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Post by chasw98 on Jun 10, 2007 16:35:09 GMT -7
Here are the 4 ohm results for the EP2500 amplifier rated at 650 watts/channel 20-20KHz at <0.1%THD both channels driven.  |
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Post by chasw98 on Jun 10, 2007 16:35:50 GMT -7
Here are the 2 ohm results for the EP2500 amplifier rated at 1200 watts/channel 1 KHz at <0.1%THD both channels driven.  |
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Post by chasw98 on Jun 10, 2007 16:36:18 GMT -7
Here are the 8 & 4 ohm results for the EP2500 amplifier in the bridged mono configuration.  |
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Post by chasw98 on Jun 10, 2007 16:37:21 GMT -7
Some comments on testing these amps. Even though the results I got from bench testing these amplifiers do not read like the published specs in the Behringer manual, they will do their rated specifications if tested the way Behringer tests them. I found heat and the circuit breaker located in the amplifier to be the 2 items that caused the amplifiers to fail the tests and not meet the published specs. I almost opened up the 2500 and bypassed the circuit breaker just to see if it would go on or go up in smoke. If I had a room that was temperature controlled to about 70 degrees with heavy duty air handling capabilities (and a duct pointed right at the intake of the amp), the amp would not have gotten so hot, so quick. Even with all that these amplifiers will not run with a sine wave at full power at 1 KHz for more than 5 minutes under any load, 2, 4, 8, or bridged! They are just not made to run like that. On the other hand, if you were to derate the power of the units, they could run all day at rated specs. SO you have to ask yourself....... Did the marketing dept. decide that this amp could do 2500 watts at 4 ohms bridged mono and the engineers said "Not really", but marketing did anyway? I don't know. Considering the money to be spent on them, for home use, they are fantastic.
I will be doing more tests next weekend with some more amplifiers from a friend so stay tuned for more.
Chuck
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Post by chasw98 on Jun 10, 2007 17:02:07 GMT -7
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Post by badmoon23 on Jun 10, 2007 17:48:28 GMT -7
can you test the Gemsound Exa-3950 please.
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Post by chasw98 on Jun 10, 2007 19:10:31 GMT -7
I would be happy to.... if you can get one for me to test. PM me if interested.
Chuck
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ryans
Full Member
Posts: 132
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Post by ryans on Jun 16, 2007 6:15:56 GMT -7
I'm confused about your distortion results. For all other measures you have listed the units of measurement. But since distortion is a ratio of noise to content, there really is no unit. This is usually measured as a percentage. But you're not showing % as units, so does this mean a result of "0.334" is 33.4% distortion? Surely not. I'm thinking you meant 0.334% distortion?
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Post by chasw98 on Jun 17, 2007 17:32:01 GMT -7
I'm confused about your distortion results. For all other measures you have listed the units of measurement. But since distortion is a ratio of noise to content, there really is no unit. This is usually measured as a percentage. But you're not showing % as units, so does this mean a result of "0.334" is 33.4% distortion? Surely not. I'm thinking you meant 0.334% distortion? You are correct. All distortion measurements are in percentage. So, yes, 0.334 is in actuality 0.334%. Sorry if that caused any confusion. I will have to remember that in the future. Chuck |
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Post by chasw98 on Jul 16, 2007 5:36:40 GMT -7
Buttkicker BKA1000-4A Tested -------------------------------------------------------------------------------- Here are the results of preliminary testing of the 'infamous' Buttkicker amplifier. It would not even come close to rated specifications. On the other hand, the specifications are rather limited. Here they are directly from the website. "ButtKicker Amplifier Specifications Model #: BKA1000-4A 1000 Watts @ 4 ohms 1900 Watts @ 2 ohms - will power 2 ButtKicker LFEs wired in parallel , and 4 ButtKicker LFEs used in individual home theater seats. Class D switching technology Variable high cutoff, 40 to 160 Hz Low cutoff, 25 Hz switchable RCA and ¼” inputs with 160mVolt and 1.25 Volt sensitivities eliminates the need for a separate pre-amplifier Five way binding post output 120v or 240v versions available Convection cooling, i.e. no fan 12"W x 11"L x 4.375"H, 11 lbs / 11.36 kg" No S/N, distortion, frequency response, etc. is given at all. Here are the preliminary results of testing at 4 ohms. It doesn't look good for 2 ohms. Power is down, distortion is up, and frequency response, well, you get the picture.  |
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Post by chasw98 on Jul 16, 2007 5:42:39 GMT -7
Here are some more numbers on the Buttkicker amplifier. I have included 2 pictures of the test rig so that you can see what I am doing and what the waveform looks like. This amp was designed for tactile transducers and performs that job very well. But if you will notice the Yellow Fluke voltmeter in the picture, it is reading the input voltage to try and get this amplifier to do what it says on the box. The front end of this amp is awful. If the input signal is too high, the waveform is distorted before you have even amplified it to send the signal to the speakers. When sending the signal to transducers, waveform does not matter! This picture is showing the input voltage at over 7 volts and the distortion is at 14%.  This picture shows the frequency (49 Hz), distortion (13.7), waveform (top trace) and distortion (bottom trace), and input voltage (7.24 VAC).  And here is chart with readings as much as I could get from the amp at 4 & 2 ohms. I had to use 125 VAC to drive the amp just to get the maximum wattage.  Chuck |
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Post by ThomasW on Jul 16, 2007 8:06:57 GMT -7
Yikes.......  Perhaps that's the reason the Guitammer company doesn't recommend it for use with subwoofers...  |
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Post by jman on Jul 22, 2007 15:26:59 GMT -7
Chuck,
when we lower the gain knob on a power amp, what overall effect does it have or is it merely a sensitivity control? If the gain is set to only half, can the amp still output to it's maximum rating?
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inm8
Junior Member
Posts: 85
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Post by inm8 on Jul 22, 2007 17:24:13 GMT -7
This may not apply to all pro-amps, but I know the behringer amps (europower line) have an "input attentuator", which as you have probably guessed, regulates the input level. Since it's not limiting the amplifiers "output" there is no reason why you can't have the amp at max output (or clipping) with the dials turned 1/2, or 1/4 of the way, you'll just have to ramp the volume up more on your pre-processor.
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Post by jman on Jul 23, 2007 8:04:47 GMT -7
Thanks. Good to know I'm not wasting power.
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Post by txsmoke on Jul 26, 2007 18:47:44 GMT -7
Just remember that if you turn the gain way down, you may overdrive the input of the amp and/or overdrive the output of your processor into clipping. Moderation is the key (ain't it always?)
Mike
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Post by longswordxenon on Aug 12, 2007 23:23:01 GMT -7
What kind of power was the EP2500 pulling during testing?
The reason I ask is, since the EP1500 was pulling 16.7 amps at full tilt, is the typical 20 amp home outlet even cpable of giving the EP2500 enough juice to even reach 'rated' power?
Excellent and interesting tests!
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