ProSoundWeb Community
Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => Pro AV Forum => Topic started by: WernerLouw on October 24, 2012, 09:55:25 AM
-
Hi,
It has been a while since i have been on here...
I plan flying a VRX sub and 2x tops on a structural beam in a new building. The beam has been certified and will carry the load. The same beam is required to fly the a 4000 lumen projector.
Is this a good idea? I am worried that the vibrations from the speakers will induce a blurry image from the projector...
The array will be flown with a steel wire rope dedicated for this.
Will the array be isolated sufficiently to prevent vibrations in the projector?
Regards,
Werner
Sent from my iPad using Tapatalk HD
-
Hi,
It has been a while since i have been on here...
I plan flying a VRX sub and 2x tops on a structural beam in a new building. The beam has been certified and will carry the load. The same beam is required to fly the a 4000 lumen projector.
Is this a good idea? I am worried that the vibrations from the speakers will induce a blurry image from the projector...
The array will be flown with a steel wire rope dedicated for this.
Will the array be isolated sufficiently to prevent vibrations in the projector?
Regards,
Werner
Sent from my iPad using Tapatalk HD
Hello Werner,
I do not think vibration will have an impact on your projector but this will depend on how you rig your projector. Do you really need to rig the subs ?
Othmane
-
It is not necessary to fly the sub. It is for a mono system install in a church. The sub can be front and centre below the pulpit. I just wanted to get as much as possible out of the way. The sight line of the whole array might be a problem, luckily i have a backup. I can put the sub on the floor in the centre of the building.
I have drawn coverage patterns etc for the speakers but have not looked at the projector. It will be just off centre.
Sent from my iPad using Tapatalk HD
-
Othmane,
Just to add to the previous post.
The projector will be hard mounted to the beam.
Sent from my iPad using Tapatalk HD
-
It is not necessary to fly the sub. It is for a mono system install in a church. The sub can be front and centre below the pulpit. I just wanted to get as much as possible out of the way. The sight line of the whole array might be a problem, luckily i have a backup. I can put the sub on the floor in the centre of the building.
Three things to consider with locating the subwoofer separate from the flown mains. First, how might the sub location affect gain before feedback for microphones? Typical subs are virtually omnidirectional so gain before feedback becomes a matter of distance from the microphone(s) and where the sub is located relative to the microphone's pattern, so you might want to think about how that might be affected for the different locations.
Second, because the subwoofer and mains are physically separated, different locations in the listener area will all have different relative path lengths from the mains and sub and thus different relative arrival times of the sound from them. Addressing the response and phase through crossover can thus be more difficult.
Finally, how do you deal with the differences in distance losses? Again, because the subwoofer and mains are physically separated, different locations in the listener area will all have different relative path lengths from the mains and subwoofer. As a result, the relative loss due to those path lengths will vary in level throughout the listener area, which in turn will lead to variations in the relative level of the sub and mains.
So like many things, physically separating the subs from the mains can be a matter of compromises.
You might want to consider something like http://www.chiefmfg.com/Products/CMA347 (http://www.chiefmfg.com/Products/CMA347) for the projector.
-
An alternative solution would be isolation dampers on the speaker hangs themselves such as these: http://www.mason-industries.com/masonind/_doc/pdf/WHD.pdf?CFID=34714436&CFTOKEN=29561702
Don't be confused by the load ratings given for each size. That is the amount of weight required to compress the bushing to get the desired isolation. For my project Mason tested the 50lb dampers to a break strength of 825lbs. You would probably want to use the heavier bushings if you intend to fly the subs as well.
-
Thanks everyone. I will try to keep the subs flown. Improves on phasing coverage etc. which was my initial reason for doing so.
I will look at isolation dampers and shock mounts for the projector...
Sent from my iPad using Tapatalk HD
-
Caleb, thanks for the assistance. Sorry i am having difficulty sending you a PM...
Sent from my iPad using Tapatalk HD
-
Ok, back to the post...
The speaker acquisition has been moved out by quite a bit... Everything except the sound system was hit by lightning, so that gets first priority.
The question now is this. The projector is setup, right where the speakers were designed to go. I cant see the projector going anywhere else.
I have two options now:
Option 1:
I have had a look at the coverage and it should work, but I am worried because I have not seen it done before. I want to fly the VRX cluster off to one side, but still run it as a centre cluster. Off to the side is approximately 2.5m in an 18m wide building. The reflections of the two side walls will be different but i think it can still be managed.
Option 2:
This option is what i have been shying away from initially. Flying satellite speakers down the length of the building in a "stereo" setup. Mains on left and right with a sub in the middle. This setup would be duplicated about 50% down the length of the building. A driverack 260 should be able to handle this.
Problem with option 2 is the complexity that it brings. Volunteers don't always understand these things and I want a system that is more or less set and forget...
Any ideas?
Sent from my iPad using Tapatalk HD