help with distortion

hey im new to the forum. i just got a 40 gig mka2. well i installed everything into my car (went well). i have a us acoustics usx4085 4 channel amp going 4 infinity 5752cf speakers. My problem is i get distortion worse in some songs than others (even at low volume). i tried lowering the eq and turning down the amp gain. it helped a little but the distortion is still pretty bad and with everything set so the distortion is down to a minimum the music isnt loud at all at 0db. its really bugging me. if anyone could give me some advice i would really appreciate it. Thanks.

Congratulations on your new toy!
check here for info on car installation; particularly the section Properly adjust the input gain level on the amplifier.

You should not take the volume past 0db for most listening settings. I have mine fixed to not go past 0 at all. Follow the procedures in the FAQ and let us know how things turn out.

Also be sure you've not wired you empeg's line level output into your amp's _speaker level_ inputs. It would definitely give the symptoms you describe (although so would having it correctly wired & your amp's gains set way low).

-Zeke

Well, speaker level inputs aren't a factor, because that particular amp doesn't have them. I was considering that model for when I upgrade my car audio. 85x4 on 12.9v - how can you go wrong? Just the thing for a kid with a Civic who doesn't want to go overboard like everyone expects him to.

Unfortunately, I know next to nothing about setting up an amplifier; I still have my empeg running through my crappy CD receiver (AUX IN is 1/8" stereo jack on front panel; blech).

It might be worth checking the amp with line out from another device. Leave the switching line hooked to the empeg & just change input leads. That'd at least show if the amp is working, there've been a bunch of posts of strange problems with amps, internal grounds being poorly connected. You never know.

Aux in on the front panel? Use the amps luke, use the amps...

-Zeke

goin' skiing. Oh yeah.

What version of the software are you running. There were some problems with earlier versions that could result in something that sounded like distortion, even though it was a software problem.

Use the amps luke, use the amps...

Wanna give me the money?

Andy has a point!

If you are running software version 2.0 beta 11, there is a known bug. Upgrade to 2.0 beta 13.

And... is "TXP" the same person as "DeadFire"?

the empeg has 2.0 beta 13 on it.

Ezekiel, im not sure what you mean but when i turn on my car and the music starts its low for a second and then once the amp gets more power the volume jumps up. so from that i would assume the amps working.

i read some good reviews about the speakers i have but, could it be that i need better speakers?

I would say that part of the problem may be the input to the CD deck. You can't be sure that it's a good connection there. Run the empeg direct to the amps and see if it persists. I would suggest you run the cd through the empeg anyway.

the empeg doesnt go through a cd deck. it runs direct to the amp.

And... is "TXP" the same person as "DeadFire"?

No, I'm me and he's him. What made you think otherwise?

txp200 didn't say his empeg was running through a CD receiver. I said mine was. Currently, I have no external amp. But when I get one, it will very likely be a US acousitcs amp.

Can you try using a flat eq whilst this is debugged?

Some people have seen quirks in the eq when certain values are selected.

when i turn on my car and the music starts its low for a second and then once the amp gets more power the volume jumps up.

That's strange. The amps should not be making any noise at all until the player activates the amp remote wire. I'd hazard a guess that there's a wiring mistake somewhere. Can you detail exactly what your component architecture is and exactly how it's wired?

This is in addition to the statement of trying it with a flat equalizer and the statement of adjusting your amp gains.

And the reason I got TXP and DeadFire mixed up is because I thought DeadFire was saying he had distortion, too. I mis-read. Sorry.

i tried a flat eq but i still get distortion in some songs. Some songs a perfectly clear and than others i get distortion. i know its not the mp3 either. im not sure what you mean when you say debugged but i did try the flat eq.

thanks.

Some songs a perfectly clear and than others i get distortion.

Boy, that sure sounds like the known bug in Beta 11. Sure you're running Beta 13?

And also... when you flattened the EQ, did the distortion DECREASE?

Make sure to read this regarding setting the EQ.

Make sure of the following:

- Hijack bass and treble set to zero.
- Loudness off.
- EQ bands all set to zero DB.
- Player volume zero DB or lower.

Still get distortion? Can you describe the distortion in more detail?

Can you describe the distortion in more detail?

"Could you describe the ruckus, sir?"

i have the ground from the empeg connected to the ground(black), the memory connected to the memory(yellow), remote turn on from the empeg connected to the amp(blue), and the ignition wire from the empeg which was red connected to an orange ignition wire. then from the empeg two patch cables going to the amp.

i also played with the amp gain a little and the higher it is the worse it gets.

Okay, that sounds like the right wiring. Do you have anything else you can plug into the amp, such as another stereo with line-level outputs, so you can narrow the problem down to whether it's the amp or the empeg?

"Could you describe the ruckus, sir?"

I can't believe I drew a blank on that one at first and had to resort to IMDB. That's one of my favorite all time movies.

i dont have another stereo with line level outputs.

but i just got in my car and put all the eq settings to 0db and loudness off, everything to what you said. and turned a song up that i had previously heard distortion on and it was perfect and really loud. then i put back my eq settings which is all lower than 0db. and still perfect sound. so i started driving and it sounded great i thought it was fixed. then i started getting some distortion and it seemed like the longer i drove the worse it got. the same song that was perfect before now has a fuzzy cracking sound. it wasnt loud but it was definitely noticable.

and i thank you for all the help that i have recieved so far.

so i started driving and it sounded great i thought it was fixed. then i started getting some distortion and it seemed like the longer i drove the worse it got. the same song that was perfect before now has a fuzzy cracking sound.

At this point I would begin to suspect the amplifier. You need to find a way to narrow it down to be sure.

i dont have another stereo with line level outputs.

Not even a portable CD player?

i have a portable cd player but how would i go about hooking that up to the amp? and how would that tell if it is the amp?

The portable CD player probably has a line level output in the form of a 1/8" stereo jack. You would get an adapter cable that had that kind of plug at one end, and a stereo RCA pair at the other...

ok thanks ill have to make a trip to radio shack tomorrow.

when i turn on my car and the music starts its low for a second and then once the amp gets more power the volume jumps up.

if i'm understanding you correctly, this is a feature of the empeg player software. when you power up the car, and the empeg completes the boot process, it is supposed to ramp the volume up smoothly to the level you had it set when you powered down. the idea is that if you powered off with the music cranking, the volume ramp gives you a moment to catch it and reduce the volume before blowing your ears out (or your passenger's ears!) .

there is a bug in 2.0b13, though, that causes the volume ramp to not be very smooth. instead of a steady ramp, it really only sets the volume to 2 or 3 distinct levels before hitting the final output level. so, you end up hearing a jerky increase in volume as you describe. i believe this is fixed in the next release.

--dan.

...and with loudness turned off, and using the standard kernel instead of HiJack might help a lot too.

i finally got a chance to test the amp with a cd player and it had distortion with the cd player also. and i cant really find a pattern with the distortion. it just seems to be on and off. it used to be the worst in the back speakers, now it seems to be really bad in the front right speaker. so i guess its the amp, is it that the amp is cheap or is there something wrong with it?

Could be a cheap amp, it could also be the wiring. If you're able, replace the wiring for the amp, including the power lines. Make sure that all connections are solid and secure. Ensure that the cables are good quality too.
It might be a dodgy connection in the signal or the power. If the problem persists, even with another audio source such as a portable CD player or radio, It's the amp itself or the speakers. If not, it's higher up the chain.
curiouser and curiouser