[digital desire]

I started a thread a couple days ago looking for a schematic, thinking I had a weird clipping problem. When I first got the ep 2500, I found on another web site a thread that showed what fan to get to make it quiet, and (the bad idea...) suggested reversing the flow. Set up the way they suggested, it pulls hot air out of the case vs. the way the engineers wanted it, blowing cold air in.


Well, before I started taking it apart, I switched the fan back to flowing the right way, and my problem is 95% gone. The red lights do not come on nearly as much as they did before. When they flicker on, it mutes the input for 5 to 10 seconds.


Still does it once in a while though, dang nabit. But now I am pretty sure it is a thermal issue. Part of the problem may be running it bridged into a tc 2K which, IIRC, is a 3.2 ohm load. May have to revert to single channel ops!

 

[michael hurd]

Reversing the airflow is not a good idea as you have found out, I bet you are just pushing it too hard. Is your TC a SVC or DVC>? If you can find one used on eBay the same, I would add another so that you aren't driving it as hard.

 

[digital desire]

I indeed have been driving it too hard.


I pulled the grill off the sub and found little deformations at the edge of the aluminum cone. Uggh. And no spare top assemblies are available anymore as IIRC, tc sounds is no more. I think a malestrom is in my future anyway. I like the one sheet build. Quick and clean.


Back to the ep 2500, I just replaced the fan back to the original one. Truth be told, I never heard it before, I replaced it to the quiet one before I ever put the ep 2500 into service. It is a bit loud. BUT: I noticed the quiet one draws .09 amps, and the stock one, .25 amps. If you keep the idea that they are equally efficient, it is moving quite a bit more air. But it sure is loud!


Waiting to see if the stock fan eliminates the problem entirely now....

 

[NEO Dan]

Sounds like a one of anything is not enough for you, time to double up or switch to something more efficient. Or both

 

[Ricci]



Quote:
Originally Posted by NEO Dan /forum/post/15406864


Sounds like a one of anything is not enough for you, time to double up or switch to something more efficient. Or both

+1


Damaged TC cones =

 

[digital desire]

Hmm.

If the maelstrom has significantly more output, I hope just it would be fine. Maybe both? One on each channel?

 

[Looneybomber]

I swapped fans in mine (actually I used 2, 12v fans), with reverse air flow. Not had a problem with mine. I've had it clip while powering a single SDX in a 4ft sealed box, but that was plenty of power for that driver! A nice balance of available power and available excursion due to a box with a lower Q than 0.7.


I also don't see how reversing the air flow would be a problem, unless the amp was enclosed in a rack, in which case you'd be pumping hot air into the rack.

 

[digital desire]

Pumping hot air is always less efficient than cold air due to density. In addition, blowing the exhaust over the sink is more efficient at heat transfer (directed charge) than just evacuating the cabinet, which is what you are doing with the fan reversed.


It indeed solved my issue. The first time I took it apart after running it with the non OEM fan, the sink was way to hot to touch. Back to stock, and it a cool unit. I am very glad I did not completely cook it. Berhinger/ QSC engineers knew what they were doing with it to begin with. I ran three concert DVD's in a row last night, not a single red light. That never even came close to happening with the non OEM setup.