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Measuring Amplifiers - Page 5

post #121 of 1913
7/11/07 at 2:10pm
Thread Starter 
Quote:
Originally Posted by thylantyr View Post

Where's the non-variac tests, you know the tests where the consumer just plugs
the amp into the wall and performance levels are realistic not optomistic

They are penciled into my schedule shortly after pigs fly! Seriously, I have to adjust my methodology and just haven't had the energy lately. But non variac tests will come.
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post #122 of 1913
7/11/07 at 2:12pm
Thread Starter 
Quote:
Originally Posted by Scott Simonian View Post

I am also looking for a similar test...

I wanna know if I can squeeze out at least 1400w RMS outta my EP2500.

1400 watts per channel into 2 ohms stereo? or 1400 watts mono?
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post #123 of 1913
7/11/07 at 2:14pm
Thread Starter 
Quote:
Originally Posted by NEO Dan View Post

Chuck,
can you measure response down to 5hz or below for these two units? I've been wondering just how much roll off in the very low end theese two units have. Being a K Series owner I've been wondering what the particular difference is between the two. Some pics of the innards of the BKA1000a4 would be enlightening.

Thanks
Dan

I can measure response down to .1 Hz on my Wavetek generator. I will probably do a special measurement of 1 Hz to 100 Hz for the K2 and Buttkicker because they are known for low end usage.
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post #124 of 1913
7/11/07 at 2:21pm
Thread Starter 
[quote=staffcurtis]
Quote:
Originally Posted by chasw98 View Post

I am a certified, factory trained Crown Technician.



What is your opinion on the crown I-tech series? I am powering 4x 15" 2000 watt RMS subs, and was looking at a used IT8000 for $2500. Would you recommend my money is better spent on 8 behringer amps? Not only do I want the power to match, but I also want the sound quality to definately be there.

PS...I had buttkickers for my subs, and they didn't sound good to me at all. Now I replaced adcom 5500's with these to get more power, so I may have just been used to how good they sounded. Buttkickers have decent power output, but the punch was not there like the adcoms.

Let me know

The sound quality of the Crown I-tech series will be better than the Behringer amps. Better power supplies, better switching, just better design. But you pay for it also. The I-tech are first and foremost a pro amplifier, meant to sit in a dusty rack in the beating down sun, running on 92 volts AC and never missing a beat. They will operate that way. They are meant to work and work under all conditions. When you bring that Crown into your living room and put it on the floor next to that Pass amplifier, it won't sound as good as it did during the concert. But if it is not over driven and run outside of its limits, it will still sound pretty damn good! Better than the Behringer. You get a lot of watts for a little money with the Behringer and they have very impressive THD and Noise numbers. But they are not a Crown. Just my opinion.

Chuck
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post #125 of 1913
7/11/07 at 2:39pm
Quote:
Originally Posted by chasw98 View Post

armystud:
This ones for you!

2.34 ohms load
bridged mono EP2500
20 KHz sine wave
52.2 volts RMS
.982% distortion
1,164 watts

Yes, it will run 2 ohms in bridged mono but not very hard or for very long.

Chuck

How long did it last?
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post #126 of 1913
7/11/07 at 2:41pm
Quote:
Originally Posted by chasw98 View Post

They are penciled into my schedule shortly after pigs fly! Seriously, I have to adjust my methodology and just haven't had the energy lately. But non variac tests will come.

No energy?

Vitamins, minerals, anti-oxidants, fish oil. I have a nice recipe that *we've* been using for the past year and I feel like I'm 20 years old again. If I had more coin, I'd be back to being a DIY madman. lol

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post #127 of 1913
7/11/07 at 2:44pm
Thread Starter 
Quote:
Originally Posted by vitod View Post

How long did it last?

Remember this is sine wave testing................




Less than 2 minutes!
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post #128 of 1913
7/11/07 at 2:45pm
Thread Starter 
Quote:
Originally Posted by thylantyr View Post

No energy?

Vitamins, minerals, anti-oxidants, fish oil. I have a nice recipe that *we've* been using for the past year and I feel like I'm 20 years old again. If I had more coin, I'd be back to being a DIY madman. lol


If I had more coin I would probably be using the vitamin 'C' we used to use. NO, wait a minute, thats bad for you these days. Got to keep my decades straight!
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post #129 of 1913
7/11/07 at 2:49pm
Quote:


1400 watts per channel into 2 ohms stereo? or 1400 watts mono?

I guess it would be 2ohms stereo because I run a bridged 4ohm load. I was hoping a clean 700w RMS could reach each RLp18.

Thanks!
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post #130 of 1913
7/11/07 at 2:50pm
[quote=chasw98]
Quote:
Originally Posted by staffcurtis View Post


The sound quality of the Crown I-tech series will be better than the Behringer amps. Better power supplies, better switching, just better design. But you pay for it also. The I-tech are first and foremost a pro amplifier, meant to sit in a dusty rack in the beating down sun, running on 92 volts AC and never missing a beat. They will operate that way. They are meant to work and work under all conditions. When you bring that Crown into your living room and put it on the floor next to that Pass amplifier, it won't sound as good as it did during the concert. But if it is not over driven and run outside of its limits, it will still sound pretty damn good! Better than the Behringer. You get a lot of watts for a little money with the Behringer and they have very impressive THD and Noise numbers. But they are not a Crown. Just my opinion.

Chuck

Should I consider one crown Itech 8000 I can get used for $2500, or two PLX 3602's? Of course the QSC's will save me a few hundred bucks, but sound quality is very important. Another helpful member is recommending the CE4000's, so I'm looking for a couple of those used too.

Let me know
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post #131 of 1913
7/13/07 at 7:27am
Thread Starter 
[quote=staffcurtis]
Quote:
Originally Posted by chasw98 View Post


Should I consider one crown Itech 8000 I can get used for $2500, or two PLX 3602's? Of course the QSC's will save me a few hundred bucks, but sound quality is very important. Another helpful member is recommending the CE4000's, so I'm looking for a couple of those used too.

Let me know

I would be very surprised if you could hear a sound quality difference between the Crown or the QSC. By using 2 QSC amps, you have built in redundancy in case an amp broke. You also have some more possibilities in the configuration arena by having 2 amps with 2 channels each for future changes. I would buy 2 QSC's. My personal opinion, and this is purely personal (no scientific fact), is that I don't like the sound of Crown amplifiers when used in a home environment. Don't get me wrong, in a live environment, they are monsters. When surrounded by 10,000+ screaming audience and 20 Itech-8000's, who will hear the subtlety of an amp? But sitting at home in a controlled environment, every last little nuance will be picked up. About a year ago, I changed out my pro amps from the main and center speakers to subwoofer use only. I replaced them with very high wattage (for home), high end audio, expensive amplifiers. I did hear a difference to the good. OTOH, I am using my pro amps for my IB subwoofers and they do the job very nicely! Sound great.

Chuck
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post #132 of 1913
7/13/07 at 7:35am
Well if the QSC actually sounds better to you, then the Behringer ep2500 is arguably the same amp. Are you referring to QSC's better lines (PLX3602, Powerlight 6.0 PFC), or most of their amps in general. I am also considering Crown K2's since I hear they have good sound.

Thanks for your help! Your testing is helping us a lot!
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post #133 of 1913
7/13/07 at 7:37am
[quote=chasw98]
Quote:
Originally Posted by staffcurtis View Post


I would be very surprised if you could hear a sound quality difference between the Crown or the QSC. By using 2 QSC amps, you have built in redundancy in case an amp broke. You also have some more possibilities in the configuration arena by having 2 amps with 2 channels each for future changes. I would buy 2 QSC's. My personal opinion, and this is purely personal (no scientific fact), is that I don't like the sound of Crown amplifiers when used in a home environment. Don't get me wrong, in a live environment, they are monsters. When surrounded by 10,000+ screaming audience and 20 Itech-8000's, who will hear the subtlety of an amp? But sitting at home in a controlled environment, every last little nuance will be picked up. About a year ago, I changed out my pro amps from the main and center speakers to subwoofer use only. I replaced them with very high wattage (for home), high end audio, expensive amplifiers. I did hear a difference to the good. OTOH, I am using my pro amps for my IB subwoofers and they do the job very nicely! Sound great.

Chuck

What model pro amp were you running on your LCR's?
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post #134 of 1913
7/13/07 at 7:41am
One more thing....I saw on ebay someone had an old crown 10,000 watt amp. This thing was huge, and required 220v 3 phase for power. It sold on ebay pretty cheap ($1000) relatively speaking. How would that sound on subs, or is that mostly for PA applications?

Thanks again
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post #135 of 1913
7/13/07 at 7:59am
im using an old crown XLS 602 for my tc-1k 15" and im no even running it bridged, and it's enough power for me...fact, im only using 1 side of the amp
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post #136 of 1913
7/13/07 at 8:35am
Thread Starter 
Quote:
Originally Posted by staffcurtis View Post

Well if the QSC actually sounds better to you, then the Behringer ep2500 is arguably the same amp. Are you referring to QSC's better lines (PLX3602, Powerlight 6.0 PFC), or most of their amps in general. I am also considering Crown K2's since I hear they have good sound.

Thanks for your help! Your testing is helping us a lot!

I would be referring to QSC's PLX and Powerlight series. I believe the RMX2450 is closer to the EP2500 than the PLX models. I should have a K2 at the end of the month to put on the bench and test.
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post #137 of 1913
7/13/07 at 8:35am
Thread Starter 
[quote=cecaa850]
Quote:
Originally Posted by chasw98 View Post


What model pro amp were you running on your LCR's?

4 EP2500's
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post #138 of 1913
7/13/07 at 8:39am
[quote=chasw98]
Quote:
Originally Posted by cecaa850 View Post


4 EP2500's

Thanks, the reason I asked is that I'm about to run 4 of the Crown XLS's in my 7.1. They were cheap enough (with the rebate) that if I don't like them, I'll swap them out. I have heard some good reports though, well see..........
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post #139 of 1913
7/13/07 at 8:45am
Thread Starter 
Quote:
Originally Posted by staffcurtis View Post

One more thing....I saw on ebay someone had an old crown 10,000 watt amp. This thing was huge, and required 220v 3 phase for power. It sold on ebay pretty cheap ($1000) relatively speaking. How would that sound on subs, or is that mostly for PA applications?

Thanks again

That would be a strange amp that Crown built under the name Techron. It is a beast. They use one at JL Audio for Klippel testing. (JL got theirs off of eBau also!). That amplifier was used mainly for outdoor live sound.

A little Crown history. Crown came about because of the need to get the word out by missionaries. SO they built bulletproof tape recorders to carry in the jungles of Africa and South America. It turns out they built such a good recorder that other people wanted to buy them. And they started to make money. Then they realized they could get the word out even better with high powered radio transmission. So they built very powerful transmitters (think hundreds of thousands of watts). At one point in time they had the largest load bank in the world for testing RF amplifiers. The radio station was and is located in Quito, Equador with call letter HCBJ (His Christ Brother Jesus).
Along came a young engineer with a thesis from college about solid state high powered amplifiers. Thus was born the Crown DC300. And the rest is history.
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post #140 of 1913
7/13/07 at 8:49am
Thread Starter 
[quote=cecaa850]
Quote:
Originally Posted by chasw98 View Post


Thanks, the reason I asked is that I'm about to run 4 of the Crown XLS's in my 7.1. They were cheap enough (with the rebate) that if I don't like them, I'll swap them out. I have heard some good reports though, well see..........

I will say that my EP2500's sounded very good and I bought a pair of Cinenova Grande amplifiers that cost me about $3,000.00 and retail for more. SO that is what I paid to have a better amp experience.
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post #141 of 1913
7/13/07 at 8:53am
If it didn't cost $120 for shipping, I'd send my Xti 4000 and XLS 402D for testing. If only I was local...
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post #142 of 1913
7/13/07 at 8:54am
The Crown startup was actually pretty interesting...I thought all churches made money anyway

Would you recommend that Techron amp if I could get it cheap?

Thanks
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post #143 of 1913
7/13/07 at 9:05am
Thread Starter 
Quote:
Originally Posted by staffcurtis View Post

The Crown startup was actually pretty interesting...I thought all churches made money anyway

Would you recommend that Techron amp if I could get it cheap?

Thanks

That Techron amp is pretty old, pretty inefficient, and if you ever had to repair it, I don't know. For use as a subwoofer amp, it would probably be just fine. But if it is 3 phase, do not plan on using one of those boxes that lets 3 phase run off of single phase. The amp will not like it and will break! And if you have 3 phase at home........ I envy you!
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post #144 of 1913
7/13/07 at 2:00pm
A slight bit off topic--but I just had to clarify. HCJB actually stands for Heralding Christ Jesus' Blessings--hence the radio station.

I was actually out in Quito last summer and went to the Antenna farm--they are actually taking down most of the antennas since the airport is moving out there. They did have one pretty sweet antenna out there--several hundred thousand watts coming out of it.... They said they keep finding dead bunnies who wandered inside the fenced area and got a little too close by

Mike
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post #145 of 1913
7/13/07 at 2:07pm
Quote:
Originally Posted by chasw98 View Post

That Techron amp is pretty old, pretty inefficient, and if you ever had to repair it, I don't know. For use as a subwoofer amp, it would probably be just fine. But if it is 3 phase, do not plan on using one of those boxes that lets 3 phase run off of single phase. The amp will not like it and will break! And if you have 3 phase at home........ I envy you!

How difficult is it to add three phase to my existing wiring? I have an electrician buddy that owes me a favor
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post #146 of 1913
7/13/07 at 2:21pm
Thread Starter 
Quote:
Originally Posted by mpotoka View Post

A slight bit off topic--but I just had to clarify. HCJB actually stands for Heralding Christ Jesus' Blessings--hence the radio station.

I was actually out in Quito last summer and went to the Antenna farm--they are actually taking down most of the antennas since the airport is moving out there. They did have one pretty sweet antenna out there--several hundred thousand watts coming out of it.... They said they keep finding dead bunnies who wandered inside the fenced area and got a little too close by

Mike


Thanks for the clarification. I am relying on my memory and the talk of some old timers at the factory from 20+ years ago. And they did mention dead small animals at the farm!
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post #147 of 1913
7/13/07 at 2:23pm
Thread Starter 
Quote:
Originally Posted by staffcurtis View Post

How difficult is it to add three phase to my existing wiring? I have an electrician buddy that owes me a favor


Generally if your neighborhood does not have it, it is very expensive or almost impossible to get. Most house have single phase entering their home. To ask the power company for 3 phase in a residential neighbrhood is very iffy. But it doesn't hurt to give them a call.
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post #148 of 1913
7/13/07 at 2:28pm
Thanks for the info...and you're saying to create three phase from one phase could damage the amp?
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post #149 of 1913
7/13/07 at 2:45pm
http://www.phaseconverter.com/cncpro.html

10kw unit cost $1000.

Easier and more efficient to get the I-T8000 for $2500 if you want high power.
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post #150 of 1913
7/13/07 at 4:13pm
Thread Starter 
Quote:
Originally Posted by staffcurtis View Post

Thanks for the info...and you're saying to create three phase from one phase could damage the amp?

Yeah, the unit mentioned by Thylantr is exactly what I am talking about NOT TO USE. Over the years I have benn forced to use them in machine design for industry. For certain applications, they will do the job, such as in running a motor. When you want them to drive transformers and electronics, they do not react well. I have had them fail regularly and when actual 3 phase was used, everything worked right.
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