noisy sound recording

I have tried using my desktop mic to record a wav file, and I'm experiencing more noise than signal. Can someone advise me as to what I may be doing wrong....

admin note: moved from the Win 2000 section

 

Flutewiz, I have only tried recording once, anyway, this is what I would look at.

Use the Windows sound recorder (in case you are trying to use a third party program). Even uninstall and reinstall the sound recorder (should be in Add/remove programs Windows Setup tab).

Check you are using the correct jack on your audio card. Check the jack is connected all the way in.

Check the recording levels.

Once you have recorded the file you can then use third party software to convert it to other file types (and edit it, etc).

Do you have any other ways to record using that microphone (cassette deck maybe), so as to check that the microphone is working?

Matt

 

Hi flutewiz

...if the "noise" is hiss and the signal from the microphone is much too low:

have a look at volume control's options menu - if you can see "Show Advanced controls" make sure that it's ticked; this may reveal a button "Advanced" under the microphone slider...

assuming you manage to find an "Advanced" button: click it, see if you get a checkbox for "Enable Microphone Boost" or similar - it's well worth trying with the boost on.

(Sorry for all the ifs - but what you get varies enormously from one sound card and driver to another; same card, different driver => different buttons on volume control)

every time I've used a sound subsystem which provides a "Microphone Boost" option like this, I've found that the performance without the Mic Boost turned on has been terrible - quite unusable. Have to turn the boost on (if it's there) to get the same sensitivity as with a card without the option altogether. It's not really a "boost" - more like an "absence of cut ".

"Show Advanced Controls" is generally off by default though...

best wishes, HJ

 

I have tried all of that, to no avail...the "noise seems to be telegraphing "through" my system...(example:moving my mouse causes additional noise in the headphones....)....any other idea what is causing this...btw, I'm using onboard mobo sound.

 

Hi again

thanks for the extra description - so you are experiencing breakthrough of "almost everything digital" onto the mic input, if I understand correctly

regret you will probably find that there's going to be a certain amount that you just cannot get rid of - the best workaround will be to preamplify the mic signal externally (cassette recorder perhaps, or you can buy little battery operated preamps) and feed into the line input of the sound card at a higher signal level

if you cannot drop the noise level all you can really do is to raise the signal...

==

I suspect you will find that even if you plugged a shorted jack plug into the mic input socket you would still get most if not all of the breakthrough

(this is worth trying if you can arrange to trial it without undue hassle: to determine how much - if any - lessening of the "noise" results from using a "dummy" microphone; ideally, rather than shorting the plug, fit a resistor the same as the impedance of the microphone. If it's an electret condenser type mic guess 47k )

you may well find that using a plugin sound card instead of the onboard makes quite an improvement...

==

Unfortunately motherboards aren't designed with audio layout at a premium!

the currents flowing around a motherboard are quite high - tens of amps - and are modulated by the (digital) operation of the computer. It's inevitable that this "drops" a voltage across even thick copper tracks. 10 amps through even as low a resistance as 0.0001 ohm will give you a millivolt...

...the sub-millivolt signal obtained from microphones stands little chance.

==

On the one I'm using at the moment the on-board sound AC97 is ~ 4 inches away from the 3 sockets for mic, line in, line out; had the board been laid out for audio these would have been adjacent.

And the closeness of the motherboard sockets to each other, although convenient, doesn't help sound quality. My mic input jack is only ~ 1 inch away from the video output - with around a volt of digital "muck" on the video connector that close to the mic socket... it's never going to be HiFi.

==

sometimes you can make things a bit better but I would be raising your hopes too much to pretend there's a "magic bullet" solution

On my old Compaq I found that I could make quite a considerable improvement (10, maybe 15 dB better - was quite gratifying ) by putting a differential amp stage between my line output jack and the HiFi - with UK earthing this breaks an earth loop
(mains (line) to computer : computer line out to HiFi : HiFi back to mains again)

the "extra" connection of the mains earth "back into" the line out jack of the computer was making things much worse than need be

but whether this sort of thing works for you will depend upon the rest of what you have connected - and, it takes quite a bit of sussing out

==

all in all your best bets would seem to be either 1) external preamp for the mic signal and 2) separate sound card

sorry it's not a more positive reply ! - but the bottom line is that motherboards are not really designed for low level audio

best wishes, HJ.