. Don't feel the need to EQ believe it or not. I might try to boost sub-bass and high treble but I wouldn't get consistent results because of room modes (bass measurements not reliable if I decide to sit on the other side of the couch) and dispersion (move your head an inch and anything above 8k goes haywire). The emphasis at 1k might be a room thing or measurement artifact as it shows up with all my speakers when using ARTA. Did you ever try the 166 on an OB? I can't recall...
And how do you suppose I would integrate a super-tweeter? Drill a hole and friction fit?
Also, first order crossovers FTW. Easier to integrate and a more coherent sound. I'm a believer.
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And how do you suppose I would integrate a super-tweeter? Drill a hole and friction fit?
Also, first order crossovers FTW. Easier to integrate and a more coherent sound. I'm a believer.
Drill hole. Nail / screw in retention bracket to keep tweeter cylinder in. Wire tie to keep in place.
First order crossovers good for certain drivers like Fostex. Bad for metal drivers which ring like below - where fourth order is almost necessitated. That's why these metal cone driver speakers you see at the audio shows sound flat and lack realism. Too many big caps and coils in the way.
(http://www.seas.no/images/stories/prestige/woofers/images_big/f_seas_prestige_loudspeaker_woofer__h1488-08_l16rnx.jpg)
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Have you tried adding shunt resistance to your OB woofers?
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Sunday morning EQ session:
Here's the response again un-EQed. Blue curve is response with mid and woofer tuned to match sensitivity. Obviously last two octaves are shelved. Teal curve is tuned to bring the treble up in level at the expensive of having a mid and upper-mid emphasis:
(http://i.imgur.com/eIlwERm.jpg)
PEQ settings were arrived at with pink noise at listening position. Curve goes from teal to purple. Aiming for ~5dB slope:
(http://i.imgur.com/977cNtv.png)
(http://i.imgur.com/ZEtylos.jpg)
This is the difference between leaning back in the sofa and standing up. Note different smoothing here to highlight differences. Not too shabby though:
(http://i.imgur.com/yLMTGwi.jpg)
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For reference, here's the response curve that gets put on the manufacturer spec sheet
(http://i.imgur.com/5BSrxkg.jpg)
:P :P :P
BTW, driving this system directly out of the Hilo's Monitor Out so that Hilo serves as (analog domain) volume control. Balanced TRS directly into the CA2. Serious win :)p1
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Update:
I've rearranged the room so that my speakers are now on the right side. Some things have improved, others have become worse. I seem to be getting better overall tonal balance at the expense of some room mode problems. A general muddiness really. Still tweaking. I'm also "biamping" now; that is I have my Parasound running the FE166 full-range and the Crest running the 15A with a 2nd order passive filter in-line.
Here's FR, no EQ.
(http://i.imgur.com/NBlc7T5.jpg)
(http://i.imgur.com/S0HA2Cm.jpg)
Here's the ETC. It's actually much cleaner past 20ms, but still got some stuff hanging around in that critical region (2.9ms, 6.7ms, 8ms). They also seem to be higher gain now. Likely from the new sidewall that is much larger and more reflective. More investigation needed into this.
(http://i.imgur.com/iN3gW2G.jpg)
Spectrogram shows less energy being stored at that 35Hz mode (previously the length mode) but more energy elsewhere. Definitely less clean here. 75Hz mode is the harmonic of the new axial width mode. Need to measure outside for good reference.
(http://i.imgur.com/cfmgajh.jpg)
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You sure the muddiness isn't coming from your $29 woofers with Q = 3.79 at 1mm excursion?
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lol, well it's more muddy in this new position
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The project evolves...
(http://i.imgur.com/dJrgtCS.jpg)
Getting excellent results
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Nice! How far away do you actually sit away from them? I wish I had the space for anything bigger than bookshelves with 5" drivers :(
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Bout 5' from back wall, I sit 8' away from baffles. I could use a bit more space behind me though.
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how. what dat in the middle? B&G planar thingie?
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AMT in a waveguide
http://hawthorneaudio.us/700-hz-amt-drivers/
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Heil AMT!
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Not Heil..the ESS Heil's kinda sound like crap from what I've heard at shows. This is supposedly to be a similar drive mechanism but a totally different take on it in terms of implementation.
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What equipment did you guys use to measure speakers, and how does one go about applying PEQ based on the measurements? Would love to see how the overnight sensations MT measure in my dorm room.
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Get Dayton or miniDSP mic if you want cheap and easy. I'm using WM61 capsule mic with hack-job preamp at the moment. Cheaper actually, but not easy.
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Dayton UMM-6 USB mic + ARTA software (can't save if demo version)
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1/3 octave smoothing. This is a 3-way at the moment. Not bad
(http://i.imgur.com/owJ4NUa.jpg)
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Here it is as a 2-way (no Fostex)
(http://i.imgur.com/TMitKga.jpg)
Flatitude!
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Saw the most recent Linkwitz kit at RMAF, the LXmini, which sounded very nice for its price of $400 or $475 (with cnc'd wood) (link (https://www.madisoundspeakerstore.com/2-way-speaker-kits/lxmini-linkwitz-lab-speaker-kit-pair/)). Depending on how my current speakers sound when the Rag comes, I might build a pair. Bass was strong but controlled (obviously will depend on room treatment), mids were excellent and highs were rolled a bit. Maybe not the pinnacle of sound, but they are small-ish and inexpensive. You don't even have to do any woodwork if you get the cnc'd parts, it's straight assembly from there. I liked them better than most of the speakers at the show, regardless of price, including the KEF LS50, which were great as well. The LX521s were more resolving and better transitioning between frequency bands, but not significantly better overall, I thought.
Info here: http://www.linkwitzlab.com/LXmini/Introduction.htm
(http://www.linkwitzlab.com/LXmini/reiter-533.jpg)
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Those things are so weird. Are the upwards facing woofers on top of the pipe a subwoofer and the forward facing woofer is full range? Also you have to biamp? Just a very weird design.. visually they remind me of those mirage omnidirectional speakers. I see a lot of people on avsforum building the diysoundgroup fusion speakers.. I guess they're home theatre oriented though
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Neither? The webpage says it has a crossover at 700Hz.
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It's an omni but that ain't no subwoofer. Like a 4". Would need further bass augmentation to work in a complete system
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It sounded like it had enough volume and extension for most music without a sub. For HT use you would need a sub.
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So, with these needing Bi-amp, would a single Ragnarok be able to power these or am I looking at needing two stereo amps?
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Different philosophy Linkwitz has. May as well throw Rag and Yggys into garbage and get some cheap Emotivas to stack if going with any of Linkwitz's designs.
I'm not a big fan of the MiniDSP stuff. Basically you will be taking output to a digital processor. ADC-DAC again (or just DAC is you use MiniDSP as the source). Separate modules for bass and treble. Advantage: no power / life sucking or veiled passive x-overs. Disadvantage: will ruin sound with crappy cheap DSP / bit manipulation.
Not saying it's bad. It will sound good. Detailed. Precise. Only limited by the drivers. But to me it will lose immediacy and sound uninteresting, sterile, and flat. I did similar DSP stuff with earlier speakers. So moved beyond that.
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It was far from uninteresting, sterile, and flat in the room at RMAF. I heard some other OB setups there, and perhaps the room wasn't well enough treated for the poor dimensions, but the others, while sounding nicely open, often sounded veiled or harsh in the treble. I was particularly impressed with the bass of the OB setups. It is like HD800 bass, impossible to localize.
Is there a way to have the Rag work with these? (sidestepping the issue of signal quality) I'm not interested in min-maxing the setup particularly, but as I will have Rag for headphones, I'd like to use it for speakers, and I imagine the LXmini sounding better than my Paradigm Studio 40 v.4.
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There shouldn't be any reason you can't implement a passive xover with them. But you would have to mimic the transfer functions with passive components. And that might turn out to be a bit pricy itself depending on your taste in caps/inductors/resistors. Actually, it shouldn't be any more expensive than a miniDSP box so long as you don't chase the dragon. And if you've already settled on the Rag you'll be saving $$$ anyway.
(http://www.linkwitzlab.com/LXmini/DSP-xo-eq2s.jpg)
I could try to mock something up for you in LTspice if you're interested in going that route. I'm also interested in building an omni after I bring my OBs to completion. This one looks a fair bit cheaper and easier than the Pluto.
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I guess I need to look at these in more detail. I've been assuming I just connect them to an amp, but it seems the DSP part is separate from the speakers so there is some complication there. Sorry for the seemingly dumb questions.
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I'm not sure if you want to implement passive of that. A high Q dip here. A bump here. Another bump there. A shelf down there. Steep slopes. Basically a lost cause. Better off with DSP.
You can integrate the Rag by doing this:
Buy two of them. Max out volume on both. Then use them as dedicated power amplifiers to accept miniDSP analog outs for the high and lows.
As far as uninteresting, and flat - it's relative. Let's put it this way. Get rid of the mini-DSP shit between the source and the amp, and you get something more interesting. The downside is that you will have to rely on simplier passive designs which may restrict driver choice. Best to use the mini-DSP x-over / preamp as the source though - feeding it directly via USB rather than suffer an AD-DA conversion, which is never good, especially with cheap stuff.
I've done this stuff and variations of this stuff 10 years ago. That's why I have two DCX2496s, three Crest CA-2 amps, and three Teac T-amps.
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I guess I need to look at these in more detail. I've been assuming I just connect them to an amp, but it seems the DSP part is separate from the speakers so there is some complication there. Sorry for the seemingly dumb questions.
Yes. It's a "system"
It goes like this:
SOURCE
to
(A-D)
DSP/X-OVER/PRE-AMP
(D-A) + (D-A)
to
HIGHS AMP + LOWS AMP
to
HIGHS SPEAKER DRIVER + LOWS SPEAKER DRIVER
If you are anal about DACs and how they sound, then obviously this system would not be appropriate. Some people don't hear differences among most DACs or even A-D D-A conversions. Just different philosophies.
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Very cool thread!
I got into headphones because they are relatively cheaper and support a higher WAF value than my previous obsessions with speakers. Who would have thought joining a "headphone" forum would lead me right back to speakers again!
Anyone seriously interested in getting into DIY speakers, especially OBs, need to read the work of Martin J. King. I'm surprised his name/links haven't come up in this thread prior:
http://www.quarter-wave.com/
My current OBs are based on his 18" Goldwood H-Frame model and I like them a lot: http://www.quarter-wave.com/Project08/Project08.html
I wanted to eventually build a passive crossover but since my choice of upper driver was a bit esoteric I knew that digital would give me the flexibility to tune experimentally to find what I really wanted, so I've been using a MiniDSP to do the XO work for some time. A Dayton EMM-6 measurement microphone (and some very long cables) let me test room nodes from my PC, usually going with REW as the miniDSP can read it's findings and automagically pick the right EQ settings for compensation. In theory this is a cool idea because you can readjust every time you move the speakers to a different room or make changes to room placement or treatment. In reality I've been using no EQ for sometime now though, just to see how good these speakers can behave under less than ideal conditions.
My OBs have the H-Frames on the bottom (3/4" 11 ply baltic birch for everything) and the Audio Nirvana Super 8 full rangers in separate, movable baffles on top with what I call a "damping box" between them which is basically about 40lbs of concrete patio blocks wrapped in the same birch plywood. The full rangers are set off center (which may have been a mistake) but have been interesting to experiment with by swapping the two sides, moving the full rangers in to center or out, respectively. Last but not least, separate top baffles allow me to experiment with time alignment (by moving them forward or backward over the H-Frames) and toe-in and would be easy to change out to a different top driver if I want to experiment in that direction too (these Moth & Cicada drivers have piqued my interest!)
I built and tuned them with a target of accurate live music presentation, specifically using the track "Haitian Fight Song" by The Charles Mingus Big Band as a key reference. They don't disappoint and double well as fronts in my home theater system too (no subwoofer for some time now).
Tops are powered by a Dayton DTA-100 t amp and the bottoms have seen a few different vintage stereo amps come and go including the Kenwood KM-209 and Yamaha M-65. I think I'd eventually like to either go passive XOs and a single really good amp (have a Yamaha MX-10000 in the works!) or something like the DEQ2496 to replace the miniDSP and a couple of good pro amps, Crown or something.
(http://i56.photobucket.com/albums/g163/oktyabr/H_frames/th_small002.jpg) (http://s56.photobucket.com/user/oktyabr/media/H_frames/small002.jpg.html)
(http://i56.photobucket.com/albums/g163/oktyabr/H_frames/th_small031.jpg) (http://s56.photobucket.com/user/oktyabr/media/H_frames/small031.jpg.html)
(http://i56.photobucket.com/albums/g163/oktyabr/H_frames/th_CIMG6303.jpg) (http://s56.photobucket.com/user/oktyabr/media/H_frames/CIMG6303.jpg.html)(http://i56.photobucket.com/albums/g163/oktyabr/H_frames/th_CIMG6289.jpg) (http://s56.photobucket.com/user/oktyabr/media/H_frames/CIMG6289.jpg.html)
(http://i56.photobucket.com/albums/g163/oktyabr/H_frames/th_CIMG6304.jpg) (http://s56.photobucket.com/user/oktyabr/media/H_frames/CIMG6304.jpg.html)
(http://i56.photobucket.com/albums/g163/oktyabr/H_frames/th_100_4005_zps59b2cf73.jpg) (http://s56.photobucket.com/user/oktyabr/media/H_frames/100_4005_zps59b2cf73.jpg.html)
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Very nice :)p1 I'd like to try the U frame or H frame eventually
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Very nice! I'm going to have to check out those drivers.
Unfortunately, the Moth Cicada drivers are no longer available and haven't been for 10 years. The AN drivers you have might be the best bang for buck.
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@OJ: did you put a Zobel circuit on your Alpha 15s?
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No longer. I found it only marginally effective.
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Was about to talk out of my ass but deleted it
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No longer. I found it only marginally effective.
Interesting. Looked up the impedance graph for the Beta 15s (have yet to measurement it) and realized a zobel would be necessary if I wanted to implement a passive x-over instead of the active I'm currently using. I'm curious how the OBs would sound if only the Rag (not the Rag + Crest) powered both the wide-banders and woofer.
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realized a zobel would be necessary if I wanted to implement a passive x-over instead of the active I'm currently using.
What are you trying to accomplish exactly? I'm guessing you want to avoid woofer's cone break-up but not use a notch filter?
As an aside, that's the good thing about these Dipole15 woofers. Very low inductance (.04mH vs 1.1mH :vomit:), especially on the 4ohm (dual 8ohm coils in parallel) version. Impedance curve doesn't start rising until after 3k which means a higher crossover point is easy.
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Not necessarily break-up, just want to slopes to be as designed, i.e. 2nd order = 2nd order, not 1st order.
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How much of a factor is dust to open-baffle?
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How much of a factor is dust to open-baffle?
Not a big deal in my experience for dynamic woofers. Probably more of a concern if you're running ribbons or AMTs.
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Did this to my A5s since my room acoustics are very poor. Mounted them on biscuit tins that I stuffed with modelling clay. Theres a sub below which is more of a midbass unit. Needa get em measured but my EMU unit broke before I finished getting everything in order. At the very least, I'm not getting the boxed up sound and room modes before this.
For my next one, I'm kinda exploring full range boxes and more specifically BMR OBs.
(http://www.changstar.com/index.php?action=dlattach;topic=1436.0;attach=10048;image)
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Hentai master chief approved. Is that a patchoulli and koakuma puzzle in the back?
How do the A5s sound like that?
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Yup! It is, I got it from doujin store White Canvas when they had a booth at a con. I have a couple of puzzles that I have put of from finishing :3
I don't think I'm getting a much better solution with smaller speakers(like less than 5") than I'm getting with this one without spending a ton on say Genelecs.
To put it concisely.
The good:
-Wide sweet spot
-good imaging but not exactly pinpoint
-clean treble
-open sounding without port farts and any enclosure modes
The bad:
-3k peak that decreases with distance and toe in.
-not exactly the cleanest midrange
-1 note bass courtesy of the sub I'm using(not the A5's fault)
-drivers not exactly capable of concert level SPLs, tweeters tend to distort at 3k at that point. :X
Misc:
-Decent detail but does not dig as deep as the HD800. A/Bing stuff is more difficult on this.
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Well this gave me some ideas popcorn
Could I use car speakers for it? Here it's impossible to find some good sounding speaker for under 300 local bucks, just some edifier stuff that are pretty meh.
Although I could find some pionner or selenium woofers for 60 bucks and some tweeters for 40...but I don't have an idea how to integrate them and also how to amp properly, is there any guide for DIY speaker?
BTW, I would use it on my computer desk.
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Got my mike a few weeks ago and had a go measuring my speaker's in room response which... was pretty darn bad haha. Did some eq from there but will probably do some more detailed eqing or integration some other time. Got the imaging to be more or less precise enough. The drivers hide some low-level detail but for now I'm satisfied with what I have.
(https://pbs.twimg.com/media/CLs6s-_UAAA0C79.jpg)
Mic setup is a EMM-6 on a mic stand with a Cross-spectrum labs cal.frd at 90 degrees incidence. 1/12 octave smoothing for this
(http://www.changstar.com/index.php?action=dlattach;topic=1436.0;attach=10556;image)
Looking at a bunch of stuff as always since I will be a student again in sometime with access to a good workshop so I really hope to capitalise on that to get projects going and done. As always I'm on a shoestring budget and its really more for my desktop scenario with little space. Keeping those in mine, I'm seriously giving a few drivers/speakers in mine. Mostly point source implementations.
Some stuff I'm looking out for,
Fostex: I doubt they have much good for me since their stuff are always in larger setups.
Tang Band: Their new drivers look really attractive, currently one of my more go to options.
Cotswold BMR drivers: Seems like the way to go as well,full range in a small form factor.
Sorry for missing this altrunox, I would go with the above for a desk. The best place to start with integrating stuff would be to read up on how crossovers work.
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Did this to my A5s since my room acoustics are very poor. Mounted them on biscuit tins that I stuffed with modelling clay.
I love it! You have literal CANS on your desk! :)p13
I'm guessing enclosures would help the sound from those car speakers. Heh, reminds of the time my roommate blew out one my cheapo speakers. He replaced with a Pioneer car speaker.
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I think the smaller (4-6") Fostex drivers could sound great in a small bass reflex cabinet on a desk. Especially if you can augment with a decent subwoofer. That was going to be my next project actually. I can send you the FE126En that I used in my BLH if you pay for shipping.
Not familiar with the BMR tech but might be fun to play with.
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Don't laugh. My kids could not stop laughing though.
One of these days, I'm gonna get EC or maybe piggyback with Schiit to show these speakers as is at T.H.E. SHOW.
The problem with these Lowthers is the 8kHz peakage and massive beaming. EQ sorta works, but the polar response is so foobar. I was working on a notch filter circuit, but decided to shelve that idea because it required an additional cap, coil, and resistor - something I was loath to do. I am running the TT more often, so I couldn't rely on digital EQ anymore.
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Marv, are you using the rag to drive those speakers or using it as a pre-amp?
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Using the Rag as a speaker amp right now. I had the Studio in last week, but I don't like leaving it around because of kids.