On Sat, Jun 19, 2004 at 09:28:17 -0700, R Parker wrote: Well, it can't help right :) I'd record at the final output rate where you have the choice. - Steve

On Sat, Jun 19, 2004 at 04:30:26 -0400, Chris Pickett wrote: I vaguely remember being shown a paper where a group of people were played sine and saw waves at 15+ kHz and they could tell them apart. If I rembered it correctly that does mean that humans can detect the presence of partials at 30ish kHz, but my memory of it is vague. Internally many processes upsample, process and then downsample. - Steve

Hi Ron, Nope. Don't want to get into that argument! I merely am suggesting that anyone who says that 44,100 samples per second is quirky, odd, strange, or evil probably hasn't thought about any of the advantages of using that sample rate from a theoretical perspective. Both theoretically and practically, 44,100 is better for some things and worse for others. Practical (I'm sure that you already know this, but some may not have though about it): An important consideration is the actual clock speed of the sound card (for example, emu10k1's don't run at 44,100 samples/second) and also the sample rate of already-purchased libraries. Steve Harris advised that it is best to record at the anticipated release sample rate, but this needs to be weighed against where one starts from and what one has to go through. To truly follow Steve's advice would mean to obtain a card that actually runs at the anticipated release sample rate and obtain/generate samples that run only at that rate, also. Some people think that because they select recording at 44,100 samples/sec, that this is what the card runs at --- some do, some don't. Oh yes. I think most people would say that there is more than just a potential --- you probably mean a potential to actually hear it. Still yes. Not knowing what brands, etc., I'm just guessing that you're hearing a lot of the difference between 16- and 24-bit. A lot of detail is lost at 16-bit. 24-bit is not just 50% better, it's 256 times better (2^8 more accurate for each sample). In short, "DSP processing." I do my own extensive processing of audio files for simulating 3-D spaces. One stage in preparation for this processing (but not the processing itself) requires the use of double-precision floating point arithmetic. So I got into the habit of using as precise a representation as I can manage, meaning 24/96 or 64/96 due to inaccuracies I've seen. I use some impulse response functions that have very sharp spikes. These are best represented at as high a frequency as one can obtain. Admittedly, though, the benefit of twice as high a sampling rate pales in comparison to using 24-bit representations rather than 16-bit ones for most purposes. But for extensive processing (effects calculations) another factor of two is a good thing --- probably worthwhile despite the need for downsampling at the end. This is merely to ensure less of a chance of producing audible errors with long chains of audio processing. -------------------------- I'm sure you've read a lot about all this sample rate and bit-width business as many of us have. A big problem is that everyone is speaking from their own perspective and leaving out a lot of assumptions that may not affect others. User beware, I guess.... If you ask the potential user community about which sample rate to use for the library, my guess is that you'll hear good arguments for both 48,000 and 44,100 --- weaker requests for 96,000. Gosh, who knows which of the 4X's is best? It's not as obvious as some might claim.

Hallo, R Parker hat gesagt: // R Parker wrote: At a samplerate of 48kHz you can record frequencies higher than 22050, at 44.1kHz you cannot. If that's important to you, then you need to go 48kHz. Ciao -- Frank Barknecht _ ______footils.org__