Submitted by Then-Effective5434 t3_ydamru in headphones
knvngy t1_itrqnhy wrote
Reply to comment by rhalf in Sincere question: does technicalities exist, or everything what matters is FR graph? by Then-Effective5434
If you can hear non-linear distortion then the transducer is very low quality, excessive power is applied beyond what the transducer was designed for, or both. Most of this distortion is usually concentrated at very low frequencies. Decent transducers do not produce audible distortion other than the frequency response itself at normal listening levels.
Since most people who talk about technicalities do not measure nor talk about how the transducer creates distortion nor any technical aspect associated with distortion such as levels, their talks about "technicalities" can be dismissed as gibberish.
> waterfall plots
These plots which are nothing but a fancy and convoluted plot for resonances are can be very misleading and not very useful to meaningfully interpret data. Even more useless for headphones and iems.
rhalf t1_its15a1 wrote
I think you may have just demonstrated your lack of understanding of how a driver works. I touched on it in the first post, so I'll begin where I left it. A transducer reproduces sound most accurately near it's resting state. This means that small amplitude vibrations are clean. The further away the diaphragm gets from the center, the less linear it gets and consequently the more the sound distorts. I think so far we are on the same page. So here's where your logic is failing - it's a fullrange driver. At the same time as it plays the lows that push it far from it's comfort zone, it simultaneously plays the highs, that are being reproduced in and out of that comfort zone. The small, high frequency vibrations are subjected to the same modulation of forces as the bass. This causes often audible distortion throughout the range.
The reason why opinions like the above circulate is because many people learn from basic theory and looking at graphs instead of using reasoning and insight. The distortion that you see in reviews is a so called THD or total harmonic distortion. Let's break down this cluster. HD or harmonic distortion is a measurement. It's not a physical property of a driver. It's an oversimplified measurement procedure that is older than sound reproduction itself. It wasn't adapted to your psychoacoustic model, and neither does it describe accurately the troubles of reproducing music. It is simply playing a SINGLE tone and seeing what other tones come out. Total HD is simply a way of presenting this data in even simpler form. No wonder you don't know how a headphone works, you're basing your knowledge on a simplification of an oversimplification. Real distortion test that's representative of sound quality is a multitone intermodulation torture test and a set of compression curves known from Klippel. There are plenty probably other flaws in your concept , but let's just stop and digest this. IMO the OP makes a great point. The basic measurements that we use dont fully describe sound quality. It may be enough for you, but that's just like your opinion, dude.
knvngy t1_its801k wrote
> multitone intermodulation torture test
I think you are missing the point here.
Even if it is true that the 'real and true' measurement for audible distortion is the 'multitone intermodulation torture test', absolutely nobody is using that to review headphones or iems to talk about 'technicalities' or 'sound quality' except perhaps for some obscure nerdy gnome in a cave.
Secondly, that 'multitone waterboarding test' is kinda silly because the overwhelming majority of the distortion is usually concentrated at very low frequencies, since that's where the drivers has to move more to displace air. That's where the non-linear distortions rear their ugly heads first. Something that can be more easily identified with a normal a total harmonic distortion measurement. If the transducer can't pass simple that test at decent loudness, I don't see what's the point to continue with more exotic tests.
> The basic measurements that we use don't fully describe sound quality
If people measure the headphone at 150db and is distorting like Death metal guitar of course that the frequency response is rather useless.
But if the traducer is not significantly distorted then I don't see what's the point that you are trying to convey here. If it matters then measure it and report at what level the distortion becomes audible. Then obviously, do not measure the frequency response when this is the case. Such a silly and moot point...
rhalf t1_itsbj1a wrote
I feel like you didn't really read what I said and only implied an insult either to me or the OP with a malevolently worded ad populum. The fact that most people use THD instead of a more adequate form if measurement has nothing to do with your disdain and hateful view of this community. It's simply the easier thing to compare. THD is a standard, and Multitone tests are custom. You can't compare the results between different users who use different test procedures. The problem that I'm pointing at however is that you're not using THD for that. You use it to draw ignorant conclusions on working principles of transducers. Your reasoning only applies to multi way devices. A fullrange driver distorts in it's entire bandwidth. This is an obvious fact known to everyone who designs audio and a primary reason why it's worth to build multi way speakers. If a fullrange driver is playing bass, the vocals distort. That's just how it works. HD plots don't display that. Multitone tests do, because unlike HD, they were specifically designed for testing music reproduction.
knvngy t1_itsicmw wrote
Just show that distortion is significant/audible beyond certain level, then do not measure/publish the frequency response beyond that level. At that point the whole discussion about "multitone intermodulation torture test " becomes utterly irrelevant to the frequency response . It is that simple.
JivanP t1_iuiox2o wrote
> beyond certain level
At what frequency/frequencies?
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