1990 Riviera speakers

[RivNut]

The speakers in my '90 Riviera are starting to get fuzzy.  Some time ago, I found a set of six speakers to replace the ones I have. 

 

I have two 6"x9"', Delco Electronics Part# 16070930 in the rear deck - made in the USA

Two 5.25" Delco Electronics Part #16062214 in the doors, - made in Japan, and

Two tweeters for the doors.  The tweeters are sealed in a plastic cage and I cannot read the number nor do I know where they were made or what size they are.

 

The two 6x9'  speakers are rated at 10 ohms

The two 4.24" are rated at 4 ohms.

I cannot tell anything about the 2' tweeters.

 

From what I've read, I should not be running 4 ohm speakers when the radio is rated at 10 ohms.  A 4 ohm speaker will draw twice the current of an 8 ohm and cause the amplifier transistor  to run very hot and cook the head unit.( Copied and pasted from Electro Techs website.) 

This is referring to "transistor radios."  

Does this not apply to the factory radio in the 1990 Riviera - is it not considered a transistor radio?

Why wouldn't all speakers have be rated the same from the factory?

I don't want to swap speakers just to blow up the head unit.

 

Anyone have any ideas?  

Edited March 10, 2020 by RivNut (see edit history)

[SpecialEducation]

Well, when people talk about “transistor” radios, it’s usually a contrast to tube sets. 
 

Pretty sure your ‘90 Riv doesn’t have tubes, as my ‘90 Reatta doesn’t either... lol

 

Yes, dropping the ohms too low equals higher power consumption and possible heat issues in the power amp transistors. 
 

That said, if the front speakers are wired in series, simply add the impedance of the two. In other words, if the 4” and the tweets are both 4 ohm and in series, the circuit would be 8 ohms. That would not be a significant difference in operation. 
 

Now, I don’t KNOW that it’s wired that way, but it’s my best guess with given data. I need to replace speakers in the Reatta too, so I’ll try to look it up tonight to be sure. 

[J3Studio]

Do you have the standard radio or the Bose?

[RivNut]

No to the Bose.  Just Delco speakers as I mentioned and a Delco AM/FM with cassette and 5 band equalizer. I got a RediRad for my birthday and before installing it, I'm going through the rest of the system.

[RivNut]

6 hours ago, SpecialEducation said:

Well, when people talk about “transistor” radios, it’s usually a contrast to tube sets. 
 

Pretty sure your ‘90 Riv doesn’t have tubes, as my ‘90 Reatta doesn’t either... lol

 

Yes, dropping the ohms too low equals higher power consumption and possible heat issues in the power amp transistors. 
 

That said, if the front speakers are wired in series, simply add the impedance of the two. In other words, if the 4” and the tweets are both 4 ohm and in series, the circuit would be 8 ohms. That would not be a significant difference in operation. 
 

Now, I don’t KNOW that it’s wired that way, but it’s my best guess with given data. I need to replace speakers in the Reatta too, so I’ll try to look it up tonight to be sure. 

After reading your post, I Googled '1990 Buick Riviera radio wiring diagram' and found something listing the color codes for the speaker wires.  Strange that only LF and RF, and LR and RR were listed.  I pulled the speakers I got some time ago from the box.  I found that the midrange and tweeter for each side share the same color wires, the pair are being treated as one.  Based on this new info, I'm thinking that you are correct and the midrange and the tweeter in each door are wired in series.  I'm ready to move forward. Thanks. 

 

Ed

[SpecialEducation]

My Riv/Reatta book wasn’t where I expected it to be so I couldn’t check the schematic last night, but if you’ve got the speakers out, you could do a quick continuity check. One of the wires between the front speakers should be zero ohms (or pretty close). That would solve the mystery pretty quick. 

[SpecialEducation]

Ok, here we go:  4 ohms per speaker is correct for the non-Bose door speakers. 
 

I couldn’t find a wire diagram to see how it’s actually wired, but the troubleshooting trees give us some clues. Apparently the Bose system still uses 10 ohm speakers all around.