Here is my compact line array for 100-seat venue PA

[Beau]

Re: Here is my compact line array for 100-seat venue PA

Actually it was conceptually very simple, I just tapered the sides of the box opposite each other and screwed the plywood down to them. I probably should have steam-softened the plywood first, as the stiffness caused a little warpage in the boxes, but not enough to cause a problem.

Maybe putting some diagonal kerf cuts in the back of the baffle might of also been helpful?

[Bwarchitect]

Re: Here is my compact line array for 100-seat venue PA

That baffle must have been a headache to make in a twist like that! Very cool design, a unique design for a unique desired outcome!

Actually it was conceptually very simple, I just tapered the sides of the box opposite each other and screwed the plywood down to them. I probably should have steam-softened the plywood first, as the stiffness caused a little warpage in the boxes, but not enough to cause a problem.

[Adam_G]

Re: Here is my compact line array for 100-seat venue PA

That baffle must have been a headache to make in a twist like that! Very cool design, a unique design for a unique desired outcome!

[Bwarchitect]

These are the new PA speakers I just built for my weekly live music series known as the Local Music Project.

The goal in building them was to achieve most of the benefits of the increasingly popular line-array PA speakers now offered by Bose, Carvin, Fender, Fishman, and others, but without spending over $2,000 for a pair as they are priced. Those benefits include a natural sound with wide horizontal dispersion for even coverage, plus narrow vertical dispersion to reduce feedback and extend the effective distance covered.

Now that I have finished the build and given the speakers their first trial I am quite happy with the results. The tone quality is much warmer and more natural than the speakers I replaced, and feedback resistance is much better. Knowledgable audience members were favorably impressed.

In the design of this speaker, I took a slightly unconventional approach to maximize horizontal dispersion, by twisting the faceplate through about 60 degrees as you can see in the construction photos.

The drivers are Dayton Audio ND-65 4ohm, nominally 2-1/2" (which turns out to be the flange diameter) and I wired 8 of them together series/parallel in each of two sealed enclosures for two 8 ohm speakers. They are rated to handle 15 watts rms each driver, so the combination takes 120 watts, and I am driving them with a Behringer A500 "ultra-linear" stereo power amp marketed for studio use, which puts out about 150 watts/channel into 8 ohms. Even though each driver is only 2" in diameter, the system extends cleanly down to about 120 HZ where it begins to drop off. I use a commercial PA subwoofer to fill in the bottom end very effectively. The subwoofer is a Behringer 12" 500-watt powered unit with stereo in/out, and a built-in high pass filter at 100 hz for the main throughput, so the line arrays don't see anything below 100 hz.


Cost of the subwoofer plus all the materials for the build of 2 main speakers came to about $625 (not counting my own time and labor of course) so I would say, "mission accomplished"!