[Meelis]

Hi
 
Why highest frequency response of portable players isn't 22050?
 
Philips muse 18kHz
Cowon J3 / iPod touch 20kHz

 

[ClieOS]

Because it is general belief that human hearing can reach 20kHz, so it is a lovely, rounded off number to use for marketing purpose.

As for why different DAP list frequency range differently, again, those are mainly because it is a common practice in the electronic world to list a beautiful number down which might or might not really mean anything.

 

[Meelis]

Can they be the specks of supplied headphones?
I can hear 22 kHz mosquito ringtone with my K702, but with previous headphones it was 17kHz and speakers 18,5 kHz.
 
What's the frequency response of S:flo 2 ?
 
Audio CDs go to 22050 Hz, HD 24/96 tracks go atleast 30 kHz
I wonder what PHILIPS thinks of their fullsound restoring heights over 22050 Hz and then cuting to 18 kHz

 

[Nagasaki_Kid]

I remember a networking teacher who was involved in the early days of digital networking and development of early digital standards told me they orginally set standards to double of that of the human range of hearing just to be sure 44.1khz. I'm kinda hazy n that because the lecture was so long ago.

 

[ClieOS]

Can they be the specks of supplied headphones?
I can hear 22 kHz mosquito ringtone with my K702, but with previous headphones it was 17kHz and speakers 18,5 kHz.
 
What's the frequency response of S:flo 2 ?
 
Audio CDs go to 22050 Hz, HD 24/96 tracks go atleast 30 kHz
I wonder what PHILIPS thinks of their fullsound restoring heights over 22050 Hz and then cuting to 18 kHz

I suggest you visit the sound science subforum for more in-depth reading as I am not the most qualified person to answer all your question. but here are a few points to consider: One, If you take a look at this chart, you will notice we don't need anything beyond 20kHz for music. Two, most adult's hearing is only up to around 16~18kHz. Three, most resampling done in DAC will filter out frequency > 20kHz because there is where the noise from the resampling process is. Four, commercial music generally doesn't record much pass 20kHz, even 24bit/96kHz track.

Also, you are reading too much in spec. 18kHz could be +/- 0.3dB (which is a great spec), +/- 3dB (decent), +/- 30 (bad). In the same principle, J3 / iPhone's 20kHz could also be +/- 0.3dB, +/- 3dB, or +/- 30. If we would to determine only by spec, a 18kHz +/- 0.3dB will absolutely be better than 20kHz +/- 30dB. As I have said before, spec like those listed by manufacturer is generally meaningless. Just because a company decided to or not to list some spec doesn't in anyway mean something is good or bad. For an example, Triple.fi 10 used to listed at 16kHz, but now the same model is listed at 20kHz after Logitech take over Ultimate Ears - do you really think Logitech has some magical power that automatically make TF10 sounds better than it was? Those are just marketing trick!