I'm an audiophile and I've always had an aftermarket sub and amp connected to the stock system to fill in the low end bass. Seems like all these "premium" audio systems are tuned to protect against blowing speakers or tuned for the general masses (very boomy). Also noticed the quality of speakers aren't as great compared to past generation Toyota speakers (90's ie.). So here's a thread for those who will look into upgrading their Supra's audio in the future. I'd like to kill the factory amp, or kill the lines going to the 2 8" subs and put my own amp to drive those speakers. It just doesn't produce the proper frequency for the low end. An alternative may be to add an additional subwoofer (small of course) in the trunk just to fill in the low end. The mids and highs are very good tho. Although I had to tune the equalizer to get it to sound as natural as possible. The normal settings were really bad. I'm sure someone will figure out the best and cleanest way to get some killer audio in this car.