Loud and distorted audio problem (EPIA / M-Audio)

-al- · 10-08-2003, 11:14 PM

I have my new epia m10000 running an internal m-audio revolution sound card. All audio is loud and the bass is distorted - almost like a gain is cranked up somewhere. I turned all the volume gains down, and the sound gets lower, but the bass is still distorted - it sounds like it's clipping. The sound card is plugged into a car amp via RCA cables. The gain on the amp is at MINIMUM. When I plug the small self powered computer speakers into the sound card, it sounds better, but still clipping the bass I think. I'll connect a scope to it tomorow and see if it is clipping. I know it's not the car amp because I tried 2 different ones.

Could it be a setting in device manager? I have the HD and DVD rom on the same IDE cable.

It sounds crappy on .wav files, AND songs direcly played from the dvd rom. I even tried the VIA on-board audio output and it clips even worse than the m-audio card.

osirisdon · 10-09-2003, 12:21 AM

make sure you disalbed onboard sound. That can be a big problem

-al- · 10-09-2003, 07:26 AM

"make sure you disalbed onboard sound. That can be a big problem"

How do you disable onboard sound? In "device manager" you select which audio device it uses, and you can only select 1, so if the m-audio card is working, dosen't that mean onboard sound IS disabled?

Defiler · 10-09-2003, 07:35 AM

Quote: Originally Posted by -al-

"make sure you disalbed onboard sound. That can be a big problem"

How do you disable onboard sound? In "device manager" you select which audio device it uses, and you can only select 1, so if the m-audio card is working, dosen't that mean onboard sound IS disabled?

I believe you can disable it in the BIOS and in device manager. In DM right click the device and select disable and it will have a red X over it.

-al- · 10-09-2003, 08:04 AM

I'll try disabling that tonight.

In reading other posts, maybe the problem is with the power supply - OPUS 90w. Maybe the 12v or 5v line is sagging...I'l check tonight.

I dont't think I need a preamp because the sound is very loud even with the pc volume turned down, and amp gain at minimum. UNLESS, the amp is loading the soundcard...hmmm maybe I do need a preamp. I;ll look at the soundcard output with a scope tonight.

sq_geek · 10-09-2003, 05:47 PM

yeah, please let us know what you find, as I will be running that exact same setup very soon (M10000, 512MB ram, DVD, 7" Touchscreen, M-Audio Revolution 7.1), althought I plan to get an EQ/LineDriver to help boost the voltage. I haven't measured what it is, but I bet it's super low, like 1v or something weak as hell...

MeanGT · 10-09-2003, 06:20 PM

al, what kind of MP3 Software are you using?? I have found that in winamp, if you play with the EQ settings to an extreme, it will distort the audio output pretty badly

-al- · 10-09-2003, 08:52 PM

Yup, it is clipping. I connected a scope on the m-audio card output and the bass causes the signal to clip. The weird thing is that is clips at all volumes, even very low setting. I even tried eliminating the OPUS, and using the AC power supply...same results. Also tried disabling the ac97 sound (in bios setup)...no help.

The voltage out of the m-audio card can get up to 2 volts p-p, which is plenty to drive car amplifiers.

I was using windows media player during all this, only because I don't have winamp loaded yet, but will try winamp now and report back in an hour or so...

frodobaggins · 10-09-2003, 10:56 PM

Quote: Originally Posted by -al-

I was using windows media player during all this, only because I don't have winamp loaded yet, but will try winamp now and report back in an hour or so...

Make sure that you aren't boosting the bass in the EQ or the SRS WOW Effects

also check in windows mixer settings and make sure you don't have bass boost enabled there(under advanced)

-al- · 10-10-2003, 07:29 AM

Well, I think the problem is fixed...there was not really a "problem", but there may have been a few contributing issues.

I guess in all the exitement of finally firing up the system, I didn't follow good troubleshooting teqniques:

1) DUH, the bass was boosted in the windows media player EQ.
2) I disabled the on-board ac97 audio drivers.
3) The source CD (I based all my conclusions on 1 recording, I know...bad idea) is at a very high level. It is louder than most other CD's I have. The group is P.O.D. , CD from 2002 if anyone is interested.

Also, it seems that .wav's generated by windows media player are louder than .wav's generated from Exact Audio Copy. I guess I'll stick with EAC.