The problem with six speaker systems is the signal timing. The speed of sound is NOT instant, so the sound from a speaker right next to your ear arrives before the sound from a speaker in the back of the car. Many modern aftermarket systems have methods of dealing with this, by adding delays - in the millisecond range - to the signal for the closer speakers, usually the front ones. In bigger systems, big delays are added to the fronts, smaller delays to the rears, and the subwoofers are usually left alone. Without these delays, sharp instant sounds, like drumbeats, bells, and string instruments that are plucked as opposed to played with a bow, lose their definition and smear over a longer period of time instead of being a single, precise hit.
This delay system works fine - as long as you only have to worry about 4 speaker locations plus the subwoofer. As soon as you add in the two hatch speaker locations, things start to fall apart again, because the deck can't add delays on six channels.
Stock stereos that are properly tuned from the factory with more than 4 locations have non-adjustable delays built into the sound system - so you can't, for instance, take the head unit from one car, put it in a totally different vehicle, and expect to get the same fantastic sound. Nobody does this anyway, simply because the wiring for stock systems is such a pain in the ass, and proprietary to each manufacturer.
Our car is simple to build a system for.
- Get some of the 91+ speaker pods for the front doors, and get some decent speakers for those.
- Replace the rear seat speakers with a decent set.
- Junk the hatch speakers, and, if your car came with it, the stock amp and sub.
- Add a small subwoofer box and a decent sub in the hatch. I'm fond of something in the 10" range, commercial mass produced enclosures can be had for cheap in this size, and they will fit under the targa.
- Either get a couple of amps - one 4 channel for the speakers and one monoblock for the sub - or pick up a 5 channel amp that will handle them all.
- Replace the head unit with something modern. Preferably something that can filter the low end signal to the sub, and the mid and high end signal to the rest of the system.
You'll now have a system that sounds far better than what came with the car. Without going to a really high end setup - many amps, even more speakers, and lots of custom work to make it fit - this is about as good as it gets.
If anyone wants specific advice about car audio in the Supra, we have several folks that are very knowledgeable - post a thread and ask for suggestions.
