Picture - What Is This - Stereo???

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This is in the trunk of my 90 SC - two wires are hanging down - the one on the right looks like a power feed of some sort (I'm guessing) with yellow and red wire. - the other looks like it is hanging down from the shelf above the trunk.

I don'tsee a subwoofer in the trunk so I guess it has been uninstalled long ago. would these wires have fed the sub - I put in a new head and sony head and the stock speaker sound so bad that I was wondering if these wires had something to do with the weak sound?

thank you
 

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Yes, the connector hanging down from the left comes from the amplifier into the subwoofer amp. The connector on the right is the power for the subwoofer amp. The sub in my '91 was blown and made awful noises....I umplugged it and it took away any bass the other speakers had. I plugged it back in for the time being, next spring I'll replace the sub or buy an amplifer from a Tbird with NO subwoofer connections.
 
Where is the subwoofer amp? is there only 1 amp in the trunk, or 2?

if there is a 'subwoofer amp', how may i access it?

the subwoofer is missing from the car but is this needed to get the bass back?
i noticed that the interior speakers sounded weak, more treble than bass.
 
Thats exactly how my speakers sounded with the sub unplugged. It was like turning the treble all the way up and the bass all the way down. The only way you will be able to fix that is buy a sub or buy an amplifier from a SC with just "Premium Sound". The subwoofer amp is different, it is located on the sub box itself whereas the other amp is in the rear package tray.

You can see the subwoofer box and amp in the picture below.
 

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thanks a million zillion - so you are saying the wire on the left plugs into one side of the subwoffer setuo and the feeder wire on the right plugs into the other side. I'll have to find this stuff now - i'll be in the hunt...

thanks again - do you know of anyplace that sells this setup???
 
So doeas nayone know anything about the amps in these cars. My TBird came with the Premium sound package, but I am the second owner. The guy before me, replaced the head unit with a Kenwood CD player/changer and is powering the 4 speakers (which I believe are still the stock ones) with a RockfordFosgate 160 amp. It sounds great. But now I have an amp that I am not using. What is the power output on this Ford amp. I might end up wirring it back it to power some speakers if it is worth while.

Blown95
 
Blown95, sorry I can not be much help to you. All I can say is I remember reading that someone tested the output of the factory amplifier and found it was not that bad. I don't know who did it or the results, maybe you could create a post and hope the person responds!
 
wwwtbirdforumcom said:
thanks a million zillion - so you are saying the wire on the left plugs into one side of the subwoffer setup and the feeder wire on the right plugs into the other side. I'll have to find this stuff now - i'll be in the hunt...

thanks again - do you know of anyplace that sells this setup???

I have the subwoofer box and amp if you want it. I replaced it with an aftermarket system. I had to repair the surround with silicone because the foam deteriorated. The speaker still works. You might be able to replace the speaker. I'll take 30 bucks for it. Let me know.

Mike Donley
 
blown95

Blown95.. I believe the stock interior speaker amp is 4channel, with a rated output of 35 watts per channel. The sub amp is rated at 70. As I recall however, the results of the test were more like 20 per channel for the interior speaker amp, and 35 watts for the sub amp.
 
you guys are lucky! i want one. is there a way i can hook up a stock sub woofer and amp to my sc? i don't see any wires or anything in my trunk and i never had premuim sound in my car. but i have a sony xplod cd player, rockford speakers in the rear and mtx speakers in the front. is it hard to hook up? thanks
 
Well, I could see if the one in my car is still working. I don't see a reason why it wouldn't work. And then I can put it up for sale if soemone is interested.
 
sub amp

you can actually run an aftermarket deck to push the factory sub setup. At work we did something similiar to a ford exploder with the premium system. just run the rca outputs from the new deck right into the connector for the input of the sub amp. requires a junker set of rca's for cuttin up to splice into, but works well. especially if you have a deck with sub control.

cheers.
 
Re: blown95

Digitalchaos said:
Blown95.. I believe the stock interior speaker amp is 4channel, with a rated output of 35 watts per channel. The sub amp is rated at 70. As I recall however, the results of the test were more like 20 per channel for the interior speaker amp, and 35 watts for the sub amp.

So, let's say you get an aftermarket headunit rated at 45W per channel. Are you better off bypassing the factory amp and running the aftermarket outputs straight to the speakers? Or would it sound nicer to use the aftermarket unit's pre-outs to the factory amp?

I like the Pearl95sc's idea of running the factory sub with the aftermarket deck. I'm going to have to give that a shot!

I can't afford to do it all at once so I'd like to start with my new deck, then upgrade the amp and sub later. But I'd rather invest in go-fast parts than sound-good parts :D
 
Ok, some facts for you.

First:

JBL system. Includes head unit (+ optional CD player), 4 channel high pass amplifier which powers 4-4" component speakers with passive crossovers and 1" silk dome tweeters in 6x8 enclosures, a mono amp connected to a 6.5" subwoofer in a sealed enclosure. Power ratings were not given for these amplifiers, but the system was originally advertised as a 200-240 watt system. Logic would tell you that could be divided up as 100/4 for the mids and 100 for sub, or 120/4 for mids and 120 for sub. Either way those had to be some sort of max rating as the system has in fact been tested and documented at 12.5 rms/channel for the mids and 35-45 rms for the sub amp. Certainly not worth bothering with unless you just happen to come across the stuff free or really cheap. Consider that the many newer head units with the Mosfet chip in them claim 22 rms/channel.

For those who wish to use parts of this system:

The entire low side of the system (inputs) are a voltage divided floating (internally bridged) mid/low level input. The system will accept any audio input, however the results will vary from downright lousy to pretty decent. If you send in an RCA level input, you will not achieve full volume as the voltage levels are just too low. If you run speaker level inputs from an aftermarket deck you will meet the floating inputs requirement, but you will not be meeting the carrying voltage requirements and will see a lot of noise and background hiss because of this. You will also be overdriving the inputs causing distortion, screwing up the crossover frequency and risking damage to the amps. There are a number of adapters made for the purpose of making the outputs of an aftermarket deck fully compatable with the system. The best of these by far is the Install Edge adapter from Rockford Fosgate. They run about $40.

So that is the complication with running an aftermarket head source. As for the speakers themselves, they are only 4", so I would not run a full range signal to them from an aftermarket radio. If you are using an aftermarket radio or amp without the JBL amps I would most certainly make sure you have a 125hx crossover on the main speakers. Either way you cut it you really need a sub to get decent sound from the JBL speakers.

Regarding the subwoofer, I don't know if Ford even offers a replacement anymore, but I do know that the Explorer has a 6.5" sub in it as well and they are about $65 from the dealer. Less if you have connections. I don't see why this wouldn't work. Some people have also modified the enclosure to accept an 8" aftermarket sub. Word is that this works really well.

I have also used the factory sub to power an aftermarket 10 and 12" sub mounted free air to the rear deck. This works pretty good also if you don't have the original enclosure or don't want to replace the blown stock speaker.

A regular premium sound amp will work in a JBL car if you have no sub anymore, but expect pretty poor sound for the reasons listed above.

As for adding JBL components to a non premium sound car, forget it, it's just not worth it unless you have a subwoofer already and just want to use the 6x8 enclosure speakers. Nothing else is useful to you.

If you do have premium sound already, all you really have to do is plug in the amps. You will need to run a 10ga power wire from the battery for the sub amp though. Remember though that the premium sound speakers are only paper dual cone 6x8's so the JBL speakers would be a big plus here.

That's about it. With the low cost of aftermarket stuff these days though, I wouldn't bother to mess with it unless you are going after a restoration type thing.

:)
 
The stock JBL system is more than sufficient for someone not going into a battle of car audio. But yes, without the sub it will sound terrible as the bass signals are not even sent to the other speakers.

The person I bought my car from took good care of it and did a good job upgrading the head unit to a Pioneer. The subwoofer had died on him so he replaced it with an 8" unit in a home made box using the stock JBL sub amp.

It's got more than sufficient boom to stay nice and clear, yet make it difficult to use the rear view mirror. So if you have a malfunctioning JBL system, it would be worth it to get it going if it isn't going to cost you more than a couple hundred.

But as others have said, if you don't have JBL, it' isn't worth it to try and get it. A properly designed aftermarket system should be able to walk all over the JBL. And just a good aftermarket system should match it.
 
I agree with XR7 Dave. My 90 had the basic system in it. I've already blown my budget on the car and a Viper alarm system so I needed cheap. Didn't look into free air subs though.

I picked up 4 5x7 Infinitys off eBay for $40 and a decent Kenwood CD player from a local electronics repair shop for $45. I'm mounting a 10" sub in a box and attaching it to the rear deck next to the tray. I've got a couple of amps laying around I'm going to try out. Won't be great but a lot better than the stock stuff.

I'm never 100% sure of used equipment, especially subs. Seems if anything gets abused it's them! Most electronics repair places warranty units they fix and people abandon so I'm not too worried there. Used equipment aside, new stuff is getting pretty cheap. Especially compared to a few years ago.
 
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Dave,
How did your 10" off the stock sub amp sound compared to the stock sub? I've got a boxed 10" running off of it, due to a blown sub when I got the car. It does sound okay, but you don't get much bass without positioning the box in the corner behind the tail light (read: in the way). Then, it sounds good, but looks low rent. I've been kicking around ditching that and replacing the stock sub in the factory box. Would I be disappointed in the sound change? Do you know what is needed to fit an 8" in that enclosure?
 
You have to cut out the opening in the stock box. Sawsall, jigsaw, something like that.

I prefered the free air in the rear deck over the factory enclosure. It's a little boomy compared to the 6.5, but much louder. I just made a thin plate out of particle board, sealed it to the rear deck, and mounted the sub directly to that. No cutting or crazy fabrication needed. I mounted the JBL amp to the bottom of the factory amp/computer rack. I didn't worry about the type of sub I used, since you are only putting 45 rms through it, you don't have to worry about overextending a sub. I used a JBL GT series 12". I had a Pioneer deck with EEQ so it was easy to tune out the bit of boominess it had. The reason it is a little boomy is that the factory amp is EQ'd to comensate for the little sub and also the crossover frequency is pretty low. (sounds to me like about 65 hz)

With low power levels like the JBL system is, you are fighting wave cancellation in the trunk. That is why it sounds lousy in a box back there. Mounted in the rear deck is MUCH better.
 
This ought to be "STICKY" somewhere!!

Wow, Dave that was FANTASTIC advice!!!

So how do these devices work that claim to interface your aftermarket stereo to your factory premium sound amps/speakers? I was referred to this device by someone else on this board for hooking my planned aftermarket head unit to my JBL amp, speakers, and sub:

The Pac Accessory OEM-1 System Bose Integration

Is this a worthy product or do you know of a better/cheaper alternative?

Thanks again for the loads of enlightenment!!
 
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