[Tfug] Sound digitizing

[Richard Smit]

On Sep 19, 2007, at 4:45 pm, Bexley Hall wrote:

> Hi,
>
> Any suggestions/warnings about trying to digitize
> sound (specifically, speech) on *any* sort of
> computer?
> I suspect the biggest issue is getting away from
> the "machine noise"?
>
> Beyond that, how much do microphone characteristics
> etc. play a role in overall quality?

How detailed?

If you just want intelligible speech, look into radio amateurs'  
equipment. Usually, the cheaper the mic, the better the speech  
quality. At this price, dynamic mics are generally worse than  
electret mics for the same money. Then you want a 1kHz bandpass  
filter. Do all this at the analog end and keep the line level as  
close to 0dB as possible.

If you want sexy late night presenter audio, you're going to be  
stiffed at the music shop. Again, start with the mic -- you can't go  
wrong with a Shure SM-58 or a half-price clone. Cradle it in a  
springy rubberized mic holder and plop that on a solid based desktop  
mic stand. Then you should get the fattest, shortest mic cable and  
dump it into a preamp -- tube or tranny, your call :o)   After this,  
aim for 0dB line level again.

The hardest thing is keeping the signal path clean. Graphics chipsets  
make a chirruping noise in audio signals, and LCDs amplify this.  
Laptops are crap for audio recording because nothing's isolated. The  
absolute cleanest way is to make a headless box and control the  
recorder by keyboard. I *do* have some tips for recording audio on a  
laptop, if you want...

But ask around any Hams you might know. Their opinions will range  
from the lucid to the absurd, but you'll collect some good advice  
along the way. And some bad advice.

Anyway -- I hope this doesn't count as "absurd" :-)

R.