# Adding a cooling fan to amps, push our pull?



## jmardy (Jun 8, 2010)

My Soundstream Rubicon 702 that drives my sub doesn't have a lot of space and gets pretty hot.
I got one of these:
Newegg.com - GELID Solutions FN-TX12-15 120mm Case Fan with Superior Temperature Control

Nice fan, very quiet and with a tempertature sensor.
Anyway, the question:
Should it push air into the top of the amp or pull air away from it?

Thanks guys.


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## Sonus (Jun 28, 2010)

I depends on how the amp's installed I'd say. Is it in an enclosure, were would it draw air from/push air into? Is the fan mounted towards the warmest parts of the amp ot the colder side?


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## jmardy (Jun 8, 2010)

Sonus said:


> I depends on how the amp's installed I'd say. Is it in an enclosure, were would it draw air from/push air into? Is the fan mounted towards the warmest parts of the amp ot the colder side?


Thanks Sonus.
The amp is in the spare tire area of an S2000 and I've removed the insulation and cut a hole above it for ventilation:


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## Sonus (Jun 28, 2010)

Hm, slight problem here as I'd recommend having the fan blowing from one side along the cooling fins, but you either blow hot air from the 702 onto the other amp or blow already heated air from the other amp onto the 702. If the other amp doesn't get very hot I'd recommen mounting the fan above the soundstream blowing cold air from the vent down onto the 702 and then let it spread outwards either side,l but make sure you've got somewhere for the heated air to go. And remember hot air rises, cold air sinks 

HTH


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## jmardy (Jun 8, 2010)

Thanks. Yes, this helps.
The little amp runs very cool. I suppose I could just do a test, it's only a matter of flipping the fan over.
Cheers,
-John


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## Catman (Mar 18, 2008)

If you just have one hole for the fan and the amps are in a 'sealed' area the air has to have somewhere to 'go' ...otherwise you just slightly pressurize the area. Get good cool air into it and across the amps and give the warmed air a place to go. Don't draw your cool air from the same space that the warm air is going otherwise you just create a heat exchanger and equalize the air temp.

>^..^<


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## jmardy (Jun 8, 2010)

Catman said:


> If you just have one hole for the fan and the amps are in a 'sealed' area the air has to have somewhere to 'go' ...otherwise you just slightly pressurize the area. Get good cool air into it and across the amps and give the warmed air a place to go. Don't draw your cool air from the same space that the warm air is going otherwise you just create a heat exchanger and equalize the air temp.
> 
> >^..^<


Thanks Catman, our paths cross again  (miata.net)
There is a fair amount of air flow in this space. I took a closer look and I think it would be best to pull air through the fan and push it up and out of the area through the vent (hole) I made in the plastic panel above the amp. I'll do some experimenting this weekend.


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## Catman (Mar 18, 2008)

jmardy said:


> Thanks Catman, our paths cross again  (miata.net)


I thought that might be you. 

In my '97 Miata I had the amps sealed in the trunk depression. I cut a 4" hole in the sheet metal trim panel behind the passenger seat (at the front of the rear deck) ...I mounted a 4" muffin fan in a PVC fitting and ran 2" back to the 'enclosure' ...I forced air into the area on one side ....then vented it with another similar PVC piping setup which pulls the air out the other side of the area. These fans are are triggered with a relay off of my amp turn on lead.

>^..^<


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## GibTG (Mar 11, 2010)

Nice little US Acoustics amp. Is that a zed unit? What is it exactly?


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## jmardy (Jun 8, 2010)

GibTG said:


> Nice little US Acoustics amp. Is that a zed unit? What is it exactly?


It is a Zed. Series II, USA2075.
It's a great little amp, I'm using it to drive the Aura bass shakers in my seats.


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## jmardy (Jun 8, 2010)

Catman said:


> I thought that might be you.
> 
> In my '97 Miata I had the amps sealed in the trunk depression. I cut a 4" hole in the sheet metal trim panel behind the passenger seat (at the front of the rear deck) ...I mounted a 4" muffin fan in a PVC fitting and ran 2" back to the 'enclosure' ...I forced air into the area on one side ....then vented it with another similar PVC piping setup which pulls the air out the other side of the area. These fans are are triggered with a relay off of my amp turn on lead.
> 
> >^..^<


Nice! Like an electric supercharger


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## GibTG (Mar 11, 2010)

Bass shakers? What? And I thought you were cool!

Just joking, but really, do those things work? What purpose do you think they're serving you?


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## MarkZ (Dec 5, 2005)

If the amp is mounted with fins facing up, it makes sense to blow air up and out. If the amp is upside down, blow air towards the fins. Hot air rises. That's how I'd do it at least.

If it's mounted on its side, however, I would be more inclined to blow air ON to the fins. This is actually how most CPU fans work. Those fans suck air instead of blow out. The idea is that the air not only cools the entire surface of the CPU sink fairly evenly, but also that it moves air along the motherboard cooling the other hot components. In the case of your amp, since the fan is (presumably) much smaller than the surface of your amp, the same principle would apply -- air would "spread" across the entire surface.


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## jmardy (Jun 8, 2010)

GibTG said:


> Bass shakers? What? And I thought you were cool!
> 
> Just joking, but really, do those things work? What purpose do you think they're serving you?


:biggrinflip: I was waiting or some flack about those. I was skeptical too...
I installed them before I decided to go with a sub.
I have them low passed at 60hz and connected to the rear channel of the deck so I can control their level via the fader. I generally have them set pretty low level but they do add a nice kick to the sub. If they are too loud, it's noticeable/annoying but if set at the right level they're nice.









Here's my sub:


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## MarkZ (Dec 5, 2005)

jmardy said:


> :biggrinflip: I was waiting or some flack about those. I was skeptical too...
> I installed them before I decided to go with a sub.
> I have them low passed at 60hz and connected to the rear channel of the deck so I can control their level via the fader. I generally have them set pretty low level but they do add a nice kick to the sub. If they are too loud, it's noticeable/annoying but if set at the right level they're nice.


I throw up at the idea that more people don't use them, actually. Good for you, man.


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## 95lexsc300 (Sep 8, 2010)

nice set up


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## sqshoestring (Jun 19, 2007)

Blowing air on the sink is going to cool that sink the best....just like a CPU is the hottest thing in a PC so it has a fan blowing on its sink. If you circulate the air in the space, the amp will have to cool on its own but will have some cooler air to do that with. So it depends on if the area is getting hot, or is that amp just running hot more than the area heating up? Either way if you don't blow air through a tire well everything is going to get hot in there over time. I'd probably blow outside air on that hot amp, its not like it will heat all the air in there up to its temp fins are not that efficient by far, it will just warm it a little and with circulation temp should stay stable. I'd try to direct some flow to the other amps. Anyway, forcing the air over a sink cools it best....air moving in the area cools it far less (as the air will tend to go around objects) but would be better than it sitting on the floor of the trunk with no flow at all.


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## bob s (Jul 24, 2020)

And remember hot air rises, cold air sinks 

HTH
[/QUOTE]
What is it, a hot air balloon? Hot air rises. Air. That "rule" applies to heated air. Thats called convection. It doesn't apply to heatsinks which is conduction. It also is absolutely no factor in a forced air movement situation.


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## bob s (Jul 24, 2020)

jmardy said:


> Thanks Catman, our paths cross again  (miata.net)
> There is a fair amount of air flow in this space. I took a closer look and I think it would be best to pull air through the fan and push it up and out of the area through the vent (hole) I made in the plastic panel above the amp. I'll do some experimenting this weekend.


Do you want to cool the space or the amp? Cooling fans are far more effective if you blow directly on the heat sink.


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## Fish Chris 2 (Dec 18, 2019)

Hey Jmardy, so I recently had my mono amp, a 2400 x 1 Wolfram, overheat and go into thermal protection. Of course it came back on after it cooled off, but the bad thing, was that it apparently confused my HU which started popping up a message "Amp Error" and would not turn on... Even after the amp cooled off ! Had to pull out the HU and disconnect everything, then after that everything worked fine again, but what a PITA. Sure didn't want to do that again.

So, I first tried a cardboard shroud over my two amps (as a test) with a 200 mm case fan in the middle, pulling out air out, and sucking cool air in from both ends. Worked okay.

Next, I removed the shroud, and blew air onto the center of both amps. That seemed to work even better.

So, I bought another fan, and built a little stand to hold them both, blowing onto the amps side by side. Works a little better that one fan.

Now, with my AC cranked to keep the cabin cool, and the fans on, I think it would be hard to overheat my amps, even beating on them to right below the clipping point non-stop, it's hard to get them above 115F and I think it can get to 140'ish before it actually shuts down...
Then, even with only a really short break between songs, or quieter passages during a song, it quickly drops 10 or 15 degrees.

No more overheating issues 🙂


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