[Toom]

I can't hear beyond 15khz so why should I give a monkeys about all this stuff?

 

[StanD]

  I can't hear beyond 15khz so why should I give a monkeys about all this stuff?

analogsurvivor cannot accept the fact that humans have limitations. He tends to use ultrasonics as a tangential distraction when he cannot answer someother topic. I really wish he'd stop doing.

 

[Dobrescu George]

  analogsurvivor cannot accept the fact that humans have limitations. He tends to use ultrasonics as a tangential distraction when he cannot answer someother topic. I really wish he'd stop doing.

Ultrasonics can affect what we hear.
 
I can hear ultrasonics btw. I was at the university, and we were using an ultrasonic defectoscopy meter, and i was able to hear the ultrasonic, something, it was quite awfull.
 
Also the noise floor of a normal public university is around 95DB

 

[StanD]

  Ultrasonics can affect what we hear.
 
I can hear ultrasonics btw. I was at the university, and we were using an ultrasonic defectoscopy meter, and i was able to hear the ultrasonic, something, it was quite awfull.
 
Also the noise floor of a normal public university is around 95DB

Exactly what frequency.

 

[imackler]

Looking for some advice:
I want to do some testing out of various amps/dacs into a pair of headphones. Is there a device that would let me match volumes between two sources with a single out into one pair of headphones and switch input between the two (or more sources) easily? 
At some point, I'd recruit someone to help me with the test while I didn't look. 

 

[Dobrescu George]

  Exactly what frequency.

18Khz to 19.5Khz.
 
After setting the defectoscopy meter higher, i would not hear the noise anymore. 

 

[StanD]

  18Khz to 19.5Khz.
 
After setting the defectoscopy meter higher, i would not hear the noise anymore. 

That is not above 20 kHz. Also testing with an background noise level of 95 dBSPL is absolutely rediculous.

 

[Dobrescu George]

  That is not above 20 kHz. Also testing with an background noise level of 95 dBSPL is absolutely rediculous.

I was not testing for ultrasonics, i was using an enginerring tool for detecting holes in metals, the result was me staying with hands on ears the entire time..
 
I have been thinking that i should really do something about staying in a place with 95 db of noise floor, it is awfull.

 

[Roly1650]

OK, I would have guessed the ''perceived headstage'' of audioplayers like the Sansa could be explained by that... BUT if the differences are quite small and -88 is already really good I think it has nothing to do with the ''headstage'' differences between audio players.

So how could the Sansa's headstage be small then, ignoring placebo.

Can't help you with the Sansa, I've never heard one, but there could be any number of reasons why the perception is what it, without there being any real difference. Level matching not being as accurate as it should be, impedance issues, group confirmation bias, echoic memory being short term, the list goes on. If the Sansa measures similar to other audibly transparent players, then it should sound similar.

Sorry I can't be anymore help.

 

[StanD]

  I was not testing for ultrasonics, i was using an enginerring tool for detecting holes in metals, the result was me staying with hands on ears the entire time..
 
I have been thinking that i should really do something about staying in a place with 95 db of noise floor, it is awfull.

In any case we were discussing ultrasonics as above 20 kHz, your numbers were below that.

 

[Dobrescu George]

  In any case we were discussing ultrasonics as above 20 kHz, your numbers were below that.

quite true... but still, if the instrument is named ultrasonic, why on earth would it use frequencies that can be heared by some people, it is plain wrong...

 

[Steve Eddy]

Around - 60 dB.

Which is not to say that improving an amplifier from around 90 dB to below residual noise is not audible - it is; but it will only be appreciated over long listening sessions.
And even that not directly - unless you test with two of the same type amps, one left at 90 dB or so, other "all the way". It will be the most noticeable when you go from the better back to the worse ... - AFTER you have familiarized yourself with the better one.

That is why , sometimes, manufacturers offer both stereo amps in one box - or mono blocks, which share nothing but the power line. At a cost - but it is hard to disagree - once heard the same circuit powered in stereo (common supply) or mono block version. Yet both will usually exceed  90 dB separation no matter what - with mono blocks, it should be unmeasurable and impossible to improve upon further.

So closed back headphones and IEMs should be used? Because I can't imagine any self-respecting audiophile doing anything but running away screaming from a pair of these. My god! How could anyone bear the crosstalk?



se

 

[maverickronin]

  Looking for some advice:
I want to do some testing out of various amps/dacs into a pair of headphones. Is there a device that would let me match volumes between two sources with a single out into one pair of headphones and switch input between the two (or more sources) easily? 
At some point, I'd recruit someone to help me with the test while I didn't look. 

 
I'm not aware of any inexpensive ABX boxes.  As for volume matching, there are a few ways to do it.
 
For volume matching different headphones, I have a Radio Shack SPL meter with an old CDR bluetaked to around the mic.  Just center it against the pad and take a reading.    You can use either a 1khz test tone or white/pink noise depending on your preferences.
 
For volume matching the same headphone on different amps you need to be more precise and measure the output voltage of the amp with a multimeter.  For that you should hook up the headphones to the amp with a Y splitter and measure the voltage from the other end end of the Y splitter while playing a 60hz test tone.

 

[upstateguy]

 

  Looking for some advice:
I want to do some testing out of various amps/dacs into a pair of headphones. Is there a device that would let me match volumes between two sources with a single out into one pair of headphones and switch input between the two (or more sources) easily? 
At some point, I'd recruit someone to help me with the test while I didn't look. 

 
I'm not aware of any inexpensive ABX boxes.  As for volume matching, there are a few ways to do it.
 
●1●  For volume matching different headphones, I have a Radio Shack SPL meter with an old CDR bluetaked to around the mic.  Just center it against the pad and take a reading.    You can use either a 1khz test tone or white/pink noise depending on your preferences.
 
●2●  For volume matching the same headphone on different amps you need to be more precise and measure the output voltage of the amp with a multimeter.  For that you should hook up the headphones to the amp with a Y splitter and measure the voltage from the other end end of the Y splitter while playing a 60hz test tone.

 
Hey MR how have you been?
 
Quick question:  If procedure ●1● works for different headphones, why can't you use procedure ●1● for matching the same headphone with different amps?

 

[maverickronin]

  Hey MR how have you been?
 
Quick question:  If procedure ●1● works for different headphones, why can't you use procedure ●1● for matching the same headphone with different amps?

 
I've been OK.  Sometimes life just get in the way and all...
 
Unless you've got a full fledged acoustic lab, level matching via an SPL meter is much less precise than measuring voltage with a even a cheapo DMM so the DMM would be the preferred method.  Of course that wont work for different headphones since different models have different efficiencies and even different pairs of the same model will vary slightly which rules out matching the voltage to match the volume and only leaves measuring SPL.  Since headphones already vary much more widely in their sound than amps and DACs do, the uncertainty introduced by using a less accurate method is usually swamped by the difference between the headphones themselves.
 
If you're testing two different amp or DACs then level matching is much more important since, all else equal, the slightly louder one will be perceived and sounding better and lead to false positives.