CHANGSTAR: Audiophile Headphone Reviews and Early 90s Style BBS
Lobby => Headphone Measurements => Topic started by: Marvey on July 13, 2012, 07:28:42 PM
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Hans+nums send these in to me. These are his notes:
They currently have the FA-003/HM5 pads on them, but I also included the stock pads if you want to mess with them. If you're interested, here's the mods I did to them (originally posted on HF):
1. Dynamat inside the cups, including on the side walls. I covered the vents.
2. Creatology adhesive foam (thin) on top of the Dynamat
3. Acoustic stuffing inside the cups. This includes 2 layers of Acousta-Stuff with a layer of cotton in between. For the cotton, I simply teased a cotton ball up and used that as the layer of cotton.
4. Dynamat on the back of the driver magnet (no holes covered)
5. Donut of a specific type of felt covering that area around the driver magnet (the part where the OP covered half of the holes)
6. Adhesive foam (same as above) on the ear-side baffle. I covered the white, thin material but left holes for the screws.
7. FA-003 or Brainwavs HM5 pads. They're a bit loose, but they work well and sound good to my ears.
8. The treble was a bit hot for me, so I placed a foam disc in front of the drivers (temporarily held in place with my ears and clamping force). For this, I just used the ear pads from the KSC75 and cut them up until I had the disc shape I needed. I also did the same thing with a super cheap headphone from Parts-Express, so I ended up having 2 layers of foam in front of the drivers.
I did some listening through SineGen (not terribly accurate, I know), and I expect to see a dip in the 3-5KHz range. Bass sounds more elevated than neutral (compared to my Paradox). It does not sound out of control to my ears, though. Extends fairly low. Seems smooth up to 2KHz or so. Treble is a bit rough at times and has a couple peaks (can't remember where I heard them). Might be rolled off. Again, though, I know this isn't a terribly accurate way of assessing headphones.
I also would expect to see some channel imbalance. The left driver makes noises when you move the headphone (air pressure?), and I'm hoping it's not deformed (or in danger of becoming deformed). Of course, these are $25 headphones. Both cables have been included. I generally use the longer one.Ignore the weird "stickers" on the outside of the cups if you'd like. I replaced the headband padding with memory foam. It does not look pretty, and it doesn't seem like it will stay on too long. But it is comfortable!
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A small peak up in the mid-treble - not sure - it's low in magnitude and balanced in relation to the rest of the spectrum. In order words, it's easily tolerable to me and I'm not running away screaming like with the HD700 or K550.
These headphones don't sound even in the mids. A bit wonky with a strong cupped hands / sea shell coloration. Similar to the Koda's characteristics (bumped mids with a depression in cloud region and high mids), although not nearly to the extent of the Koda.
Measurements coming up.
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Modded Monoprice 8323 Measurements
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Cool! Wasn't expecting them to measure particularly well, but it's great to be able to match up what I hear with some graphs. Thanks, purrin! This gives me a good base to go from, since I'll likely keep poking around with them for fun.
Tyll has measurements for the stock can up on Innerfidelity as well.
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Love the audiophile stickers. Those seem to be all the rage these days!
Also good to see a generous amount of comfort foam.
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Love the audiophile stickers. Those seem to be all the rage these days!
Also good to see a generous amount of comfort foam.
I didn't make the connection with this and another well known pair of stickered modded headphones until I had already shipped them off. I was just goofing around at the time. But I would estimate it makes them sound anywhere between 3.7 to 9.2% better overall. ;D
I apparently have a baby's head, as that's where comfort kills me (top of my head). Even LFF's suspension headband on my Paradox hurt my head, so it's heavily cushioned now as well.
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Regarding that large dip in the mids, Tyll's measurements of the stock headphone has a large dip in the 3KHz-7KHz range with the roll off starting around 2KHz. That might be just be a spot that's hard to correct.
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I think the stock models measurements looked better :)
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I think the stock models measurements looked better :)
I wouldn't disagree with that, but Tyll's measurements for the stock headphone don't seem entirely accurate. They have the same midrange suckout, but they have much less low bass than I heard with stock. They also have that weird spike right around 10KHz, which a lot of his headphone measurements seem to have.
Oh well. I wasn't going for something great with these, though I think they have some decent potential for being so cheap. I just slapped some mods together until I got something that wasn't offensive to my ears (I was having fun listening to them). Did some listening and some sweeps on SineGen to try to guess how the FR measurements would look.
I figured they would not turn out great, and I let purrin know this before sending them in. My primary purpose was to simply translate what I heard into measurements, as that's something I wish I were better at. It was quite helpful, actually. I knew they would have that midrange suckout, but I had a hard time hearing that dip that sits just above 200Hz.
I am happy that the treble turned out about how I expected. It's rough and has some peaks, but relatively balanced with everything else. No major ringing. At least my ears aren't total shit in that regard!
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Did they become any less sensitive after the mods done? And did they seem to still have that suckout around 200hz before the mods? I might want to play around with one of these cans too just to practice with modding cans in general before I destroy a t50RP :)
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If they did become less sensitive, I didn't notice.
Tyll's stock measurements show a somewhat similar dip around that area (350Hz or so), but it is less pronounced than how my modded ones measured here. How stock would look with purrin's setup, I don't know. I didn't particularly notice the suckout on mine, modded or not, but that's why I wanted to have them measured...to see where my ears were right and wrong, more or less.
I think they're pretty nice budget cans, if you don't mind a "fun", V-shaped sound. I thought they responded favorably to simple mods, so it might be a good way to practice with that.
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The dip between 100 and 500 Hz might be the result of the cup damping scheme. You might have to replace the cotton with some foam or sheep's wool, could be worth a try.
The StratoKOSSters showed a similar dip, because I just stuffed some cotton into the cups. After purrin replaced the cotton with some medium density foam that dip was gone. The image shows the difference in the FR with the cotton (above) and the foam dampening (below).
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I had noticed that, and that was something I was considering trying when I get them back. Though, purrin still has them and said he might poke around with them when he's less busy, so we'll see what happens. :)
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- Removed fiberfill and replaced with medium density foam.
- Taped over the vents on the baffle to make sure no air would could out (they were already covered with kids play foam). NOTE: I eventually removed the tape. It sounds better with just the kids play foam over the vents.
- L&R channel differences at 200Hz are due to internal volume differences since left channel has "stuff" in it for the connector.
(http://www.changstar.com/index.php?action=dlattach;topic=405.0;attach=2227;image)
I couldn't do anything with the dip at 3kHz. I wonder if it's a driver thing. (I will take a separate baffle measurement). The treble is a little bit more elevated and flatter though. See original: http://www.changstar.com/index.php/topic,405.msg6681.html#msg6681 (http://www.changstar.com/index.php/topic,405.msg6681.html#msg6681)
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Raw driver (on the stock baffle). Hmm. This may make a decent open headphone.
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Interesting "love hump" (as RD would say) at 1k. How big are the drivers? I wonder if they'd fit Grado cups.
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They are a little bit bigger than Grado size.
Not the best distortion, but better than Shure in the bass and mids.
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Driver = 50mm. Could be a very interesting driver looking for transplantation ...
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Definitely.
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Thanks, purrin! I think these cans have a lot of potential for being so cheap! I'm particularly interested in how they measured without the cups. I'm not sure if I'll ever get around to experimenting with modding these into open headphones, but hopefully someone will if I don't! Any tips if someone were to try that?
Some other questions...Do you think memory foam would work better than the foam you have (assuming they were to be of similar densities)?
Do you have any thoughts as to what's causing the dip around 300Hz? As you've probably noticed, I covered the cup hole vents. That was accidental when modding, and I was too lazy to change it, haha. They were originally covered with a thin felt, which I also accidentally destroyed. I'm wondering now if it would have been better to leave those as they were stock. I'm also wondering if the HM5/FA-003 pads have something to do with it.
In your opinion, would it be better to have the front of the baffle "sealed" as it is or leave it stock with nothing covering that white paper/felt stuff?
Did you happen to experiment with the stock ear pads? Are you still using the foam in front of the drivers?
Any other suggestions?
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- I think denser memory foam would better. I couldn't find my stash.
- I noted less of a dip with the foam compared to the fiberfill. Denser memory foam may help. A larger cup may also help. Let me try opening the vents...
- HM5 pads are better. More open. More air and space. They don't affect the 200-300Hz dip.
- Keep baffle partially sealed with the Creatology. I liked this the best. It sounded too shouty with the baffle windows open and too dead with them sealed closed with tape.
- Foam is still being used in front of the drivers. This actually has a measurable effect of taming the peaks slightly around the 10kHz area.
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Really interesting results! (specially on the raw driver 3k dip removal.) Are the distortion measurements raw driver or fully assembled HP? The bass distortion is lower than the HD650 which I think use 40mm driver (though probably different material.) I wonder if the larger size driver trades off distortion on the bass for the tremble.
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- I think denser memory foam would better. I couldn't find my stash.
- I noted less of a dip with the foam compared to the fiberfill. Denser memory foam may help. A larger cup may also help. Let me try opening the vents...
- HM5 pads are better. More open. More air and space. They don't affect the 200-300Hz dip.
- Keep baffle partially sealed with the Creatology. I liked this the best. It sounded too shouty with the baffle windows open and too dead with them sealed closed with tape.
- Foam is still being used in front of the drivers. This actually has a measurable effect of taming the peaks slightly around the 10kHz area.
Cool, thanks! I'm glad my ears weren't lying to me about the foam in front of the drivers. I've found that to be pretty effective in taming certain treble trouble spots without messing up the rest of the sound.
BTW, don't feel like you have to send them back immediately if you still want to poke around with them!
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Really interesting results! (specially on the raw driver 3k dip removal.) Are the distortion measurements raw driver or fully assembled HP? The bass distortion is lower than the HD650 which I think use 40mm driver (though probably different material.) I wonder if the larger size driver trades off distortion on the bass for the tremble.
I'm also curious how the distortion measurements were taken. Also, for the raw driver measurements, did you do those without ear pads or anything?
I'm strongly considering buying 2 more of these. One for "regular" modding and the other to try an open configuration. Still wondering if anyone has suggestions on how I might approach an open mod since I have no measuring gear to confirm my findings.
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Distortion is taken on a solid plate lined with Creatology foam. A mic wand is attached to the plate and care is taken to ensure a good seal. The headphone was set to 90db SPL A-weighted with white noise.
For the raw driver, I simply placed the microphone on a free-air coupler next to the baffle removed from the cups. So the measurement does include the baffle around the driver.
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Distortion is taken on a solid plate lined with Creatology foam. A mic wand is attached to the plate and care is taken to ensure a good seal. The headphone was set to 90db SPL A-weighted with white noise.
For the raw driver, I simply placed the microphone on a free-air coupler next to the baffle removed from the cups. So the measurement does include the baffle around the driver.
OK...but with the distortion, was that with the headphones fully assembled and modded? And the raw measurements don't have any sort of seal around the driver (no ear pads?)?
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raw measurements don't have a seal - just the baffle and placed on the coupler.
harmonic distortion was with full headphone.
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I see. I'm strongly considering trying an open mod with a pair of these. Those raw measurements are just too interesting to not try at least! Just wondering what kind of pads would be best (HM5, stock, something velour, etc.), if I should leave the adhesive foam on the front of the baffle, and if I'll need any sort of damping behind the drivers.
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Ah, I had one other question that I had forgotten about. Any thoughts on the felt ring I placed on the back of the driver? This info has been very helpful. :)
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I've got two more of these on the way, along with some velour DT250 ear pads. I'm planning on trying an open mod with one. :)p1
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Ah, I had one other question that I had forgotten about. Any thoughts on the felt ring I placed on the back of the driver? This info has been very helpful. :)
i thought that felt ring was stock.
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Nope!
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I got my two new pairs in last night. Tried modding one into an open headphone by cutting out the back wall of the cup. Tried the stock pads and the Beyer velour pads. They didn't sound very good. The bass response isn't quite as elevated, but the dip in the mids is still present. Other than that, they sounded very confused and stuffy. They sounded much more distorted than they did closed.
I tried seeing how the sound changed when I moved them away from my ears...it's interesting how good they sound even from a couple inches away ("good" is very relative in this situation). I'm still thinking they could make for a good open can, but they'd need some specific tweaking. I'm guessing the pads I've tried won't work so well for them as they are.
I was going to see how they'd sound with memory foam in the cups (still open), but then I accidentally disconnected the solder points...OOPS.
I'll get back to those later.
I should mention that the stock unit sounded noticeably more bloated than my modded unit. Bass was just thick and overwhelming. The dip in the mids sounds much worse stock. At least, it sounds like it is much broader and deeper overall.
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I just finished modding a pair of these for a friend. Tried some new techniques and material. Left the cup vents stock this time (open with felt on the inside). Don't have any felt directly behind the driver (outer ring). Drawer liner on top of cup damping. Memory foam for main damping. No foam on the ear-side baffle.
They sound noticeably more even than my previous pair. Both of the two main dips in the sound are less severe than previously. I think they're an enjoyable listen!