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invader9000 · Posted - Mon Oct 08, 2001 5:57 am

Recently i upgraded my PC to a M/B DFI AK75-EC Rev A+ and AMD Athlon 1.2GHz. My mainboard has on board audio and in CEP i can see tha it supports up to 96KHz/24 bit recording. Anyone have this mainboard? Is this 96KHz/24 bit hardware or software (like wave mapper) dependent? I need to know that, because the sound card sounds and records great. Also, how can i find my soundcard's noise level? By doing Monitor Record Level, i get up to -24Db, but i cannot hear any noise when recording. Thanks in advance...

invader9000 · Posted - Mon Oct 08, 2001 11:41 pm

Hmmm! Why do i get this feeling that I AM ALONE ON THIS PLANET!! No one else has the same mainboard with me? Any one else with board audio?

Syntrillium M.D. · Location: USA

Hi Invader. Though I can't speak directly about your motherboard, I can tell you that the 24/96 support that the onboard sound is referring to is more than likely a 'wave-mapper-type' emulation.

More than likely, the onboard soundcard will do it's own form of resampling/emulation to be able to 'supposedly' playback 24/96 files. This is not really 'true' 24/96 operation.

Again, I can't say for certain (as I don't really know much about your motherboard) but I've seen other consumer cards (and on-board sound configurations) that do this, and it's really just emulation - not true 24 bit. It's still a 16-bit card, most likely.

---Syntrillium, M.D.

invader9000 · Posted - Fri Nov 16, 2001 7:22 am

Well Synt, thanks for the answer. The sound circuit uses AC97 codec. Well about the noise, do i just Monitor Record Levels and open Line in, or Mic? What do i do?

SteveG · Location: United Kingdom

This is a bit of a minefield! We've discussed it in some depth recently here:

'What's a Good Noise Floor?'

But the simple answer to your question is this: to find out what the real converter noise floor is, disable all inputs except line in the windows mixer, set the record level to zero, click on the CE meter in record-pause to get it into record preview and see where the meter sits. It will jump around a bit, but basically, this is the noise floor of your A/D conversion stage. If you increase the record level, the noise level will go up, as you are introducing line preamp noise into the equation.

So, when your record level controls are set in their normal recording positions with no input applied, the place where the meter red strip is resting is effectively your real noise floor ref 0dBFS (as loud as it gets!)

Steve