Hello All,
My church is currently upgrading their very old PA system to JBL vrx928la arrays. They will be flown, with 3 units on each L&R and Martin xp118 subs onstage. The 3 vrx928 will be powered by a Xti6002. I'm learning this as I go and am unsure about how to hook up the 3 vrx to the xti in bridge mode. Plus this is the first time for me working with Neutrik NL4. Any help you can provide will be greatly appreciated. I don't want to blow some $1600+ speakers. I want to be sure I hook them up correctly. This will be easy for a pro, but our congregation doesn't have such a person and they want to avoid hiring one if they can help it.
TIA,
Dan
My church is currently upgrading their very old PA system to JBL vrx928la arrays. They will be flown, with 3 units on each L&R and Martin xp118 subs onstage. The 3 vrx928 will be powered by a Xti6002. I'm learning this as I go and am unsure about how to hook up the 3 vrx to the xti in bridge mode. Plus this is the first time for me working with Neutrik NL4. Any help you can provide will be greatly appreciated. I don't want to blow some $1600+ speakers. I want to be sure I hook them up correctly. This will be easy for a pro, but our congregation doesn't have such a person and they want to avoid hiring one if they can help it.
TIA,
Dan
You do not want to use that amp in bridge mode to power 3 x VRX928.
Those three cabinets represent a nominal impedance of 2.7Ohms, and the amp is only rated down to 4Ohms in bridge mode.
Plus, it is already about the right amount of power when run in standard 2 channel (stereo) mode.
HTH,
David.
Those three cabinets represent a nominal impedance of 2.7Ohms, and the amp is only rated down to 4Ohms in bridge mode.
Plus, it is already about the right amount of power when run in standard 2 channel (stereo) mode.
HTH,
David.
Hi David,
Thank you for the reply. I'm not sure if i can link a youtube vid so i took a screenshot and attached it. That's where I got the idea on running bridge mode. Also i downloaded JBL's VRX900 Application Guide and tried to follow it on page 6. So running xti6002 in stereo, do i hook up say L channel to 1 vrx, and hook the other 2 in parallel to the R channel?
Thanks,
Dan
Attachments
That amp only has a spec for 8 ohms when in bridge mode.
You don't know what it can do into lower than 8 ohms, if at all.
You don't know what it can do into lower than 8 ohms, if at all.
NO.. all 3 cabs are wired in parallel to a single channel, and then the other hang of 3 cabs go to the other channel.
Will there be any external processing used for these speakers? These boxes are well known for having a fairly agressive sound.. some would say that is being far to polite, in any event it will take some work with the EQ to tame them. Do you have somebody doing that?
Thanks, rayma. yes the 6002 will run in 8 ohms bridged or 4 ohms bridged like David pointed out. I will run it normal stereo as suggested but just wanted to make sure that I hook it up correctly. 1 vrx in channel 1 and 2 vrx in parallel in channel 2. Correct?
Hi conanski,
I didn't see your post when i replied to rayma. Are you saying that i can power all 6 speakers with a single xti6002? 3 on each channel? Re-reading the application guide i now saw that too! Geez i misread it and got 2 xti6002. I guess we'll see if the 3/array is loud enough and maybe looking at adding 1 more vrx for each side so we can fully utilize the 2nd amp. If I understand correctly the 6002 has built-in dsp, and that you can hook it up to a laptop via usb and load the dsp file specific to the VRX928s. Either that or you can flip switch on each box to set shading. Still a lot to learn for me.
Thanks,
Dan
There is no way to utilize these amps in bridge mode powering 3 boxes each... that is a 2.66 ohm load, and the 2ohm single channel rated ouput is plenty to completely melt these speakers so I suggest you send the second amp back and recoup the money.
I also hope these speaker clusters are going to be aimed down at the congregation and not just hung pointed striaght back? That may neem obvious to some but a church I sometimes do work for recently installed a similar 3-box hang of constant curvature array speakers and they didn't aim them at all, so only the bottom 2 of the 6 boxes actually point at listeners.😳
I also hope these speaker clusters are going to be aimed down at the congregation and not just hung pointed striaght back? That may neem obvious to some but a church I sometimes do work for recently installed a similar 3-box hang of constant curvature array speakers and they didn't aim them at all, so only the bottom 2 of the 6 boxes actually point at listeners.😳
I had an approximation, so I ran to church to take more accurate measurements. It's a gymnasium 92' L x 56' W. From the front of the stage to the back wall is about 83ft. I forgot to measure ceiling height, but I'm guessing it's about 18ft high, which might be too low for a 4 box array according to JBL Application Guide. thanks.
I installed a church system with speakers of the same sensitivity as these JBLs and I was able to produce more output than wanted with a regular domestic level amplifier.
Now, the chancel and the nave were together about half the width and depth you have to cover, which suggests you would want more power, however, you have three per side so you have the sensitivity advantage, and in addition to that you are running them in parallel. Your amplifier ratings in the thousands of Watts may be quite high.
As a side note if the JBL 108dB sensitive tweeters were separately amped, as I believe they can be, you'd be surprised what levels you can get out of just 1 Watt.
So If I'm suggesting anything it's that I wouldn't be too quick to use bridging unless you demonstrate it is necessary. It's not a standard configuration I'd use for no reason other than that it is available.
Now, the chancel and the nave were together about half the width and depth you have to cover, which suggests you would want more power, however, you have three per side so you have the sensitivity advantage, and in addition to that you are running them in parallel. Your amplifier ratings in the thousands of Watts may be quite high.
As a side note if the JBL 108dB sensitive tweeters were separately amped, as I believe they can be, you'd be surprised what levels you can get out of just 1 Watt.
So If I'm suggesting anything it's that I wouldn't be too quick to use bridging unless you demonstrate it is necessary. It's not a standard configuration I'd use for no reason other than that it is available.
Actually, in bridge mode it's 4200W at 8Ohms and 6000W at 4Ohms, so like David said it may not be enough if I understood correctly. With 2 amps, i now have the option of running 2boxes on 1st channel and the other 2boxes on the 2nd channel, in a 4 boxes array (1amp/array). I'm waiting to see what AllenB will recommend for my the size of our space.
For aiming, yes we will try to aim it correctly with the help of the VRX SMAF array frames with spaced holes for angle adjustment. Thanks.
AllenB,
I will run 3 per channel in parallel (6 total on 1 amp in stereo) as suggested by everyone so far. We will keep the extra amp for backup, or in case we need to run 4 boxes per side for more volume. This is a multi-use space for the occasional services as well as weddings and other events where "loud" may be needed 🙂
Thanks to you and everyone for the help so far. I learned a lot.
I will run 3 per channel in parallel (6 total on 1 amp in stereo) as suggested by everyone so far. We will keep the extra amp for backup, or in case we need to run 4 boxes per side for more volume. This is a multi-use space for the occasional services as well as weddings and other events where "loud" may be needed 🙂
Thanks to you and everyone for the help so far. I learned a lot.
"There is no way to utilize these amps in bridge mode powering 3 boxes each... that is a 2.66 ohm load, and the 2ohm single channel rated ouput is plenty to completely melt these speakers so I suggest you send the second amp back and recoup the money."
conanski, I got it now. You meant each channel in stereo mode (3000W @ 2O) is way more than enough for even 3 of these vrx. I think I should call it a day.
conanski, I got it now. You meant each channel in stereo mode (3000W @ 2O) is way more than enough for even 3 of these vrx. I think I should call it a day.
If “loud” is often needed just run two speakers on one channel and one on another. Modern switch mode amps have much better service life if you don’t run the hell out of them. The power supplies are the weakest links. When in normal use mode, you can run all the speakers off one and rotate them periodically.