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Post by jman on Jan 23, 2008 22:58:12 GMT -7
My friend is going to come over on Saturday to help. He has an ohm meter so we can measure DCR. What is DMM?
I also checked each voice coil with an AA battery and they all work fine. Oddly the IB sounded it's best when it was wired wrong and drawing a gob of power from the first ep2500.
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Post by chrisbee on Jan 24, 2008 2:04:03 GMT -7
DMM = Digital Multi Meter.
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Post by jman on Jan 27, 2008 0:29:12 GMT -7
Results-
all drivers wired parallel/series for 4ohms, DCR was ~3ohms - amp clip light refuses to turn off regardless of no signal or gains all the way down or up
I split the array into 2 sets of drivers wired for 2ohm (series, parallel) and DCR was a predictable ~1.5-1.6ohms - amp works fine in 2ohm stereo and gain only needs to be half way up for tons of rich, full bass.
I'll have a real go at the IB tomorrow with some really loud/deep stuff. Seems to be back to it's good old self though.
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Post by chrisbee on Jan 27, 2008 2:07:30 GMT -7
You are still risking the amp with 2 Ohms per channel unless you remove the excess heat.
Perhaps you should obtain two good fans and tandem them?
It wouldn't be difficult to add another fan outside the case using longer fixing bolts through the original fan holes (or use studding with lock nuts) You can even add the grill on the outside to keep curious fingers out.
Just make sure they are both blowing the same way.
I used a cheap digital room thermometer with outdoor sensor on a long flexible wire. The outdoor sensor was fixed to the tubular heatsink to monitor the temperature when I first swapped the fan. Once I was satisfied that the temperature rise was only a few degrees I removed the thermometer sensor.
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Post by jman on Jan 27, 2008 13:31:08 GMT -7
What excess heat? The noisy fan is blowing out stone cold air so far.
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Post by chrisbee on Jan 27, 2008 14:05:28 GMT -7
What excess heat? The noisy fan is blowing out stone cold air so far. Let us hope that it continues to do so. ;D
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diru
New Member
Posts: 3
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Post by diru on Feb 4, 2008 18:53:22 GMT -7
Strange to hear so much trouble from a Behringer. So far there has been over 30 x A-500s put into service in the past 2 years. 24 of them in one house. Many 1500/2500 also now in service. In schools, churches and home theaters. And guess what, not one failed unit to date. As far as trying to run these things at the max, nope not going to do it. 1500/2500 min load stereo 4 ohms, or 8 ohms bridged. Trying to screw them down for that last couple of watts its not worth it, your not even getting 3db of amp gain at the outputs. If you let up on these amps, the better the amp will control the load. EDIT: if you need that much juice, buy another amp. power is cheap. power corrupts utterly
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Post by aespeakers on Feb 4, 2008 22:24:44 GMT -7
I set it to bridged mode and when I turn it on the left channel clip light is on solid. Hmmmmm. This is the same as what we had experienced with the units we had for the club install. Flip the switch on and off a few times and the clip light should go off. It's some kind of protect mode it gets stuck in when it does the initial power cycle. We were told it was "normal" to have to turn the amp off and on a few times. I'd also check to see what kind of DC voltage the amp is putting out with no signal input to it. John John
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Post by jman on Feb 5, 2008 13:11:00 GMT -7
The first one did that when I first turned it on but went away after a couple cycles. Ironically, it should have stayed on then since it was "seeing" 1ohm. The new replacement unit does it when fed 4ohms and cycling it over and over made no difference. Luckily 2ohm stereo works fine so that's how I'm using it. The power difference is negligible, ~1900 watts bridged 4 or 815x2 stereo.
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