Hi, I've been dealing with a bad install since April and hoping someone here can help. I have a 2003 4Runner with a stock JBL Synthesis system. I upgraded the HU to a Kenwood DNX690 at a local shop to get BT and Pandora and GPS and iTunes. The shop seemed the best out of the few available in Boise. The set up has never been right. Very weak power. Not nearly as as powerful as factory HU. Fronts are weak, Everything aft (6-8 speakers depending on if you call a 2" a speaker) is un intelligible unless you fade all to rear. DNX 690/691 is a 5v pre amp double din. The original HU and amps are 4V so they put in a module to convert.

We've tried everything to get this thing to work right. two 690 HU's, two modules, a 691 when that became available, even reinstalling the original HU and jacking the gains up for the amps before reinstalling DNX. Nothing has worked.

Shop now says amps are bad and wants to do a $1000 replacement. But they worked fine in April before the Kenwood. I'm even resorting to taking it to the dealer to see what they have to say about the set up. They use Pioneer and say they work best with Toyota premium systems. This eval is free but of course they want $1,500 for a new HU and install. Maybe I should hear what they use and buy elsewhere and install myself or tell original shop they have to try it before I will pay for amps.

I thought I would check here to see if anyone has any bits of wisdom for this fatal setup and before I get fleeced (more?).