I have a 92 LS and the problem started with the rear door speakers stopped working one day. Then the passenger door stopped but the tweeter still works. I'm down to only the subwoofer and driverside door and both tweeters working. I want to fix this but don't want to loose the factory head unit. Going aftermarket speakers and amps will be a major pain because I believe I'll have to run new wiring to the doors too. So the best solution seems to replace the amp which I believe is my problem. I know all my speakers just stopped working one day. I've never seen this in any car I've ever owned. But I can't find the amp. Also I've changed head units thinking the amp was inside the head unit but still had the exact same problem. Can anyone tell me were the amplifier is that controls the door speakers on the Nakamichi system?

Thx!

The amp is underneath either the drivers or passengers seat mate

I thought it was the series 3 that had the amp under the seat and the series 1/2 had it mounted either below or above the cd changer in the boot.

I checked both places and there is no amp in either. I completely pulled the CD Changer out with the boot removed and there is nothing. I looked under both seats and nothing there either. Now the schematics don't show there is an amp for the doors only the sub woofer. Does anyone have any experience with this?

Some one has stolen your amp!!!
No seriously it may be that the amp is part of the headunit and if you remove it and look at the back there should be a heatsink ( metal cooling fins) this would suggest it is inbuilt.

In the USA the Nakamichi Premuim sound system was always an optional extra on the LS400s. If you dont have a Nakamichi amp then as Steve suggests it is probably at the back of your head unit.

Thanks alot ! Yes, I looked on the back of the radio and I do see the heat sink. Being that I changed out head units and had the exact same problem I'm going to look at speakers then. The more I've researched, the more common I'm finding these speakers do fail often. Interesting. One more question, I can't find any posts on fixing the driver seat. I've gone through numerous junk yards and found that most LS400 seats are similar to mine which is the springs have either colapsed or something. I know something is wrong with the seat and it didn't come from the factory like this. Can anyone give me any recommendation how to fix this?