New HU install, lowest volume way too loud

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New HU install, lowest volume way too loud

Post by mrarcade » Fri May 15, 2020 3:18 pm

I have a 2007 Pontiac Vibe and bought a touch screen head unit. I believe the car has Moon and tunes. I have a sunroof, tweeters by mirrors, and a subwoofer in the back. Unfortunately when I try to adjust the amplification lower in the head unit it has no effect. At the lowest volume setting the radio is way too loud.

When I ordered this head unit I thought it had 4 channel preamp lineouts. Unfortunately it only has two channel line outs and two channel line in.

I went ahead and just wired the speaker wires from the head unit right to the speaker wires in the harness adapter. So I guess I am sending an amplified signal to the amplifier under the seat.

Is my best bet to eliminate the amplifier and make a harness under the seat that just feeds the signals straight through? Is there a way I can use the preamp lines and still have four discreet channels? Can I just somehow wire in resistors to bring my volume down, because I can't turn it anywhere near 100%.

If I return this head unit and get one that does have for lineouts but they are still 4-volt am I still going to be in the same boat?

Any and all advice is greatly appreciated!

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Re: New HU install, lowest volume way too loud

Post by ColonelPanic » Fri May 15, 2020 6:53 pm

You're spot on - you're sending an amplified signal straight into the factory amp. The volume will be loud and I've found there will also be an excessive amount of white noise.

A speaker level converter wired in between the head unit's speaker outputs and the speaker wiring on the factory harness adapter will help. You can then adjust the levels accordingly.

I have this one here: ... erter.html

Adds a lot of bulk to the install but it works well.

Some have went from the line outs to the speaker wiring, but I seem to remember a lot of popping noises/etc.
03 Vibe base. Born 10/14/2002 06:07 AM
Neptune. Auto, Moon & Tunes, power package. 135k mi.


'13 Sonic LT - 1.4L ECOTEC turbo/6A. 116k mi.
'15 Escape SE - 1.6L EcoBoost, FWD. 58k mi. (hers)

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