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Abyss Diana V2 Review (headphone)

roz

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Theres obvious conflicts of interest here, so regardless of validity, I still wouldn’t trust the “3rd party’s” measurements since there is money on the line (I.e. sponsorship fees)
 

sherm137

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Theres obvious conflicts of interest here, so regardless of validity, I still wouldn’t trust the “3rd party’s” measurements since there is money on the line (I.e. sponsorship fees)
Yep and it's sketchy when someone is doing validity measurements and doesn't disclose that relationship.
 
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amirm

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It’s on the sponsors section.
It needs to be at the start of the post. Look at how religiously I mention source of product under test as the second sentence in reviews. And any conflict of interest right after that. Jude's signature also needs a disclaimer and link to sponsor page.
 
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amirm

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I see some responses by Jude. He says:

1610742474484.png


I don't know why he says that when I clearly showed and indicated that the distortion exceeds our 40 dB threshold:

index.php


I prefaced the above graph: "In absolute terms, distortion exceeds our 40 db thresholds in the two areas we already know about: "

Since the problem was already seen and explained in ratio presentation, I didn't see the need to repeat all that again. The measurements are one in the same anyway. It is just that presentation is different.

The point of Jude's original post was that if he was going to use a log scale, then he should have presented the same graph I did above. Then they would both be using log scale. Instead, he invented a new presentation with log percentages which didn't relate to anything without carful analysis and annotation as I did.

So his assertion is incorrect. The same measurement created the two graphs so both describe the same problem. I tend to not like the THD log display as much because it is harder to see problems in it than the linear scale one I use:

index.php


See how easy it is to see the distortion characteristics.

Our goal here should be clarity and best presentation practices so that everyone can see where the problem areas are. The plots he and others have been using for distortion don't do this. This is why there has been so little light on this problem. It took me months to refine these distortion presentations so that they make sense and clearly show strength and weaknesses of headphones. I suggest Jude follows the same so that we have one way of looking at problems.

On that topic, it was so hard to read his graphs. He uses way too high a resolution (1500 pixels horizontally) and too wide of an aspect ratio. Add lack of color and I had to squint and squint to see that his measurements showed the same problems I had identified. As it is, they look like fancy graphs with no insight.
 
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amirm

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Then there is this myth he keeps repeating:

1610743152758.png


There is no such thing as going deaf at 114 dBSPL in two minutes or every concert goer would come back deaf. Even in classical concerts, levels as high as 120+ dBSPL have been measured where people sit. Are we to assume they all lost their hearing? Of course not. The whole point misses our hearing works, what music really is, and psychoacoustics.

As others Jude continues to confuse safety standards for noise to music, not understanding aspects of either. They are completely different things. Here is OSHA (US loudness standards):

1610743297351.png


Notice that the measurement is with a-weighting. This filters out tons of low frequencies:

1024px-Acoustic_weighting_curves_%281%29.svg.png


Look at the graph in blue. That is a-weighting. Notice how it completely filters out bass frequencies meaning the safety standards do not worry much about how loud the bass frequencies are. They care how loud mid to high frequencies are. That is the region which causes hearing damage. That jet taking off is creating tons of broadband noise and of course it is hazardous to your hearing.

The situation here and with music is very different. Here is a track I just pulled up to analyze, the famous Chris Jones No Sancturay:

1610743817151.png


Notice how most of the energy is below 100 Hz. And certainly by 1 kHz. A-weight filtering would knock whopping 40 dB from 20 Hz response!

What this says is that when you turn up this track to 114 dBSPL at bass frequencies, it is considered 114-40 dB = just 74 dB! Indeed that is what the fletcher munson-graphs say about our hearing sensitivity in low frequencies. Your ears are simply not sensitive to bass. Listen to tracks I have posted with deep bass and you can hardly hear them.

All of this is beside the point that we use equalization to boost bass frequencies. The Diana V2 is deficient to the tune of 13 dB from Jude's own measurements. Once we compensate for that, then we are adding 13 dB more to the response to that region, causing it produce a lot more distortion. This distortion doesn't just show up in bass. Once you have enough of it, it bleeds way into higher frequencies, potentially even making the headphone sound bright.

Yes, you don't want to listen too loud. But know that too loud means mid to high frequencies. When I turn up the music way loud, it is never the bass that sounds too loud -- it is the mid to highs. People put massive subs in their rooms with when combined with room gain, can produce incredible amount of bass SPL. Do we see people running away from rooms because of the subs? No. They run away if the sound is too bright, or too loud in higher frequencies.

So yes, take care of your ears. But make sure your eyes and brain are not confused by lay statements like Jude is making to protect the industry he serves. He should have run the 114 dBSPL just as I did. It is not like he had to listen to them.
 
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amirm

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I post this for discussion. Jude uses an expensive isolation chamber by Herzan which he used for this testing:

1610744809154.png


There is a potential problem here that boosts low frequencies. Let me explain.

The enclosure he purchased is made to keep noise from entering the chamber. That is not my concern here (I exclude noise from THD measurements using signal process so don't need the enclosure for that). The concern is what happens when sound comes out of an open back headphone. In a normal listening room, the walls are pretty far from the headphone so reflections become quite low in amplitude by the time to come back to the headphone. I experimented by putting a box around my headphone gear and it massively corrupted the frequency response (and distortion since it is relative to level of the signal). Any box put around a headphone measurement system needs to be fully anechoic, otherwise the reflections will change the response of open-back headphones such as Abyss Diana V2.

Here is the Herzan chamber Jude uses:

10028012.jpg


Notice how small it is so reflections won't have much distance to attenuate.

Then there is the issue of those foam absorbers. Those are basically useless below 1 kHz or so. Here is a quick graph showing that:

AF_07_15_01-mugXA7RMVmY47IRNjVF3K6bh8g8.u0Ls.jpg


Look at that orange curve. It doesn't get to full absorption (alpha of 1.0) until you get past the right side of the graph at 4000 Hz! At 20 Hz absorption is just 10%. Wavelengths get so large in bass frequencies that you need feet of it, not an inch or two. This is why anechoic chambers are so expensive to build.

In addition, you also get "room modes" depending on where you put measurement fixture, causing response variations.

Now, I have not tried to build a chamber like his and see the impact. I just know that putting a box around the fixture causes massive error. Jude needs to experiment with measurements inside and outside of that chamber and see what effect it has.

Noise isolation is not needed for frequency response anyway when you use high enough level as I do (and he almost does). Neither is distortion impacted at the levels we are measuring and with proper signal processing to exclude noise.

I know Rting and Tyll both use similar enclosures although the latter two are home made. I think they automatically assumed there is goodness here, not realizing acoustics of sound and impact on open-back headphones.
 

AJ571

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First time poster, long time reader.

I was within days of ordering a Diana V2 when this all kicked off. I'm not going to get into the merits or otherwise of the measurement debate, as this is not my field of engineering. I can only learn from others.

I will say I have been less than impressed by the commentary from Abyss themselves and the spectacle surrounding this. So that's a purchase intent cancelled.
 

KTN46

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I also want to ping @GoldenOne back here. Only 2 hours after their measurements were posted, you left a comment there saying:

"Thank you so much for this incredibly thorough and detailed response. I think given the evidence shown here the issue can pretty much be put to bed.
Objective measurements are incredibly useful. But of no use to anyone if there are obvious flaws which the provider of said measurements refuses to even entertain the possibility of addressing (or that it is a flaw at all)."


It's interesting how you can so easily state "demonstrably faulty" criticisms here, and yet so uncritically accept Jude's measurements as gospel. I'm not saying that one measurement is more 'right' than the other, or that there is a true way of doing things that either Amir or Jude stick closer to. However, given how much discussion there has been on both sets of measurements, it's odd that you have only scrutinised one side.
 
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Tachyon88

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I saw someone mention this in another thread, but I am of the same. When I move headphones around on my head, wearing and not wearing glasses, I do not really notice a difference in the sound. This has been true for all of my headphones I've owned. I saw a video of DMS talking about positioning of the Diana for sound change, but I did it also when watching the video on my V2 and did not agree. Not saying it doesn't for others though.

My feelings of the DV2 haven't changed since the measurements came out. It is what it is. I like em, but they are not worth the price......by a long shot. No headphone is worth over 2k and that is being very generous, IMO. I'd feel this way even if they measured "perfect" or if they subjectively sounded like the most amazing jaw dropping life changing headphone ever. Build quality of the DV2 is much better than the HD800S, but I like the way the HD800s sounds more.
 

abdo123

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@amirm

I remember a big fiasco happening for a dip in the sub-bass of the Neumann KH 80 DSP review that was later attributed to low operation temperature.

I was wondering whether a similar behavior can happen with headphones measurements (since we obviously do heat up the drivers with our ears). Or is Diana's claim that the 'drivers need to heat up' complete bogus?
 

maxxevv

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@amirm

I remember a big fiasco happening for a dip in the sub-bass of the Neumann KH 80 DSP review that was later attributed to low operation temperature.

I was wondering whether a similar behavior can happen with headphones measurements (since we obviously do heat up the drivers with our ears). Or is Diana's claim that the 'drivers need to heat up' complete bogus?

There are BIG difference there.

i) Neumann has all their documented test data in place to verify the issue. Abyss doesn't, or they have not demonstrated that they actually do.

ii)Neumann was in the view of something being amiss / was missed in the measurements rather than dismissing an independent measurement and they wanted to find out why. Which they managed to.
 

Maki

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I saw someone mention this in another thread, but I am of the same. When I move headphones around on my head, wearing and not wearing glasses, I do not really notice a difference in the sound. This has been true for all of my headphones I've owned. I saw a video of DMS talking about positioning of the Diana for sound change, but I did it also when watching the video on my V2 and did not agree. Not saying it doesn't for others though.

My feelings of the DV2 haven't changed since the measurements came out. It is what it is. I like em, but they are not worth the price......by a long shot. No headphone is worth over 2k and that is being very generous, IMO. I'd feel this way even if they measured "perfect" or if they subjectively sounded like the most amazing jaw dropping life changing headphone ever. Build quality of the DV2 is much better than the HD800S, but I like the way the HD800s sounds more.
I perceive significant FR changes in nearly all of my headphones. The only ones that don't are the ones where the openings are so small they can't be moved around much.
 
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amirm

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@amirm

I remember a big fiasco happening for a dip in the sub-bass of the Neumann KH 80 DSP review that was later attributed to low operation temperature.

I was wondering whether a similar behavior can happen with headphones measurements (since we obviously do heat up the drivers with our ears). Or is Diana's claim that the 'drivers need to heat up' complete bogus?
The Neumann thing was a big fight over so little. We were arguing over a dB or two near bass. The end outcome was something they were not aware either and we both had to run experiments to figure out if temperature was a factor.

Anyway, in the process of testing headphones, I run a good number of sweeps and pure tones before finalizing the measurements. This process can last at least half hour if not more. So if something needs to be run some before measurements, it is. :)
 
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amirm

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I perceive significant FR changes in nearly all of my headphones. The only ones that don't are the ones where the openings are so small they can't be moved around much.
I don't think you perceive the type of changes we measure. If you were then the sound would constantly change as you moved your head. I can make a headphone measurement changed by simply holding the cable differently!
 

Tachyon88

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I perceive significant FR changes in nearly all of my headphones. The only ones that don't are the ones where the openings are so small they can't be moved around much.

Yeah thats what I was reading and expecting too when I got into headphones. There is probably a head and ear shape factor.
 

Maki

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I don't think you perceive the type of changes we measure. If you were then the sound would constantly change as you moved your head. I can make a headphone measurement changed by simply holding the cable differently!

Probably not positional shifts that small. However if I move the cup a half cm forward or back I can tell the FR has shifted. Not a lot but it's enough to irritate me. With some headphones I even had to make a shirt clip because the cable was causing uneven pressure at the bottom of the cup.
 
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