jmlee44

So I finally got around to adding a sub to my max. Car has the factory Bose but at some point someone added a JVC deck. I looked up the model, it has a sub out - great! So I buy and amp kit, installed the amp kit and ran the wiring. I found a Kicker Comp 12 in a sealed box run by a 250x2 Kicker amp - bridged this amp should be a nice fit for the sub.

So I get everything hooked up and barely any bass - in fact, I have the sub out on the deck at max, the gain and bass boost at max on the amp. I now hear the sub, but with the bass boost cranked at 45hz, the bass isnt' even or smooth at all - and at low volumes, it is non-existent.

My research led me to find out (after the fact) that this factory bose system has amps in each speaker that "SHOULD" be fed signal level only. Whoever installed the JVC deck fed them with speaker level signal directly. (and since it only has one pre-out - I can't easily fix that).

So what is happening is this, the bose system is getting a much stronger signal than it is expecting, causing my JVC deck to be at max volume (beginning of distortion and damn loud) at volume level 15 - the max is 50 on the ****. Basically, the car is double amping the main audio - and since the sub is wired in-to the sub out on the deck "normally" - it is responding to what would usually be a low volume level if the individual speakers weren't amped.

So is my only option now to do a speaker level input into my amp and not be able to use the RCA output from the deck to keep the levels the same?

I also have 1 back speaker that is intermittently scratchy - think it is the internal amplifier. Has anyone done a repair on those?

J

1996blackmax

iTrader: (2)

I would dump the Bose system & get a four channel amp & some speakers. I think you may be much happier in the long run going this route.

jmlee44

I figured it out dear friends...

The answer, well it was hiding in my post (sorta).

Since they PO had wired the speakers directly to the deck, they were getting full signal. I pulled a wiring diagram from another forum that showed where the level input was for the rear deck lid speakers and I spliced into both sides, running the wires to my high level input on my amp.

Worked like a charm, and I didn't get any of the weird feedback and signal processing from tapping in after the bose amp. It's a hack in a way - but consider what my goal was/is.

I bought the sub/amp combo on craigslist for 50 bucks, an 8GA wiring kit from wally world, and in 2 hours - done more or less. It sounds good. Not great, my old camry I had alpine components up front, 6x9s in the deck and a JL 12W0. Better SQ for sure than this - but this is a cheap car and a cheap solution. I don't go sub crazy, i'm never one of those people who would install 2 huge subs in a sedan. I just feed them in to pickup the low bass where a good 6 inch speaker just can't go...

Quickywd01

iTrader: (16)

When I did this on my '99 se I tore apart an old vcr and salvaged the rca plugs and spliced those to the back of my bose headunit so I could plug my amp rca's right into there. Single apline type-r 12" in a sealed box and a alpine m1000 amp. People thought I had two subs. Also replaced the factory battery with a walmart maxxstart 34n about 1000CA. In the future I want to either upgrade to just a 2000w amp or a jlw7 and 2000w amp depending on funds.

nismos14

iTrader: (56)

This is nothing new, been happening since 1995.