Quieter Fan Mod for Behringer EP2500

**looneybomber** · **09-03-07, 03:44 AM**

Quote:

kesa32 wrote:

Hi, l've got a electronics mate installing a thermal switch in my ep2500 tommorow to turn the fan on&off .......it is adjustable too , so we'll start with 35 degrees celcius and go from there, if this does'nt do what l want l'll hunt up an even quiter fan as the one l got isnt quite enough for me.

l'll get some pics happening of the instal too

Ken

Yeah, get some pics if you can. What I ended up using was two of these fans.
http://www.enermaxusa.com/catalog/pr...roducts_id=102
They flow the same amount of air as the one from Newerk.com, but are only 14db compared to the 24v fan's 21db.

I'm thinking of replacing the OEM fan, but using it as an exhaust instead of an intake, and then a second (wired in series for that 24v rating) at the front of the heat sink to blow fresh air through it from the front of the amp. 20bucks is a fair chunk of change to spend on something like this though.

*edit* I've been a member for 1 year and this was my first post. Huh. Oh well...

*edit #2*
I have both fans installed...sorta. I was unable to place the second fan infront of the heatsink without grinding away part of the amps front plate. I still have yet to find a good place to put the second fan. I may place it with my exhaust fan in the back inside that shrowd. We'll see if that works. It is very quiet though I will say!

*edit #3*
Well, I have both fans piggy backed in the existing fan location, but both blow out instead of in. The air flow is lower than with the original fan, but even playing for 20-30mins with the clip lights blinking occasionally, the amp never gets hot. The air coming out is warm, but it doesn't get near as hot as my receiver does!

**Danny** · **09-03-07, 07:30 AM**

If you're doing that make sure the air still flows in the same direction as before, some heatsinks work best with a positive negative pressure differential.

**ccdoggy** · **09-03-07, 11:15 PM**

just do the single fan and it will be fine. On a 90 dregree day i watched Return of the king and the amp never kicked out or had any problems at all, even though it was quite hot.

it will be fine.

**Egil** · **11-01-07, 05:48 AM**

After several months with that awful loud noise from my EP2500 I finally got a new fan in the mail! A Papst 8414 NGML (19dB). I just cut the wire on the old one, and used some electrical tape to connect the wires on the new fan. The result? Around 62dB right next to the EP2500.. but my listening position(s) is 4 meters away from the EP2500 - so you don't notice any noise while listening to music or watching movies. Great mod

**toecheese** · **11-01-07, 09:46 AM**

Is there a definitive list of part numbers to check? The Newark one doesn't list the noise level for that model.

Edit: the NMB P/N is the same as the 21dB Panaflow. Guess they're the same company.

**warnerwh** · **11-01-07, 07:24 PM**

Just finished the fan mod. At least on my amp it was easier to cut the wires near the fan and solder the new fan wires to them. All you have to do is cut the black shield back and slit between the red and black to separate them.

Trying to use an exacto with that much hot glue would have taken a lot longer.

**Josuah** · **11-01-07, 09:40 PM**

Only took me about 30 seconds to cut through the glue and disconnect it. I'm using an Vastech Alien I.

**warnerwh** · **11-04-07, 09:13 PM**

Quote:

Josuah wrote:

Only took me about 30 seconds to cut through the glue and disconnect it. I'm using an Vastech Alien I.

Well I guess you're more patient than I am.

**toecheese** · **11-30-07, 11:47 AM**

I just did the mod using a fan bought from Newark. Awesome. Verrrrry quiet now. Be careful about that fan shroud because it isn't correct in Chris' original photos, but someone's follow is correct.

**Chrisbee** · **11-30-07, 01:16 PM**

I'm glad somebody else has noticed the "deliberate" mistake.

**toecheese** · **12-02-07, 02:39 AM**

Your mistake is better than mine. I had started the fan mod last summer and took the shroud out. Initially I was going to do the in-line resistor. After reading about it (starting playing with circuits again and know that a 24v source really prefers a 24v output), put the project aside until recently when my neighbor wanted one for his 1500. We ordered a pair, and I did the fix... but forgot where the shroud went. I think I threw it away! So now I'm shroudless, and I don't feel like going to Turin to get a different one. I reversed the flow and did some testing, but can't get the amp even a teeny bit warm, so I'm satisfied with the setup.

**zamboniman** · **04-02-08, 11:52 AM**

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.

**atledreier** · **04-02-08, 01:16 PM**

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.

**ccdoggy** · **04-02-08, 01:26 PM**

yea, the fans are not getting enough power. although, when is it running warm? when you are pushing the amp and using allot of power or just sitting there?

24v fan is the way to go through.

**atledreier** · **04-02-08, 01:36 PM**

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.

**looneybomber** · **04-02-08, 01:44 PM**

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.

**mike c** · **04-02-08, 06:59 PM**

Quote:

looneybomber wrote:

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!

**looneybomber** · **04-02-08, 09:48 PM**

Quote:

mike c wrote:

im curious with this series'ed 12v fans ... please post pics looneybomber!

I knew eventually someone would want pictures. I should have taken some as I was doing it. Homework is pretty heavy right now, but hopefully I can get some taken for ya. It's really pretty simple, four wires remain routed through the metal shroud, and four or five go up over the top of the heat sink (taped down flat). The fans I'm using aren't deep ones, so they fit. If you found some deep 80mm ones, they wouldn't fit.

I'll edit this post once I get pictures taken...which may be a little while from now.

**mike c** · **04-02-08, 10:10 PM**

i was thinking of using 12v PC fans (generally 3/4 - 1" thick each)

do you have a wiring diagram instead?

sorry for being too pushy

**atledreier** · **04-03-08, 03:56 AM**

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 - ----
                                                                    |
           -   --------------------------------------

**mike c** · **04-03-08, 05:29 AM**

Quote:

atledreier wrote:

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?

**atledreier** · **04-03-08, 10:08 AM**

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.

**looneybomber** · **04-05-08, 02:48 PM**

Quote:

atledreier wrote:

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.

**kouack** · **04-05-08, 03:17 PM**

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 :-)

**fperra** · **04-24-08, 10:59 AM**

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.

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