help me you stereo pros!!

[allballsmustang]

i have an 89 foxbody and im putting in a new head unit...i just installed the speakers and i am wondering about the factory amp...do i have to remove it? i believe mine has one, theres a small box bolted to the floor directly below the factory stereo with all kinds of wires comming out of it which i believe to be it. i know the speakers are rated for more than the head unit puts out so is this a concern?? has anyone actually done this? thanks

 

[89stangWhiz]

with a new head unit, you are either going to want to take out the amp(thats what I did), or bypass the amp. The factory amp is probably a lot less than your new head unit, and your aftermarket head unit probably cant use the Ford factory amp. While you have access to it, if you can, just remove it. Its dead weight now.

 

[sunil6784]

I believe Crutchfield sells the bypass kit.

 

[Daggar]

I believe Crutchfield sells the bypass kit.

You got a link?

 

[89stangWhiz]

amp bypass wiring at crutchfield

But why bypass it when you can take it out? What better bypassing is there than not having it

 

[Daggar]

amp bypass wiring at crutchfield

But why bypass it when you can take it out? What better bypassing is there than not having it

I agree. Do you have step by step instructions for doing this?

 

[89stangWhiz]

hmm, no i dont have instructions for doing it, but from what i can remember it was pretty straightforward.
With the head unit out, the amp just unbolts and the amp wiring should come right with it since its unplugged from your old headunit.

I guess most of the instruction for installation depends on your head unit. If you have an internal amplifier in your head unit (most do, mine does), then its just a matter of wiring your head unit directly to your speakers. The head unit should come with very simple diagrams for wiring. Each wire has a seperate color and color w/ stripe for which speaker location it goes (indicated in the diagram in head unit instructions).

Generally the stripe is for the negative terminal.

As the article from crutchfield states, the idea is to save you from dash work. I will admit, to do the job well, and keep things hidden and as stock as an aftermarket unit could look, I went to great deals in time to do things neat.

If you read the article, you already have to splice and connect wires in this bypass kit.
The two things you are saved in this are
1) Dont have to think about anything, just match their colors and connect the wires, and plug it into the harness to the amp. Doing it yourself, you have to make sure you have the white wire going to the correct location speaker(left front or whatever it is).
2) Dont have to do all the work in the car behind the dash.

Further, I recommend running new high quality speaker wire to your new speakers and head unit. I used monster cable. After all, you are putting in new speakers and head unit for quality right?

If you are using an external amplifier the job is probably even easer. You run the speaker wire straight to the amp, and with just about any new aftermarket head unit, your probably just running an rca cable from head unit to external amp. Good luck finding a spot for that in certain mustangs...

 

[89stangWhiz]

why does ford even have a factry amp?

In case you might be wondering, its because of the simplicity of the stock head units. They have no internal amplifiers like i mentioned in my previous post. Thus, they soley rely on some external amp.

There ARE aftermarket head units available in this setup. I almost bought one (Alpine CDA-7895, yes its an old model, I did this 2+ years ago), but instead I got the CDA-7894 ~250 watt internal amp.

If i didnt have a convertible, I probably would have gone with the 7895. It may seem crazy to buy a head unit with no amp, but the whole point is to get an awesome, quality amp to power everything. Not that I am into it, but people who have competition systems certainly dont have head units that have internal amps, they have head units that focus on external accessories.

As far as I can tell (maybe I am wrong) most people just get amps for there subs (2-4ohm etc... combined for 1-2 outputs). If I had the room, I would have gotten a much different amp which could power each speaker. Thus, the amp would do all the powering, eliminating the need to the head unit to power the speakers.

Its very important to consider what you want in advance for just about everything you do. I tried to imagine what speakers I would want, and then how are they going to be powered, whats the best way to do it.

Can you give some insight into what speakers you got, etc...?

FYI, my setup is the alpine deck, directly wired to the speakers, with one of my RCA outputs going to my recently added self-powered sub. I have Infiniti Kappa 6.5's all the way around, and an Infinity BassLink II sub.

Another important thing about your setup is the wattage. Do you know what your speakers can handle. Remember that there is a huge difference in the numbers the salesman gives you on the speaker and what it can really handle. I think my speakers are rated for 270 watts peak. Thats a safe 180 watts rms. (RMS = Constant wattage it can handle, whereas a peak, or at one moment, it can handle this peak voltage).
So, if you have a 200 watt peak rated speaker, you DO NOT want to send it 200 watts continuous power from whatever power source.

Let us know and surely we can help choose/suggest some setups.

(Thank goodness something I can actually try to help with, in hopes that when i have $$$ I can get help with other stuff in the future! )

 

[allballsmustang]

so what would happen if i hooked up my head unit with the factory amp still installed?

 

[89stangWhiz]

so what would happen if i hooked up my head unit with the factory amp still installed?

Your bypassing your factory amp one way or another.

Your head unit wont hook up to the factory amp without a bypass kit.
The bypass kit will bypass the amp, but use the amp wiring to the speakers.

If you wire the speakers directly to the amp, your amp is still in there, and still bypassed.

Maybe I misunderstood your question? How did you mean the factory amp would still be installed?

 

[Daggar]

If you DID manage to hook your new head unit in-line with the factory amp, it would sound like ass.

 

[89stangWhiz]

If you DID manage to hook your new head unit in-line with the factory amp, it would sound like ass.

+1

 

[allballsmustang]

well i bought the harness that you just wire to the head unit and plug it into the factory harness...but i dont think its the same one as the one you are showing me on the crutchfield sight...so from what im gathering ill probably have to disconnect the factory amp and rewire the whole thing so that the speaker outputs go directly from the head unit to the speakers? also one other question, does any of the other wires route through the amp like power and illumination becasue then i would have to wire those direct as well?

 

[allballsmustang]

oh and to help with the whole senario im using a jvc headunit 50x4 amd the door speakers are 4 1/2 explodes and the rears are pioneer 3 ways... dont remember the wattages of the speakers off hand b/c im at work...

 

[millhouse]

Here is how I remember it. You have a connector coming out from the factory head unit which goes to the amp. This connector will not work with the adaptor as the adaptor is made head units with built in amps. Now from what I remember there is a second connector tucked behind the dash which is plug and play into the new adaptor. Finding it is the tricky part…but I believe it's somewhere behind the glove box. This will allow you to use the standard adaptor without having to splice anything.

 

[89stangWhiz]

well i bought the harness that you just wire to the head unit and plug it into the factory harness...but i dont think its the same one as the one you are showing me on the crutchfield sight...so from what im gathering ill probably have to disconnect the factory amp and rewire the whole thing so that the speaker outputs go directly from the head unit to the speakers? also one other question, does any of the other wires route through the amp like power and illumination becasue then i would have to wire those direct as well?

If you got some sort of universal ford bypass wiring it shold work.
Yes, there is some power too it, but dont you have power going to the head unit anyway, so dont worry about it