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Quieter Fan Mod for Behringer EP2500

148K views 206 replies 86 participants last post by  KraftwerkTurbo 
#1 · (Edited)
Hi

The Behringer EP2500 has been getting more and more popular with IB subwoofer builders. (and other sub builders of course)

It offers plenty of power at a price that makes domestic stereo power amps seem foolishly expensive. For our subwoofer needs we aren't looking for "air", pinpoint imagery or crystal clear highs. Crossed over at around 80Hz you couldn't ask for a more affordable tractor to get those big cones moving. (and stopping just as quickly)

My opinion (shared by others) is that the original cooling fan is far too noisy. Niagara Falls or Victoria Falls don't even come close. (I'm joking of course but you get the picture) ;)

These amps are designed for live performances where they are probably screwed up to maximum volume into 2 Ohms and left that way until the gig ends.

For HT use and reproducing music at home these amplifier don't get nearly the same hard treatment. That means we can slow the rush of cooling air with quieter fan options.

The original fan is a standard PC size but runs on 24 Volts. I couldn't obtain a quiet Panaflow locally in 24 Volts so ordered a Papst from the Danish importer instead.

First you must remove the screws which hold the amplifier lid down. These are fixed along both sides near the top and along the back only at the very top. Don't start unscrewing the socket fixing screws further down at the back. You'll also have to remove the 4 screws which fix the lid down to the heatsink. Use a decent crosshead screwdriver to avoid damaging the screws. They are fitted quite tightly so you will ruin the screwheads with a poorly-fitting screwdriver!

Here are a some images to show what's involved in swapping the fan. The twisted red, black and white wires are the motor connection to the small PCB on the left. (seen from the front of the amp)

If you're past your guarantee period you could just snip the wires and use a connector block to join the new fan wires to the old ones wherever you consider convenient.

My amp is still under guarantee so I didn't want it to be blatantly obvious that I'd swapped fans.

Behringer do not approve of fan swaps. You can't really blame them considering the abuse they get in a live gig. The modded amp might be sold on with the quiet fan and nobody would be the wiser until the amp got fried. The unhappy new owner would then start badmouthing Behringer products. So keep your original Behringer fan in a safe place in case it's needed in the future.

The original fan wires have a little plug which is held to the PCB with hot glue. A scalpel or similarly sharp tool will release the glue and the plug can come free.

Careful examination of the tiny plug will show that it sits in a little holster which then sits on the pins protruding from the PCB. If you are lucky you may be able to do a plug swap in the original holster. My new Papst fan came with bare wires so I had to find a plug on another cooling fan which was compatible with the holster.

General view of Behringer EP2500 with arrow pointing to twisted fan motor wires.



Here's where the plug fits on the PCB pins.



The new silent Papst fan fitted. It blows air forward through the long, box-shaped heatsink.The fan sits in a thin, folded metal shell and is held by four long screws. The same screws hold the wire protective cage to keep fingers out of the fan blades.

Do not undo the four fan screws until you have the lid safely off the amp and can see inside.



I have monitored the amp temperature with a digital temperature probe and found a maximum of 4F above ambient after an hour of Metallica's Black Album at a steady 100dB on my RS meter. On action films the amp doesn't get enough exercise to warm up above ambient at all. In use a quite ticking can be heard if I stand close enough. A far cry from the roar of air from the original fan. Which could be heard form 12 feet away through the cones of my IB.

Others have mentioned using resistors to slow the original 24Volt fan. Perhaps somebody will chip in with their experiences using resistors and the values required. :)

UPDATE:

Here's a picture of the original Behringer fan. The size is 80 x 80 x 25mm.



Note that the wire is double insulated with a black sleeve over black and red. NOT the twisted R/B/W wires shown above.

It plugs into the small PCB on the left exactly as shown above.

Here's an image of the original plug within a plug. I had to buy a cheap fan with the same kind of plug because no local computer dealers sold the plug on its own.

 
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#62 ·
Re: Quieter fan mod for Behringer EP2500

Just an update..... If you have an EP2500 - DO THIS MOD !!!

I just did and it's a world of difference.... now my HDDVD player is louder than this.

Also the fan is back in stock at Digikey... and out of stock at newark.

For a little under 20bucks with shipping etc... and 30 min of work.... can't beat it.
 
#63 ·
Re: Quieter fan mod for Behringer EP2500

I did the 2 12V in series mod, and put the 'extra' fan in the cae beside the transformer. The fans seem slow compared to the single 24V, and the airflow is alot less. The air coming out now is warm, not hot, where it was almost cold with the original fan. Maybe the fan controller can't supply the power needed for the two fans? I might as well get a new 24V silent fan and be done with it.
 
#65 ·
Re: Quieter fan mod for Behringer EP2500

It's slightly warm sitting idle.

I haven't really pushed the amp over a period of time, so I don't know if it ever warms up more. After a period of very loud music I felt no difference. I'd feel more comfortable with a single 24v fan though, so I'll order one up soon.
 
#66 ·
Re: Quieter fan mod for Behringer EP2500

I did 2, 12v fans in series, but both of them are at the end of the heat sink with air flow front to back. Butting the fans up does cause a tiny bit of cavitation because it makes the fans spin a tad faster, but the noise is still low. I also get more air flow than when having only one fan at the back of the heat sink.

It was tricky making it work, I had to re-route half of the wires that are bundled together back there up over the heat sink. The second fan fit inside the metal shroud, thus why I had to reroute wires.

You might try putting both fans at the rear of the heat sink.
 
#67 ·
Re: Quieter fan mod for Behringer EP2500

I did 2, 12v fans in series, but both of them are at the end of the heat sink with air flow front to back. Butting the fans up does cause a tiny bit of cavitation because it makes the fans spin a tad faster, but the noise is still low. I also get more air flow than when having only one fan at the back of the heat sink.

It was tricky making it work, I had to re-route half of the wires that are bundled together back there up over the heat sink. The second fan fit inside the metal shroud, thus why I had to reroute wires.

You might try putting both fans at the rear of the heat sink.
im curious with this series'ed 12v fans ... please post pics looneybomber! :reading:
 
#70 ·
Re: Quieter fan mod for Behringer EP2500

If you are using two fans in series it's a matter of wiring from the red from the plug, to the red on one fan. Then the black of the first fan to the red of the second fan. Then the black from the second fan to the black on the plug. Simple series wiring.

Code:
 PLUG   +   ------  +  Fan 1 - ------ + Fan 2 - ----
                                                                    |
           -   --------------------------------------
 
#71 ·
Re: Quieter fan mod for Behringer EP2500

If you are using two fans in series it's a matter of wiring from the red from the plug, to the red on one fan. Then the black of the first fan to the red of the second fan. Then the black from the second fan to the black on the plug. Simple series wiring.

Code:
 PLUG   +   ------  +  Fan 1 - ------ + Fan 2 - ----
                                                                    |
           -   --------------------------------------
thanks, so just like a subwoofer driver. so will the amp see 24v if two 12v fans are in series?
 
#72 ·
Re: Quieter fan mod for Behringer EP2500

yes, the amp will think it's one 24V fan that draw double the current. I don't think the fan module in the EP2500 is up for that, though. Both fans spin really slow, so I get too little airflow. I'm getting a 24V proper quiet fan.
 
#73 · (Edited)
Re: Quieter fan mod for Behringer EP2500

yes, the amp will think it's one 24V fan that draw double the current. I don't think the fan module in the EP2500 is up for that, though. Both fans spin really slow, so I get too little airflow. I'm getting a 24V proper quiet fan.
Actually wiring stuff in series double's the voltage, but keeps the current the same.
Wiring in parallel keeps voltage the same, but double's current.

Each of the fans I installed draw .16 amps, so 1.92watts per fan. I'll look at the stock fan when I get home, but I'm pretty sure it draws more than 4 watts, which is more than my 2 fans draw. That is because my fans are quiet fans and thus they rotate slowly to keep noise down. You can get faster fans that move more air, but they will draw more power (not a problem) and are more noisey (that's a problem to me). Something else you could do, is install a switch. In one position your stock fan will operate as normal, in the other position, a resistor will be wired in to drastically reduce fan speed and noise. You could then have a quiet "night" position and a "day time rock and roll" position for maximum cooling.

Ok, I got home and checked the fan. The stock fan is 24v, .25A = 6watts.
 
#74 ·
Re: Quieter fan mod for Behringer EP2500

What about using 1X 12 volts fan and a 75 ohms resistor in series to create a voltage drop and to keep the voltage @ 12 volts to the fan? If my math is ok 12 volts/ 0.16 amp = 75 ohms and you would need 12 volts X 0.16 amps = 1.92 watts so a 5 watts resistor would be more than enough :)
 
#75 ·
Re: Quieter fan mod for Behringer EP2500

I replaced the fans on 5 QSC amps and my EP2500 with 12 volt fans, but I did it a little different than I've seen in this thread. I just fed the 24 volt fan supply to a 3 pin 12 volt regulator IC and fed the 12 volt output to the fan. Works like a charm.
 
#77 ·
Re: Quieter fan mod for Behringer EP2500

Thanks to this thread, I picked up the 24v FBA08A24L1A from arrow dot com for about $19 including second day air (I was in a rush). I have less than ten posts here, so I can't post the direct link to arrow.

Installing the fan was one of the easier things I've done lately.
Results are very good. The EP2500 is not what I would consider "silent". But the fan is inaudible from more than a few feet away, or at my sitting distance. I can only hear it when I walk right past it.

I would do this mod again. And it's safer than going with a 12v fan.
 
#89 ·
Re: Quieter fan mod for Behringer EP2500

Don't mess around with 12v or series or anything else odd. Just do it right the first time.

What I quoted below is all you need. It is absolutely innaudible from three feet away in an absolutely silent room.
Get your refridgerator going or the A/C and you can't even hear this fan with your head right next to it.

Thanks to this thread, I picked up the 24v FBA08A24L1A from arrow dot com for about $19 including second day air (I was in a rush). I have less than ten posts here, so I can't post the direct link to arrow.

Installing the fan was one of the easier things I've done lately.
Results are very good. The EP2500 is not what I would consider "silent". But the fan is inaudible from more than a few feet away, or at my sitting distance. I can only hear it when I walk right past it.

I would do this mod again. And it's safer than going with a 12v fan.
 
#78 · (Edited)
Re: Quieter fan mod for Behringer EP2500

Just got done with the fan mod myself. Got the one from newark that was posted earlier in the thread.

With my bad hearing I have to stick my ear right next to the front of the amp to even hear it running and I can barely hear it at that. The stock fan could be heard from my seating position about 10 feet away. Again, my hearing is not too good.

The glue can be sliced through in short order without heating it. Soldered up the new fan and all is good.

I did do something a little different than others. I used some metal foil tape (the real duct tape) and sealed off the gap between the fan shroud and heat sink. I also mounted the fan blowing out the rear so it draws air from front to back now. It has been sitting idle for about a half an hour now and the air coming out the back feels just slightly warmer than ambient. The top of the unit is stone cold except the area directly over the heat sink. That area is only slightly warm to the touch.

It just didn't make any sense at all to me having the fan blowing from the back to front, gaps in the heat sink, blowing hot air all around the inside of the amp and heat soaking all the other parts. This way the fan draws air through the front of the heat sink and blows ALL that hot air out the back.

UPDATE!

Watched a movie for a bit. The air coming out of the back of the unit is now very warm. Good indication that it is pulling a lot of heat from the heat sink. The top of the case is warm to the touch directly over the heat sink and still cool to the touch everywhere else.

I'm happy.
 
#79 ·
Re: Quieter fan mod for Behringer EP2500

Coolerguys has a good selection of fans.... http://www.coolerguys.com/80.html

MECHATRONICS #A8025S12D for $4.25

  • low noise design
  • Sleeve Bearing
  • 12V DC thermal protection type
  • PBT UL94V-0 frame and impeller
  • DC Brushless

SPECS:
Model - A8025S12D
Size - (80 x 80 x 25mm)
3.15 x 3.15 x 0.98 inches
Bearing options: Sleeve Bearing
Connector - 3 Pin/2 wire w/10" lead
Speed - 1500 RPM
Noise - 20 dba
Air Flow - 25 CFM
 
#87 ·
Re: Quieter fan mod for Behringer EP2500

So is the newark the most commonly used 24v?
Seems easier to use a 24v than switch to a 12v.

These suckers are fairly loud, lol.
The Panaflo model is most commonly recommended, because after a long series of attempts at resistor mods and fan replacement, the Panaflo was found to be the lowest noise option in a certain extended length thread concerning Ep2500 fan options, and by a significant margin, based on my imperfect memory.

-Chris
 
#90 ·
Re: Quieter fan mod for Behringer EP2500

hi - i just changed out my fan from a QSC GX5 amp - i put in the panaflow model 24 volt - low speed -

works excellent in terms of noise - i cant hear it at all now - almost wonder if its working :) -- i did check it before i closed the amp - it worked - i just spliced the wires because i didnt have and cant find the 2 pin connector -

i have a guestion if anyone would know - does this fan spin the same speed all the time ? or does it speed up as more volts are sent to it when the amp gets hotter ?

i hope this fan is enough to keep it from shutting down or doing any damage - i am using it for HT use and music - i do listen to music loud at times - but not for that long - has anyone had issues when using this low speed fan ?

thanks
 
#91 · (Edited)
Re: Quieter fan mod for Behringer EP2500

Wish I had already did this...got my sub going tonight. Still have some finish work to do yet but I thought I'd go ahead and try this baby out. Sounds real good WHEN you can hear over this ******** EP1500 stock fan.

Needless to say I got the FBA08A24L1A on order from Digi-key. I guess I'm gonna take apart on old sub and run my new sub off an old amp till the part arrives...I gather running it without a fan is a no no even at light load.

EDIT:

Got the fan in and installation was pretty easy. Fan mod cut the noise in half...still audible from about 8 feet away but tolerable. No louder than my PS3.
 
#92 ·
Re: Quieter fan mod for Behringer EP2500

Are there any concerns with running a fan at ~1/2 the CFM and Back pressure? :huh: I don't know the circuit, but unless the circuit is looking at the temp, this mod would seem to put internal components in jeopardy.
Anyone have this mod installed and more than a couple months of use to put my mind at ease before performing the mod.
I think I am going to talk to a couple of reps from work and see if they can find a closer match to the original fan with less db's.:nerd:
 
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