How is Behringer NU6000 delivering 1500RMS into 8ohms with IRS2092s?

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
I could get this schematic on some online website
Dropbox - behringer_nu3000_nu6000_sm.pdf
I was going through how come IRS2092 with +/-82V able to deliver 1500RMS into 8 ohms. Even if two channels of the IRS2092 amp is bridged each at +/-82V how will it be able to deliver 1500RMS into 8 and 3000 into 4ohms?
V² / R? So +/-82V is 164V p-p. 164 / 1.41 = 116V RMS. Over 8 ohm's gives 1691 Wrms. Naturally there are losses, but 1500Wrms is doable. Or do I make a mistake?
 
It does, for few dozen milliseconds, until the unregulated PSU output drops or enters hiccup mode, safety limiting kicks in, and things get hot.

In fact, I can recognize the hints of some marketing text I wrote, a few years ago, for more powerful and rugged amplifiers (that can do rated power for seconds before limiting), in the ads of these cheap amplifiers (and others). Nowadays the marketing is being copied too, but with a difference, the text I wrote was telling the truth. The copiers know no truth. They are like cameras taking and selling pictures of whatever they like. But the essence of things is far more ample than capturing static images.
 

ICG

Disabled Account
Joined 2007
It does, for few dozen milliseconds, until the unregulated PSU output drops or enters hiccup mode, safety limiting kicks in, and things get hot.

Nope, it does not. The amp was tested with several different test modes and one of them was the burst mode test which signal consists of 20ms 1kHz burst, followed of 480ms silence (like described in the IHF-A-202/IEC60268 specs), which resulted in less than 1300W per channel (1252W & 1239W, to be precise). That means it does, in fact, not deliver that power for 'a few dozend ms' or actually any relevant period of time.
It was not a 'monday-amp' either, other tests revealed there are examples which only able to deliver a bit over 1100W per channel at 8 Ohm.

It's not a horrible amp, still one of the better 'bang for the buck' choices but it simply does not deliver what it promises. A lot other amps don't do that either but sometimes it's worth investing a little bit more.
 
Nope, it does not. The amp was tested with several different test modes and one of them was the burst mode test which signal consists of 20ms 1kHz burst, followed of 480ms silence (like described in the IHF-A-202/IEC60268 specs), which resulted in less than 1300W per channel (1252W & 1239W, to be precise). That means it does, in fact, not deliver that power for 'a few dozend ms' or actually any relevant period of time.
It was not a 'monday-amp' either, other tests revealed there are examples which only able to deliver a bit over 1100W per channel at 8 Ohm.

It's not a horrible amp, still one of the better 'bang for the buck' choices but it simply does not deliver what it promises. A lot other amps don't do that either but sometimes it's worth investing a little bit more.
I've seen that 1300W test too... And it makes me wonder under which testing-conditions Behringer measured the output power they claimed. Under "normal" operation conditions the claimed power proves to be an illusion. ( marketing guys are very bad people and ought to be jailed for that)

The other measurements prove that the amp would deliver if it had been specified as a 1000W/Ch. amp.
 

ICG

Disabled Account
Joined 2007
Behringer got a lot of very good products like the DCX2496 Ultradrive controller (best sold, most used DSP over here) or the X32 digital mixer which are very competitive in price and performance. So I don't see why they have to rightout lie about the specs, it would still be a very good deal with the actual power output. They aren't the only ones though, even a hefty price tag does not alway guarantees you get the promised performance. I guess in the times of facebook and Trump the ones win who are the noisiest, sad but true. :(

Surprisingly, some brands actually deliver more than they promise though, i.e. the Thomann Proline 3000, which is by far not the top of the price range of the amps but rock solid, stable and relyable.
 
Unfortunately that t.amp Proline 3000 is class H and is made up of 37kg of natural resources whose extraction and processing provokes about 10~20 times more disease and war than a cost optimized class D amplifier doing 750W/kg continuous and 2kW/kg for few seconds. (This is an affordable attainable ratio, requiring dedication, though.)

I have a Spanish word for that: "Mastodonte". For this case meaning something like: that the "project" got "fed" (ma)ternally yet (st)ubbornly, so gr(o)wth happened as a si(d)e effect, then it continued gr(o)wing , it got i(n)creasingly huge, turning agains(t) its cr(e)ators.
 
Last edited:

ICG

Disabled Account
Joined 2007
Unfortunately that t.amp Proline 3000 is class H and is made up of 37kg of natural resources whose extraction and processing provokes about 20 times more disease and war than a cost optimized class D amplifier doing 750W/kg continuous and 2kW/kg for few seconds. (This is an affordable attainable ratio, requiring dedication, though.)

I didn't say it will be easy. :p (in doubt substitute with 'lightweight' ;))
What you are saying is ofcourse true but it's simply an example that there are amps that over perform and more than fulfil what they are advertised with. And since we are already 'here': These are heavy duty amps (in every meaning of that) but if you compare them with those lightweight, underperforming class D amps, at PA subs you'll notice they are on eye level or even above with a lot of amps rated twice the power. No, that's not a tell-tale-story, compare their output at 30 and 40Hz with class-D amps. How comes that? Well, firstly, their switching counterparts very often drop a lot in power in the lower regions. Combined with the exaggerated power specs and the much, MUCH shorter burst/impulse reproduction ability you end up slightly (but not surprisingly) below the Proline. If you care for the sound quality, it's even more drastically, the Proline are delivering so much more stable and souvereign bass performance.

I have a Spanish word for that: "Mastodonte". For this case meaning something like: that the "project" got "fed" (ma)ternally yet (st)ubbornly, so gr(o)wth happened as a si(d)e effect, then it continued gr(o)wing , it got i(n)creasingly huge, turning agains(t) its cr(e)ators.

Heh. :p Well, over here we call them 'Eisenschweine' ('iron pigs'). Okay, if you are on the road, often the weight does matter. But you wouldn't go on the road that with an iNuke, the flimsy case and plastic front will deteriorate rather quickly with such use and I don't want to start on relyability. You end up with much more expensive ones than the iNukes which can take that. If you use the amps at a venue, cinema or at home, the weight can be ignored altogether and if you compare price/performance instead of weight/performance, you'll have a very, very hard time to beat that performance with an equally priced class-D amplifier, even if that huge material battle should cost a lot more in theory.

I'm not saying A/B / H amps are better, I just want to tell these (still) have their justification, depending on what you're doing.
 
I'm not saying A/B / H amps are better, I just want to tell these (still) have their justification, depending on what you're doing.

In terms of power I doubt that. (Discussions about sound details are not in the focus of this post.)
Back to power: If the power can be delivered longer or shorter and for bass or mid only is not a question of class A/B/H or D. You can design any of these amp types for short term power or for reproduction of a continuous sine wave as well.
Edit: ...well, classA needs already full power design for idle operation. So classA cannot really be designed for short term power.
When designed to the same power spec the class D amp will be smaller, lighter, less resource hungry, less energy hungry and - if you exclude R&D cost - less costly.
It's just a question of the specific implementation, which is a consequence of the specification. The struggle is about the specification.
Inapropriate power specs, which do not fit to the intended use case, have tradition since the world of audio amplifiers is advertising power.
 
Last edited:

ICG

Disabled Account
Joined 2007
In terms of power I doubt that. (Discussions about sound details are not in the focus of this post.)

I was not only talking about the sound, also on relyability and they are very easily serviceable over a very long period of time. You cannot say the same about class D and SMPSs and if any of the defective ICs are out of production in most cases the amp is ready for the bin.

But I have to repeat myself, I just mentioned the Powerline amp because they over-deliver the specs by a remarkable margin. It just happened to be a class H amp. When was the last time you saw a reasonable priced class D amp which exceeded the specs in realistic, actually usable situations?

Back to power: If the power can be delivered longer or shorter and for bass or mid only is not a question of class A/B/H or D. You can design any of these amp types for short term power or for reproduction of a continuous sine wave as well.

Yes, you could. But looking at the market, noone does it (RMS) at class D amps, at least not up to much, much higher price levels.

Edit: ...well, classA needs already full power design for idle operation. So classA cannot really be designed for short term power.

Well, noone uses Class A in these ranges of output power, there are none you could buy. If you need high power, the requirements in power supply and heat/cooling are simply too high.

When designed to the same power spec the class D amp will be smaller, lighter, less resource hungry, less energy hungry and - if you exclude R&D cost - less costly.

Yes, that's right and I know that. I nowhere claimed anything else.

It's just a question of the specific implementation, which is a consequence of the specification. The struggle is about the specification.
Inapropriate power specs, which do not fit to the intended use case, have tradition since the world of audio amplifiers is advertising power.

Well, that's not always the case. I just pointed out there actually ARE amplifiers which exceed the specs easily and I also said that's not a matter of a high price level. The Proline example sells well so there's no need to actually lie.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.