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Measuring Amplifiers - Page 10

post #271 of 1913
9/18/07 at 7:34pm
SMPS + BCA + PFC = kicka$$
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post #272 of 1913
9/19/07 at 5:38am
the EP2500 has always been the bang for buck champ.....no doubt.

but keep in mind that despite almost identical measurements to the K2, the EP's will still clip easier and more frequently than the K2 during transients and bursts...the K2 is pretty hard to clip in comparison to the Ep2500:

http://www.avsforum.com/avs-vb/showp...&postcount=319
http://www.avsforum.com/avs-vb/showp...&postcount=325
http://www.avsforum.com/avs-vb/showp...&postcount=438
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post #273 of 1913
9/19/07 at 9:30am
Thread Starter 
Quote:
Originally Posted by ssabripo View Post

the EP2500 has always been the bang for buck champ.....no doubt.

but keep in mind that despite almost identical measurements to the K2, the EP's will still clip easier and more frequently than the K2 during transients and bursts...the K2 is pretty hard to clip in comparison to the Ep2500:

http://www.avsforum.com/avs-vb/showp...&postcount=319
http://www.avsforum.com/avs-vb/showp...&postcount=325
http://www.avsforum.com/avs-vb/showp...&postcount=438


Actually that is not exactly true. What is true is this: The clip lights do not light up as often as they do on an EP2500. While testing the K2, I never once got a clip light to do more than flash for a millisecond. Yet the waveform on the oscilloscope clearly shows a distorted waveform, not clipped, but distorted. OTOH, I could get the IOC lights (input output comparators) to light up very easily. The IOC lamps are the true clip lights for a Crown amp.
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post #274 of 1913
9/19/07 at 9:46am
Quote:
Originally Posted by chasw98 View Post

Actually that is not exactly true. What is true is this: The clip lights do not light up as often as they do on an EP2500. While testing the K2, I never once got a clip light to do more than flash for a millisecond. Yet the waveform on the oscilloscope clearly shows a distorted waveform, not clipped, but distorted. OTOH, I could get the IOC lights (input output comparators) to light up very easily. The IOC lamps are the true clip lights for a Crown amp.


Interesting. That is one reason why I never thought the K2 is well suited for sub duties. Sure it works, but there are better amps out there, IMO.
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post #275 of 1913
9/19/07 at 10:35am
Quote:


Actually that is not exactly true. What is true is this: The clip lights do not light up as often as they do on an EP2500. While testing the K2, I never once got a clip light to do more than flash for a millisecond. Yet the waveform on the oscilloscope clearly shows a distorted waveform, not clipped, but distorted. OTOH, I could get the IOC lights (input output comparators) to light up very easily. The IOC lamps are the true clip lights for a Crown amp.

Ooof! That sounds a little scary and a bit deceiving too. Just think, youre rockin' out with not a care in the world and suddenly your subs VC goes up in smoke and youre sitting there wondering what just happened. I know it wouldnt be a common occurrence but the thought is scary. I still have respect for the K1/K2 but I think if I were in the position to purchase amp(s) and had a good chunk of change, I wouldnt even consider them anymore. They are kind of expensive too.
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post #276 of 1913
9/19/07 at 10:59am
Quote:
Originally Posted by chasw98 View Post

Actually that is not exactly true. What is true is this: The clip lights do not light up as often as they do on an EP2500. While testing the K2, I never once got a clip light to do more than flash for a millisecond. Yet the waveform on the oscilloscope clearly shows a distorted waveform, not clipped, but distorted. OTOH, I could get the IOC lights (input output comparators) to light up very easily. The IOC lamps are the true clip lights for a Crown amp.

interesting.... did you get a chance to compare the distortion waveform with the EP2500 to compare what sinewave looked like?

Quote:
Originally Posted by jpmst3 View Post

Interesting. That is one reason why I never thought the K2 is well suited for sub duties. Sure it works, but there are better amps out there, IMO.

the K2 is MORE than suited for sub duties...sorry. It is no CE4000 for sure overall, but it does a magnificent job. Better internals, completely quiet, goliath construction, is worth the extra $ for some of us, although I wholeheartedly believe the EP2500 is as good a choice for sure.
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post #277 of 1913
9/19/07 at 11:04am
Quote:
Originally Posted by Scott Simonian View Post

Ooof! That sounds a little scary and a bit deceiving too. Just think, youre rockin' out with not a care in the world and suddenly your subs VC goes up in smoke and youre sitting there wondering what just happened. I know it wouldnt be a common occurrence but the thought is scary. I still have respect for the K1/K2 but I think if I were in the position to purchase amp(s) and had a good chunk of change, I wouldnt even consider them anymore. They are kind of expensive too.

Scott, distortion in the waveform is not clipping! nothing scary about it. I'm sure if Chuck took it to the clip lights engaging, there would be clipping in the waveform as well.

chuck, any more insight? see my previous reply on distortion waveform of the EP...did you get a chance to correlate them?
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post #278 of 1913
9/19/07 at 11:08am
Quote:


Scott, distortion in the waveform is not clipping! nothing scary about it. I'm sure if Chuck took it to the clip lights engaging, there would be clipping in the waveform as well.

I see what you're saying. I just read it as a not very accurate light for the clip so maybe you could be clipping and not know it? Im not sure, Ive never owned one so you should know better than I would. Was just a scary thought....especially if you had just bought something real nice like a TC5400 and clipped the sh*t out of it. That would suck ass. Hehehe.
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post #279 of 1913
9/19/07 at 11:22am
Quote:
Originally Posted by Scott Simonian View Post

I see what you're saying. I just read it as a not very accurate light for the clip so maybe you could be clipping and not know it? Im not sure, Ive never owned one so you should know better than I would. Was just a scary thought....especially if you had just bought something real nice like a TC5400 and clipped the sh*t out of it. That would suck ass. Hehehe.

i can understand you worry, and yes, that would be a pretty bad thing. Clipping the amp is never a good thing, and thus, the electronics to protect it. Clipping the signal and not showing it would be bad............this is not the case here. There was no clip lights (ergo, no actual clipping) occuring, but the waveform was showing some distortion.

thus, I'm kinda curious on how the EP2500 correlates.
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post #280 of 1913
9/19/07 at 11:26am
Quote:
Originally Posted by ssabripo View Post


the K2 is MORE than suited for sub duties...sorry. It is no CE4000 for sure overall, but it does a magnificent job. Better internals, completely quiet, goliath construction, is worth the extra $ for some of us, although I wholeheartedly believe the EP2500 is as good a choice for sure.

No doubt, I just think there are others that are "better" suited. The quiet part is a plus for sure, no mods needed. I certainly wouldn't worry about damaging the K2, it is a proven and very robust design.

At least the K2s are now going for reasonable prices, which make them even more attractive for all purposes. I really dig that red version that is floating around too!

I don't know that I would choose the EP over the K2, but bang for buck the EP is a tough one to top.
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post #281 of 1913
9/19/07 at 11:26am
Any testing done on the Dayton 1000W amp? I just put it in yesterday to replace my EP2500 and it did very well for me, I could only drive 2 out of the 4 Q18s with it though but it still did very well.
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post #282 of 1913
9/19/07 at 11:29am
Quote:
Originally Posted by Scott Simonian View Post

I see what you're saying. I just read it as a not very accurate light for the clip so maybe you could be clipping and not know it? Im not sure, Ive never owned one so you should know better than I would. Was just a scary thought....especially if you had just bought something real nice like a TC5400 and clipped the sh*t out of it. That would suck ass. Hehehe.

To be fair, I've yet to read about a home owner burning a modern sub's VC from clipping.

And dude, the 5400 would take much more than some petty clipping to suffer any damage. Its VC is a monster.
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post #283 of 1913
9/19/07 at 11:30am
Quote:
Originally Posted by jpmst3 View Post

No doubt, I just think there are others that are "better" suited. The quiet part is a plus for sure, no mods needed.

At least the K2s are now going for reasonable prices, which make them even more attractive for all purposes. I really dig that red version that is floating around too!

I don't know that I would choose the EP over the K2, but bang for buck the EP is a tough one to top.

I'd choose a PLX or PLX2 over either.
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post #284 of 1913
9/19/07 at 11:36am
Quote:


To be fair, I've yet to read about a home owner burning a modern sub's VC from clipping.

And dude, the 5400 would take much more than some petty clipping to suffer any damage. Its VC is a monster.

True, true. Fair enough.

The 5400 wasnt the best example but not many people will have one of those.
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post #285 of 1913
9/19/07 at 11:40am
Quote:
Originally Posted by Scott Simonian View Post

True, true. Fair enough.

The 5400 wasnt the best example but not many people will have one of those.

I'd say it probably applies to most of the common DIY subs used today anyway. Rl-p/TC-2000/3000/SDX.
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post #286 of 1913
9/19/07 at 11:45am
Quote:
Originally Posted by Willd View Post

I'd choose a PLX or PLX2 over either.

well hell....I would too, but find me a PLX402 for $650, and then we talk
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post #287 of 1913
9/19/07 at 11:50am
Thread Starter 
Quote:
Originally Posted by ssabripo View Post

Scott, distortion in the waveform is not clipping! nothing scary about it. I'm sure if Chuck took it to the clip lights engaging, there would be clipping in the waveform as well.

chuck, any more insight? see my previous reply on distortion waveform of the EP...did you get a chance to correlate them?


Correct, distortion in the waveform is not clipping. I never got the clip lights to engage for any significant amount of time at all. I also did not get the amp to clip, but it would distort a lot. NOTE: CLIPPING IS DEFINED AS SQUARING OFF THE TOP AND BOTTOM OF THE WAVEFORM AS IN A SQUARE WAVE! The clip lights seem to be a circuit meant to detect 'square wave behavior' in the output signal, whereas the IOC lights detect a difference between the input signal and the output signal. The Behringer EP2500 'clip light circuit' is just a simple comparator that will flash whenever a difference between input and output is occurring. The EP2500 circuit is much less sophisticated (cheaper) than the monitoring circuits in the Crown K2. But then this is one reason the Crown costs more.

As far as comparing waveform distortion between the two amplifiers I could easily get a squarish waveform from the EP2500 and not from the K2. I have a friend that helped design the K2 and I will ask him if there are any 'soft clipping' circuits that are not, shall we say, advertised in the K2. There are clip limiter switches on the EP2500 that can be engaged.

Quote:
Originally Posted by Willd View Post

To be fair, I've yet to read about a home owner burning a modern sub's VC from clipping.

Then read about me. I have burnt a brand new 15 inch Dayton Titanic in a matter of minutes because I was not careful. Now all the rest I have burnt up professionally, I blame that on someone else.
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post #288 of 1913
9/19/07 at 12:16pm
Quote:
Originally Posted by chasw98 View Post

Correct, distortion in the waveform is not clipping. I never got the clip lights to engage for any significant amount of time at all. I also did not get the amp to clip, but it would distort a lot. NOTE: CLIPPING IS DEFINED AS SQUARING OFF THE TOP AND BOTTOM OF THE WAVEFORM AS IN A SQUARE WAVE! The clip lights seem to be a circuit meant to detect 'square wave behavior' in the output signal, whereas the IOC lights detect a difference between the input signal and the output signal. The Behringer EP2500 'clip light circuit' is just a simple comparator that will flash whenever a difference between input and output is occurring. The EP2500 circuit is much less sophisticated (cheaper) than the monitoring circuits in the Crown K2. But then this is one reason the Crown costs more.

As far as comparing waveform distortion between the two amplifiers I could easily get a squarish waveform from the EP2500 and not from the K2. I have a friend that helped design the K2 and I will ask him if there are any 'soft clipping' circuits that are not, shall we say, advertised in the K2. There are clip limiter switches on the EP2500 that can be engaged.

exactly!!!

and as I recall in your IB setup, the hard clipping lights on the EP2500 would come in much more frequently than the K2, telling me that it was not able to handle your IB load as well during burst scenes as the K2 did.

I was about to ask you about the soft clipping mechanism as well....
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post #289 of 1913
9/19/07 at 12:47pm
Thread Starter 
Quote:
Originally Posted by ssabripo View Post

exactly!!!

and as I recall in your IB setup, the hard clipping lights on the EP2500 would come in much more frequently than the K2, telling me that it was not able to handle your IB load as well during burst scenes as the K2 did.

I was about to ask you about the soft clipping mechanism as well....

Hold on now. The clipping lights on the EP2500 are comparators, not clip lights as we are talking about them now. You might say they are more comparable to the IOC lights on the K2 (which light up quite a bit under sine wave testing). The only way to truly test this is to have a set of meters or lights with integrated comparators that are equal and then hook the meter up to one channel of each amp and play the same passage through the amp and watch the external meter to see if it reacts the same or different. You really can't compare the lights on the K2 to the lights on the EP2500.

Saying that the EP2500 clip lights come on very frequently and that the K2 lights don't come on as frequently is hardly grounds to say that one amp handles the load better than another. I would want to use something like a storage scope to record each channel of the amp for slow playback so that we could see what is causing the comparator or clip lights to come on. My gut feeling is that the Crown is a better amp when put head to head with a single EP2500. Except that you can buy 2 EP2500's for the price of 1 K2. So now which set of amps is working harder?

Plus it is very easy to hook up the K2 to a pair of RLP15's and an EP2500 to a pair of RLP15's at the same time at my house when you come over and just see what happens.
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post #290 of 1913
9/19/07 at 1:01pm
Quote:
Originally Posted by chasw98 View Post

Then read about me. I have burnt a brand new 15 inch Dayton Titanic in a matter of minutes because I was not careful. Now all the rest I have burnt up professionally, I blame that on someone else.


haha! From clipping or too much power?

And hey...if/when I get a new amp for my TC-2K, think we could arrange for it to be shipped to you first for testing?
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post #291 of 1913
9/19/07 at 1:05pm
Quote:
Originally Posted by ssabripo View Post

well hell....I would too, but find me a PLX402 for $650, and then we talk

PLX402? That amp isn't even on QSC's website. Are you referring to the PowerLights or PLX3402? You can get a PLX-2402 for $520, b-stock.
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post #292 of 1913
9/19/07 at 1:38pm
I just scored another CE4000 for a little over $500.

Forget the PLX! Man, these things are the best bargains in subwoofer amplification!
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post #293 of 1913
9/19/07 at 1:41pm
Quote:
Originally Posted by jpmst3 View Post

I just scored another CE4000 for a little over $500.

Forget the PLX! Man, these things are the best bargains in subwoofer amplification!

Where do folks keep getting CE4000s for $500 and 600?!!
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post #294 of 1913
9/19/07 at 1:43pm
Quote:
Originally Posted by Willd View Post

Where do folks keep getting CE4000s for $500 and 600?!!

I got mine on ebay, 2 for $1000. I didn't even want a second one, but I threw in a low ball bid and no one else did??!

I have seen them go for $799 plus shipping, so I don't know why.
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post #295 of 1913
9/19/07 at 1:48pm
Quote:
Originally Posted by Willd View Post

PLX402? That amp isn't even on QSC's website. Are you referring to the PowerLights or PLX3402? You can get a PLX-2402 for $520, b-stock.

i meant the PLX3402
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post #296 of 1913
9/19/07 at 1:49pm
Quote:
Originally Posted by jpmst3 View Post

I got mine on ebay, 2 for $1000. I didn't even want a second one, but I threw in a low ball bid and no one else did??!

I have seen them go for $799 plus shipping, so I don't know why.

Dang. I guess I just never watch ebay close enough. Seems like whenever I check, there aren't any on there at all.
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post #297 of 1913
9/19/07 at 1:49pm
Quote:
Originally Posted by chasw98 View Post

Plus it is very easy to hook up the K2 to a pair of RLP15's and an EP2500 to a pair of RLP15's at the same time at my house when you come over and just see what happens.

now we talking!
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post #298 of 1913
9/19/07 at 1:49pm
Quote:
Originally Posted by ssabripo View Post

i meant the PLX3402

But hey, its rated for more output than your Crown, so why compare the two? The 2402, OTOH, is rated about the same.
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post #299 of 1913
9/19/07 at 1:53pm
Quote:
Originally Posted by Willd View Post

Dang. I guess I just never watch ebay close enough. Seems like whenever I check, there aren't any on there at all.

Same here, that is why I was suprised.
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post #300 of 1913
9/19/07 at 2:05pm
Thread Starter 
Quote:
Originally Posted by Willd View Post

haha! From clipping or too much power?

And hey...if/when I get a new amp for my TC-2K, think we could arrange for it to be shipped to you first for testing?


Way too much power! It burped and never spoke again. PM, we can definitely arrange for it to stop by Florida first!

Chuck
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