Over loading?

Understood.

Some math and other things:
a) If the specification for your amplifier does not clearly state the AC peak current, take rated max. audio output power per channel, multiply by 3 (efficiency of Class A amplifier is ~30% - the worst case), and divide by 110V and you have your max. AC current.   Regrettably, most of audio gear is spectacularly short of specifications. For someone from the industrial world this drives me crazy, and each such gear gives me an impression of "touchy feely" design approach and "we have no idea what we are doing, and neither do our customers" message.  Will never fly for the factories.
b) You can approximate the length of the wire between the distribution panel and your outlet. Double this (for return current - don't forger that the power company gives you current, charges for it, and then takes all the current back - great business model) and use one of countless online voltage drop calculators such as https://www.prioritywire.com/calculator_voltage_drop.php Some calculators already take into account return current path, so don't double in this case
c) Don't neglect wire connections in all the hidden boxes in your house - twist-caps and all. Every such connection is a subject to eventual oxidation and adding resistance (and heating up along the way). I would add at least 1 Ohm for that just in case.
The most problematic voltage drop is dynamic, i.e. in response to current drain to drive your subwoofer ad perhaps mid-range (tweeters don't take much power comparatively speaking). Such dynamic voltage drop would add intermodulation distortion which adds sideband frequencies to what you though was double bass sound. To deal with this you would need sufficient "inertia" at the end of the long wires.   Tooting my own horn, our CleanSweep AC filters (https://www.onfilter.com/ac-emi-filters-af-series) provide just that.

danmar123 OP54 posts

08-16-2021
9:22am

I (personally) ran 8/3 from my main, on a 60 amp breaker

@danmar123

#8 awg cu wire is rated for 40 amps (60* C). Breaker should be 2 pole 40 amp.

This is why I’m asking; I don’t want to harm my amps.

No harm. No VD on subpanel feeder or branch circuit wiring.
I assume the two amplifiers are fed from each Line, leg, to neutral.
Only the unbalanced load returns on the feeder neutral conductor to the source.

Subpanel EGC (Equipment Grounding Conductor) shall be part of the feeder wiring connected to the equipment ground bar in the main electrical panel. Feeder EGC connected to a separate ground bar bolted, bonded, to the metal enclosure of the subpanel.

Neutral bar in subpanel left insulated from the metal panel enclosure.
(Green color main bonding jumper screw not installed)
.

I stand corrected, the wire is #-6/3 into a 2 pole 60 breaker. Thanks for clearing that up.


jea48;
" I assume the two amplifiers are fed from each Line, leg, to neutral.
Only the unbalanced load returns on the feeder neutral conductor to the source.

Subpanel EGC (Equipment Grounding Conductor) shall be part of the feeder wiring connected to the equipment ground bar in the main electrical panel. Feeder EGC connected to a separate ground bar bolted, bonded, to the metal enclosure of the subpanel.

Neutral bar in subpanel left insulated from the metal panel enclosure.
(Green color main bonding jumper screw not installed)"
I don't remember, I'll look in the morning.