High Value and Good for Muliple Subwoofers
There is no better value for your money when it comes to audio power amps than these iNuke DSP amps. They pack so very much into a 2-rack unit and they are easy to transport. You can avoid needing to have a whole rack full of compressors, EQs, limiters, crossovers, etc. and just have one unit that does it all and sounds great and will not break your back or the bank. You can set up limiting based on Watt output, which is really nice and makes it easy to protect your system from overload. That is a good thing, as this amp has a ton of power and can easily blow most passive speakers.
This model can run speakers in series down to 4 ohms per channel in stereo, which means you can daisy-chain up to two 8-ohm speakers per side or one 4-ohm speaker per side for a very powerful but very simple and compact system of up to 6000 watts and either 2 or 4 speakers running off one amp with all the bells and whistles you could need. Doing this will likely push most passive speakers well past the max power you'd want to run them, so BE CAREFUL turning up the level. Don't use it without setting the output limiter in the software app well to that 75% safe level. You need to use the app over USB to do that because the built-in display does not show the wattage you are outputting, only the app does that. The app is Windows-only with no Mac version.
1,500 watts of output per speaker is going to be seriously loud. 3,000 watts coming out of one speaker is insanely loud. Good luck finding affordable full-range speakers that can even handle the full peak output of one channel of this thing without blowing. It's probably best for powering subwoofers as there are many affordable passive subs that can handle that kind of wattage but you'd want 4 single 18s or 2 dual 18s running at full blast to take full advantage of this thing. If you don't need that much bass, this thing is overkill. I myself use one of these to power two VP1520 full range speakers in stereo mode and it can easily get uncomfortably loud with amp turned up only half way. I cannot turn it up past half way without risking blowing the speakers. I cannot say it enough - this amp is so powerful that you must exercise extreme caution when using it with most speakers.
There are three downsides to this unit. The first is the noise. The built in fan is loud. It sounds like a jet engine or noisy refrigerator running. You can't notice it when the music is loud but I wouldn't buy one of these for casual home listening as you have to turn up the volume a lot to overcome the fan noise. That costs it one star for me. But I've heard replacing the fan with a better one is a simple fix and makes it nearly silent. I'll be looking into doing that modification soon.
The second downside is the lack of bridge mode, which means you cannot put the total output power of the amp into a mono signal to power one side of a sound system or the bass part of your system. You get way more power per dollar out of an amp that way and it's great for multiple-amp setups because you can use one input and get two outputs with more power going to each. This amp is basically two iNuke NU3000DSPs in one 2-space rack box that each run one mono channel and are already hardwired individually bridged. It's nice and powerful, but it only costs $160 more to buy two separate iNuke NU3000DSPs instead, run one bridged for your subs and the other in stereo for your tops and have way more control of your signal by having four channels of DSP instead of only 2. Or you could use both amps in bi-amp mode and have full stereo with four crossovers using the amps in bi-amp mode. You could also power a total of 16 separate 8-ohm speakers that way and have a huge wall of sound running from a 4-space amp rack. With the iNuke NU6000DSP, you can only run a total of 4 8-ohm speakers. I think it is more than worth the extra $160 to have the much better expandability and processing capability.
This amp also works well in bi-amp mode with one mono input but keep in mind you need at least two of them if you want to use the built-in crossover feature and get stereo output. There are also only two ins and two outs and no thrus. If a multiple-amp system whereby you want the most bang for your buck is what you are building, then the iNuke NU3000DSP or NU12000DSP or even NU1000DSP is the better choice as you will get substantially more total output per dollar spent on those units and more versatility since you can run them in bridge mode with more total channels and more DSP for just a little more cash. That costs this particular model half a star as it makes it less versatile than all the other iNuke amp models. I own an NU3000DSP and an NU6000DSP for my system and I am realizing that two NU3000DSPs would in many ways would have been a better use of money. Then I could expand my system to 16 speakers instead of 12 and would have more total volume output potential and a more versatile setup for less money and amp weight. Since there is no thru signal output on any of the iNuke amps (something that makes running two in a 4-unit rack with a single output source a bit impractical), my current configuration requires I use a mixer with a dedicated secondary sub output so I can run one copy of the signal to each amp simultaneously. I could get a splitter box or a crossover or a 1U rack mixer but then I would need a bigger rack. But if you have two identical iNukes that support it, you can get around the need for a separate mixer sub output when using multiple amps by using both amps in bridge mode or bi-amp mode. This configuration doesn't work with my setup because the NU6000DSP cannot run bridged and when it runs bi-amped it is way more powerful than the NU3000DSP, making it hard to match the output of the side it runs vs the side the NU3000DSP runs.
The third downside is the lack of 2 ohm support. 4 ohms is the lowest supported impedance rating for each channel with this model. This is lame for people who want to run a lot of speakers off of one amp. In most cases, you can't run more than 4 speakers in total off of this amp, but you can run 8 off an NU3000DSP or a NU12000DSP, or even an NU1000DSP. Given, with the peak watt rating of speakers being so high these days, you may not want to run more than 4 speakers from one amp just so you can maximize their individual output, but it was lame for me to buy this amp and not realize its limitations in that respect. Given the choice, I'll take a less powerful and lighter amp that can run twice as many speakers and can put all of its power into one mono signal than a more powerful, heavier amp that can run half as many speakers and has to split its power into two separate signals. The 440W per side at 8 ohms of the NU3000DSP is more than adequate to drive a pair of single 10", 12" or 15" of tops at quite high volume since high frequencies need so much less power to reproduce than bass, and if you want to drive 8 tops from one NU3000DSP, you can and each one will get 375 watts. That's why this thing makes much more sense for running subwoofers, huge full-range speakers with multiple 15" bass drivers in them, or line arrays. You really don't need this kind of power for single-driver tops and it is a waste of money to buy this to do that.
So yeah, you are way better off in many ways with two iNuke NU3000DSPs than one of these, but one of these is great if you just want one very powerful amp to power 2 or 4 speakers in total and don't need the capability to expand much by adding more speakers. Anything more powerful and you start needing things like 30-amp circuits with funny shaped twist-lock plugs. This is about the most power you can possibly get in a two rack-space format and is ideal for small and simple passive systems.