^ quicktime
I can\'t hear anything above 15kHz on my ipod headphones.
try listening on windows media player instead of the automatic quicktime player on your comp. Use PC speakers instead of headphones see if you can hear above 15 kHz. I couldn\'t hear anything above 16 kHz on my cheap headphones either.
...About not hearing anything over 20kHz, that\'s why they set the limit @ 20 back in the 80\'s when they were making CDs. Since then scientists have found that the human brain responds to frequencies above 20kHz, which is why audio enthusiasts prefer SACD or DVD-Audio. Also why the audio specs for blu-ray call for frequencies much higher than 20kHz.
You don\'t exactly hear the frequencies but you feel them.
Actually, even on the 21 kHz and 22 kHz tests, I could still hear it on my pc speakers, although a lot quieter or softer than lower frequencies.
With the volume control setting in optimal normal mode and volume knob on my pc speakers turn all the way up. This is how loud my pc speakers can output on those frequencies...
From 8 kHz to like 13 kHz, its pretty loud on my pc, say like about 60 dB as a guess.
At 14 kHz its a bit softer, my pc speakers can produce say like about 57 dB.
At 15 kHz its about 55 dB loud
at 16 kHz its about 50 dB loud
At 17 kHz its about 45 dB
At 18 kHz is about 40 dB
At 19 kHz is about 35 dB
At 20 kHz is about 30 dB
21 kHz is about 25 dB
22 kHz is about 20 dB...
Again those are just a guess, not really a true data to gives you guy an idea of how loud my pc speakers can produce at those frequencies. So the highest frequencies are so quiet that it\'s barely detectable unless you pay attention.
I am guess my pc speakers can produce sound at 300 Hz to 13 kHz with little roll off in dB. Lower than 300 Hz, its starting to roll off more and that\'s where the sub comes into play. Higher than 13 kHz, its roll off more too in dB. The subwoofer probably can produce 50 Hz to 150 Hz with little roll off...Lower or higher than that, it will roll off more...
About feeling frequencies higher than 20 kHz but not hear it, I don\'t know. Because I can hear up to 22 kHz just fine according to the test. Not sure about feeling or hearing higher than 22 kHz though...
I\'ve heard that you can feel frequencies lower than 20 Hz. Who knows, since I never heard those tests before. I heard some people can hear as low as 18 Hz and 16 Hz...maybe lower than 18 or 16 Hz, you might feel it but not hear it...
The CD-Audio specs are 44,100 Hz or 44.1 kHz, doubling the 22,050 Hz to reduce errors and to be able to reproduce the highest 22,050 Hz frequency. From some audio enthusiast that i chatted with last year, he said that because of space issue and to be able to record up to 74 minutes of audio on the disc, they have to slightly cut down the audio bandwidth from 48 kHz to 44.1 kHz. they added the extra .1 khz or 100 Hz to the 44 kHz for extra head and toe room where its still be able to produce sound up to 20 kHz. And according to the test as high as 22 kHz. And some people, although quite rare can hear higher than 22 kHz, as high as 24 kHz and the 48 kHz digital recording doubles that 24 kHz sound reproduction.
on DVD-Video, the specs for uncompressed audio is 48 kHz, 16 bits, stereo. Since space isn\'t much of an issue, the uncompressed audio is 48 kHz instead of 44.1 kHz that CD-Audio has.
For DVD-Audio, the specs can supports much higher than that. Such as 192 kHz, 24 bits, stereo uncompressed or 96 kHz, 24 bits, 5.1 Lossless compression.
Why 192 kHz? Its look good on paper even though it\'s unnecessary since most humans don\'t hear above 22 kHz, and some can\'t hear above 24 kHz. 192 kHz can reproduce sound up to 96 kHz which is way overkill for human hearings. Even 96 kHz digital recording is overkill too because it can reproduce sound up to 48 kHz when our ears can only hear up to around 20 kHz...
so 48 kHz recording is plenty good enough for reproducing sound up to 24 kHz...
According to that audio enthusiast, 24 bits recording won\'t make much of a difference either compare to 20 bits. 20 bits can produce sound up to 120 dB. 24 bits can produce up to 144 dB. But because they can\'t make electronics that super ultra quiet during recording, say possibly the quietest is around -110 dB. Having 24 bits won\'t make a different than 20 Bits recording. But since DVD-Audio has the space and 24 bits look better on paper than 20 bits. Why not supports it too. Beside, 24 bits only eat up a little bit more space than 20 bits recording. He also said that its more expensive to manufacture true 20 bits processor than 24 bits because of something about 8 bits = 1 bytes, and they usually go up in 1 byte or 8 bits increment for chipmakers....so 24 bits take up 3 bytes....making a 20 bits or 22 bits processor will have 2 1/2 bytes or 2 3/4 bytes...and that\'s rarely manufacture, hence why it\'s expensive...
sorry for the long and possibly boring mumbling..nevermind me then.
