I have a Toronto 420Bt currently connect to the original 6 channel amp.

This setup is lacking in volume and clarity. So I have elected to install two amps under the passenger side front seat.

1) Rockford Fosgate PBR300X2 Punch 300-Watt 2-Channel Boosted Rail Amplifier to power the 6.5 inch speakers
2) Rockford Fosgate PBR300X4 Punch BRT 300-Watt Ultra Compact 4-Channel Amplifier for the other 4 channels.

Do I need to do anything with the current crossovers in the car?

 

I'm not sure exactly how the '89 stock configuration is, but are you putting the two door speakers on separate channels? On my '86 (and most stock door speaker configurations I've seen) the door speaker pair is wired as one channel, with a filter or crossover of some sort sending only treble to the tweeter. If you were intending to use a processor of some sort to run them in networked mode then you'd need to ensure you weren't sending bass to the tweeter.

Also, on some cars the rear speakers are 2 ohm speakers, so you would need to make sure that RF amp can handle that (maybe it can, I don't know).

 

Thanks, what I was thinking is leaving the doors (as you noted with the current crossover) and using the four channel amp to power the doors and the rest of the rear speaker (mid and tweeters). I would then use the 2 channel amp (2@150watts at 2ohms) to power the two 6.5 inch drivers.

I just don't know how to treat the rear setup and crossover...

 

The fosgate amps all run at 2 ohms so you should be fine. Just make sure they have proper ventilation as they can get really hot from not having air moving over them.

I mounted a RF prime 400 4 channel amp to the fuse panel cover. It has a footwell vent blowing on it so it barely gets warm. Without adequate airflow amplifiers can get pretty hot.

Also, you should run new wire to the speakers as that will give you better clarity and allow you to run full power to the speakers from the amp. I would not trust the thin stock wire to handle over triple the power it had stock.

 

It looks like the PBR300X4 is an exception:

 

Haven't seen that one before. Thanks for the clarification on that.

 

Hey Ken, have you adjusted the EQ yet? I was able to tune mine very well powering the stock speakers, no external amp. But I do have an amp and 8" sub in the back.

Along with the various frequencies you can adjust in the EQ, you can also adjust gain Independanty on each frequency.

Out of the box mine sounded like crap.

I can wright my settings down for you if you would like to try them.

 

Hi Adam, I'd love to know, tx.

 

I just upgrated my 1989 S4 stereo 2 weeks ago and I am very happy with the end result. I still need to fine tune the system - I just downloaded Black Cat spectrum analyzer on my Ipad andd hook up the rear view camera. I used Clarion NZ503 as a head unit, Focal Integration 100 VRS 2 way component speakers in the doors, Focal 165A3 3 way component speakers in the back, Focal Solid 4 channel amp in the spare tire and Lanzar VCTBS10 subwoofar on the hatch floor. I still need to hook up the rear view camera. I managed to reuse all OEM speaker grilles after doing some creative fabrication, so all speakers look stock. Overall the system sounds amazing just after initial rough adjustements. If I had to do it again I would probably use Alpine speakers and VM Audio EXA1300 amp to cut the cost. The main challenge for door and rear top speakers is limited mounting depth available. As far as wiring, I run the signal and remote cables under the carpet along the center tunnell from the HU to the amp and power sub. I run the speaker wires directly from the amp to the rear speakers and from the amp to the pass. door sill cover where the factory amp used to be and hooked up to the factory door wires. Oh, don't forget to ground the wire from the alarm module at the HU, otherwise you will activate it. Will try to take some pics later.

 

I've already replaced the 4 inch speakers in the doors and rear hatch area with 4 Blaupunkt CL 100's. I've left the tweeters as is and re-foamed the two 6.5 bass speakers. But if I remember correctly, the tweeters and Mids in the rear hatch area are linked with the 6.5 inch base speakers with a crossover.

So my concern is do I just remove (what appears to be a crossover) from the 6.5 inch speakers and just go direct from speakers to the amps...

 

I will get you my settings this weekend. FYI I bypassed my factory amp.

 

"So my concern is do I just remove (what appears to be a crossover) from the 6.5 inch speakers and just go direct from speakers to the amps... "

Yes, I would replace the factory crossovers with something like Audiopipe 2 way crossover CRX-203 for the doors and 3 way crossover CRX-303 in the back. 2 pack deal $21.95 and $29.95 on Amazon.
Just make sure that all old crossover components are removed - some speakers have an "integrated" crossover in form of capacitor glued to the speaker. At the end you should have 4 channels - 2 front in the doors and 2 in the back.

 

The crossover mounted on the rear 6.5" speakers is not electrically connected to the 6.5" woofer. The crossover is for the 89-95 rear 4" and tweeters.

The 6.5" woofers used a low-pass filter built directly into the stock 6-channel amplifier - from memory something like 150Hz, but some digging here will probably turn up the correct value.

 

Thanks Hilton for the clarification. I knew the amp had separate channels for the 6.5 inch speakers...but that makes more sense (not electrically connected). Its been a while since I re-foamed those speakers, so I will have to pull them and have another look. That takes me back to my question, why not keep those crossovers as is...or would there be any real reason to replace them?

 

If you're using the stock rear mids/tweeters, then keeping the crossover as-is makes sense.

On a backburner currently, but I bought a calibrated mic and intend to measure the individual stock (refoamed) drivers, as well as performance with the stock crossovers, and see if any improvements can be made just by designing a custom crossover.

For now, unless you're changing the speakers for other ones, using the stuff the factory designed to work together is the path of least resistance.