Help needed choosing a design for live sound

[Pyroibw]

hey guys. im looking to build up a substage. i need sound for 800-1500 people in a 4,000 SQ venue. need response down to around 38hertz. ive been looking threw designs for a while now and am having hard time picking what to do. right now ive been looking at the speakerplans HD15 and BFM titan48 or tuba 60. witch would you recommend? are there others that i should look into?

[Cal Weldon]

Please tell us what 4000 SQ is. This doesn't sound too tough. Also tell us what you are using for the top end.

[Pyroibw]

typo, SF square foot

right now were using 6 yorkville YX15, but i will be building new ones after the subs because they sound like crap.

[Cal Weldon]

1500 persons in 4000SF complete with a stage? Really? I sure hope they're friendly. I am guessing these persons are standing? Not enough room for chairs is there?

That's not a lot of room but it is a lot of bodies so I would think you should consider around eight 15" horn loaded woofers. I wouldn't worry about 38 Hz unless there is a reason. To go that low means pretty big horns or many of them. Usually 50 or 60 as the F3 is more than enough for live music.

[Pyroibw]

Lol yea it gets pretty packed. I do extension because we have dj's all night and random live acts. What design do you recomed?

[Cal Weldon]

I think you first decide on your size restrictions and then transfer that over to the commercially available plans and see if you can get your 38Hz. After that you scale down to what will actually fit. Have you measured the available area for these boxes? It may be that you can't fit eight 15" horn loaded woofers. Besides, that's just a guess anyway. How high is the ceiling is another consideration. There's a lot of ground work to do before real recommendations can be made.

[imix500]

There are obviously many choices. The old EV MTL designs are pretty rock solid, though a bit more sensitive to driver choice than others.

[Pyroibw]

I can fit 8 no problem. There a 20ft by 6 ft section in front of the stage that's open

[Xoc1]

The HD 15 sounds OK but really needs a 2 wide x 3 high, 6 speaker stack to work.
One issue with 6 bass speakers is that the width of the cabinets if lined up at the front of the stage are wider than the bass frequencies you are trying to reproduce. This causes excessive beaming of the mid bass.
Have you ever heard of a cardiod subwoofer array? You would need an active crossover with delay to make it work.
The rear facing subs are phased and delayed compared with the front facing cabinets. This reduces bass spill on to the stage and increases the front of house area thet gets a full range bass response.
Picture shamelessly lifted from wikipedia.
A good explanation of cardoid arrays is available on the Void Accoustics website.
http://www.voidaudio.com//pdf/bass%20guide.pdf

[Xoc1]

Picture from Glastonbury Main stage
Note the Bass bin array!