bah!

[ciphergoth]

why does my new microphone record digitally perfect silence?

even if I hadn't plugged it in, I should still get a few bits of noise, not a WAV file consisting of a header and a big collection of zeroes.

Updated: OK, OK, I'll make this a useful entry rather than a whinge. I'm running Linux 2.2.19 with ALSA driver 0.5.11. ALSA reports the soundcard as 'C-Media PCI CM8738 (model 37) at 0x7400, irq 9'

I've tried wiggling all sorts of soft mixer settings, to no effect. I haven't tried with the microphone disconnected yet. I'm unlikely to get a chance to play with it much 'till I get back from Geneva, though.

Comments

More well-rounded answer

[pavlos.livejournal.com]

Sorry, I coulnd't resist. There is an explanation why the microphone could yield more silence than no microphone at all.

If you plug nothing in, you are amplifying the electrical noise induced at the dangling input wires. If you plug in the microphone, you are amplifying the output of the microphone's electronics, which can be a very strong flat signal.

Pavlos

Re: More well-rounded answer

[ciphergoth.livejournal.com]

I don't think *any* analogue problem could result in pure zeroes, could it? I'm pretty sure the problem will be in the digital realm...

Re: More well-rounded answer

[alienspacebat.livejournal.com]

Could do, if the zero was hardwired and below the input threshold of the soundcard. One problem may be power if it's an electret mic. DOes it have 3 bands on the jack or two? Some soundcards dont provide power to the mic.

Try the microphone in a tape recorder or something and connect some other source to the mic input to troubleshoot it