Author Topic: 78 single rear speaker - dealer install for dual speakers  (Read 206 times)

0 Members and 1 Guest are viewing this topic.

Offline ntgarwood

  • Jr. Member
  • *
  • Posts: 5
  • Referrals: 0
78 single rear speaker - dealer install for dual speakers
« on: July 28, 2020, 06:20:07 PM »
Hi all, does anyone have a picture of what it looked like when the dealers would sometimes install a 2nd rear deck speaker in the 78's? I'm curious what the jumper and wiring looked like (did they use the blue/blue or the yellow/brown? How did they jumper it?).

I'm reversing pretty much the only non-original piece of my 78 Y88 which had an aftermarket stereo and rear speakers installed soon after it was purchased by the original owner (my mother in law).  Car only has 32k miles, all original documentation (build sheet, window sticker, temp tag, plate, every receipt for every tank of gas, etc.).

I reinstalled the original delco radio without having to join the cut wires, just reinstalled them in the connectors.  I had the original rear deck grille in perfect shape and put it back in with some older delco 6x9 10 ohm speakers I could get my hands on (although I know they aren't the correct ones for my year, they worked for now with the radio. Just need the fiber box to go over the driver side rear speaker.

Since the deck cover was already cut for a 2nd rear speaker, I'm going to make it look as close to a dealer installed 2nd speaker as possible. I figured that was the best way to retain as much originality as possible. So put an original grille in and make the jumper look as if it did from the dealer.

Please let me know if any of you can help! Thanks!

Offline Jefe

  • Jr. Member
  • *
  • Posts: 26
  • Referrals: 0
Re: 78 single rear speaker - dealer install for dual speakers
« Reply #1 on: July 29, 2020, 05:05:30 PM »
From what I see in the shop manual, the monaural speaker would have been the right side. It should have dark blue and light blue wires. The left speaker would have had brown and yellow (coming from the deck). Buick simply jumped the left speaker from the right one. Tried to attach a photo. Not sure if it will work or not.
Jeff-
Current project
1979 Firebird Formula / in the family since new
Previous projects
68 Chevelle
72 GTO
78 DKM Trans Am #127

Offline ntgarwood

  • Jr. Member
  • *
  • Posts: 5
  • Referrals: 0
Re: 78 single rear speaker - dealer install for dual speakers
« Reply #2 on: July 31, 2020, 06:29:00 AM »
Thanks! Although mine is stereo, not mono, the single front and single rear (driver's side) took the 2 stereo channels from what I read.  The dealers would sometimes install the passenger side rear speaker from a jumper.  Your diagram leads me to believe  they used the same dark/light blue wires to jump it.  I wish I could see if they used a connector though to do this or just spliced them so that I do it correctly.

Offline Aus78Formula

  • Adv. Member
  • ****
  • Posts: 2399
  • Referrals: 0
Re: 78 single rear speaker - dealer install for dual speakers
« Reply #3 on: July 31, 2020, 08:18:24 AM »
Stereo being front and rear speakers, many prior had dash only speaker so having 2 was big time serious tunes. The install would differ from place to place and probably wouldn't look any different to if you did it now using period correct parts. The most important is to use the stock grille on top.
The stock radios were stamped with wiring arrangement for plugs so you could add options not on your car to get true stereo over 4 speakers, 3 was still more typical. Not all radios had the terminals in place, or the plugs could even have some missing when not required.
« Last Edit: July 31, 2020, 08:23:48 AM by Aus78Formula »

Offline Jefe

  • Jr. Member
  • *
  • Posts: 26
  • Referrals: 0
Re: 78 single rear speaker - dealer install for dual speakers
« Reply #4 on: July 31, 2020, 09:31:04 AM »
interesting. Of course, the diagram sent was only of the rear speaker wiring. I've always understood "stereo" to be separate right and left channels and not simply front and rear.  I guess even an old guy can learn new stuff from time to time! :)
Jeff-
Current project
1979 Firebird Formula / in the family since new
Previous projects
68 Chevelle
72 GTO
78 DKM Trans Am #127

Offline Aus78Formula

  • Adv. Member
  • ****
  • Posts: 2399
  • Referrals: 0
Re: 78 single rear speaker - dealer install for dual speakers
« Reply #5 on: July 31, 2020, 09:34:54 AM »
The original stereo option was just as you said, front and rear, rather than an extra rear. That was an accessory option, and popular to add to those that had only one or no rear speakers at all.

Offline Jefe

  • Jr. Member
  • *
  • Posts: 26
  • Referrals: 0
Re: 78 single rear speaker - dealer install for dual speakers
« Reply #6 on: July 31, 2020, 04:24:32 PM »
Yep. I get that part. Just never heard 1 in front and 1 in rear called "stereo". Like I said... even an old man can learn something new sometimes. :-)
Jeff-
Current project
1979 Firebird Formula / in the family since new
Previous projects
68 Chevelle
72 GTO
78 DKM Trans Am #127

Offline ntgarwood

  • Jr. Member
  • *
  • Posts: 5
  • Referrals: 0
Re: 78 single rear speaker - dealer install for dual speakers
« Reply #7 on: August 01, 2020, 11:21:12 AM »
Thanks guys! My 2 big questions for this...
1. I'm trying to make this look as correct as possible since the rear deck cover had the hole cut for a second speaker. I'm using the proper grilles, but if the dealer would've installed the second rear speaker was it just spliced or did GM instruct them to use a clip to split it? I'm assuming the dark blue/light blue wires would've been used.
2. Has anyone seen if the speaker fiber box cover would have been installed on the second speaker?

All in all, these details probably don't matter, and it'll look proper to 99% of people, but it's nice to have some knowledge. Appreciate the responses!

Offline Aus78Formula

  • Adv. Member
  • ****
  • Posts: 2399
  • Referrals: 0
Re: 78 single rear speaker - dealer install for dual speakers
« Reply #8 on: August 01, 2020, 08:01:29 PM »
Check that the box even fits with the jack in place.

Offline Jefe

  • Jr. Member
  • *
  • Posts: 26
  • Referrals: 0
Re: 78 single rear speaker - dealer install for dual speakers
« Reply #9 on: August 02, 2020, 07:59:49 PM »
I'm kind of a symmetry nut. If one speaker has the enclosure, in my car, the other would as well. Not to mention, a  6x9 speaker, running off of the stock head unit, with no other amplification, would sound really tin canny without an enclosure. My car is being restored to be a weekend road trip ride. We are keeping a LOT of it as factory as possible while also looking to improve on some things. When it is viewed by others, it will "look" to be completely stock. But underneath the "skin" of everything, there are many many tweaks. Including an awesome sound system and a 400+ HP 403. Mind you... mine is not a Trans Am. Its a Formula, that was ordered new by my step Dad. He drove the wheels off the thing in it's first 12 years of life. After that, it was parked, outside, until January of 2019, when we began the process of breathing life back into it.
Sounds like yours is a much less involved project.
Jeff-
Current project
1979 Firebird Formula / in the family since new
Previous projects
68 Chevelle
72 GTO
78 DKM Trans Am #127

Offline ntgarwood

  • Jr. Member
  • *
  • Posts: 5
  • Referrals: 0
Re: 78 single rear speaker - dealer install for dual speakers
« Reply #10 on: August 03, 2020, 06:44:34 AM »
That's awesome you're bringing it back to life! I agree,  I'm a little OCD about stuff too but I was trying to make it as 100% as factory as possible since the stereo was the only thing that was touched. If the hole hadn't been cut for the second speaker I wouldn't have to worry about it. However, a lot of them were added by the dealers so I'm trying to match to that.

As for a really good sound system, here's what I came up with:. I can have the original sound (original front speaker and head unit, newer Delco speakers in rear) if I want.  Bluetooth speakers have came a LONG way and JBL makes some that can be paired together. I plan to put one under each seat and have them paired together to have full stereo and stream from my phone with no cutting, no wires, and removable.  Even better... I have the camel colored carpet and they make a gold/mustard color speaker that matches perfectly!