Behringer KM750 Power Amplifier

I bought this amplifier to run two 10" in-wall subwoofers that I installed in my garage when I heated/ finished it. I knew that my stereo receiver wouldn't have the power to run 4 speakers and two subs, so I opted for this amp after a lot of reading and research. I have had the amp in play for the past 4 months and I am very pleased with its performance. I rarely run it at more than 1/4 volume and that gives more than enough punch in 2, 10", 8ohm subs (w/ boxes built into the wall). I will say, it is very fast, the bass is quick and not muddy at all.The only drawback of this amplifier in a practical sense for home theater, etc, is that you may need to pair it with an equalizer as the amp itself only has volume control. I did this in the garage instead of running another lowpass filter to my subs, but this was just because of my implementation more than anything.The fan can be a bit noisy but if you have it in a cabinet, or the music/ theater system at a typical volume for listening then I doubt you will hear it, I don't until I turn the music down.Overall, great performance for the price and it sounds great!

My 40 year old Bryston 4B, used as a subwoofer amp roasted one channel last week and appears un-repairable, so I started looking for a low investment replacement (I am retired and have much better ways to spend $1000+ than on an amp these days). I read the reviews and comments regarding the KM750 here on Amazon (none of the high end magazines and audio webzines have gotten around to it yet) and for the price decided to take a chance.For reference the 4b was reviewed by The Audio Critic in 1978 and declared the then–$1195 amplifier "the best power amplifier we've been able to find so far" (Vol.1 No.4, p.41).The KM750 arrived today so these are my initial impressions.Still in the box, the first thing that struck me is how light it is...especially compared to the 4B. Setting it up is pretty straight forward, but the binding posts arent what I would expect of something labeled "binding posts". They are not 3-way or even 2 way posts. They do not accept spade lugs or banana plugs, only bare wire or pins. I suspect the contace surface is minimal too since the tightening nut is non-conducting. At least the pin/wire post accepts as large as a #10 (solid) copper wire and tighten up reasonably well. I wasnt prepared to go with a pair of SpeakON connectors but ordered a set today as that seems to be a better connection than these "binding posts".Once hooked up (RCA inputs, Stereo, .77V sensitivity, Limiter on, Ground isolation off) to my system - it drives 4 Dynaudio 30W54 drivers configured 2 channel compound loaded in tuned enclosures - and powered on, I was pleased with the low/lack of fan noise. I had read some owners found the fans noticeably loud, even when when first powered up. Even after a couple hours playing demanding music at pretty high levels, the fan noise was all but imperceptible when the room went quiet.As this amp is used below 100Hz (6db lopass so there is some mid-upper bass reproduction as well), I cannot and will likely never hear how it sounds in the midrange and treble. Its still brand new so things may evolve with time but as new it does a great job of driving the Dynaudio 12" (4 ohm nominal impedamce) drivers to which it is attached. Very controlled, deep and dynamic. Where the subwoofer overlaps the KEF/Class A MOSFET amp mid-range, this seems to blend as seamlessly as the 4B did before it.I have not removed the top or done any bench testing, but on some pictures I have seen I would guess impedances well below 4 ohms would severely limit the amps output because of the heat dissipation limits of the heatsinks I have seen in photos.So far (1 day) I am extremely happy, this amp bats way above its price.Update (3/21/18)I have had the unit in place and running for a few days now. Still love it. Nothing to complain about. I have switched the ground lift switch to the lift position as I occasionally heard a low level 60Hz in the subs when idle. They are now dead silent. Also went with the SpeakON connectors from Neutrik for the speaker outputs. The speaker wire I use is #8 stranded and the terminals on the Neutrik NL4FX connectors are limited to "4mm^2" for the screw type termination which works out about #11 stranded or #10 solid so I added some #10 solid pigtails to my speaker wires in order to attach them to the NL4FX connector terminals. I think the SpeakON provides a better mechanical and electrical connection than the 1-way binding posts supplied with the amp.

This amp ROCKS! No issues 5 months later. Highly recommended amp!Original: Bought this from the warehouse at an incredible savings. Using to power my DIY home theater subwoofer with a Dayton Rss315HO-12 4 ohm driver. When running in 'stereo' mode, the sub sounded anemic, no authority like it did with the 500 watt plate amp this KM750 replaced. I wasn't thrilled, but it wasn't so bad I would return it.Then, after having a few adult beverages one night, I made the executive decision to try bridging the amp and see what happens. Let me say, the sub came alive. I mean to the point of when it was 'stereo', and gain almost 100%, still sounded anemic. But with being in bridged mode, the gain is not even 1/2 way and the sub is ALIVE! [insert menacing laughter]. This is a GREAT amp for consumer use. Missing having a trigger control, which can be problematic, I got one of these that was recommended to me in a forum: https://smile.amazon.com/gp/product/B00WV7GMA2/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1Now, the actual review since you now know how it is being used.The weight is good. The build/finish is 1st rate. No banana plugs can be used, but pins will work. I just used bare wire, 12 gauge. The power light is an extremely annoying and extremely bright white LED. A piece of electrical tape covering it cured that nuisance. The fan...what can I say. It isn't horrific sounding, but it IS annoying AF watching a movie and having it in the same room. Cool air is drawn in thru the top and warm air is exhausted out the left side. Used in a noisy commercial environment, the noise won't be noticed, but in your living room...What I did was to just plain disconnect the fan. I measured for several days the internal temperatures before, during, and after heavy home theater usage and have determined the very small gain in heat will be easily tolerated by the electronics for years to come,I recommend this amp. Dollar for dollar, pound for pound, watt for watt, you will find no better.

I didn't really know what to expect for such a low price. Well, it's great. Absolutely no problems at all and it seems to have plenty of power for my Polk Speakers. I'm actually going to buy another one of these and run it in bridge mode for my 15" 1000w subwoofer. This is my second Behringer Amp so I'm now pretty happy with this brand. They make great stuff for a low cost. I'm planning on buying some other components from them too. I look forward to it. By the way, I have a $2000 Pioneer Elite Receiver/Amp and this sounds just as good. I'm never going to spend that kind of money again unless it's for a class A tube amp.