Posted by Dave Rat on March 21, 2002 at 11:07:09:
In Reply to: boxes posted by Ron S on March 18, 2002 at 00:13:52:
Hello Ron,
I think you are headed in a better direction. There are a lot of so called 'rules' of sound system design. On 'rule' was that "pointing multiple drivers in the same direction, creates all kinds of comb filtering and phasing problems". System designers went to great lengths to build arrays with very controlled dispersion horns with minimal overlap in the coverage area. With the proliferation of line arrays, it has been clearly proven that multiple drivers can be pointed in the same direction. Building a functional line array is no easy task and as you experienced, stacking some drivers, just does not cut it in HF region. Line array boxes, even when well designed are very temperamental and unforgiving and if improperly set up, easily lose any advantages they may have had over other system designs. Unless you have access to a high quality HF line array horn or are going experiment with ribbon drivers, you are probably better of staying away from the home made line array.
The 12", 10", 2" box you describe sounds like it could work or at least head you in a better direction. You may find some useful info in the Rat Sound "evolution" pages (http://www.ratsound.com/evolution/evol1.html). Here we describe how we dealt with similar issues.
Dave Rat
: I understand this might be tough to answer but Im just looking for opinion. I currently
: have a 36" widex 18"high x 30" deep box with 2 x 12" mounted on each side of a 60 degree flair and 2 x
: 2"B&C drivers mounted one on top of the other at the back of the flair. The idea was
: these boxes could be stacked up to 6 high outdoors for a festival style event or could be
: stacked on top of the subs as per a normal style trap box setup.
: When the boxes were stacked 4 high the worked fairly well but when we went with a bass
: bin and mid hi type setup more of a lets get good dispersion 2 x subs 2 x tops x 4 they
: were hellish in the upper mid - hi area.
: To the point where I would say unusable.
: What we are trying to do is have a box that can be used in a line array setup and well as a
: trap setup. Being a smaller regional company we cannot dedicate ourselves to either
: format we need both.
: What I am now proposing after is this.
: A box that is 36" wide x 12.25" high x 24" deep with a 12" 10"and 2"on a 60 degree horn.
: This will allow me to carry quite a few as per trucking and the drivers will be as close as I
: can possibly make them for coupling. With info from Meyers. Tom Danley , Brock Adamson it seems obvious now that true line array can only happen at a few freq. and that similar to your larger box idea getting as many componets packed into the tightest area seems to make sence.
: Your thoughts?
: Cheers