I'm curious to know if anyone knows what the specs on the factory 79 AM/FM radio are. I just want to know how many peak watts per channel it puts out. Is it capable of powering 4 modern day 2 way 4 inch speakers? (or whatever the factory size is). I'd like to keep the looks of the factory radio and not cut up the dash to install a CD player. I think it would look goofy to have both a CD player and the factory radio in the car...

I just want a basic 30-40 watt 2 way bolt on speaker to replace the old speakers. They sound ok, but they are way too flat sounding.

Also does it make enough power to split the signal from the fronts and run wiring for speakers to the rear cargo area? I thought there were already speakers back there hence the speaker grilles, but when I peaked behind the panels it was empty! We've all been had!

 

I think its all of 4-6 watts, typical for the Day. I popped some nice Polks into the front cavities on my 80 SA and they sound much better even with this wattage. No worries adding speakers. Try it first then go for an in-line amp if you want more punch later.

The rear speakers, when fitted, used an upgraded OEM radio with a small (10-15wt) in-line amp fitted in to the system. Again you can power both sets of speakers off the existing radio, try it and see...

I'm with you - didn't want to chop up the dash w/an aftermarket system. I just use my iPod/transmitter combo for tunes - no cuts, no clutter.

Stu Aull
80GS
Alaska

 

Just watch your total impedance per channel, and you'll be fine.

Speakers wired in series add their impedance (Rt = R1 + R2 + R3...)

Speakers wired in parallel , take the reciprocal of the sum of reciprocals (1/Rt = 1/R1 + 1/R2 + 1/R3...)

Shortcut: two equal-impedance speakers in parallel cuts total impedance in half.

So, if you parallel-wire two 8-ohm speakers, you get 4 ohms impedance. If you series-wire two 4-ohm speakers, you get 8 ohms.

If you let your impedance get too low, you'll blow the amplifier transistors. Too high, and you'll lose loudness.

 

I've built home theater systems before so I'm not worried about the wiring and all. I was just curious on the power capabilities of the factory radio. I saw that the speakers are 5 watts when I popped them out. I just couldn't find any specs on the factory radio wattage / channel. Not in the FSM.

What is the frequency response of the factory speakers? All the part store replacements were 100hz-15k with 88db sensitivity... youch that sucks! I'm used to building home theater setups with 12hz-22k response and 94db.

 

Considering the "state of the art" of car stereos in the 79-80 time frame, I doubt you'd find a factory spec on audio power. The fact that it was "AM/FM Stereo" would have been about as far as they'd take it on a factory system.

You can be sure from the speaker ratings that the total power per channel would be less than 5 watts, though.

We ( I was finishing high school at the time) were still often using 8-track players at that point. Not the most high-fidelity of units. Auto-reversing casettes in cars were still rarities. Dolby noise reduction was only out a couple years. Jensen was still considered a top-quality brand of speaker.