1000watts? Are these really?

[greenalien]

For a fine example of 'big numbers' you need look no further than the Behringer iNUKE NU6000 Power Amp. It's claimed that it

Delivers 2 x 3000 Watts into 4 Ohms, 2 x 1500 Watts into 8 Ohms

...

 

Without any reference as to how these power figures were obtained, they are meaningless - but good marketing!

 

Wow - that was my 500th post, I just got promoted!!

[Bobbsy]

 

For the "1 million watt" opening ceremony it will more likely be temporary generators. No doubt someone on here actually knows, but probably isn't allowed to say...

 

It's still going to be a stadium after the Olympics--not as big but it'll still need a lot of power for night football matches, concert bookings, whatever.

 

A megawatt isn't huge in power terms for a large structure. The last TV complex I managed the technical side of had a supply of about about 750KW when you factored in standard office stuff, technical stuff, studio lighting and then all the air conditioning to cool it (not a factor in an outdoor stadium).

 

...and that's if the "million watt" PA is the actual requirement or just the max output--just like this thread is discussing, a "thousand watt amp" doesn't always put out a thousand watts and doesn't draw that much either.

 

I don't know what the power requirements for a stadium like the Olympic one will be--but based on other work I've done, a megawatt supply doesn't sound all that impossible to me.

[Shez]

From the 2010 Eurovision diary:

So here are the guys watching over 6 out of the total 14 generators used for this production. The first 4 you see, starting from the furthest, are for PRG lights, video and rigging generating 4 Megawatts of power. Another 2 are for OB and the portable offices outside (2 Mw), 1 for air conditioning (1 Mw), 2 for catering and the press centre (1.5 Mw), 2 for OB for other countries ( .5 Mw), plus 1 Megawatt spare and they're all backed up! We'll use an estimated 400,000 litres of diesel over the course of the production to power these babies.

No mention of power for sound, strangely...

Back on topic though, 350 x 3KW amps for an Olympic stadium certainly doesn't sound too unreasonable.

[fincaman]

For a fine example of 'big numbers' you need look no further than the Behringer iNUKE NU6000 Power Amp. It's claimed that it

Delivers 2 x 3000 Watts into 4 Ohms, 2 x 1500 Watts into 8 Ohms

...

 

Without any reference as to how these power figures were obtained, they are meaningless - but good marketing!

 

Wow - that was my 500th post, I just got promoted!!

 

I have long disagreed on how power amps are rated as watts does not convey to non technicals how much output and amplifier can deliver IE 200 watts is not twice as loud (I am avoiding using terms like SPL) as 100 watts it simply requires the speaker to dissipate twice as much heat.

[Bobbsy]

From the 2010 Eurovision diary:

So here are the guys watching over 6 out of the total 14 generators used for this production. The first 4 you see, starting from the furthest, are for PRG lights, video and rigging generating 4 Megawatts of power. Another 2 are for OB and the portable offices outside (2 Mw), 1 for air conditioning (1 Mw), 2 for catering and the press centre (1.5 Mw), 2 for OB for other countries ( .5 Mw), plus 1 Megawatt spare and they're all backed up! We'll use an estimated 400,000 litres of diesel over the course of the production to power these babies.

No mention of power for sound, strangely...

Back on topic though, 350 x 3KW amps for an Olympic stadium certainly doesn't sound too unreasonable.

 

One thing to remember though is that 2010 was in Baku--I suspect they wouldn't have relied on the local supply for anything, no matter what it was rated at.

 

I'm pretty sure they'd have to augment the stadium supply for something like the opening but I was just taking slight issue with the idea that a megawatt (and a dedicated sub station) would be in any way unreasonable for a large stadium.

[timsabre]

I'm pretty sure they'd have to augment the stadium supply for something like the opening but I was just taking slight issue with the idea that a megawatt (and a dedicated sub station) would be in any way unreasonable for a large stadium.

I wasn't disagreeing with you, I'm sure it will have a very large permanent supply, I was just suggesting that the extra power requirements of the opening and closing ceremonies, given the temporary nature, will most likely be met with generators.

[kerry davies]

Most of the generation, I imagine, should be for the hundreds of TV channels that insist on their own centres. Millennium in Cardiff has an 8 megawatt supply, for instance so has little need of generators other than for really special events. I fully expect Stratford to have rather more than one or two "sub-stations". ;)

A similar sized main substation in Kuwait.

 

EDF Energy will design, construct, own and operate the electrical distribution network that will supply electricity to the 2.5sq km Olympic Park as well as the Stratford City development. The combined electrical network will consist of more than 100km of electrical cabling and over 100 local substations.

 

Hmmm. Thought so!

[timtheenchanteruk]

Its like PC speakers, they claim to be 10.21GiggaWatts yet the actual RMS figure is somwhere around the 3 or 4W mark, RMS, MPO, PMPO, all bar the first are pretty useless, used by "ICE" manufacturers and pc speaker makers, although the trends seem to be spreading.

 

Whats the quote Mr Twain?, there are three types of lie, Lies, Damn Lies and Statistics.

[John M]

First of all - Thanks

Cantankerous for your short but to the point answer about watts and also Grumpy old git for noticing my typo.

I recently sold my old original Tannoy Lancasters (with Monitor golds) for a very decent price and one of the very noticeable things about them was their efficiency and sensitivity. They came very close in loudness to my 650 watt powered JBL EONs but they were only rated at 50 watts. Another very loud but low wattage amp/combo was the Vox AC30 - but of course most of the loudness was in the mid/high guitar frequency so although loud to the ears they were not putting out the real low power watts that would/should/could be measured.

Maybe of interest to some of you - I was featured in most national newspapers and several radio stations late last year because my system was considered so loud at a very posh wedding that it made guests "physically sick". This was using two JBL EON 515s (the original low sensitivity model) in two separate rooms - so one per room, set as high as the speaker stands would go, with the speaker level set at half way and the mixer main output about a 1/3rd of the way up - so quiet that the singers (professional west end show singers doing Opera and Abba) could not hear the track. I was standing virtually in front of one of the speakers. I turned the system down several times (Its not exactly heavy rock!) and I don't have any reason to want it loud but the client had her mind set that other than turning off the system it was too loud - by the way the set lasts about 20 minutes. She has very good contacts with the press to when we came out of court (A local court in Hertford) it was a very strange feeling to be met with about 8 national newspaper journalists and photographers.

So dont forget when you next set up your system to take plenty of cotton wool for the guests and most important plenty of sick bags - in fact perhaps that could be a great money making scheme at festivals - selling sick bags

 

 

Actually thinking about my past post - maybe a great way of measuring loudness would be to use the SB/m - sick bags per minute.

[dboomer]

Typically the power rating of amps in this class of speaker are rated at "peak" or "burst" power. Nothing wrong with that as long as the manufacturer specifies how the rating was derived. Peak power probably has more bearing on sound quality than average/RMS ratings but there's not an industry wide method of rating peak power.

 

In the case of the speaker mentioned, the specs on the website are on the short side. It says there's 1000W of amplification but it does not break down how it is distributed in the bi-amp setup. Typically these days that translates to a pair of 500w amps. Now you could deliver 500W to a woofer, but the tweeter is only going to handle 10-20W. So while you may have 1000W of amp power you'll never actually deliver more than 500+ to the speakers.

[djandydee]

EV have done exactly what should be done - drive the motor units with the recommended 2-4 times the RMS power under close DSP supervision guaranteeing undistorted clean power. I would be driving the passive version with at least 1000w and have the DP226 set to -6.

 

I have sold the full ELX range and have had nothing but positive comments.

 

 

[greenalien]

I'm revisiting this topic as the Inuke 6000 amps have been around for a while now, and there are some decent reviews available online, with the general consensus being that they really do produce 1100W per channel, RMS, into 8 ohms. Given the relatively low price, currently a tad over £250 each from Thomann, I've just bought a pair - and I'm very impressed.

I'm using them to power my Nexo rig - 2 x PS15 tops and an LS-1200 sub, leaving a spare channel for a second LS1200 in the future. The only minor snag I've found so far is that the first set of breakout leads I made didn't work for the tops, only for the sub. I couldn't work out why I wasn't getting any output from the tops, until I realised that I'd used single-pole speakon plugs for the breakouts, which only work on speakon channel 1, whereas the PS15s use speakon channel 2! Closer examination of the amps rear panel also showed that amp channel 'A' is connected to both speakon channel 1 and channel 2, while amp channel 'B' only outputs on speakon channel 1. A quick rewire of the breakouts solved the problem. (In case you were wondering, the breakout leads are to provide feedback connections from the speaker outputs back into the Nexo TD controller, an essential part of the rig, which not only acts as the crossover, but also actively monitors the signal going to the speakers fropm the amps and modulates it as necessary to prevent exceeding the speaker's capabilities. Clever stuff.)

So, what are the amps like - clean, clear and powerful, just what was wanted - and at only around 7kg each, they make my amp rack a lot lighter! The switch-mode power supplies are very efficient, so the amps don't get very hot, although their fan cooling is more than adequate. Good value for the money.

[S&L]

this is pretty much what I have been saying about their EPQ series amps for the last couple of years. light, never more than a little warm running, clean and they just keep running and running.

[Dmills]

But here is the thing, RMS does not really tell us what we want to know, I would find 500W average with a supply that can support say 4KW into a reasonable speaker load for a few tens of ms at 10% percent duty cycle **FAR** more useful then an amp that supports 1KW average but is limited to that by bouncing off the supply rail.

 

RMS (They mean average, RMS is not a meaningful calculation for power), makes for a simple number to quote for the hifi crowd, but actually a thermally limited power and what the current and voltage limits are would be **FAR** more useful in a professional product.

 

I actually appreciate knowing that that Lab or Camco or whatever can swing a load a **LOT** further for a short time then it can manage for a CW tone, this is actually a very useful ability when you consider that even a compressed program will have something like an 8:1 peak to average ratio (And in fact you will probably find with a bit of digging that that is what the amps are rated for).

 

On power supply sizing, remember that the protection is typically to a first order a thermal trip (at least for small overloads) and that these inherently have a rated I^2T value, keep under that and you can quite safely pull a **LOT** of power from the grid for a few hundred ms, it is RMS current integrated over some seconds that matters for supply protection.

6 or even 12Kw of Camco or Lab off a 13A socket is not a stretch until dodgy dave doubledecks turns up.

 

Regards, Dan.

[sam.spoons]

But here is the thing, RMS does not really tell us what we want to know, I would find 500W average with a supply that can support say 4KW into a reasonable speaker load for a few tens of ms at 10% percent duty cycle **FAR** more useful then an amp that supports 1KW average but is limited to that by bouncing off the supply rail.

 

RMS (They mean average, RMS is not a meaningful calculation for power), makes for a simple number to quote for the hifi crowd, but actually a thermally limited power and what the current and voltage limits are would be **FAR** more useful in a professional product.

 

I actually appreciate knowing that that Lab or Camco or whatever can swing a load a **LOT** further for a short time then it can manage for a CW tone, this is actually a very useful ability when you consider that even a compressed program will have something like an 8:1 peak to average ratio (And in fact you will probably find with a bit of digging that that is what the amps are rated for).

 

On power supply sizing, remember that the protection is typically to a first order a thermal trip (at least for small overloads) and that these inherently have a rated I^2T value, keep under that and you can quite safely pull a **LOT** of power from the grid for a few hundred ms, it is RMS current integrated over some seconds that matters for supply protection.

6 or even 12Kw of Camco or Lab off a 13A socket is not a stretch until dodgy dave doubledecks turns up.

 

Regards, Dan.

 

Interesting, I found the same thing when I was trying to work out if I could run a reasonable sized rig off a cheap ebay 2KVA genset. The 8:1 figure turns up in several active speaker specs and my measurements/tests confirm that it is probably a realistic measure of the power a decent class D power amp would draw. My mate reckons that an active sub would draw rather more amps than the 1/8th figure but I ran my rig (2 x QSC K12s, 1 x EV sBa 750 sub, 3 Yamaha DXR10s, 1 x Alto TS110A and a Mackie DL1608 desk) on a pub gig with a power meter inline and, even with the 5 piece soul/funk band playing full on, 105dB at 10 metres from the FOH, it never exceeded 2A. Now I don't know what averaging my Maplin Power meter does but I bought the genny and when I ran pretty much the same rig (less the sub and TS110A but plus backline) from it (the genny), it never even broke a sweat (and I even had a couple of LED PAR64s on there).