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Amplifier meet
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colinmono View Drop Down
Young Croc
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Points: 1113 		Post Options Post Options   Thanks (0) Thanks(0)   Quote colinmono Quote  Post ReplyReply Direct Link To This Post Posted: 03 September 2009 at 2:44pm
Originally posted by colinmono colinmono wrote:


I guess its no real surprise, but one thing that is very clearly illustrated by the tests is the variation in manufacturers current methods of measuring lightweight power output. For example the PL380's stated output is 4000 Watts per channel vs the E90 at 8000 Watts per channel, yet they came out pretty close in this test.

Originally posted by Duncan Duncan wrote:

The difference in a few dB at these power levels is as much as a few kW. Even 0.8 of a dB is a lot of power.
 
The differences may look small, but they are not.



Fair point, although...

Originally posted by biotec biotec wrote:

The QSC PL380 was extremly close to keeping up with the bigger amps, and I was suprised at how capable it was given how little I hear about them.


I could have picked other examples - the T5N and the FP6400 both had the same max SPL in the test, yet one manufacturer quotes an extra 700 watts per channel. The K10 was louder than the E90 in the tests, and the manufacturer quotes 2000 watts less per channel.

Just trying to make the point that current lightweight power ratings aren't as helpful as they could be to end users.

Everyone seems to have liked the sound of the E90 and its obviously in the top tier, my comment wasn't aimed at MC2 specifically, just a general observation.
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Tim Bespoke Audio View Drop Down
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Hello .....
 
Ok i was at the meet and all i can say is thank you all so much for turning up bring your kit i loved it.
Rog - you are one of the nicest guys i have ever met and iam again very sorry for any comments i may of made in the past you are truely a fantastic bloke to meet.
 
Duncan - Wooow my friend you are going places and that E90 is a complete beast ive used it on 1 of my jobs and it has some scary power in there LOL all i keep thinking is what the hell will you be making in 10 years time ConfusedClap.
 
Mike - Hes ok i quess.... joking a side thanks for putting the event on and hopfuly another soon.
 
Barry - FUNNY AS f**k ALL DAY MATE LOL
 
Great day and great results Big smile
 
Tim
 
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djtuffer View Drop Down
Young Croc
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I am a little disappointed at how the Matrix amps performed but it seems that this could be to due to with the fact that the amps are not specd to run 2 ohms and thus the meters are not calibrated accordingly (UKPs anyway).  They might have been a way off peak in reality. Not sure if this is affecting the XP's and Infinite X also.
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Sounds_d_b View Drop Down
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Points: 1025 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Sounds_d_b Quote  Post ReplyReply Direct Link To This Post Posted: 03 September 2009 at 3:07pm
Yeah, The Infinate X is a real disappointment, especially considering how authoritative the 8V2 is, and indeed the anecdotal qualities of the previous 7V1 model.


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Jake_Fielder View Drop Down
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With the matrix amps, were they just turned up until the limit light showed, or just maxxed out with limit light on alot?
 
Same question but regarding the inf8, was it just cranked right up with lights on constantly, like how Rog says it should be used??
 
 
EDIT: Should have said 0db light


Edited by Jake_Fielder - 03 September 2009 at 7:10pm
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Rog View Drop Down
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I've just got the old calculator out and done a bit of maths.
 
If the Infinite 8 V2 was giving 3800 watts into 2 ohms per side and you dropped that power to 2500 watts per side, which is what the 5000VZ quotes as its power output then you would expect the new SPL to be 135.6dB, which is very close to its measured 135.2dB figure.
 
If you drop the power to 1400 watts per side then you should get 133.1dB so the Crest P8001 which was producing 131.6dB was a bit out.
 
If you raise the power output from 3800 watts per side to 5000 watts per side then you would expect to see 138.6dB, but this assumes zero power compression taken place with the drivers. The FFA 10 did 136.2dB which is 2.4dB down from what you would expect to see. This 2.4dB is easliy explained by power compression taken place within the drivers. PD quote 1.6dB power compression with 800 watts going in. The FFA 10 was putting 1250 watts into each driver so a 2.4dB drop with an extra 450 watts per driver over its rated input sounds about right.
 
If we raise the output level to 8000 watts per side then we would expect 140.6dB to be produced the our speaker stack. The MC2 E90 managed 136.5dB which is 4.1dB down from what could have been expected. Each driver would have got 2000 watts which is 1200 watts more than the 800 watt limit that gives a power compresson figure of 1.6dB So would that extra 1200 watts pere driver give rise to a 4.1dB loss in output. I'd have to say yes, as I've tested drivers with 1500 to 2000 watts going into them and measured as much as 5 to 6 dB of power compression.
 
So its quite possible that the bigger amps really were putting out the high power levels they clam, it was just being eaten up in power compression.
 
Next question.
 
So can any one warrant putting 2000 watts into each driver. And do we need amps that can do this.
 
 
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Ben_Lawrance View Drop Down
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But don't forget Rog, that we were only using 2.5mm cable.

You said in the pub last night that had we been using 6mm cable, you would have expected an increase of maybe as high as 10dB.
 
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Rog View Drop Down
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The Infinite X7 didn't work corretly out of the box. It was a prototype and I didn't have time to even check it before the test.
 
It came on but made the drivers sound like they were all broken so we turned the amp off straight away. Its a shame as I know it can do good things and is getting better all the time. It was just too soon to have it running into that load with that track.
 
Next time will be different ha ha.
 
Yep was great to meet you too Tim. I guess we just work better as people when we are chatting face to face.
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Rog View Drop Down
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Well I said that I've been to a few dub systems and replaced there very long runs of 2.5mm cable with 6mm cable and measured a 10dB increase in output.
 
Mike was not using very long runs but if he had of used 4 or 6mm cable I do believe we would have see more output at the stack. But what you have to remember is that all the amps used the same 2.5mm cable so no single amp would have had an andvantage. Increasing the cable diameter would have just made all the readings louder. If it was bell wire then the bigger amps bit have caused a bit of heating in the very thin cable and that might have been resonsible for a greater loss, but 2.5mm is big enought even with 8000 watts to not cause any power lose due to heating or inmpedance changes.
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rich21 View Drop Down
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Points: 632 		Post Options Post Options   Thanks (0) Thanks(0)   Quote rich21 Quote  Post ReplyReply Direct Link To This Post Posted: 03 September 2009 at 3:45pm
fantastic job guys
a real world test is what was needed and is what we got
spec sheets mean very little
very glad to see the FFA10 up there with the best (i have 2)

rich
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biotec View Drop Down
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Originally posted by Rog Mogale Rog Mogale wrote:

 
@nick (biotec). Wow, our version and thoughts of the amps were virtually identical. Did you read my post first or just type it now. It's good in a way as it means the diffrences were big enough to be spotted by more than one person.


I hadn't read your post. I started writing my post yesterday actually but couldnt be bothered to finish it because I was too tired. Hopefully the similarity means that my ears aren't too mangled to hear what others hear. Or perhaps our ears are equally mangled.

Sorry I couldn't hang around and go to the pub. Having my car with me meant that going to the pub would have meant an increased chance of ending the day badly!
me so horny, me love you long throw.
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Duncan View Drop Down
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Originally posted by colinmono colinmono wrote:

Originally posted by colinmono colinmono wrote:


I guess its no real surprise, but one thing that is very clearly illustrated by the tests is the variation in manufacturers current methods of measuring lightweight power output. For example the PL380's stated output is 4000 Watts per channel vs the E90 at 8000 Watts per channel, yet they came out pretty close in this test.

Originally posted by Duncan Duncan wrote:

The difference in a few dB at these power levels is as much as a few kW. Even 0.8 of a dB is a lot of power.
 
The differences may look small, but they are not.



Fair point, although...

Originally posted by biotec biotec wrote:

The QSC PL380 was extremly close to keeping up with the bigger amps, and I was suprised at how capable it was given how little I hear about them.


I could have picked other examples - the T5N and the FP6400 both had the same max SPL in the test, yet one manufacturer quotes an extra 700 watts per channel. The K10 was louder than the E90 in the tests, and the manufacturer quotes 2000 watts less per channel.

Just trying to make the point that current lightweight power ratings aren't as helpful as they could be to end users.

Everyone seems to have liked the sound of the E90 and its obviously in the top tier, my comment wasn't aimed at MC2 specifically, just a general observation.

My comment was general as well. Just worth remembering the scale of power in dB.
 
Powersoft conservatively rate the K10, I have had a lot more out of it than they quote on paper.
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