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Power Amp/Subwoofer combo...any advice or opinions?

TotalChaosPro

Hi Guys/Gals..:)
I have recently acquired a pair of JBL MRX528S Dual 18" Subwoofers: http://www.sweetwater.com/store/detail/MRX528S/ and have approx. $1000 remaining in my current equipment budget for a power amp to drive them.
I am considering buying a Crown XTi 4000: (Price: $999) http://www.sweetwater.com/store/detail/XTi4000/ for the job.
I want to make the best choice for my budget, and being "newish" to pro-audio set-ups... I'm really hoping someone here could give me their opinion or any advice they might have on this amp / speaker combination.
Any thoughts you might have to point me in the right direction would be very much appreciated.
Thanks in advance for your help!:)
Peace,
Jerry
January 11, 2008 @02:21am
RotorOnTop

I had the occasion to gig with a band last year that used 1 Crown XTi 4000 as a mains amp, running 2 B-52 2-15 w/horn cabs and it was awesome! This Crown amp has very usable power, clean amp, plus the included DSP section adds alot to its funtionality, the sub harmonic bass generator will rattle the walls. Even the XTi 2000 model ran in mono operation would be a great choice for a sub woofer amp. Your system should kick.
January 11, 2008 @01:08pm
JBLman89

Jerry,
I have 2 JBL MRX518S subs (only 1 - 18" driver per cab) and I power them with one Crown CTs 2000 delivering 1000 watts to each sub at 8 ohms. This setup provides more than adequate power for almost any application.
I also do all my processing with a DriveRack PA and not let the amp do it.
However, since the power handling of the MRX528S is 1000W / 2000W / 2000W you should put at least 1000W into each sub. Perhaps even 2000W to each sub. Its better to have a more powerful amp than speaker because you're more likely to blow a speaker with distorted signal from the amp than a signal that is too high.
You should perhaps ask JBL their opinion about which Crown amp to use. Sweetwater engineers are also very helpful!
February 19, 2008 @08:19pm
cas-audio

Crown amps are great but I have always used QSC & had great results. One QSC Powerlight PL236 should handle them if they are rated at 1000 watts @ 4 ohms. You also can get a 6 year warranty on them right now. They are rather lightwight also. I would not want to use any amp bridged at a 4 ohm load for very long or under extreme conditions.
Cas-audio
February 24, 2008 @05:18pm
JBLman89

I agree with cas-audio about bridging amps....not a good, stable, long term solution.
February 25, 2008 @10:34pm
RotorOnTop

I understand the heat, over-load of a bridged amp at 4ohms...but why? I have been running stereo amps bridged mono and have never had a failure, even down to 2 ohms-bridged mono on a sub setup for years. I'm not saying this is a good option, but it is an option for more power and its there if the speakers can handle it.
February 26, 2008 @10:54am
Cory Cooper

Good rule of thumb for amps/speakers - 1.5x to 2x the power rating of the speaker.
February 26, 2008 @01:37pm
Dad Loves Toys

Near as I can tell, the JBL subs are 4-ohm and you'll need a minimum of 2,000 watts to each. I can tell you that I've used the QSC RMX4050HD with exactly this configuration and it cranked! My understanding is that the HD (heavy-duty) designation means that the amp is designed specifically for 4-ohm and 2-ohm operation with extra thermal capacity. If you bridge the amp, you'll be sending 2,000 watts to each of the speakers. Trust me, you'll be thrilled with the results. The 6-year warranty helps too :-)
Jerry,
I have 2 JBL MRX518S subs (only 1 - 18" driver per cab) and I power them with one Crown CTs 2000 delivering 1000 watts to each sub at 8 ohms. This setup provides more than adequate power for almost any application.
I also do all my processing with a DriveRack PA and not let the amp do it.
However, since the power handling of the MRX528S is 1000W / 2000W / 2000W you should put at least 1000W into each sub. Perhaps even 2000W to each sub. Its better to have a more powerful amp than speaker because you're more likely to blow a speaker with distorted signal from the amp than a signal that is too high.
You should perhaps ask JBL their opinion about which Crown amp to use. Sweetwater engineers are also very helpful!
February 29, 2008 @08:04pm
stuff82s

I currently run a pair of Peavey Versarray 218 with a CS4080. These subs really pound and get nice and low with amazing clarity. I am definitely looking to upscale and get a couple more pair.
However, the CS4080 isn't exactly the lightest, but the Crest Pro9200 is a lighter alternative at a price.
May 11, 2008 @06:43pm
Krynos

I play in a very Heavy-Low, rock band. We have the MRX 528 dual cabs as well. We first purchased the QSC RMX 2450's and bridged them at 2400 watts for each sub cab. But that wasn't enough. So now we use the QSC PLX 3602's on the subs. We have 1 amp bridged for each Sub, giving them 3600 watts each. It makes all the difference having that headroom on the subs. Plus the amps are so much lighter.
October 7, 2008 @05:11pm