Will mismatched impedance loads ruin my head unit?

[BigMike5G]

I recently upgraded my Toyota Camry from the boring base factory system to a Sony XAV AX5000 head unit, Focal IS 690 components for the front and JBL 9631F 6x9's in the rear. The Focal component set has a 4ohm load, while the JBLs in the rear have a 3ohm load. The JBL's claim to use a 3ohm load to pull more power from the head unit to make up for shotty factory wiring. My question is, will having two different impedance loads hooked up to my head unit damage it in the long run? I know the AX7000 and AX8000 have beefier amps built in which can support 2 ohm loads but I see nothing about that with the AX5000. Thanks in advance for any insight.

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[Popwarhomie 5,000+ posts]

No.

 

[Squirrel!]

In your case, no. Running loads the HU can't drive, like 1ohm, is what cooks the outputs.Have you measured the 3ohm? Probably closer th 4 than 3 at the end of the day.

 

[Lasherž]

I recently upgraded my Toyota Camry from the boring base factory system to a Sony XAV AX5000 head unit, Focal IS 690 components for the front and JBL 9631F 6x9's in the rear. The Focal component set has a 4ohm load, while the JBLs in the rear have a 3ohm load. The JBL's claim to use a 3ohm load to pull more power from the head unit to make up for shotty factory wiring. My question is, will having two different impedance loads hooked up to my head unit damage it in the long run? I know the AX7000 and AX8000 have beefier amps built in which can support 2 ohm loads but I see nothing about that with the AX5000. Thanks in advance for any insight.

According to your manual:

https://www.sony.com/electronics/support/res/manuals/4732/455f40ecf39615259f1d8a12231c8e8f/47320621M.pdf

I wouldn't personally recommend your current solution. Granted, it's only going to be a problem at higher volumes, but your HU is only rated for 4 max. It's also 20W rms, so the odds of you hitting a clipping point are rather high in my opinion. I think reading extra quality from Sony gear that's not specifically listed in the manual is a bad idea. This head unit is very good still, I think a small 4 or 5 channel amp would take it to the next level though as most people who own it would be utilizing the RCAs. You're powering 75W RMS speakers with an under-powered HU. Just like subwoofers and mono amps, it's generally best to have matching RMS values or with the amplifier (head unit in this case) slightly higher. Something for the future maybe, but as it is I'd say be cognizant of the sound of a clipping speaker and turn it down quickly if you ever encounter it, it'll likely last just fine if you avoid running it clipped for extended periods.

When measuring speakers, the resistance reading given by a multimeter will be about 2/3 to 3/4 of the true impedance of the speaker. I would expect a reading of ~ 2.3 Ohms between the terminals for a normal/working 3 ohm speaker and ~2.8 Ohms for a 4 ohm speaker.

 

[Louisiana_CRX 5,000+ posts]

I recently upgraded my Toyota Camry from the boring base factory system to a Sony XAV AX5000 head unit, Focal IS 690 components for the front and JBL 9631F 6x9's in the rear. The Focal component set has a 4ohm load, while the JBLs in the rear have a 3ohm load. The JBL's claim to use a 3ohm load to pull more power from the head unit to make up for shotty factory wiring. My question is, will having two different impedance loads hooked up to my head unit damage it in the long run? I know the AX7000 and AX8000 have beefier amps built in which can support 2 ohm loads but I see nothing about that with the AX5000. Thanks in advance for any insight.

It wont hurt a thing