so ive looked through 19 pages and frankly i dont have time for anymore lol.

im new to this site but im on supramania and cencalsupras.com alot, i have picked up my second sc400..its an electric teal 1998 with blk interior, has the nak stereo. in my previous sc400 i had the pioneer and it sounded great. this pos on the otherhand....heres the run down

at lower volume..it just doesnt seem to have clear sound..very muffled..and noooo bass..or its distorted...at volume..i seem to be having to turn the volume up higher to get decent sound..and decent is being generous...the bass sounds distorted...and i get a poping and cracking sound coming from the tweeters....

i have replaced the fried components excluding the sub and tweets, those are in good shape. ive read alot on how the naks are problematic, is this a simple ground issue? anything i can test and if so...how do i go about doing this test? i can work my way around wireing somewhat and ive installed many aftermarket stereos.....

ANY help would be welcome...thanks!!

 

also...ive been reading on how the "sub amp" is separate from the one half assed under the cd changer and is located under the speaker deck...i have no such amp there but my sub does work...just the whole thing sound like shnit.........anyone know where my "sub amp" is? its a nak system btw.. ty

 

It's very likely just your factory amp showing its age. The amps in the older Lexus vehicles were not the most resistant designs to begin with and with the car now being about fourteen years old, you're lucky it's still working at all.

Check the passenger side of the trunk area for the amp and check

1. If it's there (if you're number X in a string of owners, you never know what could have been done)
2. If there's any moisture in the area. If it's at all wet back there, that's likely your culprit.

Regardless of the amp's condition/existence, I'd recommend installing a new amplifier anyway. Whether you simply get a new head unit and bypass the factory amp or install a 4-channel amplifier, you're really doing yourself a disservice by upgrading your speakers and keeping the same 10+ year-old source equipment.

 

i suspected the amp....im just a purist and like the stock stuff...specially since my other sc with the pioneer was sooo nice sounding....

i have no moisture, and everything is there..and all the speakers work...the highs sounds great...its the distorted/muffled bass thats absolutly aggrivating.

how would i go about taking out the old amp..and wireing in a new on in its place? is there a pnp harness for this? i was thinking of disconnecting the sub from the stocker..and just wirering in another amp to run just the sub...leaving the rest on the factory one.....any ideas on what wires on the rear 4"ers is the positive and negatives?

 

Here is a diagram for the Nakamichi in a 98 SC400.

 

awsome!!! TY!!!

but i have a question...i am seeing the "sub power amp" again....i can not find this in my car...my pioneer was above the gas tank...this nak....all im seeing is the one under the cd changer..........any ideas? or pics? orrr.....idk...lol

 

ok...so heres what ive done....


i tapped into the two speakers on the side of the woofer...wired an amp into the factory b+ and acc wires in the trunk so my aftermarket amp works inconjunction with the factory one...disconnected the woofer and hooked my 300watt pioneer into it...and BAAM...sounds mean...my highs sound waaaay clearer...bass is deep and throughty...and my amp has remot gain and thats mounted into where the ash try was

all things considered im very pleased with the results....