New PA in a gym

[Tom Smit]

The Story: After a few years of telling the school principal that I had an idea of how to make the sound in the gym be better, he gave me the go-ahead. I had offered to build the cabs for free if he could find the money to provide for materials. I will try and follow the 3 C’s.

Condition: difficulty in understanding speech through the PA and lack of clarity
Cause: a gymnasium with a lot of reverberation which leads to multiple time arrivals of the same sound
Correction: TLAH PRO

And that is what I built, as well as a T60 19” width.

Condition: Sub woofer needs a corner for maximum return, and there is no real corner.
Cause: sound waves may cancel each other out if said sub is located away from the corner
Correction: build a riser in the storage area and place the sub on top so that the mouth is about 2 feet from the corner.

After consulting and engineer (but not qualified for structural), we decided to place the TLAHs in the storage area. All that was needed to be done was to move a stud over in each location, carve out a hole in the paneling, and fab up a grille. Using this calculator http://www.metroaudiosystems.gr/pages/. ... tor-en.xls
the TLAHS are toed in by 16 degrees and tilted by 12 degrees for the best overall coverage.

The Peavey XR 680E powered mixer is now tapped at the "EQ out" which is fed into the Behringer DCX2496. The signal is divided into mains and sub. The sub is limited to 50 volts, and with a 48 db/octave LR high pass at 25hz and 48db/octave at 80hz low pass. The mains are limited to 105db, and have a high pass at 80hz at 48db/octave LR.

Last week Saturday tried tuning the system using the RANE RA30 and I got things relatively OK, but I wasn’t satisfied because it didn’t sound just right and the sub wouldn’t hit 22hz (Woofer Cooker song). So this past Saturday I went back, shut off the “low cut filter” on the Behringer EP4000. Aaaaaahhh, yeeeeesssss, satisfaction. And the rest of the system works/ sounds wonderful! Songs I tried ranged from choral, Vivaldi, pipe organ, Phil Keaggy, Gershwin, what I call “The Woofer CD”, Sarah McLachlan, Toby Mac, Grits, just to name a few.
I am a happy camper!

Pics to follow soon.

Edited for additional info on cross-over points.

[shawn_g]

Nice work! Let's see those pictures!

[Gregory East]

Is it supposed to hit 22hz with power behind it?

[Tom Smit]

Edited my first post to add cross-over settings.

[Tom Smit]

And the pics as promised. The storage areas are just that, storage.

Before the change-over.

....and after.

The 28 x 80" grille

The TLAH behind the grille. A strap is screwed onto the top, which in turn is screwed to another strap in order to locate the tilt. Quick-clamps helped do the job for initial setting of the angle

Toe-in held in place using cleats that are screwed to the plywood floor.

[Tom Smit]

The view behind the Canadian flag. Had to relocate the stuff in the storage area to make room

The original site....had to remove the white plywood and relocate the stud.

The riser strapped to the wall.

T60 on top of riser, strapped to the wall, mouth 2 feet from the ceiling.

[LelandCrooks]

Nicely done.

[shawn_g]

Good work. That's great that you donated your time to do that; it must have taken quite a few hours to pull everything off.

[safebet]

Very nice job Tom. Thank you for sharing.

[Radian]

Nice job Tom! The school doesn't know what they've got there!

A question comes to mind though..Are the Peavey's going to stay up there?

Cuz, you know everyone's gonna think all that awesome sound is coming from them.

[Grant Bunter]

Love it Tom!

People like yourself deserve medals/awards/public acknowledgment for community service!
Despite my boys having left the school they attended (they are now both in the workforce), I still try and help out with presentation and variety nights with sound and lighting.
I'm presently trying to sort out why a self powered behringer foldback that belongs to the school isn't working. Narrowed it down to the input stage so far...

[Tom Smit]

Thanks guys!

The Peaveys and cages are coming down and gonna be sold.