# Using a power supply?



## bambino (Feb 21, 2010)

I was looking through Parts express and noticed they have 40 amp 12volt power supply and got to thinking (my wife and freinds warned me of that) What if i use one of those to power a car amp for my subs. I no many would say just buy a pro amp but i was just curious to know what you guys thought other then it's a bad idea. Would the preout on my Denon have enough voltage to supply the amp with signal? would the power supply burn out or have a shorter life span then a pro amp? My car amps are 3000 watts apiece class D, I know when i had them in my truck they never got so much as warm and i only had a 60 amp fuse on each one plus they were each driving a 15'' sub far more powerful then the ones i've got for my DIY's. This is all purely hypothetical and just wondering what anyones thoughts were. Thanks in advance for any input. :huh:


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## tonyvdb (Sep 5, 2007)

My only issue would be that the power supply would get very warm driving an amp.


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## bambino (Feb 21, 2010)

tonyvdb said:


> My only issue would be that the power supply would get very warm driving an amp.


It says in the ad that they are made for testing high current loads for extended periods of time but how long does extended mean was my concern along with the heat factor now that you mention it. Do pro amps run hot or do they just get warm? :scratch:


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## tonyvdb (Sep 5, 2007)

Pro amps usually just run warm but if you push them they can get hot, Thats why the have fans. I used an old H&H V800 to drive two Community subs Both had 4-10" drivers and it would run very warm and the fans would ramp up to about 3/4 there full speed.


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## bambino (Feb 21, 2010)

Thanks for your response's Tony. They will help me make a decision on what i'm gonna do. If anyone else has any advise to throw out ther i'd appreciate it.


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## mdrake (Jan 31, 2008)

I use a computer power supply to power my 500 watt 4 channel class A StreamStream car audio amplifier for my mains and it works great. I say go for it.  

Matt


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## Anthony (Oct 5, 2006)

My first sub amp was a California Profile 100W amp powered by a Radio Shack 12V,10A power supply.

It worked great and I still use that setup for speaker testing and such. In my case, the main drawback was the power limitation (120W max). Also, big beefy amps are designed for momentary surges above their nominal rating. I can't say how that power supply would react, but it seems up to the task.

You also need to ask what your overall savings would be. There are some good plate amps between 300 and 400 dollars. That power supply is 250 and will only get you about 500W.

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=300-806

is 500W and only $325. It is self-contained and has a crossover and parametric EQ adjustment.

But if you already have the parts . . . 

Good luck and let us know how it turns out.


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## bambino (Feb 21, 2010)

mdrake said:


> I use a computer power supply to power my 500 watt 4 channel class A StreamStream car audio amplifier for my mains and it works great. I say go for it.
> 
> Matt


How many amps does your computer power supply deliver? And do you use it for extended periods (movie watching, music listening)? One last question is how long have you been running your system off it? Thanks for your input.:T


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## bambino (Feb 21, 2010)

Anthony said:


> My first sub amp was a California Profile 100W amp powered by a Radio Shack 12V,10A power supply.
> 
> It worked great and I still use that setup for speaker testing and such. In my case, the main drawback was the power limitation (120W max). Also, big beefy amps are designed for momentary surges above their nominal rating. I can't say how that power supply would react, but it seems up to the task.
> 
> ...



I'm gonna give it a shot i've just gotta know. Plus like you said i've already got the parts, the worst that could happen is i burn up the supply and send it back for a refund. The main reason i'm concidering this is cause the amps i've got are super efficiant and deliver lots of power, and the amps i've currently got (Dayton HPSA1000r's) are not up to the task of driving the subs. If it works out with the power supplys I'd be willing to sell the daytons for what the power supplys costs.:spend:


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## Anthony (Oct 5, 2006)

The HPSA's aren't up to driving the subs?

I have the standalone unit of the HPSA-1000 and it drives my dipole twin 15" sub at almost zero gain. What do you have that this isn't enough for? :dunno: Not criticizing, just curious.

In either case, good luck. As long as you enjoy it, it isn't a bad choice


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## bambino (Feb 21, 2010)

Anthony said:


> The HPSA's aren't up to driving the subs?
> 
> I have the standalone unit of the HPSA-1000 and it drives my dipole twin 15" sub at almost zero gain. What do you have that this isn't enough for? :dunno: Not criticizing, just curious.
> 
> In either case, good luck. As long as you enjoy it, it isn't a bad choice


I'm driving a 15'' Kicker CVX in a 5 cu.ft. ported box tuned to 22hz with 1 HPSA1000R it clips very easily when i was testing it but i did not tweek the amp at all plus it's wired for 8ohms being that the subs are 4ohms per coil which is why i think there is not enough power if the amp could deliver power into 2ohms then i think i'd be golden. And i am definatly open for critisizim. Thanks again.


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## Anthony (Oct 5, 2006)

That low port tuning is probably it. You are getting extreme excursion where it is asking for the most power -- a combination that really taxes the amps. In my case, I have drivers with very stiff suspensions, so even with the high power requirements, the amp has more "control", if that makes sense. A rumble filter should help with that, but I thought the HPSA series had one built-in? :dunno:


Also, are you sure it is amp clipping? And not Xmax of the drivers? They both can have similar sounds (that muddy, "thhhhppppttt" sound at high excursion). I'd hate for you to go through all this just to get the same result because it was driver limited.

Oh, any my gain was on about the 30% position, not zero  I checked this weekend.


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## Mike P. (Apr 6, 2007)

The sub is wired for a 8 ohm load, this is the cone excursion with 500 watts and the HPF at 18 hz. The sub can handle 2000 watts to reach Xmax. A suggestion would be to wire both subs for a 4 ohm load and use one amp to see if it makes a difference in output.


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## bambino (Feb 21, 2010)

Mike P. said:


> The sub is wired for a 8 ohm load, this is the cone excursion with 500 watts and the HPF at 18 hz. The sub can handle 2000 watts to reach Xmax. A suggestion would be to wire both subs for a 4 ohm load and use one amp to see if it makes a difference in output.
> 
> View attachment 20963


I'll try it and see what happens. thanks for chiming in Mike.:T


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## swong46 (Feb 15, 2010)

I have a cascade car audio power supply in 55 ad 90 amps
I have used both power supplies to power amps at 500watts or more and they never get hot even after long uses. They have fans to keep everything happy.


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