| Re: One PLX 3602 in stereo or two PLX 2502's bridged? [message #321280 is a reply to message #320807 ] |
Fri, 09 May 2008 15:55   |
 kevinjames
Messages: 132
Registered: October 2005
Location: San Jose CA. |
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So my dilema continues lol. I have decided to go with something that will give between 1.5 and 2x RMS so that part of it is over. However I am still concerned with AC draw and the ability to run 2 amplifiers in 4 ohms bridged mode from ONE 20 amp circuit with each amplifier powering a pair of SR 4735X cabs.
So another option has been recomended to me which is to go with 2 Crown XTI 2000 amps. The XTI 2000 will give 2000 watts bridged into 4 ohms and will draw 9.9 amps. The QSC PLX 2502 will give me 2500 watts bridged into 4 ohms and will draw worst case 11.2 amps.
So the question is, how do the Crown amps compare to the PLX's and would this be a better option? I like the QSC's b ut am concerned with tripping breakers. The Crown will give me a little bit less power but should not never trip a breaker if the amps are kept out of clipping.
So the question is, for running to amps bridged into 4 ohms from one 20 amp circuit, should I go with the QSC PLX 2502's or the Crown XTI 2000's?
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| Re: One PLX 3602 in stereo or two PLX 2502's bridged? [message #321333 is a reply to message #321280 ] |
Fri, 09 May 2008 19:35 |
Sean Chen
Messages: 90
Registered: February 2008 |
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No Message Body
[Updated on: Fri, 09 May 2008 19:39]
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| Re: One PLX 3602 in stereo or two PLX 2502's bridged? [message #321355 is a reply to message #321339 ] |
Fri, 09 May 2008 21:27 |
Sean Chen
Messages: 90
Registered: February 2008 |
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20 Amp x 120 V = 2400 W available from wall
1200 W of desired output per speaker x 4 = 4800 W of program output.
4800 W x 1/3 program power ratio = 1600 W of total RMS output
Required efficiency = 1600W / 2400W = 66.7%
You will need amplifiers that have efficiency bettern than 66.7% in order to get full power you want and still not trip the 20A circuit.
PL 380 will deliver it with flying color, at 85% efficiency.
On the other hand, Crown XTI 2000 have following efficiency of
Input power = 9.9 Amp x 120 V = 1188 W
Heat loss = 460W
Efficiency = (1188-460)/1188 = 61%
So with XTI 2000 you won't trip the 20A circuit, but you will only get 1000W per speaker. Should be fine.
[Updated on: Fri, 09 May 2008 21:28]
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| Re: One PLX 3602 in stereo or two PLX 2502's bridged? [message #322100 is a reply to message #321363 ] |
Mon, 12 May 2008 17:57 |
kevinjames
Messages: 132
Registered: October 2005
Location: San Jose CA. |
Has No Life |
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LOL I hear ya, but when it comes to money it's not always that simple.
Simply put, I really muld MUCH rather go with the two 2502's than the two XTi2000's, BUT I don't have endless money to spend so I don't have the luxery of buying, trying and then finding out I made the wrong choice. It needs to be done right the first time.
I am thinking with just over 2 x rms to each cab i should have sufficiant headroom that I won't need to drive them too hard, thus meaning I wouldn't trip a breaker BUT on the other hand there is NO guess work with the Xti 2000, a little less output power at 1.5 x RMS per box and its Crown not QSC but I WON'T trip a breaker going that route.
Its the classic situation.. my heart says get the QSC's... you'll be fine, my brain on the other hand says go for the XTi's and you KNOW you won't trip a breaker.
Download my latest mixes here:
www.musicv2.com/artist/dj_kevin_james
New Mix added 4/12/08
Watch me spin live Saturday's 3-5 PM Pacific here:
[url]http://www.stickam.com/profile/faderwaveradio
Baba Booey!
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| Re: One PLX 3602 in stereo or two PLX 2502's bridged? [message #322104 is a reply to message #321370 ] |
Mon, 12 May 2008 18:04 |
kevinjames
Messages: 132
Registered: October 2005
Location: San Jose CA. |
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I just checked out the CD series, it only shows a rating for bridged mono in 8ohm.. and I don't see anything stating that you can run them bridged to 4ohms, which leads me to beleive that may not be safe.
Download my latest mixes here:
www.musicv2.com/artist/dj_kevin_james
New Mix added 4/12/08
Watch me spin live Saturday's 3-5 PM Pacific here:
[url]http://www.stickam.com/profile/faderwaveradio
Baba Booey!
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| Re: One PLX 3602 in stereo or two PLX 2502's bridged? [message #322401 is a reply to message #320555 ] |
Tue, 13 May 2008 14:20 |
Ryan Garnett
Messages: 360
Registered: November 2005 |
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Stick with the pair of PLX2502's. Those QSC 1/8th ratings mean light clipping (occasional flicker of the clip lights) and since you have 2x rms you will never even need to hit the clip lights or even come close to get the power you need out of those speakers. If you are, they you're risking the speakers more then tripping a breaker.
There are other options too, seeing as how this is only powering tops, I assume there will be other circuits with other gear. Lets say you have two circuits total, you can put one amp on each and then disperse the other gear between the two. So...
Circuit 1:
#1 PLX2502
FOH (mixer, processing, etc)
Circuit 2:
#2 PLX2502
Stage (backline, a fan, some LED lights, etc)
Rather then
Circuit 1:
2 x PLX2502's
Circuit 2:
Stage Power
FOH
I know it's a simplified example, but the point is, you dont necessarily have to load down the circuits like you were intending.
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| Re: One PLX 3602 in stereo or two PLX 2502's bridged? [message #322466 is a reply to message #322401 ] |
Tue, 13 May 2008 17:40 |
kevinjames
Messages: 132
Registered: October 2005
Location: San Jose CA. |
Has No Life |
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Sounds good, I think I will stick with the two 2502's. Also I require a MINIMUM of 3 20 amp circuits to even consider taking a gig they would be set as follows:
Circuit 1:
2 PLX 2502's on mains running above 100hz bridged at 4 ohms
Circuit 2:
2 Sub amps running below 100hz (currently 2 Crown CE 2000's soon to maybee be 2 MORE PLX 2502's) also bridged to 4 ohms
Circuit 3:
DJ Booth (3tech 1200's, 3 CDJ 1000's,Rane MP/XP2016a rotary mixer, Thrive audio Isolator),1 pair JBL Eon 15G2 Booth Monitors + 1 DBX 166 monitor limitor, DBX Driverack 260 processing for main system, fan for amp rack, Soundcraft Spirit M12 mixer, Toshiba laptop computer, and any other misc gear i may need.
P.S. I am now lookinging into a distro for when a 50amp outlet is available but don't know what to look for. Looking for something with 6 seperate 20 amp circuits and a 50 amp input.
[Updated on: Tue, 13 May 2008 17:42]
Download my latest mixes here:
www.musicv2.com/artist/dj_kevin_james
New Mix added 4/12/08
Watch me spin live Saturday's 3-5 PM Pacific here:
[url]http://www.stickam.com/profile/faderwaveradio
Baba Booey!
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