Hey all,
As I'm a new Altezza owner, I'd like to say hi and say that this club is great... lots of good info. I can't seem to find any explicit info though on this topic.

I need to know the speaker impedances of the base 6 speaker audio system and for the upgraded 8 speaker unit with the external amp.

Also, does anyone know if there are differences b/w the 6 disk head units of the base vs upgraded system (mine is the minidisk version)? Does the upgraded unit have high-level outputs to the external amp? And further, could the external amp then be added to the base system ?

Thanks a bunch.

The 8 speaker version has 2ohm on the woofer and 6 ohm for the tweeters on the rear 6x9's I believe.
On the front door speakers on the back of the Woofer it states 4ohm 17.5W (in the IS200 with 8 speaker system).

Examining the Tweeter reveals that there is a small Capacitor crossover on it's rear
(to filter out the Bass frequencies). There appears to be no ohm rating. I would suggest
these present a total 4ohm load to the OE Amplifier.

It may be different on the Altezza, obviously tread carefully as the impedence is very important.

I would suggest the base 6 speaker model would not be compatible with the External Amp of the 8 Speaker system.

Thanks Wozza. I appreciate the info.

Any ideas on the rear 6x9's in the 6 speaker setup? Anyone replaced the factory ones while keeping the OEM headunit (non-amp)? ... i wish I had a volt meter ...

Climb in the boot with a torch, should have the impedence written on them I would guess.
They are just one speaker each side with a total impedence rating on the back of them,
so if it is 4ohms you are sorted .