Using computer PSU to power amplifier

[jonnymorgan.jm]

I’ve done my research and found out how to wire a computer PSU for my car amplifier but I can not seem to find the dangers of running my amplifier with less wattage than it states.
I’m using a 1000 watt amplifier (according to the label) and a 450 watt subwoofer and will be using a 300 watt PSU.
I’m not intending to get the sound I get in my car as this will be in my room but what are the dangers of doing this?

 

[Darkbreeze]

what are the dangers of doing this?

Fire. Factory smoke. Melted plastic smells. Ruined hardware and amp. Need I go on?

 

[maestro0428]

It can be done. I wired a Corsair 750w to an Orion High Current car amp. https://www.youtube.com/watch?v=ujYRF_2-bJ0

 

[Darkbreeze]

I'm sure it CAN be done, but I would sure as hell not recommend trying to power a 1000w amp with a 300w power supply. If you want to power a 1000w amp, it would be very advisable to have AT LEAST a 1200w power supply, and since we know that subs can sometimes overdraw the amp, having a decent CAP in the mix might not be a bad idea either to handle peaks. Regardless though, there are probably better ways to do this than with a PC power supply. There are other types of power supplies much more suited to converting AC power to DC for audio equipment or other purposes.

OFTEN, just because something CAN be done, doesn't mean it SHOULD be done.

 

[doolittle]

it is possible, you have to look at your amp's detailed specs and what load you are going to drive, then for the power compensate for about 50% efficiency and then should be good to go. I am actually doing this with a Riot 1100M and an old FSP Saga 450R 450w power supply for the past couple of years and sounds awesome.

The specs on the Riot 1100M:

https://www.bossaudio.com/product/car-audio-sound-system-auto-monoblock-amplifier-boss-audio-r1100m/

1100 W MAX Power 1 Channel
825 W X 1 RMS @ 2 ohm
413 W X 1 RMS @ 4 ohm
207 W x 1 RMS @ 8 ohm (I calculated this using ohms law, since I am driving a 4-ohm dual-coil sub bridged into 8 ohm)

FSP Saga 450R specs: +12v (combined) @ 360W max

So far so good, since I am most likely not going to drive the amp at full capacity the realistic ceiling I have 180W with this PSU. I had to trace the +12v1 and +12v2 and make sure I combined them into the amp + and remote power inputs (it is much easier with single-rail units), connect up the same # of black / ground to the negative, grounded the amp and PSU chassis together with the usual green wire (color does not really matter lol - but most chassis ground wiring is green, and I have some)

Using my DC clamp meter I can estimate using about 100W max on my amp at good volumes to match my 60W/ch Onkyo 5.1 @ 50% volume levels (which is just about right for a higher powered sub amp, and right on target for the efficiency of both the amp and power supply). For the record, my sub is the old BSR 15" passive sub from the DAK catalog that was available some 25 ~ 30 years ago.

 

[jsmithepa]

As long as you don't turn it up. Provide proper ventilation for PSU, placed on a flame resistant surface away from framable materials, monitor its temp and put a proper ammeter on it to find out exactly how much is going through that wire. Cheaper ways to do this, an inline car fuse, if it blows you know.