jbl prx......need advise

**bass dan** · #1 12-16-2010, 10:37 PM

I have been wondering about these speakers and was hopeing some folks have used these in the way i want to use them.

I primarily play upright bass thru a fishman pro plat. pre into a powered mixer. The speakers we are using are jbl mrx515's. I love the sound of my upright thru these speakers. At times i play with other bands that don't have very good speakers and the bass usually sounds pretty rough thru those systems.

Are the prx series speakers like the mrx only powered, or are they closer to the jrx series?

I was wanting to get one of the prx615's and plug my fishman preamp straight in it for gigs were the pa sucks. I'm concered that the fishman wont be able to push the poweramp in the speaker. I know the fishman is too weak to push a regular poweramp. The prx claims you can run virtually any sound source into it without a mixer.

Do you guys think this will work? I do have a pretty nice rig for my upright but quite honestly i think the jbl mrx speakers sound better than my rig which is a EA micro 550 and a pair of VL 108's.

I was also curious about the dual 500 watt amps. I assume that one 500 watt amp powers the speaker and you can daisey chain a passive speaker or sub for the other 500 watt amp to power. If so i only noticed a xlr out for chaining another speaker. Most speakers dont have a xlr in so it would be tough to find a speaker with a xlr in. I could be wrong about this but that what it looked like when i looked at the speaker on musicians friend.

Anyhow i would really appreciate any help from someone with experience with these speakers.

Munjibunga · #2 12-16-2010, 11:16 PM

In the quality pecking order, I think the PRX are in line with the MRX series, a notch above JRX. However, they're not just an MRX cab with an amp thrown in. They're engineered from the ground up.

In my acoustic trio, we use PRX612Ms for mains. We used to use PRX512Ms, but now we use those as monitors. We put three vocals, two guitars, and the bass straight to the board through DIs. I have been very happy with the sound of both my ABG and electric bass through them (I don't play upright). I think a PRX615M or even a 612M would work great for your purposes. Don't worry about the preamp pushing the amp hard enough. There are two input levels: line and mic. Start out using the line level input, but be careful. If you switch over to mic, you might blow your eardrums out. There is a level adjustment pot that adjusts either input.

The dual 500 watt amps cannot be used separately. They are used solely to drive the speakers in the cab, and there is no output to drive anything else. The XLR out on the back is to daisy chain the cabinet to another powered speaker. This is in case you want to have more than one main per side of the stage, or if you are running a mono mix and it's more convenient to daisy chain than to run two cables from the mixer.

Anyway, bottom line, I've been very happy with the 612Ms. I would point out that the amps get very warm but, so far, no problems.

Oh, by the way, if you buy them, give Northern Sound and Light a phone call. No one can touch their prices. You have to call them to get the right price.

**bass dan** · #3 12-17-2010, 06:42 AM

Thanks, i was hoping someone would say they would work for that. I may be looking at one of these soon.

modulusman · #4 12-17-2010, 07:14 AM

The PRXs are a much better speaker than the JRXs. I have some PRX512ms and 535s and as Munjibunga said there will be plenty of gain. I have just plugged an electric bass directly into the cabs and had plenty of volume.

**bass dan** · #5 12-17-2010, 09:56 AM

I am not real clear about the dual 500 watt amps. Are both amp pushing the speaker? I would guess so if you can't power another speaker with one of them. Sure would be nice if you could power a passive sub with the speaker. That would make this really versatile for me. I could run it as a bass amp or use it for full band pa with a sub.

These speakers sound like the ticket for me regardless. Makes me wonder why more bass players have not tried this or maybe they have and i just don't know about it. It seem like a great solution for someone that just likes to run stompbox type preamps like the sansamp bassdriver or vt pedal. The specs look to be pretty good for bass?

Passinwind · #6 12-17-2010, 10:14 AM

Quote:

Originally Posted by bass dan

I am not real clear about the dual 500 watt amps. Are both amp pushing the speaker?

It's biamplified. One amp for the woofer, another for the mid/highs.

There's an active thread in the Amps Forum about using the PRX 635 for bass duty at the moment.