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Topic: RCA's into premium sound and stock speaker power handling (Read 2018 times) previous topic - next topic

RCA's into premium sound and stock speaker power handling

I am working on a CarPC for my 'bird and was wondering two things:

1.  Is it possible to bypass the factory headunit and send a signal straight into the factory amp (88 TC, premium sound) and if not:

2.  How much power can the premium speakers handle.  I want to run them, for now, with a multichannel amp.  Don't want to get an amp so small that it's useless when I upgrade speakers and don't want one that will destroy my current speakers...
1988 Thunderbird Turbo Coupe
'89 5.0 w/ ported intakes, Mallory Adjustable FPR, BBK shorties and H with 2.5" Flows, 130 amp 3G, 89 Mustang comp/wiring, Aluminum radiator w/ elec fan, T5 trans, King Cobra clutch, 3.55 gears, 13" Cobra brakes (front), Wilwood prop valve, Mustang A-arms, Front Coil-overs, MM CC plates, Silver 17x9 R's, 03 Cobra IRS, Aluminum DS, 2002 Mustang dash/console etc..., custom leather seats

RCA's into premium sound and stock speaker power handling

Reply #1 –
Because of the shared ground in the factory stereo, its kinda a pain to wire up to the factory amp but its possible...it won't sound too great though. You can follow the wiring diagram HERE.  Connecting some rca's to the end of the colored cables while splitting the black/white for the ground should get you where you need. I did this years ago.

As for an amp, just don't set the gain very high and you'll be fine to run them with any speakers. Really though, just set the amp at its rated (RMS!) output and run a software crossover to the factory speakers. As long as you don't clip the amp, the factory speakers should be able to handle some power. Factory speakers are 3.5", 5x7/6x8", and something slightly smaller than aftermarket 6.5" in the doors . I'd try feeding them 10w HP 160hz, 20w HP 100hz, and 20w HP 63hz and no more as the voice coils are lacking in the power handling department before they burn up. Factory amp will run the dash and door speakers at the same crossover points and power levels so be careful. Also be sure that them being wired in parallel won't kill any new amp you may purchase.

Aftermarket, I have 25w going to my dash speakers, 80w going to my 7" 8ohm door speakers (very efficient, same output as a similar 4ohm drawing twice the power), and 500w going to two 4ohm 10" subs firing into the cabin through the rear seat. Matted and foamed, sound is very clear with low current draw and no reason to add more power as its unbearable to turn it up near half potential current draw. Dash speakers/only tweeters are having problems keeping up at higher volume levels though.
1988 Thunderbird Sport

RCA's into premium sound and stock speaker power handling

Reply #2 –
Does saying it won't sound to great mean worse than with the stock head unit?
1988 Thunderbird Turbo Coupe
'89 5.0 w/ ported intakes, Mallory Adjustable FPR, BBK shorties and H with 2.5" Flows, 130 amp 3G, 89 Mustang comp/wiring, Aluminum radiator w/ elec fan, T5 trans, King Cobra clutch, 3.55 gears, 13" Cobra brakes (front), Wilwood prop valve, Mustang A-arms, Front Coil-overs, MM CC plates, Silver 17x9 R's, 03 Cobra IRS, Aluminum DS, 2002 Mustang dash/console etc..., custom leather seats

RCA's into premium sound and stock speaker power handling

Reply #3 –
My EVTM shows the ground as wht at the amp and it switches to blk/wht in between the amp and the radio.  If this is correct, why do I have both (wht and blk/wht) at the amp?  Also, the wire that connects to the stud on the back of the radio...  what's it's purpose?  Do I need it or can I run it elsewhere without the radio?

And what about the or/lt blu running parallel to the yl/blk (which I'm assuming is 12v ign source)?  What does that or/lt blu wire do?
1988 Thunderbird Turbo Coupe
'89 5.0 w/ ported intakes, Mallory Adjustable FPR, BBK shorties and H with 2.5" Flows, 130 amp 3G, 89 Mustang comp/wiring, Aluminum radiator w/ elec fan, T5 trans, King Cobra clutch, 3.55 gears, 13" Cobra brakes (front), Wilwood prop valve, Mustang A-arms, Front Coil-overs, MM CC plates, Silver 17x9 R's, 03 Cobra IRS, Aluminum DS, 2002 Mustang dash/console etc..., custom leather seats

RCA's into premium sound and stock speaker power handling

Reply #4 –
I wouldn't say it would sound worse than the stock stereo, but it may not have  noticeable improvement other than better radio reception, being able to play cd's, etc.

The white to black/white wire is the ground you need to wire up to the speakers by splitting it into 4 separate grounds. The connector on the back of the stereo is a ground and most new headunits have a threaded hole in the same place for the ground. I recommend using it, especially if you use a Pioneer deck as they're known to blow an internal fuse when relying on the wiring harness ground alone.

Orange/light blue is your REMOTE turn on lead, yellow/black is your 12v from ignition.
1988 Thunderbird Sport
 

RCA's into premium sound and stock speaker power handling

Reply #5 –
Ok, well I'm not to worried about the connector on the back of the HU then as I will have no in dash HU.  It's all running off a computer which is assembled on the panel where the ABS and PRC computers used to live and will be operated by a 7" widescreen touch display that will sit in place of the clock and the air vents (vents will be rerouted to come out just about the stock radio location).  anyway, thanks, this helped a lot!
1988 Thunderbird Turbo Coupe
'89 5.0 w/ ported intakes, Mallory Adjustable FPR, BBK shorties and H with 2.5" Flows, 130 amp 3G, 89 Mustang comp/wiring, Aluminum radiator w/ elec fan, T5 trans, King Cobra clutch, 3.55 gears, 13" Cobra brakes (front), Wilwood prop valve, Mustang A-arms, Front Coil-overs, MM CC plates, Silver 17x9 R's, 03 Cobra IRS, Aluminum DS, 2002 Mustang dash/console etc..., custom leather seats