For the past year or so, I've been listening to my empeg and noticed a slight distortion-like sound on certain songs. This usually seemed to occur on mid-range frequencies, but it happened sporadically - with different songs. I thought it strange, since I never had this problem when I played a CD of the same music on my head unit (uses the same amplifier, empeg is plugged into it, etc). Also, my MP3's are encoded at 256 SBR so I wouldn't expect it to be a bad encoding problem. Also, the max volume on the empeg is locked to a max of 0db.

Finally, today on the way to work (at a light) I went into the Hijack controls and noticed that the Automatic Volume Control was on Medium. Not really sure if this was the cause I shut it off. After that, everything sounded better and the odd distortion-like sound went away.

Has anyone ran into this before? I searched the faq and the forum to no avail. I'm curious about this.

I wouldn't be surprised. The automatic volume control adjusts it on the fly so you might have odd distortion appearing.

The Voladj feature of hijack should not cause any clipping or distortion unless you've set your EQ up so that some of its bands exceed 0db.

If you have your EQ set to exceed 0db, then there is a chance for certain passages of any music, voladjusted or not, to clip if you have the empeg's volume cranked up. Having voladj turned on simply means the quiet parts of the music are louder therefore increaing the chances that might happen.

Does it only happen when the empeg's volume is cranked really high, say, -10db or louder?

That is a good point, but It happened at any volume. Also, the eq on the empeg is left flat and I pretty much just use my kenwood head unit for equalization settings for convenience.

I was wondering if it was the encoding of the MP3's and was going to slap V3Alpha8 on it to play some FLACs of the offending songs, but just haven't gotten to it yet.

The behavior that I described occurred mostly on stuff like jazz where the voice is louder than everything else or a rather clean-sounding instrument was soloing like a spanish guitar.

Odd. There's nothing that Voladj does which should add distortion to tracks at low volume under those conditions.

Since you use the Kenwood to control the sound, does it also control the volume, too? In other words, do you leave the empeg at 0db and do all your volume changes from the Kenwood? If so, try setting the empeg to -10db or so, instead of 0db, and see if that fixes it.

hmm, I have begun hearing it again (I just got to a song that makes it more prevelent than others) and the VolAdj is still off. So at this point I believe that the VolAdj has absolutely nothing to do with this issue

Yes, the configuration you described matches mine. When I did brng the empeg's valume down, it still did it. This seems to point the finger at the MP3's even more. But how could I have distorion in the MP3 when it is ecoded at 256 static (using lame) from a source CD that sounds fine?

Good suggestions.

Also see if you notice the distortion when the empeg is plugged into your stereo (or through your computer's line-in). If the distortion disappears in that case, then you might be looking at a problem with your car amplifier, speakers, or wiring, unrelated to the empeg.

Another thing to consider is that the Kenwood deck's line inputs might be rated at only 1v, and the empeg's in-car outputs are 4v. In that case you might need to significantly reduce the empeg's output volume before the distortion disappears.

These are great ideas. I'll try most of them and report.