I have a 93 sc400 w/104k car is very tight except for the left front speakers. Every once in a while the bass gets very distorted throughout the voulume range. So my question is, Is it the speakers or the amp???

 

More probably the amp or connections. You may have a bad coupling capacitor in the amp. If it was the speaker it would tend to do it all the time, unless what you're hearing is the speaker distorting only when certain frequencies are present.

 

maybe youre sending too much bass, how did you set up your audio controls? is the bass far up?

 

Thanks for your replys, it appears there is a small a tear in the speaker possibly due to dry out that is causing the distortion at certain frequencies.

Next question then, What is a good replacement for the front speakers that will work with stock head unit?