Amp install question

[Johnny Racer]

Okay so my 4 channel amp arrived today and I am going to install it on my 99 GMC Yukon 4 door this Saturday and something dawned on me.

The 2 front door speakers are 1 channel. The 2 rear door speakers and the 2 rear cargo area speakers on a stock Yukon are the rear channel and if I am not mistaken there is a factory amp that runs power to all of them. How in the hell am I going to hook this amp up to have it function properly and not damage the speaks and/or the amp?

 

[Done Deal DR]

...I'm back. LOL

I thought you had an aftermarket Alpine headunit? Can you confirm?

 

[Johnny Racer]

I do.... an Alpine CDA-9886

Not sure if it will matter but the rear cargo 4x10's are these:

Kenwood KFC-415C
4" x 10" Custom-fit Car Speakers
Power Handling:
Peak: 320 watts per pair / 160 watts each
RMS: 160 watts per pair / 80 watts each
Injection molded polypropylene cone woofer
2-3/8" Polyamide balanced dome tweeter
4 ohms impedance
8.2oz Magnet structure
Top-mount depth: 2-7/16"

 

[Done Deal DR]

Can you confirm how its currently wired? Because typically, if you installed a headunit with a factory externally amplified system, you would have to account for that during the headunit install.

What I mean by that is that when the headunit was wired, you will either have auxiliary cables going to a factory amp, or in some cases the factory amp accepts speaker level inputs where it would simply be a speaker wire, HOWEVER when installing an aftermarket headunit that has an amp (small, but it's there) you would have already run into issues if this was the case. You'd know right off that bat if this was the case because it would sound like absolute shit, if it made sound that resembled music at all.

So, in regards to this amp - what you need to do is figure out which speakers you want to amp. I'm assuming you have door speakers (6.5's) and rear doors (6.5 as well) that you want to amp per your other threads. Now what you need to do is go to the back of your headunit, which only has speaker level outputs with speaker cable and disconnect those wires from your headunit. Now connect the auxiliary cables you purchased (should be 4 total on each side) to the headunit, then connect the other side to your amp in the appropriate channels. I would recommend completely disconnecting the rear 4x10's as 4x10's suck by nature, and you wouldn't even be able to hear them given they are all the way in the back and because they aren't amplified like your 6.5's will be.

---------- Post added at 01:44 PM ---------- Previous post was at 01:35 PM ----------

That is a solid deck and those 4x10's are actually decent.

You could actually do the opposite of what I did, and do the front 4 channels to the amp via aux cables, then from the amp run speaker cable to each speaker (you have to do this regardless unless you somehow mount the amp under the dash right next to the deck, which I've never seen), and then connect the rear 4x10's to the rear channel on the deck via the speaker level outputs (speaker cable connections).

Make sense?

 

[Johnny Racer]

I wired it just like the Alpine manual (found here: http://support.alpine-usa.com/products/documents/OM_CDA-9886.PDF) has it layed out.

I didnt stray from it or bypass anything.

So what you saying is, if I run seperate speaker wire to each individual door speaker (god thats gonna suck), then to the amp, those will run off of that. Then just take the factory rear channel speak wires (behind the stereo in the dash) and leave those connected they would power the 4x10's and all six speakers will fire?

 

[Done Deal DR]

One moment, let me check that link out.

Okay never mind, I see it's just the manual to the Alpine 9886. So you didn't have anything special, there was no external factory amp...although I'm not 100% certain how you had 6 channels of audio with just the Alpine 9886 unless you doubled up the rear wires together, which would essentially create a 2ohm load on those outputs on your headunit (which is not safe for your headunits internal amp - they are not 2ohm safe, though it would push out more power, albeit not clean power).

So what you need to do is confirm how many wires are currently connected to the rear of your headunit. If you can't get behind it this very second, you should also be able to verify by turning the sound all the way to the rear via your headunit menu settings, then put your ear up to ear rear 6.5 and 4x10 and confirm if you get sound. Also try the front. If they are doubled up, i.e. all 4 front 6.5's have audio when sound is moved completely forward, or rear 6.5's and 4x10's have audio when sound is all the way to the rear, your speaker wires are doubled up on the headunit speaker level outputs (standard speaker cable).

Once you establish that, you just need to disconnect and wire in the aux cables for the 4 outputs, and you can leave the rear 4x10'S on the rear output of speaker level outputs on the deck. Wiring new speaker cable to each speaker cable is always necessary when amping speakers because the wire will need to come from the amp. Does this all make sense?

 

[Johnny Racer]

Sure it makes sense and the wiring diagram is on like page 46 or something there. These Tahoes and Yukons have factory amps the run the rear 4x10's. Its located under the drivers seat. When I adjust my fade... the front door speakers and seperate tweets stop working. All sound is coming from the rear passenger door speakers and the 2 rear cargo speakers. One of the reasons I have the blue remote lead hooked up... it turns that amp on which is another question... how to I turn on the new aftermarket amp since that remote wire is in use with the factory amp?

This whole setup will change soon (a month or so... maybe longer depending) since I want to go with 6x9's in the cargo area and an amp to run those.

 

[Done Deal DR]

******** this ninja editing site is confusing. LOL

Yes, that is correct. You will have to run the 4 aux cables from your headunit to your amp (that carried the "pre amp" sound to your amp). Then you run individual standard speaker wires to each of the 4 speakers. It is a PITA but it will be worth it, and speaker cable is dirt cheap.

The rear 4x10's you will want to leave connected to the amp as they currently are if you want sound from them. Although, i sincerely doubt you will be able to hear them over your soon to be newly amped 6.5's.



---------- Post added at 02:12 PM ---------- Previous post was at 02:08 PM ----------

Sure it makes sense and the wiring diagram is on like page 46 or something there. These Tahoes and Yukons have factory amps the run the rear 4x10's. Its located under the drivers seat. When I adjust my fade... the front door speakers and seperate tweets stop working. All sound is coming from the rear passenger door speakers and the 2 rear cargo speakers. One of the reasons I have the blue remote lead hooked up... it turns that amp on which is another question... how to I turn on the new aftermarket amp since that remote wire is in use with the factory amp?

This whole setup will change soon (a month or so... maybe longer depending) since I want to go with 6x9's in the cargo area and an amp to run those.

Quoting should make this easier.

You should be able to double up the remote leads no problem, or I think I've even seen them daisy chained but I can't confirm that 100%. Can you explain how the rear factory amp is wired to your headunit? Via aux cables or speaker cables?

===============================================================================
Ok just found your wiring diagram, I see now you have 6 aux cables outputs on your headunit, which now completely makes sense.

There should already be 2 aux cables connected to go to the rear amp, and the rest of your speakers should be currently connected via the speaker level outputs. So you will disconnect those, and run 2 more sets of aux cables to go to your amp, double up the remote turn on lead, and you should be good to go.

 

[Johnny Racer]

No clue on how the factory amp is wired. Gotta be speaker wire... I have never messed with it. LOL

Thats what I was figuring. So... 4 channel rca cable to amp input, 4 seperate speaker wires to each respective door, dont do shit with the rear 4x10 rear channel stock wiring... leave it hooked up to the radio for now. Got it.

Still not sure how what to do with this remote lead since I need to turn the aftermarket and factory on on together. Might have to splice those 2 together for that one if I just dont say screw the 4x10's and wait til I pick up my Alpine SPR-69C 6x9's and amp for them.

Thanks again for all the help. I have all the wire and what not I need to install this thing at my door as we speak. LOL

 

[Done Deal DR]

Sweet, and yes you should just be able to splice the remote turn on lead that is already near the rear of the cabin. Most people choose to install the amp under the front passenger seat or under the rear seat. It's probably going to be easiest just to remove the seats entirely.

I bought a 92 2 door Blazer that was completely jacked with, so I have no idea how these trucks were originally, although I doubt mine had a factory amp. In the short few months I've had this truck, I've completely gutted it down to bare metal, swapped in a new dash I painted a "BMW black", cleaned the floorboards, installed sound deadener, new black carpet, etc) Mine doesn't even have a location for front door speakers, so that is a custom fiberglassing project in the future for me. I've got silly 4" speakers up front on the dash running off headunit power, and the rear 6x9's wired to the amp (that was stolen, fantastic ), and also wired up a location at each front door for future use. See what I mean by opposite of your current project?

Best of luck on your project.