center clustered subs

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brodave2
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center clustered subs

#1 Post by brodave2 »

I've been doing subs on each side for many years. I'm all for improving my sound, particulary bass dispersion. Did a gig last night in a renovated theater. I put the subs on the floor in front of the 3' tall concrete stage, laying down. Mains were put on stage on either side. Bass was brutal in the first three rows. Attendance was low (this is basically an outdoor venue), it was 37 degrees here where it was 85 degrees two weeks ago. I like the idea of center clustered subs, but I wound up having to cut the subs back to keep from hurting people on the front row.

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davygrvy
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#2 Post by davygrvy »

I know what you mean. You fly tops to get above people's heads to get even coverage, and to make sure you don't hurt anyone from 133dB(SPL)@1M coming from them. But when you group for center subs, levels might be 137 cause its now coming from one source and now right next to people. At least the pain is in the belly rather than the ear canal..

Maybe a wide front cluster would help even it out?

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DAVID_L_PERRY
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Re: center clustered subs

#3 Post by DAVID_L_PERRY »

brodave2 wrote:.. Bass was brutal in the first three rows..
Are these front loaded subs ?

For subs to be brutal and then drop off after three rows does not sound ideal..... they should not be so proximity effected unless its harmonic distortion from front loaded subs you are hearing ??

All you have done is realized that when you do place subs together you gain output. Having said that when I clustered my old front loaded subs the bass response was still fairly even...
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brodave2
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#4 Post by brodave2 »

yes, still using the old double 18's, the titans aren't quite finished. About 3 rows back the tops finally caught up with the subs because of placement. First two rows center were just inside where the tops covered. There is a 6 db drop after doubling the distance, that also came into effect. The third row is about twice the distance from the subs as the first row. In your usual gig that close up is probably the dance floor, where the bass would not be a problem with folks standing. This was seating, and everyone up that close was actually sitting. I'm not arguing that centered subs as a concept is not good, I in fact agree with the concept, just in this case, it was very interesting. The guy onstage's mother was in the second row, and I suspect her $$$ were funding the project.

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Tim A
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#5 Post by Tim A »

Try them clustered to one side. As long as you have room gain it'll work pretty well and it takes the oomph off the people in the front.

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Bill Fitzmaurice
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#6 Post by Bill Fitzmaurice »

The problem isn't center clustering, it's using direct radiator subs. The ear is relatively immune to high level problems below 100Hz; that fact is why OSHA noise specs are specified in A weighting, with the lows fltered out. Direct radiators even crossed over at 80 Hz or lower create harmonics well above 300 Hz, and it is those harmonics causing your problems. Folded horns filter those harmonics out. But beyond that, close seating to any high level source is just plain stupid. Move the seats.

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brodave2
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#7 Post by brodave2 »

Move the seats.
I set the rig up and sound checked for a crowd of 400. 50 showed up. 25 in the first 3 rows and 25 in the back 3 rows, go figure. Plenty of seats, all bolted down, people sit where they want. My titan 48's are done, one is tested, the other isn't, they'll be getting integrated soon. You can't see the subs in the photo, but they're centered up right up next to the stage, 3 double 18's.

http://www.flickr.com/photos/7655072@N05/2069155108/

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Bill Fitzmaurice
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#8 Post by Bill Fitzmaurice »

In that case those who found it too loud should have moved. :roll:

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