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Old 02-24-2021, 06:44 AM   #1
cuda
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Default Volvo factory stereo wiring (4 vs 8 ohm impedance)

I want to upgrade the speakers on my 97' 940. I would like to keep the original Volvo head unit (i like the period correct look) and add an amplifier but i'm a bit confused on how the factory wiring is set up.
The original HU is 4 ohm (CR-916) but all the speakers in the doors seem to be 8 ohm. As i understand it is possible to run a 4 ohm amp with 8 ohm speakers without anything blowing up but in this configuration the speakers would be running on 1/2 of the nominal power? Why was Volvo running 8 ohm speakers on a 4 amp HU? Am i missing something here?
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Old 02-24-2021, 08:12 PM   #2
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I want to upgrade the speakers on my 97' 940. I would like to keep the original Volvo head unit (i like the period correct look) and add an amplifier but i'm a bit confused on how the factory wiring is set up.
The original HU is 4 ohm (CR-916) but all the speakers in the doors seem to be 8 ohm. As i understand it is possible to run a 4 ohm amp with 8 ohm speakers without anything blowing up but in this configuration the speakers would be running on 1/2 of the nominal power? Why was Volvo running 8 ohm speakers on a 4 amp HU? Am i missing something here?
I have seen 1992 960 sedan with 8 ohm speakers in the rear doors and rear package tray. These were wired to create a 4 ohm load. The front door speakers may have also been 8 ohm wired with 8 ohm dash speakers depending on the head unit installed.
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Old 02-25-2021, 08:13 AM   #3
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I have seen 1992 960 sedan with 8 ohm speakers in the rear doors and rear package tray. These were wired to create a 4 ohm load. The front door speakers may have also been 8 ohm wired with 8 ohm dash speakers depending on the head unit installed.
this makes sense, yes, if you connect 8 speakers in parallel to 4 channels. but i have a wagon with only 4 speakers in the doors and a 4 channel HU.
were volvo just lazy to create a different setup for lesser spec models with 4 speakers and just ran 8 ohm speakers directly from 4 ohm head unit at 1/2 power?
i mean 15 or 20 watts RMS per channel wasn't something to brag about even in 97 and i assumed they would use matching speakers to take the maximum out of the factory sound system
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Old 02-25-2021, 03:13 PM   #4
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Don't forget about the tweeters in the dash. Are they wired in parallel to the door speakers?
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Old 02-25-2021, 05:24 PM   #5
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Don't forget about the tweeters in the dash. Are they wired in parallel to the door speakers?
Don't have the dash speakers
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Old 02-25-2021, 08:11 PM   #6
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Originally Posted by cuda View Post
this makes sense, yes, if you connect 8 speakers in parallel to 4 channels. but i have a wagon with only 4 speakers in the doors and a 4 channel HU.
were volvo just lazy to create a different setup for lesser spec models with 4 speakers and just ran 8 ohm speakers directly from 4 ohm head unit at 1/2 power?
i mean 15 or 20 watts RMS per channel wasn't something to brag about even in 97 and i assumed they would use matching speakers to take the maximum out of the factory sound system
They probably did. I have never seen any 4 ohm Volvo factory speakers.
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Old 02-25-2021, 11:37 PM   #7
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Usually aftermarket head units and amps are not safe to push 8 ohm speakers. You might be safest running the speakers in parallel (RR, LR & LF, RF).
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