bklusa1

Do I have to use RCA connection to connect an aftermarket headunit to a metra harness or can I use wire inputs? Reason I ask is my Headunit only has 2 sets of pre-outs, and the rear can be changed for sub amp, which is what I've always used it for. Won't have an extra set to connect to sub amp if I have to use RCA inputs on the metra harness.

Paul350Z

iTrader: (1)

RCA = line level signals
Wire = speaker level signals

Depends on what you're connecting your Metra harness to.

If you're connecting a new headend via a Metra harness to the factory base speakers you're fine.

If you're connecting into a factory Bose you'll overdrive the amplifier's inputs and likely damage them.

Some aftermarket amplifiers allow for speaker level inputs as well as the more typical line level inputs.

In the later two cases are aftermarket adapters which will drop speaker level signals down to line level amplitudes to you don't overdrive/smoke an amplifier. You'd connect the new headend to the adapter and then into the Metra harness which would drive the stock Bose amplifiers.

bklusa1

this adapter should be readily available at a audio shop correct? Not something I'd have to special order?

Paul350Z

iTrader: (1)

In a well stocked shop ... no. In many shops - special order. You can order one from Crutchfield and hand it to the installer to use or just call the install shop and give them a heads up. (WAY) Back in the day when I did custom car stereo installations I had probably 80% of the antennas, speaker mounts, and wiring adapters in stock in the store I worked in. I had a lend/lease agreement with the shop across town to share stuff back-n-forth at dealer cost plus 10%. It worked out best for both sides and I'd nearly always had the right parts between me or the other companies store.