[analogsurviver]

 
so - ear induced intermodulation - is that a good thing? should I see a doctor? I've been playing many times side by side with a trumpet player, what I was hearing was distortion?
 
maybe so (it's always very loud, so...) but in the studio the recordings didn't sound exactly the same (they sounded much better), was this because of the low resolution of the studio equipment?
 
nobody wants to play (or just be) in front of a trumpet player, so it's difficult to hear the same as the recording (poor mic!!!)...
 
So what he means is that 'distortion' cannot be recorded in 20Hz to 20kHz..... but will be heard in the room... is that so?
 
or just in 'high res' systems/recordings?

Live. Heard in the room. From the position of the listener - NOT microphone.
 
Recordings should simply duplicate sound heard live best they possibly can. It is my experience over decades  that ANYTHING that can play past 20 kHz sounds better - and now we actually do have equipment that can both record and playback to 100 kHz - so why not ?

 

[MacacoDoSom]

 

 
so - ear induced intermodulation - is that a good thing? should I see a doctor? I've been playing many times side by side with a trumpet player, what I was hearing was distortion?
 
maybe so (it's always very loud, so...) but in the studio the recordings didn't sound exactly the same (they sounded much better), was this because of the low resolution of the studio equipment?
 
nobody wants to play (or just be) in front of a trumpet player, so it's difficult to hear the same as the recording (poor mic!!!)...
 
So what he means is that 'distortion' cannot be recorded in 20Hz to 20kHz..... but will be heard in the room... is that so?
 
or just in 'high res' systems/recordings?

Live. Heard in the room. From the position of the listener - NOT microphone.
 
Recordings should simply duplicate sound heard live best they possibly can. It is my experience over decades  that ANYTHING that can play past 20 kHz sounds better - and now we actually do have equipment that can both record and playback to 100 kHz - so why not ?

why not indeed... but not reproducing... because... already shown/demonstrated by many people and...

because:
 
1) frequencies above 16kHz are so directional that if you move or rotate your head you will miss them.
2) those frequencies tend to be absorbed by the air in the room
3) they are very low in SPL
4) your hear is less sensitive with those frequencies http://newt.phys.unsw.edu.au/jw/hearing.html
5) if you could actually hear them you wouldn't because your music would be so loud that you'll drop dead...
6) the sound of a trumpet at 16Kz harmonics is more than -60dB than the fundamental,,, and going down....
 
there are no musical overtones above 16kHz, only random noise.........................................................
 
record a trumpet on tape (make sure it has any information above 20kHz) play it back at 1/8 speed, your 40khz would be now 5kHz and tell me what you hear (if the note played was A440kHz, is now A55Khz, put an high pass filter at  2.5 kHz and you are hearing the ultrasonic part...)
or just transpose it using a good software while maintaining the speed...
 
or put your trumpet peaking a 0dB put a high pass filter at 20 kHz and slide it to 40k and check the peak levels...
 
and by the way, do the same with a 192kHz recording (not DSD or you will see the noise going up)

 

[cjl]

To test this, you would either need to record and play back a trumpet which would require the microphones and transducers are highly linear at those ultrasonic frequencies, or use an actual trumpet and some acoustical filtering so you could alternately filter out the ultrasonics and do some blind listening tests.
 

I'm curious - why do you think this would be a better test than digitally generating an 80 and an 83kHz sine and testing if there is any audible intermodulation product? With the digitally generated tones, you wouldn't have to worry about the linearity, distortion, or frequency response of the recording side of the chain at all, and you should be much more sensitive to intermodulation tones when you don't have all the normal trumpet sounds masking them. There is still the issue of making sure the transducer doesn't have substantial distortion, but I do like the idea suggested above of using two separate transducers and playing a single sine frequency through each. That eliminates intermodulation from the transducer as a concern.
 
Of course, if a tone is heard in this test setup, that still doesn't show it would be audible with a trumpet, since the levels of the harmonics may not be high enough to generate the tone at sufficient volume to be heard over the rest of the trumpet's sound, but that would be a later test once you've shown that it's audible at all (under as close to ideal circumstances as possible).

 

[Steve Eddy]

There is still the issue of making sure the transducer doesn't have substantial distortion, but I do like the idea suggested above of using two separate transducers and playing a single sine frequency through each. That eliminates intermodulation from the transducer as a concern.

Oh, I didn't see that. Yeah, that would work. Derp! Should have thought of that.

Of course, if a tone is heard in this test setup, that still doesn't show it would be audible with a trumpet, since the levels of the harmonics may not be high enough to generate the tone at sufficient volume to be heard over the rest of the trumpet's sound, but that would be a later test once you've shown that it's audible at all (under as close to ideal circumstances as possible).

Exactly.

Would be nice to go straight to trumpet and clear it up once and for all.

se

 

[Exacoustatowner]

 
Many thanks analogsurvivor!
 
Funny you said that..I was actually listening to Mahler's 2nd and Schubert's 8th when I noticed it..i.e. pieces with very wide dynamic ranges..
Part of me thought that the degradation in quality with the increase in volume was in my imagination.
I guess not then..
Do you happen to have any experience with Kevin Gilmore amps? (KGSS, KGSSHV or KGST)

Try listening to Mahler's 8th, SFSO, MTT. When all the soprano's hit the high note in conjunction with the strings, brass and organ it can blamed and distort into a screech-it is my ultimate test as the right preamp tubes I can somewhat resolve the voices, strings etc- and the PAIN goes away. 

 

[arnyk]

Oh, I didn't see that. Yeah, that would work. Derp! Should have thought of that.
Exactly.

Would be nice to go straight to trumpet and clear it up once and for all.

se

 
These files 
 
http://www.hydrogenaud.io/forums/index.php?showtopic=107570&view=findpost&p=894877
 
Comprise both a test for the audiblity of > 20 KHz sounds, and at the end there is a short low-level audible tone followed by a number of tests of the linearity of the playback system. Designed to be played with FOOBAR2000 with the ABX plug-in. 

 

[Joe Bloggs]

 


Many thanks analogsurvivor!

Funny you said that..I was actually listening to Mahler's 2nd and Schubert's 8th when I noticed it..i.e. pieces with very wide dynamic ranges..
Part of me thought that the degradation in quality with the increase in volume was in my imagination.
I guess not then..
Do you happen to have any experience with Kevin Gilmore amps? (KGSS, KGSSHV or KGST)

Try listening to Mahler's 8th, SFSO, MTT. When all the soprano's hit the high note in conjunction with the strings, brass and organ it can blamed and distort into a screech-it is my ultimate test as the right preamp tubes I can somewhat resolve the voices, strings etc- and the PAIN goes away. 

The whole disc? :tongue_smile: A time code and track number reference would be nice :tongue_smile:

 

[Exacoustatowner]

The whole disc? :tongue_smile: A time code and track number reference would be nice :tongue_smile:

Sorry! Disc One Track 5 2:00-2:20 is a good section

 

[Exacoustatowner]

The whole disc? :tongue_smile: A time code and track number reference would be nice :tongue_smile:

Do you have the recording?

 

[Joe Bloggs]

Do you have the recording?

Maybe you could send me just that track? It's only two minutes or so AFAIK so should be ok in the grand scheme of things? :tongue_smile: