CHANGSTAR: Audiophile Headphone Reviews and Early 90s Style BBS
Lobby => Headphone Measurements => Topic started by: ultrabike on May 12, 2014, 06:43:14 AM
-
Lots of impressions about these in this thread:
http://www.changstar.com/index.php/topic,1589.0.html
Frequency Response
(http://www.changstar.com/index.php?action=dlattach;topic=1590.0;attach=6440;image)
Distortion Right
(http://www.changstar.com/index.php?action=dlattach;topic=1590.0;attach=6430;image)
Distortion Left
(http://www.changstar.com/index.php?action=dlattach;topic=1590.0;attach=6432;image)
CSD Right
(http://www.changstar.com/index.php?action=dlattach;topic=1590.0;attach=6434;image)
CSD Left
(http://www.changstar.com/index.php?action=dlattach;topic=1590.0;attach=6436;image)
PM-1 vs HD600
(http://www.changstar.com/index.php?action=dlattach;topic=1590.0;attach=6442;image)
Note the distortion levels in the upper bass and lower mids which peak to about 3.5%. This might, at least in part, explain the low-fi-ness issues which a kilo-buck can should not exhibit.
Relative to the HD600s, these exhibit less bass and some loss in the 2.5 to 5 kHz region (specially in the 3 to 4 kHz range). I still feel these are somewhat neutral... a little south in the bass, but not too bad IMO.
EDIT: Also note less air in the PM-1s, which may explain why some felt these sounded a bit like closed cans.
-
Thanks,
Explains a lot to me.
Thanks for posting these.
The FR plot is missing the 10kHz to 20kHz part (in IEM measuring setting ?) but is shown in the THD plots.
-
Thanks SD! corrected plots :)p5
-
Looks VERY similar to the jergpadded HE500, minus the bass tilt (this one goes down while HE500's go up).
Ultrabike did you also get a chance to measure the HE560s at the meetup?
-
Wow thats pretty shitty for such an expensive headphone. Wonder why they tuned the treble like that?
-
Looks VERY similar to the jergpadded HE500, minus the bass tilt (this one goes down while HE500's go up).
Ultrabike did you also get a chance to measure the HE560s at the meetup?
Well, the jergpadded HE500 did not seem to have that many issues with distortion and seemed to have more air. Unfortunately I did not bring my measurement rig for the HE560s. It was pretty awesome though.
Wow thats pretty shitty for such an expensive headphone. Wonder why they tuned the treble like that?
Could be that both extension and distortion are driver limitations, but dunno.
-
Looks VERY similar to the jergpadded HE500, minus the bass tilt (this one goes down while HE500's go up).
Ultrabike did you also get a chance to measure the HE560s at the meetup?
Well, the jergpadded HE500 did not seem to have that many issues with distortion and seemed to have more air. Unfortunately I did not bring my measurement rig for the HE560s. It was pretty awesome though.
Even though HE500s roll off in the upper treble too, it's not nearly as severe as the drop with PM1 past 10kHz. Makes sense that the relatively better extension contributes to airiness.
-
Did anyone check the gorgeous box for specs from Oppo, did it read 20hz-13khz @ -7dB??
So who's ready to put down a mortgage payment for these? Maybe Bigshot?? :)p8 Now we know why everything sounds the same to him if this is his standard reference. facepalm
-
:)p13 That was some serious (and heavy) box there. Post Office will love it. Costumer return discouragement.
-
I don't think Bigshot has heard anything but the HD650 and the PM-1. Anytime he's asked he ignores the question and responds to something else instead.
-
Did anyone check the gorgeous box for specs from Oppo, did it read 20hz-13khz @ -7dB??
So who's ready to put down a mortgage payment for these? Maybe Bigshot?? :)p8 Now we know why everything sounds the same to him if this is his standard reference. facepalm
I wish my mortgage payment was only $1100...
Well, the specs on their website says:
"Frequency Response In Free-Field : 10hz - 50kHz"
They forgot to put "@ -100 dB" at the end of the spec sheet. :)p13
I guess everyone's measurements are wrong.
-
Whoa, check out these measurements of the PM-1:
http://www.audioholics.com/headphone-reviews/oppo-pm-1/measurements (http://www.audioholics.com/headphone-reviews/oppo-pm-1/measurements)
-
WTF! Everything is flat! p:8
OK.... about 60 dB of SPL range & stretched a bit on the y-axis = everything is flat.
They do show a slant down but I got it at 1kHz instead of 500 Hz (so did Tyll it seems (http://www.head-fi.org/t/685704/oppo-pm-1-a-new-planar-magnetic-headphone/1590#post_10472455)). Furthermore, there should be a peak around 10 kHz which is all but gone on those... Not sure how they got those upper treble results either.
I think their HD600 measurements made more sense (though too rolled off on the bass area based on what I hear and measured)... Dunno.
+++
"They [PM-1 vs HD600] not only sounded louder but fullermuddier, especially in the midrange."
"...the high frequencies were a bit more laid back on the PM-1s while they were a bit more detailed and airy on the HD600s." <- that I agree.
-
He made an ear out of a styrofoam cup and you guys are surprised by the measurements?
-
LOL, styrofoam cup.
-
Nah maybe that works out. Seems a similar cup was used for the HD600 measurements (http://www.audioholics.com/headphone-reviews/sennheiser-hd-600-headphone-review/hd-600-recommendations-measurements-and-conclusion.html).
That said, given the extra volume to drive, the bass roll of in the HD600 measurements make sense to me. Not sure what to make of the PM-1s... Maybe I'll give the styrofoam cup a try later...
-
That measurement of the HD600 is nothing like any other measurement out there.
-
I think the styrofoam cup yields more volume than the cans are supposed to drive. The upper mids and treble on the HD600 measurements don't look that bad to me. Perhaps a bit too smoothed out. However the lows really went down south.
That's why I'm sort of surprised the PM-1s measured flat all the way down to 20 Hz under similar conditions ... but dunno.
-
Seems like with Styrofoam they isolated the driver from the original acoustic environment of a given can quite a bit. Therefore pads for example don't have much affection to the resulting FR anymore. The original headphone volume was also compromised which leads to a weird overall balance. On top of that HF amplification also seems to go into play via reflective surface of a given Styrofoam.
-
Alex sent me his modified Oppo PM-1 cans. Thanks mang :money:
I do not have the stock PM-1s with me anymore, but at the meet I thought the modded PM-1s had a little more bass than what I'm hearing right now. Who knows, maybe I'm a bass head or something. Anyway, to me the impact is perhaps lessened (even from the stock if my memory serves me), but it's not gone. If anything, these are a little more laid back in the bass region. The treble is pretty good. I think the treble on this is an improvement over the stock. More airy. It is a bit brighter though.
I dig these. They sound perhaps a little less low-fi to me. Note I did not dislike the PM-1s in their stock form, but didn't go crazy about them either.
These seem also a little heavier than the previous ones I heard (perhaps due to the mods). Still, pretty comfy though, and not as heavy as some other orthos.
Here are some measurements...
Frequency Response
(http://www.changstar.com/index.php?action=dlattach;topic=1590.0;attach=6712;image)
Distortion Right
(http://www.changstar.com/index.php?action=dlattach;topic=1590.0;attach=6714;image)
Distortion Left
(http://www.changstar.com/index.php?action=dlattach;topic=1590.0;attach=6716;image)
CSD Right
(http://www.changstar.com/index.php?action=dlattach;topic=1590.0;attach=6718;image)
CSD Left
(http://www.changstar.com/index.php?action=dlattach;topic=1590.0;attach=6720;image)
Impedance
(http://www.changstar.com/index.php?action=dlattach;topic=1590.0;attach=6722;image)
-
Comparo with stock PM-1s:
(http://www.changstar.com/index.php?action=dlattach;topic=1590.0;attach=6724;image)
Comparo with HD600 and SR-009:
(http://www.changstar.com/index.php?action=dlattach;topic=1590.0;attach=6726;image)
-
Impressive. The modding evened out the recession around the upper mids ~ lower treble, and boosted the treble extension dramatically, without raising any previous peaks/humps. That's a pretty darn impressive frequency response. The overall tilt might be a bit off though, and what's with the bass, is it a seal problem?
-
Don't think it's a seal problem. These are full size open, and have measured the stock version with velour pads. I remeasured some other cans I have to double check my rig and things look good.
One may be conditioned by plots. However, I do hear cans before I measure. These did sound a little leaner in the bass area than even my HD558s. I don't think that's how I heard them before though.
Alex mentioned he did more mods to them after the meet, so they should sound different from then. At the meet I though the had more treble and more impact relative to the stock PM-1s. This time around the bass seems mitigated. I think they sound a bit brighter too because of this.
-
Don't think it's a seal problem. These are full size open, and have measured the stock version with velour pads. I remeasured some other cans I have to double check my rig and things look good.
One may be conditioned by plots. However, I do hear cans before I measure. These did sound a little leaner in the bass area than even my HD558s. I don't think that's how I heard them before though.
Alex mentioned he did more mods to them after the meet, so they should sound different from then. At the meet I though the had more treble and more impact relative to the stock PM-1s. This time around the bass seems mitigated. I think they sound a bit brighter too because of this.
A good seal is still incredibly important for low bass / sub-bass, especially for cans with a hermetic seal between the driver, the cup, the earpad, and the face. All Audeze cans operate in that regard, similarly with HE560 I find (even breaking the seal slightly makes the driver lose control of very low frequencies).
But that massive roll-off you measured there with the modded PM1 is way more severe than what an improper seal would introduce. So it's definitely something else.
-
There is some driver dependency, and the impedance does seem to show a resonance at around 60 Hz.
That said, I measured these LCD-2s (http://www.changstar.com/index.php/topic,17.msg32535.html#msg32535) the same way I measured these cans. And so did the stock PM-1s (http://www.changstar.com/index.php/topic,1590.msg42029.html#msg42029), HE-500s (http://www.changstar.com/index.php/topic,1154.msg39774.html#msg39774), and all full size open dynamic cans.
I could however remeasure these with a non-leaky baffle (like I now do stats and closed cans). It would fill up the lower bass in the measurements, but results might no longer be easily comparable to other similar type cans measured with the leaky baffle.
-
The seal on the PM-1 isn't all that important as the chamber between the ear and headphone is intentionally designed to leak. Igor's theory is that headphones usually leak quite a bit more than what is shown in measurements as usually there is hair and glasses that create leaks anyway. So the PM-1 will be relatively insensitive to pad seal, but will also no show the kind of bass compression that headphones with a sealed coupling will show with a good seal.
Much more info coming with my review in a couple of days.
-
I'll try with the sealed measurements later tonite to see what I get. I think the LCD-X did benefit from sealed measurements, but that seemed more an exception than a rule in regards to full size open orthos. Thanks for the info Tyll and looking forward for your review! :)p5
-
Here are FR plots using a sealed baffle (leaky baffle in white for comparison purposes).
(http://www.changstar.com/index.php?action=dlattach;topic=1590.0;attach=6728;image)
The depression at 4kHz and the relative hump in the upper bass are perhaps the result of seal together with the use of the leather pads. Like Tyll said, perfect seal maybe difficult to achieve due to hair and in some cases head shape (makes me wonder about certain stats sometimes which seem to require pretty good seal to bring up the sub-bass).
In this case however (unlike some stats, and perhaps the LCD-X), sub-bass roll off seems to persist with the sealed baffle.
-
Ultrabike, thank you very much for your measurements and impressions posted. I really appreciate your effort!
In my own measurements they go to -5db at 30Hz relative to the HF peak at its highest point. They also have better extension in LF department then the previous mod you have heard at the meet. Quoting you: Oppo PM-1 (mod) vs PM-1 original - Same as above, but perhaps a little more treble and bass on these. I think more bass you heard at the meet most likely can be attributed to a slight peak around 100Hz the other mod had which is now gone.
They could still be better especially in LF though if my left driver was as good as the right one but unfortunately as mentioned before in the other thread my beta units came heavily unbalanced and had to be modded differently to match each other better while sacrificing the ultimate extension in both (left had much better top while right was much more extended at the bottom). I am not sure but suspect one of the drivers in my unit was from beta-1 batch while the other was beta-2, either way when I spoke to OPPO reps couple of weeks ago they were very much surprised my left and right drivers measured so different while I thought it was a norm for a beta test sample :-) . This explains why OPPO wanted to keep all the beta impressions closed, when one deals with a pre-production unit everything should be expected.
Good thing it looks like all the production units measure pretty consistent not only between left and right but also between different sets which tells a lot about their quality control standards.
-
It makes sense. These beta drivers seem to show lower distortion numbers around the mids though. Proly some trade offs took place before arriving to the final product.
Thanks Alex!!!
-
You are welcome and thank you! No, decreased distortion is the attribute of my mods as originally my drivers showed numbers similar to yours.
Darin Fong Audio will have a booth at THE Show in Newport and Darin has agreed to demo my PM-1 to all the interested parties.
To not confuse general public with the sound of my modded unit for the original OPPO we decided to keep it under the table but everyone is welcome to ask him for a demo. There you can compare it to both HD-800 and Stax-009 directly and I surely would love to hear your impressions and critique if any;-).
-
where's my swabbie mop and bucket...
http://www.head-fi.org/t/712932/oppo-pm-1-planar-magnetic-headphone-impressions-thread/2295#post_10587016 (http://www.head-fi.org/t/712932/oppo-pm-1-planar-magnetic-headphone-impressions-thread/2295#post_10587016)
-
I quite like the Oppo PM-1 overall. I also have a lot of reservations about it. While I can see why many consider this a disappointing product, I think it has a lot going for it and, at the very least, shows enough signs that future iterations could be damn good.
Presentation, Looks, Comfort
You've all heard about the packaging and the box. It's a very, very nice touch. That all alone makes me want to believe this headphone is truly worth the price. Would I rather have simpler packaging and, hopefully, pay a bit less? The box is so pretty, but, yeah...I think I would.
The headphone itself looks and feels great. The design is simple, modern, and stylish. It looks expensive. The build quality is good. It feels expensive. I quite like the ear pads and how easy they are to replace, but the modder in me is disappointed that the design and implementation is rather unique and would be hard to work with for other pads (I think some deficiencies could be slightly improved with different pads). The cable seems nice, but I'm not sold on the connectors they use in the cups. They feel and look good for being small, but I could see them being a weak spot as well.
Comfort is pretty good. Again, the pads are nice. The headphone isn't too heavy overall, but it could use a bit more cushioning in the headband or perhaps a better shape/fit for weight distribution. The top of my head started to get sore within an hour, but it could be worse. I'm picky in this regard.
Sound
I'm probably in the minority here in that I actually really like how the PM-1 sounds. It's not perfect by any means, but it just so happens it's very agreeable with my ears. I find it to have a very natural and effortless presentation. I generally thought it had a good tone and overall frequency response balance. It has a bit of a warmth and bloom to it, and it is rolled-off at the extremities. That said, it still has decent, but not great, extension and an overall balanced, fairly neutral sound. It's one of the few headphones with a sound I didn't have to adjust to when I pressed play. I could just slip right in and enjoy the music.
But, as I said, not all is perfect with the sound. The center image is good and has decent depth, but the rest of the soundstage seems to wrap right around the side of your head. For some genres, this doesn't matter too much. Thankfully, this isn't an area that bothers me a whole lot. I know some are less tolerant with these sort of issues.
The sound could also use a bit more liveliness and dynamics to it. Part of this is simply due to the rolled nature of the sound signature at either end of the spectrum. They are certainly a laid-back, smooth headphone (something I like). Yet, part of it just sounds like the headphone is stifled and over-damped despite that. The sense of air is lacking, and it seems there is little room for reverb and decay. For a lot of what I listen to, I don't mind it, but sometimes it can get weird. Ignoring the warmth, while the headphone is fairly clean and fast as a whole, it also has a slight limp-dick or ethereal quality to it. They also aren't super resolving and are, if anything, a bit veiled (again, still fast and clean). I don't mind all this so much. In fact, I most often find these traits to be desirable when listening, as I am very quick and easy to develop hearing fatigue. It all comes down to personal tastes. But, still, a bit more oomph in all categories wouldn't hurt. However, sometimes all that matters is if I can melt into a headphone without thinking about it. The PM-1 does this better FOR ME than most other headphones. (I'm really wondering what I'd think of the HD600/650 and LCD-2.)
EQ seemed to help the headphone's resolving abilities quite a bit, and it did help extend the soundstage a touch more to the front and sides. It still wasn't great. I'm wondering how much you could change this with mods and, in particular, angled ear pads. EQ in the bass and treble can bring back some of the liveliness, but it still retains that somewhat soft quality before it just starts to sound weird, shrill, and off (EQ can only do so much...).
I know a lot of these downsides can just kill it for some people. Just look at the mixed reactions already available on this site. But, for whatever reason, I simply really like how these sound. They fit my tastes and do well where I need them to, and the downsides just simply don't matter as much to me as they might for others. Do I think they are worth $1K+? Even with the nice box, no. Ditch the box and I'd easily drop $300-400 on the PM-1, though not before demoing the HD600/650 and making sure they wouldn't better fit the bill. If a newer model releases in the future and addresses the downsides I mentioned, I could see myself paying $600-700. Maybe offer the nice packaging and box at an extra cost for those that want it (and I admit, I might...).
Measurements and Analysis (Velour Ear Pads)
Updated measurements using new compensation curve: http://www.changstar.com/index.php/topic,1590.msg44503.html#msg44503
I've attached the following measurement images:
1. Frequency Response
2. Left Channel FR and Harmonic Distortion (ignore dip in D2 from 1-3KHz, as it is an artifact...should be fairly linear line)
3. Right Channel FR and HD (ignore D2 dip again)
4. Left Channel CSD
5. Right Channel CSD
6. Left Channel Raw - two measurements of left channel from left and right ear each, averaged for above FR (before compensation)
7. Right Channel Raw - same process
My measurements indicate that, at least as I hear it, the Oppo PM-1 has a sort of upside down, U-shaped frequency response. Fairly smooth and linear overall, though the balance does explain a lot. I think my measurements overestimate how rolled they sound, subjectively. Channel matching is good. The harmonic distortion from 100-500Hz isn't great, though I don't find this to be too detrimental to the sound. It may further contribute to the warmth and bloom I heard. Other than that, the distortion is low. CSDs are fairly clean, and that matches what I heard. My raw measurements suggest the headphone is relatively insensitive to position and seal (subjectively confirmed), which is nice. It does appear my two ears produce slightly different results, which is why I take measurements of each channel on both ears and average them when I can (PM-1 works well for this, but some headphones simply do not). This seems to work well in the end.
Compare to Ultrabike's measurements at the beginning of this thread (same PM-1) and Tyll's measurements here: http://www.innerfidelity.com/images/OppoPM1VelourPads.pdf (http://www.innerfidelity.com/images/OppoPM1VelourPads.pdf)
-
Nice, thanks for that.
I think I should try to fit "limp-dick" into more of my reviews.
-
It may be too technical for the masses...
-
It may be too massive for the techincal ;D
-
Such a small thing could be easy to overlook though. :P
-
I'm kinda curious how limp-dick somehow equates to ethereal :-Z
-
It just trends towards a somewhat light and soft sound due to the rolled nature at either end, that and likely the damping material used. Rolled bass gives it a slight lack of presence, body, weight, impact, etc. The rolled treble is soft and inoffensive. Not the most proper use of "ethereal" based on its definition, but that's just what made sense in my head when listening. That and "limp-dick." The Alpha Dog, in comparison, actually had some balls and could get itself up at the expense of not sounding quite as smooth and natural. Even metal can be relaxing on the PM-1.
It's audio. The terms don't have to make proper sense. :P Alternatively, look at my avatar and assume it's better to not try to understand me sometimes. :)p12
-
I was gonna say something about 'U-shaped' versus bell-shaped but we get your point.
-
Just got these out of the loaner program.
The FR seems good, but there's something decidedly mid-fi about them. Can't pinpoint it.
Edit:
They're bad enough that I like my Stock T50RPs more.
-
^ I know that feel, first time I disliked an ortho's bass characteristics.
-
I'm kinda curious how limp-dick somehow equates to ethereal :-Z
Ethereal is not necessarily a bad thing. I do like the STAX 009. Just not enough to get one and keep a good amp for it. Now if Frank Cooter had been willing to sell his blue tube SE stat amp, things could have been different for me.
Limp dick is always bad.
Hans review is good.
-
That's not very fair. Stock T50RPs are truly awful, like iBuds level of audio destruction.
The PM-1 may not be your cup of tea, but they are certainly far more technically capable than stock Fostex.
-
It's audio. The terms don't have to make proper sense. :P Alternatively, look at my avatar and assume it's better to not try to understand me sometimes. :)p12
Perhaps limp-dick could also translate into forgiving or polite? wimpy?
It's definitely one of those personal preference things. Anax and I have a tendency to not like overly forgiving or polite sounding gear. Leben, cough cough. But a lot of people do. Dammit, the PM-1 is sounding like the new direction of Porsche.
-
Limp dick means first time intercourse won't be as painful. Good headphone to ease into when you first put them on. Positive!
-
That's not very fair. Stock T50RPs are truly awful, like iBuds level of audio destruction.
The PM-1 may not be your cup of tea, but they are certainly far more technically capable than stock Fostex.
You don't understand. I'm not insulting or joking. I AB'd them with a two-jack amp. The Stock T50RP's are better pretty much across the board.
-
Limp dick means first time intercourse won't be as painful.
Or first time intercourse doesn't work.
-
Maybe the PM-1 has impactful bass until you put them on.
-
Perhaps limp-dick could also translate into forgiving or polite? wimpy?
It's definitely one of those personal preference things. Anax and I have a tendency to not like overly forgiving or polite sounding gear. Leben, cough cough. But a lot of people do. Dammit, the PM-1 is sounding like the new direction of Porsche.
Forgiving and polite, absolutely. Not to the point that everything becomes boring, but definitely relaxing (ah, yes, sit back in my robe with a pipe and listen to relaxing...metal). A bit on the wimpy side with bass and treble. Great and easy to sink into when you first hit play, but you lose interest after a while.
I do tend to prefer more forgiving and polite gear, and while the PM-1 overall fit my tastes very well, it was still too much for me. I think that says a lot. OTOH, the PM-1 has enough promise that future iterations might be exactly what I want.
That's not very fair. Stock T50RPs are truly awful, like iBuds level of audio destruction.The PM-1 may not be your cup of tea, but they are certainly far more technically capable than stock Fostex.
Could it be variations in T50RPs or the rumored production changes that happened some time ago? I remember the first unit I got was awful stock. The 2nd, purchased months later, sounded noticeably better and actually decent out of the box.
-
That's not very fair. Stock T50RPs are truly awful, like iBuds level of audio destruction.
The PM-1 may not be your cup of tea, but they are certainly far more technically capable than stock Fostex.
That's not very fair. Stock T50RPs are truly awful, like iBuds level of audio destruction.
The PM-1 may not be your cup of tea, but they are certainly far more technically capable than stock Fostex.
You don't understand. I'm not insulting or joking. I AB'd them with a two-jack amp. The Stock T50RP's are better pretty much across the board.
Honestly, in my inconsequential experience, the T50rp drivers can be somewhat Jeckyl and Hyde, especially unit to unit, amp to amp. Despite their flat impedance curve from being an ortho, they do respond better to some gear versus others. I recall when I was modding some back when I had the Fiio E9 I could never predict how the T50rp would sound that day from the E9 using just a stock pair. Just putting that out there.
Sometimes it was a piece of shit experience, others I wondered if I needed anything more type of evening.
-
Forgiving and polite, absolutely. Not to the point that everything becomes boring, but definitely relaxing (ah, yes, sit back in my robe with a pipe and listen to relaxing...metal). A bit on the wimpy side with bass and treble. Great and easy to sink into when you first hit play, but you lose interest after a while.
I do tend to prefer more forgiving and polite gear, and while the PM-1 overall fit my tastes very well, it was still too much for me. I think that says a lot. OTOH, the PM-1 has enough promise that future iterations might be exactly what I want.
Yup, a natural easy-going sound that can easily become boring. They'd have to fix the treble to interest me--it just sounds so shoved down.
-
I think the new site motto should be "Aarrr! Me limp-dick headphones be effin' ringin"
Or at least change it to that every June 21 to commemorate the first known use of the term "limp-dick" in a headphone review.
Though I do think Julian Hirsh used the expression in his review of the Bose 901 speakers... (dinosaur reference for the old-timers out there).
-
I don't expect any of this to make the PM-1 a less confusing headphone. If you read my recent post on one of the HD600 measurements threads, you'll know I've made a pretty big tweak in how I compensate for bass since I've measured the PM-1 or HA-RX700. Originally, my loopback hardware measurements exhibited a large bass roll-off, roughly 14dB down at the 20Hz mark. When originally experimenting with my compensation curves, I compensated based on that. However, I felt I was getting exaggerated bass response results. So, I tuned down the bass compensation, subjectively. At the time, this boosted the bass at 20Hz by roughly 5dB from raw measurements. I later changed this to ~7dB for the RX-700 measurements. I was also tweaking the 2-5KHz area and area above 10KHz, toning both areas down after compensation.
I had planned on using the HD600 as a reference point for my measurements, given how many sources of measurements exist for this headphone and their relatively consistent results. With my previous compensation method, my bass results weren't too far off Tyll's results for the HD600...but I had too much bass roll-off relative to almost every other available measurement. My quick HD600 measurements also showed I had been cutting off too much of the response above 10KHz. On some headphones, I thought my 2-5KHz results were exaggerated, but considering I found that hard to repeat in other headphones, I decided to dropped it and reasoned that was just a subjective error on my part. So, I've stuck to my plan and have used the HD600 to arrive at a compensation curve that gave me the results I was expecting for the HD600, my reference point in a sense, and one that is pretty agreeable (simple) for me to keep in place as a final compensation curve. All I'm doing now is simply compensating for my hardware as my loopback measurements indicated. This doesn't account for the mic, and other measurements floating around on the internet of the mic I'm using vary...I simply decided to leave that as-is, but all it would generally change is slightly decreasing the response above 9KHz or so after compensation.
That said, I've kept my raw measurements around for this exact reason and wanted to apply my new compensation curve to my PM-1 data. I've attached images below (read note below about HD numbers getting screwy with CSV exports).
So, wait, are we still dealing with floppy sausage? Subjectively, yes. I still think these measurements make sense, and more so than my previous ones. I subjectively found the PM-1 to have good bass extension and a fuller response than my measurements indicated, so what these measurements show doesn't surprise me. What measurements can't tell you is that it's not particularly impactful or forceful bass. It is faily clean, balanced, and extends well, yes, but it had a subjectively light and relaxing quality to it. The HD600 generally sounds livelier in this regard, but I'm wondering how much of this is due to the slight hump around 100Hz and the extra distortion relative to the PM-1. Some of it could be the different types of drivers. As an example, I've found T50RP driver to not be as impactful sounding as other drivers at times despite measurements being roughly similar. I'm guessing the PM-1's damping configuration also plays a role in making it sound weak and constricted. These graphs still support the idea that they are a fairly warm sounding headphone.
The upper response still has missing information and has a fair amount of roll-off, enough to explain their relative lack of treble liveliness and air relative to other headphones. You can think of it more as a rapid drop in the response after 5KHz with a small-ish peak around 10KHz or so. And, again, these things really sound like they're just over-damped in general or something of that nature. So, in the end, we're really just left with extra bass that I thought I heard anyway, and I did occasionally mention in my prior post that I thought the measurements didn't quite match what I heard. The new results make a bit more sense in hindsight.
As was the case with my HA-RX700 measurements, the exported CSV data for distortion didn't come out right. I don't have the PM-1 on hand to get new measurements, but you can tell it's pretty clean. Most of the elevated spots (bass, treble, NOT the mid-bass area) have exaggerated results after being exported to CSV, and I don't know why. I will be experimenting with ARTA, new versions of the software, and my HD600 in the near future to see if I can fix this on future measurements.
Raw data from before is obviously still the same. CSDs change like the FR does but look pretty much the same otherwise.
TL;DR: New changes to compensation curve, mostly means moar bass. Updated PM-1 measurements. Does not change the boring sound.
-
So, wait, are we still dealing with floppy sausage? Subjectively, yes. . . . I subjectively found the PM-1 to have good bass extension and a fuller response than my measurements indicated . . . What measurements can't tell you is that it's not particularly impactful or forceful bass. It is fairly clean, balanced, and extends well, yes, but it had a subjectively light and relaxing quality to it.
That's how I heard it too. Its bass is like a bomb explosion with only the aftershock.
-
Those look good - as how I perceive the tonal response. Dark tilt with upper mid / lower treble depression. Pretty good FR. But FR isn't everything.
-
Can we get overlay with HD600 and any other 'phones you have on hand?
-
Yup, once I get measurements for it. I lied and didn't do it over my weekend like I said I would...oops!
-
HD600 vs PM-1, as requested.
-
The PM1 looks good in the measurements. Thing is the high and treble range seem missing.
The HD600 is good headphone and seems to offer a more balanced sound. I now understand the comments. Thanks ahoy
-
Thanks Hans,
The comparo with a well known headphone is all I need to know !
Now absolute correctness of the rig is irrelevant to me.
Far from neutral and dark sounding with a missing top-end extension.
Not my preference but others may very well like it.
-
This would explain what I thought of the PM-1. I heard some comments of poor man's Stax but I'm still unconvinced. I did not like what I heard anyways.
-
"PM-1 is a poor mans STAX." In some ways, it does make sense if you think about it. It does have some similarities to the SR007mk2.5. But it ain't no STAX.
More on this later. I heard a PM-1/2 with some modified pads (from OPPO) which provided some good results.
-
More on this later. I heard a PM-1/2 with some modified pads (from OPPO) which provided some good results.
Pretty interested in this