Now This is a sub! Bertha...W bin

[m R g S r]

I stumbled upon these renderings/plans and i am pretty darn sure that these are the subs used in the GSA system at district 36 in nyc. The bass from 4 of these on a small(ish) dance floor is unreal!! As i mentioned in another thread, this system produces the strongest bass i have ever heard! (i've been to my fair share of clubs with good systems installed)

here they are, the EAW bertha...





here they are in the GSA stack...


and im pretty sure Gary Stewart uses the crown 5002 to power each one...so with two woofers and bridged on that amp i figure about 5000rms?


obviously these are permanent install only and they are not meant to be moved around at all.

[epa]

this sub is a double EV TL4025 model .
ive bild 2 many years ago (single ones) verry efficient not so low .
haven't seen the extender be4.
this looks like it wil make some noise.

[kenpeter]

Your rendering differs from the drawing.
Missing cut aways to connect dead space to the back of the speaker?

[m R g S r]

they're not mine, they are renderings i have found from other forums.

[djk]

"this sub is a double EV TL4025 model ."

The GSA box holds 18s, not 15s (like the EV box).

[epa]

Originally Posted by djk

"this sub is a double EV TL4025 model ."

The GSA box holds 18s, not 15s (like the EV box).

hmzz correct.
maybe the ev was the basis of that design.
fold is the same,but the dimension differ a bit.

[Top Shelf]

When I was a teenager we had a school dance and there were two of the ones in the pictures center stacked. You are right they made my head rattle and my vision blur. Same effect as two Ev MTL-4's

[pgolde]

The most powerful bass I have ever heard, or feared my internal organs would explode, was 4 BDEAPS, 2 over 2 powered by a PL9 at Paul Bells club in NYC. Mark Seaton was driving and had a techno beat pumping that not one in attendance was brave enough to walk within 10 feet of. I walked the room and the bass was even throughout. Clean to 40hz at full output, first time Paul lost a bottle off the bar shelf and popped a breaker.

[m R g S r]

paul bells club? where is it? i've never heard of it...

[ticknpop]

I worked with Richard Long in 1985. The bass box is called Bertha and the extension with a 96 x 42 inch mouth is called a Levan (after Leroy Levan). The drivers were custom made Eminince 18's - maybe some RCF 's later . There were also a few Levan's built with 120 inch x 42 inch mouths with a third bend . (I worked iwth Richard on a club called the Copa in Toronto with 4 of the 120 inch Levan's that were double stacked for a 10 foot x 84 inch mouth). Sometimes Richard made the Bertha's or EAW made some for him as well. The 10 foot mouth was only ever made by Richard - i gave him a hand in his NYC shop for a day doing the final cuts of the mouths for the Copa. The Bertha/Levans are run 20 to 100hz on an effects output with a gain and cut control on the RLA 3000

The problem with the GSA system is the phase cancellation on the 15 inch low mid box where the horn loaded back radiation meets the direct radiator 15's output. - maybe about 250 to 400Hz range ) It was better done by Richard with 2 of 2 x 15 inch fully horn load bent front loaded bass horns running 40 to 250 HZ per stack and then a 250hz crossover to the double D 2 x 12 inch horn ( RCF ) with large long phase plugs Richard called the Double Dildo before crossing to the JBL 2395's at 1200 Hz which ran full range while the 2402 JBLs ran off the RLA 3000 crossover from 7 K and up on an effects output of the RLA 3000 crossover . The second problem with the GSA's 15 inch box is they don't go down to 40 HZ which was needed for the crossover points Richard used, but they may well have thier own crossover points based on their driver choices and cabinet design.