What's the use of a 192 kHz sample rate?
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From: dpierce.cartchunk.org on 5 May 2008 13:27 On May 5, 9:44 am, rajesh <getrajes...(a)gmail.com> wrote: > If we cant percieve freq higher than 20k doesnt > mean that they are not present As the lawyers say, true but irrelevant. If we can't perceive them, then their presence or absence is irrelevant.
From: dpierce.cartchunk.org on 5 May 2008 13:30 On May 5, 9:56 am, rajesh <getrajes...(a)gmail.com> wrote: > but at what cut off frequency is it being filtered in case of 192 > kHz ? THEORETICALLY, such a sampler is capable of a bandwidth of < 192/2 or less than 96 kHz. But... > I dont think its 20...its much much higher. PRACTICALLY speaking, no. Recordings are NOT made with B&K 1/4" or 1/8" laboratory condenser microphone: they are made with microphones of FAR less bandwidth, like 20 kHz or so. Look at the attenuation of air at ultrasonic frequencies, and such.
From: dpierce.cartchunk.org on 5 May 2008 13:33 On May 5, 10:09 am, rajesh <getrajes...(a)gmail.com> wrote: > On May 5, 7:05 pm, Oli Charlesworth <ca...(a)olifilth.co.uk> wrote: > > If we can, then of course a higher sampling rate will sound better. > > But that goes against the premises of the OP, and is nothing to do > > with the ECC or interpolation that you've been going on about! > > > -- > > Oli > > I said we cant percieve, but i didnt say they arent there.. Again, true but irrelevant. > i will continue the dicussion on ECC tomorrow. Hopefully, you will be much better prepared. As a hint: the issue of proper sampling vs bandwidth is a topic COMPLETELY separate from ECC. You might want to keep that in mind during your preparations.
From: Oli Charlesworth on 5 May 2008 15:26 On May 5, 3:09 pm, rajesh <getrajes...(a)gmail.com> wrote: > On May 5, 7:05 pm, Oli Charlesworth <ca...(a)olifilth.co.uk> wrote: > > > On May 5, 2:56 pm, rajesh <getrajes...(a)gmail.com> wrote: > > > > On May 5, 6:50 pm, Oli Charlesworth <ca...(a)olifilth.co.uk> wrote: > > > > > On May 5, 2:44 pm, rajesh <getrajes...(a)gmail.com> wrote: > > > > > > There is no gurantee that the audio signal is bandlimited. If we cant > > > > > percieve freq higher than 20k doesnt mean that they are not present > > > > > If the audio signal has not been appropriately bandlimited before > > > > sampling, then of course there will be problems. But in the real > > > > world, the signal is explicitly filtered before it hits the sampling > > > > circuitry. > > > > but at what cut off frequency is it being filtered in case of 192 > > > kHz ? > > > I dont think its 20...its much much higher. > > > But you've just acknowledged that "we can't perceive freq higher than > > 20k". > > > If we can, then of course a higher sampling rate will sound better. > > But that goes against the premises of the OP, and is nothing to do > > with the ECC or interpolation that you've been going on about! > > I said we cant percieve, but i didnt say they arent there..i will > continue the dicussion on ECC tomorrow. You're going round in circles again. If we can't perceive frequencies >20kHz, then it doesn't matter whether or not they are present in the original audio source, nor whether or not we reproduce them with our digital audio system. However, if they are still there at the point where sampling takes place, then the anti-aliasing filter has been incorrectly implemented. What exactly are you trying to say that differs from any of this? At the moment, it's impossible to tell what your argument is, because you appear to be changing your mind on every post. -- Oli
From: rickman on 5 May 2008 16:48
On May 5, 1:27 pm, dpierce.cartchunk....(a)gmail.com wrote: > On May 5, 9:44 am, rajesh <getrajes...(a)gmail.com> wrote: > > > If we cant percieve freq higher than 20k doesnt > > mean that they are not present > > As the lawyers say, true but irrelevant. > > If we can't perceive them, then their presence or > absence is irrelevant. Are you guys still arguing over this??? The issue is not whether ultrasonic signals can be perceived, it is about the sample rate. The microphone may well have a cutoff at or below 20 kHz so that there is nothing in the inaudible range. Still, a sample rate higher than 40 kHz can be a good thing. |