Just got the amp in the mail today.

I noticed there are 3 sets of inputs. I'm not sure (have to check) but I think my deck only has one set of pre-outs.

Here's my idea; take my existing RCA cable and run two RCA Y-plugs off it, then I'd have THREE sets of RCA connectors. That would work wouldn't it? It's only an input signal right?

If anyone needs pics I can provide them. TIA for the help.

 

What HU are you running? on most there are 2 sets of RCA Outputs; Front and Rear; if this is so, just Y the rear RCAs.

 

There may even be a control on the amp itself that feeds one of the other inputs to the sub's input for those that don't have HU's with 3 sets of outputs.

 

It's an Alpine 7874.

http://akamaipix.crutchfield.com/pro...00CDM7874.jpeg

I took a look last night and there are two sets of RCA plugs (4 plugs total) in the back of the car now.

According to the book that came with the amp, I can just plug in the 4 plugs I have to the amp and I'll HAVE that sub output signal I need. It talks about several different ways to hook up speakers to it, that's where it gets a little confusing for me.. All I want is to run amp power to each 6.5" speaker (4 total), filter the lows out of them, and run a sub to the amp.

 

This headunit has 2 pre-outs. Front and selectable rear / non-fading rear.
Read the amp instructions. I'm sure the solution is there.

 

I would run your front and rear RCA's to your amp and Y your rear RCA's for your sub.

 

I would do just the opposite. I would use the Y adapter with the front RCA cables. That way you can use the fader to control the amount of rear fill without turning down the sub.

 

Then you won't have fading front and back if you run all 4 speakers off the front RCA's. That would be alright if you didn't want fading. What I would do is sell the radio and get somthing with front, rear, and non-fading preouts.

 

Click on my Cardomain page in my sig and, at the bottom of the front page you'll find some pics I just uploaded of the amp, wiring, and the sub.

I think what I'll do first is just hook up the 4 connectors to the amp and see if I have output to the sub that way. If not, then I'll buy a y-connector and play with it that way.

It would be nice if I still have the fade control, but if I can't I'll make due until this deck takes a dump. I have no plans to replace the deck just so I can have fade controls if that's the case. I have mod money that needs to go other places, like in the hp dept.

 

You will still have fader control. I didn't say run all 4 speakers off of the front RCA's. The sub will go up and down in volume with the front speakers. Not having the sub connected with the rear speakers allows you to use the fader to control the loudness of the rear fill speakers. Personally I don't believe in using rear speakers unless you have a true surround sound setup.

 

OK problem:

I basically hooked up the amp last night just to make sure it works. All I did was wire up the sub. I turned on the deck and the amp comes on fine, just no output. Further inspection revealed that the "Protect mode" light is on. According to the book the only way to reset it is to turn the deck off then on again.

The amp shouldn't care where the RCA's are connected, so I'm ruling that out. When you disconnect the RCA's with the amp turned on, it turns itself off. BTW, I read a bit more in the book, and with only 4 RCA plugs plugged into the amp, the 5th channel (the sub channel) gets a "mixed input signal" from the other 4 channels, whatever that means.

The only thing I can think of at this point is that maybe my ground isn't sufficient enough? Where's a GOOD spot to ground an amp in the back of an F-body?

 

You say you only hooked up the RCA (and I would assume a speaker). Hook EVERYTHING up. Maybe one speaker on a channel may send the amp into protection because you're now pushing an odd amount of ohms. Was the remote turn on hooked up?

There are WAY too many possibilities as to what could be wrong when it isn't even hooked up fully. Hook it up fully, and THEN troubleshoot it if need be.
I'd also take the time to read the product manual. You mentioned having it, and every question you've asked so far is normally covered within the pages of an amp manual.

 

Ha! Figured it out! With a little help of course.... I called up the tech. support at lunch today, and, my theory turned out to be correct. My ground wasn't sufficient to run this amp. It had JUST enough ground to turn itself on, but not enough to power any speakers. So I found a different/better grounding point and sanded it down to bare metal. That did the trick. Before I got off the phone, the tech guy said to leave all speaker connections and RCA's unhooked, and just leave the power, ground, and remote wire hooked up. Turn the radio on, and I SHOULD have a green power light. IF I didn't at that point then it would point to a power/ground problem. That's what it was. I'm happy now that it works.

Man this thing pounds for just one 10" sub, and I only have the gain cranked up 1/2 way. Can't wait to get the rest of my speakers hooked up to it as well.

I did read the manual, it was very short and kinda vague in a few places, but Hifonics' tech support cleared things up with me over the phone. I can say that they are extremely friendly and helpful.

Thanks for the help guys.

 

My bad. I didn't read the post completly.