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Subwoofer Placement, Low End Issues

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Mark Norgren:
I am wondering about placement of subs in a ballroom we currently play occasionally.  The room is much wider than long, maybe 160 ft wide and 80 ft deep?

We seem to get a lot cancelling in the low end about 30-40 ft out in the center.

I own 4 KW181's and I run  2 of the KW153's for tops, Midas M32R for a board.  I have been stacking a 153's on two 181's on each side.  The subs are pointed directly out and the tops, slightly inwards.  I am contemplating putting all four subs together in front of the raised stage, either four in a row center front or 4 as a stack of two each next to each other (2x2).

Not sure if this will help the cancelling or create more problems.  I will have to figure a way to get the tops in the air, I may be able to have them on stage with us and still have them high enough to get out over the dancers?

I appreciate any suggestions or help!

Ivan Beaver:

--- Quote from: Mark Norgren on November 20, 2019, 08:01:28 am ---I am wondering about placement of subs in a ballroom we currently play occasionally.  The room is much wider than long, maybe 160 ft wide and 80 ft deep?

We seem to get a lot cancelling in the low end about 30-40 ft out in the center.

I own 4 KW181's and I run  2 of the KW153's for tops, Midas M32R for a board.  I have been stacking a 153's on two 181's on each side.  The subs are pointed directly out and the tops, slightly inwards.  I am contemplating putting all four subs together in front of the raised stage, either four in a row center front or 4 as a stack of two each next to each other (2x2).

Not sure if this will help the cancelling or create more problems.  I will have to figure a way to get the tops in the air, I may be able to have them on stage with us and still have them high enough to get out over the dancers?

I appreciate any suggestions or help!

--- End quote ---
It could be room modes (cancellation based on the physical dimensions of the room).

Not much you can do about that-except with a bulldozer------------

Luke Geis:
Subs are best either as close together as they can be, or as far apart as they can be. Both of those options may not be practical for you. Another rule of thumb is to place the speakers in the 1/3rds locations of the room. So with a 160' wide room, you would want the subs to set around  40' off of each sidewall and would have the subs setting about 40' apart and then with an 80' deep room you would want to have the subs setting about 20' off the back wall. This has the subs setting in real estate that usually isn't practical or available for that purpose.

Placing all the subs next to each other may work better provided there aren't any room modes that are hindering things. Getting the subs 20' off the back wall may not be a problem, but a long line of subs may narrow the coverage pattern too much off the sides ( perhaps not a bad thing? ). Going with a cardioid array may help rid cancellations caused by reflection off the back wall? Prediction software may help with that. There are a lot of variables and not anyone is the magic fix. It will likely take some experiementing and if you have access and time, a bit of energy spent with a predictions software may really help.

Mark Norgren:
Thanks guys!  I will try the upfront approach next gig there.  Will report back!

David Morison:

--- Quote from: Luke Geis on November 20, 2019, 03:56:54 pm --- Another rule of thumb is to place the speakers in the 1/3rds locations of the room. So with a 160' wide room, you would want the subs to set around  40' off of each sidewall and would have the subs setting about 40' apart
--- End quote ---

Posting before coffee this morning?

40 is 1/4 of 160, not 1/3.

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