Headphone Output Observation / Question

Mickster

Well-known member
Here's something I've noticed and would like to understand better. When I listen via my Denon amp...my Sony amp...my Tascam DP24 recorder....and my Zoom R16 AI....using each of their headphone outputs....each one has a slightly different sound for sure.

I use a number of headphones....Senn HD600....Sony MDR V6....ATH-M50....ATH M40X and they all have the same reaction so it's not all about the headphone resistance....etc....I think. The Sony receiver has more bass and less top end for sure. The Zoom R16 has less bass and more top end and seems very open. The Denon receiver is excellent and seems very balanced and open.....but that's probably my bias. The Tascam DP24 has a sort of flat / dull sound with not a lot of air / clarity. I've been testing these and using all of these over time so this is not a recent discovery. The HD600's show the most differences....probably because they're so detailed and flat to start with. All things being equal with volume output....same wav track...and all being set totally flat for EQ etc....what's the deal? I could be crazy....but maybe not.

Just wondering.

Mick
 

Chris Drums

New member
These things are often attributed to tiny differences in playback level. If you want to go all scientific, you could build a splitter where you could insert a dB-meter / volt-meter between the output and the cans. Blind tests are preferable too.
 

Mickster

Well-known member
I agree with Lazer.......

I understand that small differences in volume can make a difference or at least seem to. Trust me....what I've learned is that playing the same wav on each output device produces the same results as I described above. If I play the same wav louder or lower on each device.....the basic sound profile does not seem to change.

As an example....if I use my HD600's on the Denon and vary the volume and then compare using varied volumes on the DP24 or any other.....the same results occur. Each device has a different sound profile.....small differences...but different.

I'm thinking Dave can explain this.
 

grimtraveller

If only for a moment.....
I could be crazy...
Yeah, you could well be. But if you are, I'm joining you because since around 1977, I've noticed the same thing.
Right now, everything I might use with headphones or earbuds sounds slightly different. Some seem to give a better bass, some seem to have a clearer stereo spread, some are more tinny.....and it's not just the phones themselves although it also applies to them. But I find it even happens with speakers too. There are just so many variables that after a while, one just adjusts and gets on with it. I don't know why it is :confused: :wtf:and I don't really care, beyond the kind of interest that departs once I find out.
 

ecc83

Well-known member
"
I'm thinking Dave can explain this." Nope! Just to many imponderables. You could try recording the signal at the headphone jack WITH the cans connected so we can all have a harken? A quick and dirty test would be to clap the cans around an LDC? ( "C" for CAPACITOR that is !)

Dave.
 

gianluca68

New member
Different output stages have different sound, but the most difference is due to the output impedance. If it is different than zero, it makes a voltage divider with the headphone impedance. If the headphone impedance is not constant with the frequency, the voltage divider has a different attenuation with the frequency and headphones frequency response is altered, boosting frequencies at which impedance is higher. The frequency response copies impedance graph.
 

rob aylestone

Well-known member
It's also down to volume. The BBC fit limiters to their headphones as a safety feature, and even though the limiters used are 'transparent', everyone turns the driving device up to try to get a working level, and the result is very unpredictable. Some just get louder but some sound terrible - and you hear it because the limiter turns the volume down, which your ears can then hear very clearly, as the built in compressor in your ears prevents quality assessment when they are compressing to various degrees as the angle of the bones change.
 

ecc83

Well-known member
Different output stages have different sound, but the most difference is due to the output impedance. If it is different than zero, it makes a voltage divider with the headphone impedance. If the headphone impedance is not constant with the frequency, the voltage divider has a different attenuation with the frequency and headphones frequency response is altered, boosting frequencies at which impedance is higher. The frequency response copies impedance graph.

Hmm, there has never been any solid evidence that well designed power amplifiers can reliable be told apart if run inside their ratings. I know the 'tweaky, beardy subjectists' don't like to hear that information but it really is up to them to prove the matter. The making of a flat, low distortion headphone amplifier is hardly rocket science these days.

The idea that a resistance in the output of the HP amp causes response irregularities due to the varying impedance is an attractive on on the surface but falls on two counts. The ACTUAl resistance of say 32 Ohm cans is very close to or equal to the nominal 'impedance' so you cannot avoid series resistance anyway. Then, headphone manufacturers KNOW amps have a non-zero output resistance and surely design their products accordingly?

Lastly, the OP says he detects the same differnces with a variety of headphones. Once again I woulod dearly like to see and hear some recordings!

Dave.
 

Mickster

Well-known member
Ok Dave......if I find some time in this holiday week I’ll give it a try. Not sure how to do that because I’ll be using my AI to play the wav so I really can’t record the result on my daw. Also not sure what you’re getting at. I do hear discernible audio differences from the outputs. I guess you’re thinking I don’t and somehow a frequency graph will prove me wrong. If it proves me right...then we’re back at square one......with my original question asking what the possible reasons could be.
 

ecc83

Well-known member
Ok Dave......if I find some time in this holiday week I’ll give it a try. Not sure how to do that because I’ll be using my AI to play the wav so I really can’t record the result on my daw. Also not sure what you’re getting at. I do hear discernible audio differences from the outputs. I guess you’re thinking I don’t and somehow a frequency graph will prove me wrong. If it proves me right...then we’re back at square one......with my original question asking what the possible reasons could be.

No offence meant, just a search for information. I do not question your findings but the fact is you get all sorts of claims on forums. "night and day" results from 'NOS' or 'Cryo' valves. What we never get is hard facts such as voltage tables or even recordings.

You have discovered an anomaly, such things abound in the audio world but the ONLY way to hope to find an explanation is to "science the ***t out of it" The more data we can assemble the better the chance of coming to an understanding. We might never do that but without such data we don't stand a h in h.

You could put a track as a .wav on a phone and play that in. The headphone output is not too foul if you keep to -10dBV levels.

Dave.
 
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