Can you fit a HU650 into a car with an HU-850?

Post by **scot850** » 28 Apr 2026, 23:19

My buddy has a 2007 V70 T5 with a failed HU-850 head unit. Money is not plentiful so looking at options.

I have a spare HU-650 unit. Can it be connected to the HU-850 amp and wiring without any modes being needed? I know in the P80 you can fit any head unit to any car, but to use the under seat or behind dash amplifier you need an additional harness unless your car had a SC-900/901 head unit which came with the amp and cable as they did not have an internal amp just like the HU-850.

Thanks,

Neil.

Post by **DavidE7** » 03 May 2026, 22:48

Yes - You will loose the center channel. Everything else will work. Plug an play!

Post by **scot850** » 04 May 2026, 13:56

Thank you very much. Why do you loose the center speaker as my 06 has one on HU-650 (well it did before I swapped it out for a bluetooth unit). I am assuming it still works but maybe I need to check it!

Neil.

Post by **DavidE7** » 05 May 2026, 18:38

The HU-650 doesn't have the output or amplifier for the center speaker. Only the HU-850 (2005+) and the HU803 (2001 to 2004) have this extra function along with the 3-channel stereo and Dolby surround.

Post by **scot850** » 05 May 2026, 23:11

Ah, just like the P80 units. The SC-9XX units only have the Dolby center speaker output.

Thanks again. But can the HU-650 use the 850 amp? (no center speaker I know).

Neil.

EngineeringBloke · Post by **EngineeringBloke** » 01 Jun 2026, 11:33

The lead to the speakers has a plug near the head unit.
It can be plugged into the head unit for low power or into the lead coming from the under seat amp for more power.

If using the under seat amp, the round DIN plug must be plugged into the head unit line level output to feed the amp.

So 650 and 850 should both work.

I switched from 650, no amp, to pioneer HU and amp in trunk.

Post by **DavidE7** » 01 Jun 2026, 21:45

scot850 wrote: 05 May 2026, 23:11 But can the HU-650 use the 850 amp? (no center speaker I know).

I just saw your question...

Yes, HU-650 (2005-2007) and HU-613 (2001-2004) regular audio systems can be connected to the premium amplifier. This is how I ran a couple cars until the upgraded head unit was located at a junkyard. All the Volvo P2 head units have the amplifier output. The biggest audio upgrade for the P2 Volvos is to switch from the regular speakers to the premium yellow/gold label speakers. The front door panels have to be replaced to fit the bigger premium speakers.

I am still looking for a reasonably priced HU-803 and amp to put into the 2004 XC70. I installed the center speaker yesterday night and I hope to get the front door speakers installed very soon. My fleet is currently 50/50 with premium/regular Volvo audio systems.

Post by **DavidE7** » 01 Jun 2026, 21:46

scot850 wrote: 05 May 2026, 23:11 But can the HU-650 use the 850 amp? (no center speaker I know).

I just saw your question...

Yes, HU-650 (2005-2007) and HU-613 (2001-2004) regular audio systems can be connected to the premium amplifier. This is how I ran a couple cars until the upgraded head unit was located at a junkyard. All the Volvo P2 head units have the amplifier output. The biggest audio upgrade for the P2 Volvos is to switch from the regular speakers to the premium yellow/gold label speakers. The front door panels have to be replaced to fit the bigger premium speakers.

I am still looking for a reasonably priced HU-803 and amp to put into the 2004 XC70. I installed the center speaker yesterday night and I hope to get the front door speakers installed very soon. My fleet is currently 50/50 with premium/regular Volvo audio systems.

Post by **scot850** » 02 Jun 2026, 08:58

I have no way to test the HU-803 I have. It unfortunately has a scratch on the screen which I might look at swapping from one of the dead units when I get them. I am waiting for the owner of the 02 XC70 to return from a trip in a few weeks to confirm what he has fitted to his car that needs replaced. Otherwise the unit is of no use to me it was just a curiosity for me to try to figure out what fits what years. Looks like 01-04 have the different bezel and the connect differently to the 05-09 P2's. But does than mean if you swapped them as a whole would they not work with their respective heater controls. You then have the complexity of the iQ? air versions of the system. Also would the heater controls need reprogramming? It is all too hard.

I'll let you know when we figure out what unit he needs for his car and see if you would like the HU-803. Sorry no amplifier.

Neil.

Post by **vtl** » 02 Jun 2026, 09:01

DavidE7 wrote: 01 Jun 2026, 21:45 Yes, HU-650 (2005-2007) and HU-613 (2001-2004) regular audio systems can be connected to the premium amplifier. This is how I ran a couple cars until the upgraded head unit was located at a junkyard. All the Volvo P2 head units have the amplifier output. The biggest audio upgrade for the P2 Volvos is to switch from the regular speakers to the premium yellow/gold label speakers. The front door panels have to be replaced to fit the bigger premium speakers.

I am still looking for a reasonably priced HU-803 and amp to put into the 2004 XC70. I installed the center speaker yesterday night and I hope to get the front door speakers installed very soon. My fleet is currently 50/50 with premium/regular Volvo audio systems.

Can get away with regular door panels and premium non-Volvo speakers, like Focal (ISS/ICU 165 in my case). For central speaker I had mutilated a cheap TPA3116-based amp in mono-mode (100W instead of 50+50), which mixes the front left and right signals to mono input for the amp. The amp also has a noise suppressors for power and signal, to shield it from alternator.

Paired with Kenwood DDX it rivals Harman Kardon in P3 easily (which is easy, because HK is no good).