Bose Rear Speaker Compatibility/Differences

[92qatlanta]

I have a 1992 Q45 with the original Bose rear speakers. The d/s rear began generating a high pitched squeal.

I obtained a matching pair from another similar year Q45. There are some minor differences and I would appreciate if anyone could provide some additional technical background.

1992 Q45 original speakers: - Bose Sigma 797- P/N: 28138-64U15- Connector: Blue

199x Q45 speakers: - Bose Sigma 759- P/N: 28138-60U10- Connector: White

The blue and white connectors are similar but not interchangeable. The wire colors are different.

Actions:- I changed the connector, installed one of them and it sounds fine.

Questions: - What is the technical difference between the two part number revision numbers (64U15 vs. 60U10)?

- Should they be replaced in pairs or can just one be replaced?

Thank you in advance for your assistance.

JTD

[elwesso]

The speakers you listed are from the 90 Q45 bose. The 90 bose was different than the 91-95.....

[Q45tech]

The 90 head has a lower output level vs the later heads thus the 90 amplifiers have more gain than the 91-96. Each amplifier has individual equalization depending on front or rear use [speaker frequency response and diameter [area] differences in sensivity [acoustic output] per watt.

[Q451990]

Hold on to your 92 Amps... I believe they are covered in a recall - so you should be able to have them replaced at no charge.

Heath

[92qatlanta]

Thanks to all for their timely and valuable information.

Based on your input, I have come to the following conclusions regarding my 1992 Q45:

- Although I have clear sound with the one rear 1990 speaker installed, the difference in amplification between the 90 and the 91-95 Bose speakers would suggest at a minimum both rears be matched and then adjusted with the fader or not used at all and replaced only with a correct amplification 91-95 Bose speaker.

- After reviewing the recall information, my VIN does fall within the applicable units. I am the second owner and do not know if the rear speaker amplifiers had been replaced. I will assume a recall has no expiration date. I will contact the dealer, inquire if there is any recall repair history for my vehicle, and if not, schedule the repair.

Assuming it goes to the dealer.

Question: Since I already have the rear seat our and speakers exposed from above, would you suggest I leave it apart so they can repair it from above by removing the speakers or should I reassemble everything and let them go in from the trunk. Which would be perceived better to the dealer, or doesn't it really matter?

Thank you.

JTD

[Jesda]

Unless you know your service writer, I'd put it back together and let them take it apart again, so they retain liability for broken clips and such.