# QSC ILA Line Array



## Onyx (Jan 7, 2011)

I was wondering if anyone has any experience with QSC's ILA series? I am purchasing it for a House of Worship, and would like to know if there is input to be had! 
The spec called for a white Line Array, so the room will be getting 2 1x3 Line Array's (1 WL118-sw subwoofer, 3 WL2082-i line array boxes).

I plan on using the QSC SC28 system controller, and using 3 CMX2000v and 1 CMX800v amplifier. 
Here is how I work it out to wire it all up for a biamp system, can anybody tell me if this is kosher? I've don't have much experience installing line array's, and am going with QSC's recommendation of using CMX amplifiers with the SC28 process controller. 

1 CMX2000v - Channel 1: (Left) WL118-sw Channel 2: (Right) WL118-sw
1 CMX2000v - Bridged: (Left) WL2082-i Low Frequency
1 CMX2000v - Bridged: (Right)WL2082-i Low Frequency
1 CMX800v - Channel 1: (Left) WL2082-i HF Channel 2: (Right) WL2082-i HF 

The WL2082-i has dual 200W 16 Ohm drivers for Low Frequency, and dual 50W drivers at 8 Ohm for high frequency.
The WL118-sw produces use a continuous power of 850W @ 8 ohm. 

The CMX2000v has 1100W/Channel @ 8 Ohm
The CMX800v has 500W/Channel @ 8 Ohm


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## avkid (Jan 7, 2011)

How did you come up with three boxes?

Have you used EASE Focus for WideLine & ILA ?


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## bishopthomas (Jan 7, 2011)

Hey, Onyx, and welcome to Control Booth! How upstate New York are you/this church? What made you not only decide on 3 boxes per side, but why Widelines? Are you working with a company yet on this install? We're in central Jersey and have the Wideline 10's for our portable line array system. We installed a rig in a church in Princeton a couple of years ago, so if you wanted to check it out in an environment potentially similar to the one it's going in let me know. Or if you wanted a demo to come to you I could arrange that as well.

I am a little concerned with your choice to go with only three boxes and also to biamp rather than triamp the system. Part of the "magic" in the Widelines is (when triamped) the mid range shading that can be accomplished either via a physical switch or the software. Also, as far as the subs, are you planning on flying those as well? I don't have time to check out the amp specs to make sure they fit, but I should have more time later tonight.


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## museav (Jan 7, 2011)

There was a specification and all it called for was a "white Line Array"? Nothing about pattern or output capability or anything relating to the actual performance of that Line Array such as coverage, response, intelligibility, level and so on? Anything about where the arrays should or could not be located? Did they even define whether the speaker system was to be mono, stereo or LCR? Is three boxes per array sufficient and does that actually perform as a line array over a usable frequency range? I'm just trying to understand how you got from "white Line Array" to the specific system noted.

Anyways, if the system stays as is then I think you may want to make some changes to the amplifiers. With the system as noted you'd apparently be at a maximum output of 128dB @1m on the subs, maybe 131dB @1m or so on the LF (128dB or so plus some summing between the three boxes) and around 127dB @1m for the HF. That initially looks good but there may be a couple of aspects to consider.

For one thing, for contemporary worship, which I assume this is, you often want the subwoofers to be able to exceed the output of the rest of the array by anywhere from maybe 5-6dB up to 10-12dB. The subwoofers being used are rated at 850W continuous and you're providing them around 1,050W continuous, so you may want to look at a bit more power on those and/or less on the rest of the array. Or depending on the size of the space, going to two subwoofers per array.

Probably much more critical, it looks like you may not have accounted for running the three WL2082-i boxes in parallel. With three boxes per array that's a net 1,200W continuous and 2.67 Ohms rating for the LF portion of each array and 300W continuous and 5.33 Ohms for the HF portion of each array. The CMX2000V in bridge mode that you plan for the LF portion of each array is not rated for anything less than a 4 Ohm load in bridge mode, and then only at 1kHz and 1% THD, and is not rated for the 2.67 Ohm load apparently involved. In addition, the output rating at 4 Ohms is 5,000W, right close to the peak output for the speakers, so with a 2.67 Ohm load it might exceed, at least for a moment, the 4,800W Peak rating of the speakers. So the low frequency section of three WL2082-i boxes in parallel on a CMX2000V in bridge mode could apparently quite likely result in damage to the amp and/or speakers.

If you want to stick with the CMX amps there aren't any really good options to provide more power to the subs. But if you can work with some reduced output for the mains there are probably several options there. For example, I have not looked at it but you might want to see if a single CMX2000V in two channel mode for the LF sections of both arrays and a CMX500V for the HF portion would work better. If you can't afford any less output on the mains then you might have to look at different amps or maybe not driving all three boxes in each array off the same amp channel.


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## Onyx (Jan 8, 2011)

museav said:


> There was a specification and all it called for was a "white Line Array"? Nothing about pattern or output capability or anything relating to the actual performance of that Line Array such as coverage, response, intelligibility, level and so on? Anything about where the arrays should or could not be located? Did they even define whether the speaker system was to be mono, stereo or LCR? Is three boxes per array sufficient and does that actually perform as a line array over a usable frequency range? I'm just trying to understand how you got from "white Line Array" to the specific system noted.


 
The two best options in front of me to fulfill "white line array" was the QSC ILA, and the JBL VRX. 

The system is going to be Left/Right, still waiting on drawings of the room before I figure more out.


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## museav (Jan 8, 2011)

Onyx said:


> The two best options in front of me to fulfill "white line array" was the QSC ILA, and the JBL VRX.
> 
> The system is going to be Left/Right, still waiting on drawings of the room before I figure more out.


I don't know if this is a negotiated or competitive bid project but whether it is appropriate or not I can see somebody submitting something like this, TOA HX-5 Compact Array Speakers - Variable Dispersion!, as it is available in white and is just about as much an actual line array as a three box ILA system or a VRX system (not the same performance, just that all are white and all would likely be more a vertical array than an actual line array).

While I realize you're responding to their request, I'm also hoping to avoid yet another left/right "line array" system in a church that's there just because it's what they church has been led to believe they should have rather than it actually being analyzed to be a good solution for the application.


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## avkid (Jan 8, 2011)

Most loudspeaker manufacturers will do custom finishes for a small fee.
Color should not be the deciding factor.


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## bishopthomas (Jan 8, 2011)

Onyx said:


> The two best options in front of me to fulfill "white line array" was the QSC ILA, and the JBL VRX.


 
Almost any speaker manufacturer will make boxes in white. Just because it is not specifically advertised on the web site doesn't mean it's not possible. White speakers for installations is a very popular request.


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## bishopthomas (Jan 8, 2011)

museav said:


> ... and is just about as much an actual line array as a three box ILA system or a VRX system


 
A speaker on a stick would be only slightly less "line array" than only 3 boxes of anything. So, "white" really is the only qualification?


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## mstaylor (Jan 8, 2011)

bishopthomas, 
Since you are familiar with QSC rigs, what about the eights instead of the 10s?


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## bishopthomas (Jan 8, 2011)

mstaylor said:


> bishopthomas,
> Since you are familiar with QSC rigs, what about the eights instead of the 10s?


 
I've never heard the 8's myself, but a friend heard them at a demo a couple of weeks ago. He said they sounded "decent" but didn't really go into it. I'm a little skeptical myself. Just going on what the 10's sound like and knowing what happens to the sound as the speaker gets smaller, I don't think I'd like them. I always describe the Widelines (the 10's) as having great clarity and fidelity but not so much of the low mid "meat" of other line arrays. They're great for acoustic music and styles where you want vocal clarity (such as house of worship, even contemporary) but certainly not a "rock and roll" box. I fear that the 8's would be even more extreme in the defining sound.

I would definitely recommend the OP going with more subs and/or maybe trying to find a place for them on the ground. I'm not a fan of flown subs unless you really have a lot of them. And the equivalent model of subwoofer without the rigging hardware is significantly less expensive, which would allow the purchase of more (although a pair of 2x18's on the floor should be sufficient for his space).


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## mstaylor (Jan 9, 2011)

I do a room with QSC rigs multple times a year. They use eight wideline 10s per side but only six of the eights. I was shocked at the sound they produce for small cabinets. Subs are essential with both systems.


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## museav (Jan 9, 2011)

bishopthomas said:


> I would definitely recommend the OP going with more subs and/or maybe trying to find a place for them on the ground. I'm not a fan of flown subs unless you really have a lot of them. And the equivalent model of subwoofer without the rigging hardware is significantly less expensive, which would allow the purchase of more (although a pair of 2x18's on the floor should be sufficient for his space).


This is always a trade off. I am generally a fan of flying subwoofers to put them with the rest of the arrays as that typically offers numerous in terms of coverage, alignment through crossover, etc. This is especially true for installed systems. The flip side is the points noted in terms of both the cost and complexity involved in flying subwoofers.

I'm not as sure about the point regarding the quantity of subs. It may not be the case here but that perspective is often based on the concept of gain from space loading, but both measurement and theory show that the the gain achieved through ground plane loading is actually achieved as most think it is and that the impact on the direct sound levels is much less than most assume.


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