Need fade but only have L/R preout to amp.

[aweir 10+ year member]

I want to do Left/Right RCA preout of head unit to left/right channel A and left/right channel B to have front/back fade ability and low/high pass.

Have an JVC head unit with only one pre-amp output. I also have a 4 channel amp for my 4 speakers. Is it safe to use a Y cable to split the left and right output into four RCA inputs?

What are the advantages of using a head united with two preamps vs. one preamp with a RCA Y cables? Does the front/rear preamps preserve fade ability? Doesn't matter when my amp has separate gain for the two channels anyway.

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[mokedaddy 5,000+ posts]

with only one set of rca outs you will not have the ability to fade front to back. If you have two sets than yes you will be able to fade. Y-splitters will not allow you to fade front to back but will otherwise work.

 

[Prowler573 5,000+ posts]

//content.invisioncic.com/y282845/emoticons/word.gif.64b12e39f936af3b4fff38a1c0bd0244.gif

The only way you're going to get fader functionality is to either upgrade to a headunit that has more than one set of preouts or add an EQ/crossover or something that has a fadar feature.

With only your current deck? You simply can't.

 

[xhilr8n 10+ year member]

You could put a couple line out converters like you would use on a factory radio on the set of front and rear speaker wires coming off the radio itself.

Kind of a ghetto way to do it, but it would work. Other than that i can't think of another way to be able to fade 4 channels independently.

jason

 

[Prowler573 5,000+ posts]

You're right - that's ghetto. //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif

But you're also right in that it could technically work - just a whole lotta work for not much return.

I'd rather just buy a new HU.

Shoot $100 or less will get you a HU with two sets of preouts off of eBay...

 

[aweir 10+ year member]

I just want to make sure so I don't damage the amp/speakers.

I could just use the amp's (Channel A/Channel B) gain controls as a fader, right? Or does the gain have to be the same for both channels so I don't over power the amp/clip the speakers?

I have 40 watts RMS front, 60 watts RMS back speakers and a 75WRMS X 4 @4ohm amp.

 

[Prowler573 5,000+ posts]

First off please be aware that even though your amp may be capable of making 75w per channel into a 4 Ohm load you will pretty much never see that level of output while playing music.

Secondly I think you are misunderstanding the purpose of a fader.

A fader is used to adjust the level of output signal going to the front and the rear.

What would you do if you wanted to kill the output from the rear speakers? Pull the car over and adjust the gain for those outputs all the way down?

When using a two-channel source you cannot get a function reserved for four channels of output.

 

[XHiFiX 10+ year member]

I don't think it would be such a bad idea to wire a LOC from the HU's rear speaker wires to the rear RCA inputs of your amp.

 

[xhilr8n 10+ year member]

i don't either.......technically that would be a 4 channels source. I am not trying to suggest stuff beyond my knowledge though so it there is a reason why you couldn't do this someone please elaborate(could prove to be useful knowledge in the future).

jason