[Stereodude]

Here are the power output numbers. This is a measurement of one channel, though two are driven here, into a 4r load.

The amp will put out a solid 1200w per channel in this config, or 2400w total. This is at about 60% efficiency. Pushing any harder triggers protect mode.

http://i.imgur.com/ugmlOkS.png

Here are the numbers into 8r, same test, 2ch bridged, only one channel measured.
http://i.imgur.com/oc2ffFI.png

Lots of burst/peak power just where you don't need it, above 500Hz.

 

[Bassment]

So the nu-4 was being run in bridged mode, with BOTH bridged channels going at the same time, but only one measured? Is that correct?

 

[Stereodude]

So the nu-4 was being run in bridged mode, with BOTH bridged channels going at the same time, but only one measured? Is that correct?

FWIW, that's how I understood notnyt's post.

 

[Bassment]

yeah, nvm, I see now it says both channels are driven.

 

[Scott Simonian]

Lots of burst/peak power just where you don't need it, above 500Hz.

Lol! Cuz 1,200w per channel isn't enough for anything.


Big thanks @notnyt for testing. Hope you're starting to feel better.

 

[Stereodude]

Lol! Cuz 1,200w per channel isn't enough for anything.

Sure, why would anyone care if they promise 3000W and you only get 1200W...

 

[notnyt]

Sure, why would anyone care if they promise 3000W and you only get 1200W...

I'm going to try to get the 3000 and 1000 on the bench soon as well.

 

[More is Better]

Thanks, one question though. If one hooks up four 8r loads to the NU4-6000, how many watts would one realistically get per channel at say, 40 Hz please?

I looked back to see if I could find 8 ohm stereo test results and didn't find them.

This should be a close guestimate.

I got the .66 because the amp seems to put out about 1 1/2 times the power every time you halve the impedance.


40hz is 1082W @8ohm bridged

 

[Scott Simonian]

Sure, why would anyone care if they promise 3000W and you only get 1200W...

I guess that is one way.

Since we are in the place to 'know better' than to blindly follow the advertised output then really it is exactly as I'd expect it to be.

I never look at something like an EP4000 to actually output 4,000w or whatever. I look at them as something that will do 1.5kw for ~$300 and for that it is an excellent value and solid performer.

You should know better than to subject these to an unrealistic performance expectation and just look at them as they are.

 

[GizzeGutten]

I looked back to see if I could find 8 ohm stereo test results and didn't find them.

This should be a close guestimate.

I got the .66 because the amp seems to put out about 1 1/2 times the power every time you halve the impedance.


40hz is 1082W @8ohm bridged

 

[notnyt]

I looked back to see if I could find 8 ohm stereo test results and didn't find them.

This should be a close guestimate.

I got the .66 because the amp seems to put out about 1 1/2 times the power every time you halve the impedance.


40hz is 1082W @8ohm bridged

 

[More is Better]

YW

I must be having one of those days...never noticed the link in Not's post.

 

[GizzeGutten]

What does it mean when an amp is voltage limited? Is that on a channel by channel basis, and what is the purpose of a limit like that?

 

[notnyt]

What does it mean when an amp is voltage limited? Is that on a channel by channel basis, and what is the purpose of a limit like that?

Ok, simple explanation, amplifiers create voltage. They cannot put out more voltage than what the rails run at. if you have a 100v rail, the max voltage peak you'll get out of the amp is 100v. Into a 2r load this is 2500w, into an 8r load this is 625w.

Now, there's no guarantee that the amp can produce enough current to actually supply 2500w into that 2r load, if it can't, it's current limited. However, if it can supply the current demands presented by the load, then it's limited by its max voltage output. You can see running this example amp at 8r has a much lower current demand than at 2r. This is the case with the NU4-6000. It's limited to around 145 volts of output, so into a less demanding load, that will be the limitation. From my tests, we can see that the amp can put out about 2400w before going into protect. It puts out under 300w into a single channel, so even if running 4 flat out, the amp still has some breathing room.

 

[Stereodude]

I guess that is one way.

Since we are in the place to 'know better' than to blindly follow the advertised output then really it is exactly as I'd expect it to be.

I never look at something like an EP4000 to actually output 4,000w or whatever. I look at them as something that will do 1.5kw for ~$300 and for that it is an excellent value and solid performer.

You should know better than to subject these to an unrealistic performance expectation and just look at them as they are.

Yes, but my original point was that the higher "peak" power was at useless frequencies for subwoofer users. Meaning it's basically a 1200W x 2 @4 ohm amp, even if you were tempted to consider "peak" power.

 

[GizzeGutten]

Eureka! Thank you for taking the time to explain Notnyt.

 

[notnyt]

****, I wish I had another test bucket. I did some more testing on the nu4-6000 and running this in 2ch mode and it will put out 1100w per channel into 2r. This is using either A+C or A+B, with A+C doing slightly better, but not of significance. It seems the limit might not be with the amp section, but with the PS. I'm seeing about 70% efficiency at 100hz with this configuration, and about 68% at 40hz. This amp might actually be able to put out 3kw at 40hz, and closer to 4kw on the high end, not that that matters :/

This is 1ch driven into 2r. Adding a second channel basically doubles the current pull and drops like a volt off the vrms numbers.

I'm trying to think of a way to test with more channels running, but not coming up with anything. It's interesting how the efficiency increases once you start getting over 2000hz. It seems bridged mode actually decreases efficiency on the amps I've tested so far. I'm guessing this is because the output voltage is lower than the rail voltage in these cases.

Also, this amp has a significant amount of high frequency switching noise over 400khz.

 

[Tip24/96]

Not, I wonder if it would be possible to tweak some parts in the power supply in any of the iNuke series amps so that you can squeeze out some extra current/voltage?

 

[Stereodude]

Not, I wonder if it would be possible to tweak some parts in the power supply in any of the iNuke series amps so that you can squeeze out some extra current/voltage?

Maybe, but it's possible Behringer knew the PS was the weak point and skimped on other areas of the amp because they knew the PS would act as protection. If you beef up the PS something else could get damaged.

 

[Bassment]

****, I wish I had another test bucket. I did some more testing on the nu4-6000 and running this in 2ch mode and it will put out 1100w per channel into 2r. This is using either A+C or A+B, with A+C doing slightly better, but not of significance. It seems the limit might not be with the amp section, but with the PS. I'm seeing about 70% efficiency at 100hz with this configuration, and about 68% at 40hz. This amp might actually be able to put out 3kw at 40hz, and closer to 4kw on the high end, not that that matters :/

This is 1ch driven into 2r. Adding a second channel basically doubles the current pull and drops like a volt off the vrms numbers.

I'm trying to think of a way to test with more channels running, but not coming up with anything. It's interesting how the efficiency increases once you start getting over 2000hz. It seems bridged mode actually decreases efficiency on the amps I've tested so far. I'm guessing this is because the output voltage is lower than the rail voltage in these cases.

Also, this amp has a significant amount of high frequency switching noise over 400khz.

I believe this is the case in the original EP2500/EP4000 tests too that were done a few years ago, 2 ohm stereo did about 900 watts per channel, where bridged mode did 1600 watts. Something like that.