On Mon, Nov 29, 2004 at 02:53:42PM +0000, Simon Truss wrote:
> Richard Rauch wrote:
> >Thanks (and thanks to other contributors) for interesting insights.
> >
> >I guess I'll record at 44.1KHz then for convenience at burning CDs,
> >unless I find myself in possession of a much better audio source
> >than the tape players I have.
> 
> Hi,

Hi.  (^&


> I usually capture at the highest resolution possible and then convert
> down after post processing. while I agree that 44.1/16 sounds the same
> as 48/24 I believe that any significant amount of processing will reduce
> the effective resolution of the signal.

I have some issues here that get in the way:

 * Honestly, most of the tapes that I'm working from are not that
   good.  The ones that are very clean are also the ones where
   high fidelity matters the least (interviews---as long as the
   interview is clear, I'm going to move on).

 * I do not think that any of my sound hardware can sample at more
   than 16 bits per sample.  Not with NetBSD drivers, anyway.
   If I wanted to play with this, what are some rough guides to
   the cost of such sound hardware?

 * At least one of my systems appears to have some internal buzz on
   the motherboard audio.  I assume that it is interference from
   the fields inside the box.  That limits the quality of recording
   that that machine can do.


> The reason pro systems use 48KHz is they have a wider stop band, thus
> lower pass band ripple. This enables cheaper or higher quality filters

My familiarity with signal processing and audio engineering terminology
is bounded by a sphere of radius epsilon, where epsilon << 0.  (^&

Low-pass/high-pass I gather has to do with passing frequences below/above
threshholds.  What is "ripple" in this context?


 [...]
> I capture data at 48/24 and then use gwc and secret rabbit code
> (resample) before archiving. gwc is a great audio denoiser and has

I have been using "sox <src.wav> -r <rate> <dest.wav> resample -ql"
for resampling to different rates.

I had not heard of gwc before.


> proven much more stable than most alternatives I've tried even for
> simple edits. Tested on audio files > 1GB, RAM+swap < 1GB.
> http://sourceforge.net/projects/gwc/
> http://www.mega-nerd.com/SRC/quality.html

Thanks!


-- 
  "I probably don't know what I'm talking about."  http://www.olib.org/~rkr/