Testing audiophile claims and myths

[MrHaelscheir]

So, i have like 5 HD800 , don't ask why...

I was thinking if copper sheet thin metal, thin layer place within the cups. Just covering the side walls.

I can say that putting a highly acoustically reflective lining (whether solid leather or in my case, the addition of a cardstock paper insert) on the inside of the pad measurably raises the 1 kHz to 2 kHz region while relaxing the 3 kHz region, at least for the HE1000se. For the Meze Elite, that upper midrange boost from a similar paper insert is more drastic. Thin copper would simply have a slightly different acoustic impedance. Using a more absorptive inner pad lining (e.g. synthetic fabric) measurably relaxes the upper midrange.

 

[castleofargh]

I went back 15 years ago to the start of the thread. Only read the first few pages, but boy-o-boy they were certainly more pleasant and polite. How times have changed......

1/ true.
2/ @FunkyBassMan pretty much exclusively posts in this section of the forum to say that @gregorio is wrong, dumb, dishonest, insulting... It's one of those Montague VS Capulet stories, where the grudge is so ancient I have no idea what started it, even thought I've been watching the entire play. For one reason or another, true love has fully developed, and most of the time I let them go at each other simply because it tends to only hurts themselves.

So, i have like 5 HD800 , don't ask why...

I was thinking if copper sheet thin metal, thin layer place within the cups. Just covering the side walls.

I don't think there are special acoustic properties. All volumes will have a certain resonance, all materials will flex a little when sound waves hit them, and it's mostly a game of stiffness(that a very thin metal sheep would not have) and thickness that decide what wavelength will do what when reaching the surface. If you put a very thin layer of metal inside the cup, if any part of it is free, you'll probably end up with it buzzing which is not good. And if you glue the entire surface(100% of the thin metal sheet), then maybe you'll improve the stiffness of the cup(and slightly change the internal volume), so that should affect resonance a little too. I guess I'd be more worried about all the very many new internal reflections created by a not perfectly smooth metal surface coming over the well-designed plastic or wood of the cup. All that stuff points at high to very frequencies(because the thing you change relates to the wavelength of a sound wave, so tiny changes cause tiny frequency shifts or reflection of tiny wavelengths).

About electromagnetic stuff, I guess we'd first have to demonstrate that any of it matters in that one particular headphone. But you probably can at least mess a little with the magnetic field of the transducer. Not sure if that's a good thing though, but then the choice of metal could be more relevant as you'd probably get some tiny eddy current opposing the magnet if you use copper.

 

[gregorio]

I went back 15 years ago to the start of the thread. Only read the first few pages, but boy-o-boy they were certainly more pleasant and polite. How times have changed......

Not really. If you carry on reading you’ll find other examples of people posting falsehoods/false claims/marketing, others refuting those claims and getting frustrated at posters doubling down on the falsehoods, along with their refusal to learn, understand or accept the facts/science. That was over 14 years ago and you’ll find more examples throughout the intervening years.

G

 

[71 dB]

I went back 15 years ago to the start of the thread. Only read the first few pages, but boy-o-boy they were certainly more pleasant and polite. How times have changed......

20+ years ago when I started spending time on online discussion boards the overall vibe was different. People interacted more like in person and were acted accordingly. There was more respect of others. If you made someone mad with what you wrote it was closer to making a person in your life angry. Then people learned to act differently online: People want validation* and if they don't get it they get frustrated which can lead to tantrums.

I have been like that too, but I have tried to learn away from this behavior. I have accepted I will never get validation for anything from anywhere. I am just a loser waiting to die away. While waiting, I can try not to be an asshole online. This is difficult, because no matter what I say, someone is going to think I am an asshole... ...anyway, if the interactions between people were more genuine in the beginning, things changed: Bots and sock puppets arrived to create chaos and people with money and power started paying people to regurgitate propaganda online.

I don't know if people can tell it, but I am a genuine person. I am not a bot or sock puppet. Nobody pays me anything to say anything. 100 % of what I write is 100 % my own opinions (hopefully also close to the facts were in sound science forum!). I am not the most polite person you meet, but I am not mean either. I am mildly autistic and I suck at social interactions. Things like social norms are irrelevant (even annoying!) to me unless they make logical sense. In general I don't want misfortune to anyone and even if we autistic people feel like robots when you interact with us, we also have a deep sense of justice. We are humane and we advocate equity in society. My high-functioning autism gives me the "super-power" to think outside the box and find solutions to problems "normies" can't see, but unfortunately my IQ is closer to 100 than 200 and that has prevented me from becoming a new Einstein or at least a validated person in science. I am too dumb to be an eccentric genius and too autistic to became anything else, because everything else (even career in engineering it seems) needs social skills. That's why I am nothing. Well, that isn't the truth. I am me and I am the best in the World being me!

* I believe the World has changed in a way that has robbed people from getting validation in life and that leads to the need to get it online.

 

[Ryokan]

20+ years ago when I started spending time on online discussion boards the overall vibe was different. People interacted more like in person and were acted accordingly. There was more respect of others. If you made someone mad with what you wrote it was closer to making a person in your life angry. Then people learned to act differently online: People want validation* and if they don't get it they get frustrated which can lead to tantrums.

I have been like that too, but I have tried to learn away from this behavior. I have accepted I will never get validation for anything from anywhere. I am just a loser waiting to die away. While waiting, I can try not to be an asshole online. This is difficult, because no matter what I say, someone is going to think I am an asshole... ...anyway, if the interactions between people were more genuine in the beginning, things changed: Bots and sock puppets arrived to create chaos and people with money and power started paying people to regurgitate propaganda online.

I don't know if people can tell it, but I am a genuine person. I am not a bot or sock puppet. Nobody pays me anything to say anything. 100 % of what I write is 100 % my own opinions (hopefully also close to the facts were in sound science forum!). I am not the most polite person you meet, but I am not mean either. I am mildly autistic and I suck at social interactions. Things like social norms are irrelevant (even annoying!) to me unless they make logical sense. In general I don't want misfortune to anyone and even if we autistic people feel like robots when you interact with us, we also have a deep sense of justice. We are humane and we advocate equity in society. My high-functioning autism gives me the "super-power" to think outside the box and find solutions to problems "normies" can't see, but unfortunately my IQ is closer to 100 than 200 and that has prevented me from becoming a new Einstein or at least a validated person in science. I am too dumb to be an eccentric genius and too autistic to became anything else, because everything else (even career in engineering it seems) needs social skills. That's why I am nothing. Well, that isn't the truth. I am me and I am the best in the World being me!

* I believe the World has changed in a way that has robbed people from getting validation in life and that leads to the need to get it online.

You remind me of Chuang Tzu who philosophized on such conundrums nearly 2500 years ago, such as the parabole of the 'Useless tree'.

'What things are we trying to make into something else and not use in its proper way? Are you the useless tree or the useless goose? If you think you are useful, the higher question is useful to whom, or to what?'.

And his story about the lowly man wanting a high position and power to govern others, and the man in a high position who just wanted a quiet peaceful life without responsibility and having to be on hand to constantly manage the kingdom.

 

[2leftears]

Well, much of social media has made it easier for people to create virtual realities and live in information bubbles. But above all it has allowed for the world of advertising to become much more pervasive and invasive than it already was.

Combine the two concepts, throw in a lot of ignorant actors who lack critical thinking and unknowingly disseminate misinformation, add a few bad actors who disseminate disinformation, and add in AI, which is essentially a very efficient ands fast-acting robotised version of the former.

Finally, consider tech companies who seem more keen than ever to wash their hands of any responsibilities.

It is not a pretty picture, especially where information bubbles meet under the auspices of anonymity.

 

[castleofargh]

20+ years ago when I started spending time on online discussion boards the overall vibe was different. People interacted more like in person and were acted accordingly. There was more respect of others. If you made someone mad with what you wrote it was closer to making a person in your life angry.

Clearly, we've had a very different internet experience 20+years ago. In my memories of those times on the web, every female was in fact a male pretending otherwise, every male was gay(me included, based on comments), and yet all those allegedly gay men kept having sex with someone's mother(or so they often said). Those were confusing times.
Oh, and on occasion there was something to talk about, but I don't really remember what it was. Probably porn, pirate stuff, cats, or the temperature at which a magnet stops being one. Typical internet content.

I feel like the more mature, more respectful communities had to be on average the ones with people who sucked at computer stuff(AKA older people), because there was no effective way to enforce anything(most people didn't even have a fixed IP address so they didn't even need to know how to use a proxy). The worse that could happen was that you'd need to reboot, register a new account, and keep insulting whomever. Probably, your memories are what they are because you were looking more at communities themed around serious stuff to begin with. No doubt that the astrophysics forum was calmer and more respectful than one on football.

But sure enough, internet has changed a lot! For one, freedom and anonymity are basically gone(at least at the level of Google, Amazon, governments...). Also now bots make too much of the content and the motivation behind that content and most of the still human content is entirely manipulative. That can't be good.

 

[protoss]

I don't think there are special acoustic properties. All volumes will have a certain resonance, all materials will flex a little when sound waves hit them, and it's mostly a game of stiffness(that a very thin metal sheep would not have) and thickness that decide what wavelength will do what when reaching the surface. If you put a very thin layer of metal inside the cup, if any part of it is free, you'll probably end up with it buzzing which is not good. And if you glue the entire surface(100% of the thin metal sheet), then maybe you'll improve the stiffness of the cup(and slightly change the internal volume), so that should affect resonance a little too. I guess I'd be more worried about all the very many new internal reflections created by a not perfectly smooth metal surface coming over the well-designed plastic or wood of the cup. All that stuff points at high to very frequencies(because the thing you change relates to the wavelength of a sound wave, so tiny changes cause tiny frequency shifts or reflection of tiny wavelengths).

About electromagnetic stuff, I guess we'd first have to demonstrate that any of it matters in that one particular headphone. But you probably can at least mess a little with the magnetic field of the transducer. Not sure if that's a good thing though, but then the choice of metal could be more relevant as you'd probably get some tiny eddy current opposing the magnet if you use copper.

I was steering the conversation towards this topic, and it's clear that it's more complex and complicated than it seems! Factors like volume matching, resonance, material usage, reflections, absorption, stiffness, and eddy currents all come into play.

The eddy current issue makes me want to dismiss copper altogether, and silver sheets might be even worse. Probably aluminum is a safer choice, but it won't have the same audio properties as copper, unless that's all misinformation.

I initially picked copper for its accuracy, less distortion, and minimum frequency loss. However, it's clear that even copper's effectiveness depends on the sheets' quality, density, and thickness.

Using glue is likely a bad idea, as it can affect the overall sound quality. Tape is probably a better option, as it's less invasive and won't alter the material's acoustic properties.

To be safe, I might test this modification on a Sony V6, attaching the material to the back end of the cups first.

 

[gregorio]

Is it settle that metal is best for sound? Especially copper?
Yes or no and why?

No, it’s not settled that metal is “best for sound” but it depends on what you mean by “best”? Metal is good at reflecting sound because it’s relatively hard/dense but being reflective can equally make it poor for sound. Copper isn’t “especially” better than other metals and there are other equally as good materials for reflecting sound, glass, concrete and enamelled tiles for example.
Copper is especially good for transferring electromagnetic signals of course but that’s got nothing to do with sound.

I was thinking if copper sheet thin metal, thin layer place within the cups. Just covering the side walls.

Copper isn’t especially better than lots of other materials and a thin sheet of it even less so. If you want a reflective surface, then hardness and density are the determining factors and a thin sheet of copper has very little density but I’m not clear why you would want a reflective surface in your headphone cups to start with?

The eddy current issue makes me want to dismiss copper altogether, and silver sheets might be even worse. Probably aluminum is a safer choice, but it won't have the same audio properties as copper, unless that's all misinformation.

You are correct that Aluminium doesn’t have the same audio properties as copper but what you’re stating makes no sense because you’re not talking about audio, you’re talking about sound and the acoustic properties of aluminium are pretty much identical to the acoustic properties of copper. It seems you’re getting confused between audio and sound, between electromagnetic signals and kinetic sound waves?

G

 

[71 dB]

...and a thin sheet of copper has very little density...

G

Since density ρ is the ratio of (infinitesimal) mass dm and (infinitesimal) volume dV

it doesn't matter how thin or thick a sheet/block/etc. of copper is, the density is always about 8960 kg/m³ which compared to many other materials is hardly "very little density." I believe you meant to say ...and a thin sheet of copper has very little mass... that would make sense because the sheet is thin.

Now, aerogel would be an example of a material with very little density (millions of times smaller compared to copper!)

 

[2leftears]

All fascinating comments, but unless I overlooked the relevant post (which is quite possible), I'm still none the wiser as to what @protoss actually hopes to achieve. No point commenting on the suitability (or not) of copper if the objective hasn't been defined. In absence of a stated objective, one might as well debate the suitability of inserting Iceland moss in the cups.

 

[MrHaelscheir]

At worst, it is a mystical transferring of purported cable material properties into headphone cup linings instead of a scientific exploration of the measurable effects of headphone cup lining material on tonality as a result of varying reflectivity, absorption, or acoustic impedance.

 

[gregorio]

the density is always about 8960 kg/m³ which compared to many other materials is hardly "very little density."

I’m assuming he’s not trying to put a cubic metre of copper in his ear cups and therefore the achieved density would be far lower?

G

 

[71 dB]

I’m assuming he’s not trying to put a cubic metre of copper in his ear cups and therefore the achieved density would be far lower?

G

Who knows what he is trying to do and it isn't even my business, but the density of any material stays the same regardless of how much of it you have. A cubic meter of copper has the mass of 8960 kg. A 0.01 mm thin sheet (size 30 cm x 30 cm) has the mass of about 8 g. That's a HUGE difference in mass of course, but the density is the same because they are both made of copper!

 

[bigshot]

20+ years ago when I started spending time on online discussion boards the overall vibe was different. People interacted more like in person and were acted accordingly.

I’ve been online for over thirty years going back to the days of Usenet, and I can tell you that nothing has changed. The only difference is that some forums were moderated to weed out problem posters before their blatantly incorrect statement got repeated over and over again ad nauseum until everyone was frustrated. Here, every comment is assumed by the staff to have equal importance, which encourages those with Dunning Krugeristic tendencies. If there was a little “asked and answered- or see post #X” moderation combined with a 24 hour to one week thread kick, it would be much better.