guitars in the background - mixing

[Zinc]

We are having some trouble with our mix that we finished yesterday. When we mixed on the computer the guitars were good sounding, pretty full and in front through the monitors. When I play it through my big car stereo or through a real home stereo the guitars are totally lost in the mix. They are way in the background and sometimes barely audible. It seems the crappier the stereo I play it on, the better it sounds...The better the stereo, the harder it is to hear the guitars.
We play heavily distorted metal, and both guitars use plenty of mids, they aren't scooped out or anything.
What did we do wrong, or more importantly what can we do to fix it?

 

[blipndub]

How does it sound if you listen to the mix on the computer through headphones? And what do the output levels look like in you recording application?

Also did you try reburning a cd to see if something may have happened in that process? Maybe there was a problem with the audio export, what program are you using?

 

[Track Rat]

More than likely, it's the monitors you're mixing on. What are you using to mix through?

 

[Lopp]

The better the stereo, the harder it is to hear the guitars.
We play heavily distorted metal, and both guitars use plenty of mids, they aren't scooped out or anything.

Possibly too much mid boost. The better stereos may reveal a lack of fullness in the bottom end and a lack of definition in the top end of the guitars. The enhanced low and high frequencies in the better stereos may be pushing the guitars into the background.

How were the guitars recorded and mixed? Were they true stereo L+R panning of separate guitars? Using delay and panning techniques to simulate stereo with one guitar can result in phasing problems that might not be apparent with your studio monitors.

As alluded to by Track Rat, both of these problems could be a function of your studio monitors not revealing certain characteristics of a mix. They also could be a function of not realizing how a mix will translate from your monitors to other systems.