Your thoughts on a JBL MRX RIg ???
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Posted on Aug 05, 2009 04:03 pm
SDSAudio
Member Since: Aug 05, 2009
Hey guys hows it going ?. Im looking at buying a JBL MRX rig which consits of the following
2x - double 18 sub bins (1000w each)
2x - Double 15 and horn top bins (800w each)
4x - Crown XT2000 amps and all the cables etc to run
just wondering what your thoughts are on this set up and if any one has used the MRX range before from JBL ?. Be great to hear some thoughts on it
Cheers
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Aug 05, 2009 05:14 pm I worked for the guy that designed the MRX box. They great boxes.
You should have no problem with them at all.
Just one question thou. Why 4 Crown XTi 2000's?
Three should be all that is needed to run this rig.
It should be Mid/High Left on one amp. Mid/High Right on the other. And then just one for subs.
Is the 4th for a monitor mix?
Aug 05, 2009 05:24 pm Well thats the intresting thing the guys that im buying it off said they are running basicly 4x amps 1 each for the speakers
and there all bridged ! so thats 2000w per speaker. They said they tried running the subs and tops off two but didn't have the amount of head room that they were after.
Im just running this system as a two way system with a DBX Drive rack, can you sugest a better setup ?
Aug 05, 2009 07:33 pm I think that someone is trying to pull the wool over your eyes. Just to sell some gear that they have.
At 2000 watts a driver, you would have one crispy box on your hands. Emphasis on the extra crispy!
The JBL MRX system is just fine. They use to come in to flavors, 60 and 90 degrees wide. I don't know what they are now a days. And the XTI series of amps are just fine as well. They have built in DSP, so you will not need your DBX with it.
The only thing that you should do is listen to the system before you but. With this person claiming that they were running 2000 watts a driver...... I would really check things over with a fine tooth comb before adding them to your inventory.
As for a different suggestion on a system, I would need to know your budget. That will help determine what brand name to go with. And what are you looking to do with it as well? What I mean by that is, what size room will you be doing?
Aug 05, 2009 07:54 pm Sweet man i think its just for the head room all of the bins are double 18s and double 15s which are aound 1000 w each for the subs - 2000w and 800w for the tops
I was just mean amp wise ? i would love to just run a very simple two way system insted to trucking around 4 amps !.
I will be using this PA for small Dance parties clubs and Band rigs of about 50 - 500 people i also have some W bins that i can expand as well
Aug 05, 2009 08:01 pm The other thing i was worried about is running 4 XTI 2000 off just the Mains power ? im in NZ we have 240v coming out of a mains socket is that ok ? im not very good with power ratings and what not?
Aug 05, 2009 09:34 pm I just looked at the amp ratings at 120V. And the XTi 2000 draws 8.3 amps at 1/4 power.
Translation, They do have a large draw to them. At 240V, The draw will be less. I think that you will be able to put two of them per dedicated outlet.
If you are running any more amps for monitors or such, then I think that you may wish to consider tieing in power. Having a distro is not the worst thing in the world to own. It's just finding places that will allow you to do so.
I think that you would be fine to run just two way. And using just two amps to do so. The MRX's do have a passive crossover network in them. So, you should be fine with that. And then just using a single wall outlet will be fine.
But as I stated before. If you are monitors as well. And then band gear. You still may wish to consider a tie in power.
Aug 05, 2009 09:44 pm oh ok sweet so should i be able to run 2 double 18 cabs and 2 double 15 and horn cabs of just Two of XTI2000 and it should be ok ?
Aug 05, 2009 09:52 pm Sure. One amp for the tops. And one for the subs.
It should be fine.
Aug 05, 2009 10:08 pm Oh sweet i didn't think two XTI2000 would be enough for them
Aug 05, 2009 10:11 pm No. 800 watts per side is just fine for the MRX's.
Aug 05, 2009 10:13 pm including the subs ?? i know there 1000w?
Aug 05, 2009 10:48 pm Sure. I run the Trubosound TSW 721's with much less. You can easily over power your subs with that much power in bridge mode.
Aug 05, 2009 10:53 pm Oh sweet cool man thanks heeps for your help so just to sum every thing up
Best way to run this JBL rig with two amps would be
1x XTI2000 bridged for the subs
1x XTI2000 for the tops ?
Aug 05, 2009 11:27 pm That should be fine.
The thing that confuses everyone, to include me, is the way that manufacturers are now using a new rating system.
In the new ratings, you see all of these enormous figures. such as 3200 watts peak.
Now, here is the catch. And I love this one. The rating are for the smallest amount of time period. Just enough to move the driver for a half of a cycle. Say around .125 ms.
If you were to measure this in the old standard fashion, you would find it only to be around 300 watts linearly. That's it!
Now, the same goes for the amps as well. They measure an amps power @ 1/2 of a 40 hz wave. And they use 40 hz for the enormous power that it will try to draw for that short period of time.
Now the same applies for the old standards for the amps. A 2500 watt amp will test only at 175 watts linearly.
So, the configuration that I have given you will work fine. Without damaging any of your gear.
Aug 05, 2009 11:40 pm Cool cheers for that mate yea the old power rattings are very confusing thanks for all your help
