http://sp3.fotolog.com/photo/19/50/9/refugiosonido/1248065648953_f.jpg
I really wonder what these sim db wise? Four of these powered by 4 macro tech 5000 watt amps (20,000 rms total) literally make my entire body hurt at a club i go to in NYC (its called district 36, GSA system..) i'm not sure on specific drivers used...
i haven't heard the boxes without the mouth extensions, only with, at a few different places. each place that has these the bass output is ridiculous, even with those very low freq. techno tracks
I really wonder what these sim db wise? Four of these powered by 4 macro tech 5000 watt amps (20,000 rms total) literally make my entire body hurt at a club i go to in NYC (its called district 36, GSA system..) i'm not sure on specific drivers used...
i haven't heard the boxes without the mouth extensions, only with, at a few different places. each place that has these the bass output is ridiculous, even with those very low freq. techno tracks
I think the use of Bertha's with Levan horn is rediculously loud I have been exposed to this subs years ago. although they go real low but not pleasant in a club scene, especially District too small of a place wonder how much he charged the owners of the club for those Bertha's? Absolete design my opinion!
Hey all, been lurking for a bit - some great information here.
Is there a practical limit as to what can be achieved with flare extensions on a tapped horn? My first club experiences were in NYC, so I am quite familiar with the combinations of single 18 emeralds, double 18 berthas, and the levan extension, but its been almost 9 years since I've been around horns of that nature. The levan is certainly a beast, but one really needs space for it.
Enter my current scenario: I am the technician for a dj oriented club where we have 8 single 18 Dynacord Cobra Bass boxes distributed around a dancefloor of about 60 sq m (ceiling height 5-8m). Walls are solid prewar brick, and firesafe acoustic panels tame mid-high reverb. In terms of all compromises, 4 are clustered horizontally along one wall, and 2 sit side by side in the corners opposite the other 4. They are powered and processed correctly, but have never given me what I am after. We did try putting them all on one wall, but the current situation is the best we have gotten out of them.
Being a fan of diy (tops are 2x15" Bms loaded and 2/1" bms coax in a solid cabinet from the 80s), I'd like to replace the subs with th18s. My understanding is that one th18 will basically take up teh space of 2 of these cobra subs, and probably put out the same spl. If a single th18 outperforms 2 cobra subs, all the better.
However, I'd really like to increase the bass in the room. I am quite happy with the tops, but would like to pummel the dancefloor with bass while the guests can still hold conversations. AN option would be to build not 4, but 8 th18s, but the idea of building an extension interests me.
Would a klipsch corner horn style extension for a tapped horn screw around too much with the whole idea of loading the driver at a specific place on the horn path? Any additional LF response would be unnecessary, but if the end result is 6dB louder (3dB more than the simple flare), cool. It might also end up taking too much floor space, hmm.
Would a horizontally laid th18 and flare perform similarly as the vertical keystone with flare? Aside from anyone dancing on the subs or jumping with joy, the listening field is on the ground plane.
Is there a practical limit as to what can be achieved with flare extensions on a tapped horn? My first club experiences were in NYC, so I am quite familiar with the combinations of single 18 emeralds, double 18 berthas, and the levan extension, but its been almost 9 years since I've been around horns of that nature. The levan is certainly a beast, but one really needs space for it.
Enter my current scenario: I am the technician for a dj oriented club where we have 8 single 18 Dynacord Cobra Bass boxes distributed around a dancefloor of about 60 sq m (ceiling height 5-8m). Walls are solid prewar brick, and firesafe acoustic panels tame mid-high reverb. In terms of all compromises, 4 are clustered horizontally along one wall, and 2 sit side by side in the corners opposite the other 4. They are powered and processed correctly, but have never given me what I am after. We did try putting them all on one wall, but the current situation is the best we have gotten out of them.
Being a fan of diy (tops are 2x15" Bms loaded and 2/1" bms coax in a solid cabinet from the 80s), I'd like to replace the subs with th18s. My understanding is that one th18 will basically take up teh space of 2 of these cobra subs, and probably put out the same spl. If a single th18 outperforms 2 cobra subs, all the better.
However, I'd really like to increase the bass in the room. I am quite happy with the tops, but would like to pummel the dancefloor with bass while the guests can still hold conversations. AN option would be to build not 4, but 8 th18s, but the idea of building an extension interests me.
Would a klipsch corner horn style extension for a tapped horn screw around too much with the whole idea of loading the driver at a specific place on the horn path? Any additional LF response would be unnecessary, but if the end result is 6dB louder (3dB more than the simple flare), cool. It might also end up taking too much floor space, hmm.
Would a horizontally laid th18 and flare perform similarly as the vertical keystone with flare? Aside from anyone dancing on the subs or jumping with joy, the listening field is on the ground plane.
The flare extensions I used in front of the Keystone and Chorn ( post #8) added about the same 3 dB increase when used with bass reflex cabinets, they are providing added sensitivity because the frontal area increase provides forward gain, the extension simply is making 1/2 space more like 1/4 space. The low frequency response stayed about the same down to Fb/Fc in each case.
Since your cabinets are placed near walls presently, barn doors or flare extensions may not have as much effect as they do outdoors.
To actually make a horn go lower, the length must be made much longer.
One can fold a 40 Hz horn in to a relatively shallow box, but to add an extension to take that box down to 30 Hz requires another 4.7 feet, and a lot of width.
That chews up a lot of dance floor
.It is best to design a FLH cabinet from the ground up for using the corner, as the Klipshorn or Tom Danley’s Bdeap did.
A TH placed in the corner will benefit just as any sub benefits from 1/8 space loading, no extension is needed.
Placing the wave-guide/horn extension/barn door stack so the resulting shape looks like 1/2 of a square (the other 1/2 is mirrored by the floor) is the most effective shape in general for LF output.
Art
The Cobra Sub uses an Electro-Voice EVX 180B which has an Xmax of only 6.4 mm, power handling of 600 watts, and is grossly overpriced for it's performance.
It was a decent speaker back in the 1980’s, I used a lot of EVX then. Sold my last pair only a few months ago.
A Keystone TH loaded with a B&C18SW115-4 (15mm Xmax, 1500 watts), or even loaded with a pair of Lab 12” would eat the Dynacord sub for breakfast.
true
wouldn't it behave the same as puting them against the wal?
i mean the floor being the opposite boundary?
how can the subs cancel each other out when grouped together?
I think he meant the floor and ceiling boundaries would work against the boxes. We do have the steel to hang from 5 meters, but I can probably get away with losing the floor space. The present cobras all have an additional shell built around them (including the wheels, lol) to protect the finish, and there are sitting benches installed which could be reduced. The tops hang down to about 3m, so if the tapped horns were laid on their sides, people could always dance on top of them. doing so might even make the room look more cozy.
the cobras were all part of a package deal that anyone would be a fool to pass on, so they have earned their keep, but it is really time to move on. Even an EV xsub puts 2 cobra subs to shame (same drivers and amps, but more box volume)
Art, thank you for your flare efforts and the follow up response. i had a feeling that it was not going to be so simple to squeeze more performance.
I've never designed a horn, and it will be easier to get those writing the checks to invest in a single prototype based on a measured build instead of a simulation, so a custom corner horn would be more difficult on multiple levels. We do have the woodworking available, and it might be nice to build more of the same to replace the rest of the cobras and other stuff in the inventory. The club is part of a sprawling, multi-room venue with an overall capacity of over ten thousand. I don't expect the th18s to be used in the biggest room, even if they would outperform the a-list rider level gear which comes through. I'd love to see some jerichos and matching too heavy for 3 guys to lift dsl subs in that room...
if I understand your reply correctly, firing the sub downwards into an equally sized volume which then flows out to the dancefloor would be more beneficial than firing the sub against the wall/corner? I think I remember a post on the old(middle new) LAB where someone did that.
r(andy pence)
Art, thank you for your flare efforts and the follow up response. i had a feeling that it was not going to be so simple to squeeze more performance.
I've never designed a horn, and it will be easier to get those writing the checks to invest in a single prototype based on a measured build instead of a simulation, so a custom corner horn would be more difficult on multiple levels. We do have the woodworking available, and it might be nice to build more of the same to replace the rest of the cobras and other stuff in the inventory. The club is part of a sprawling, multi-room venue with an overall capacity of over ten thousand. I don't expect the th18s to be used in the biggest room, even if they would outperform the a-list rider level gear which comes through. I'd love to see some jerichos and matching too heavy for 3 guys to lift dsl subs in that room...
if I understand your reply correctly, firing the sub downwards into an equally sized volume which then flows out to the dancefloor would be more beneficial than firing the sub against the wall/corner? I think I remember a post on the old(middle new) LAB where someone did that.
r(andy pence)
the reason i mensioned it was, a long time ago i was going to a disco bar saturdays.
they had a space 7m*10m*8m w*l*h they had 2 boxes agianst the ceiling facing downwards.
the sq was good.
another time i was standing on a lader near the ceiling ,when the music was playing at low volume with the boxes on the floor.
i was amazed how loud the low end was compared to the rest of the room.
that said in theory it might be wrong.
the boxes should be against the ceiling to benefit from the ceiling boundry.also don't put them in the middle, but a bit of centre.
if its not to diffecult to try ,it cant hurt(unless you get a cab on your head)
a tapped horn wil outpreform the cobras with ease.
you could choose XCO1 th 18 ,or Weltersys keystone,both are tryed and proven to work verry wel.so no gambling there.
they had a space 7m*10m*8m w*l*h they had 2 boxes agianst the ceiling facing downwards.
the sq was good.
another time i was standing on a lader near the ceiling ,when the music was playing at low volume with the boxes on the floor.
i was amazed how loud the low end was compared to the rest of the room.
that said in theory it might be wrong.
the boxes should be against the ceiling to benefit from the ceiling boundry.also don't put them in the middle, but a bit of centre.
if its not to diffecult to try ,it cant hurt(unless you get a cab on your head)
a tapped horn wil outpreform the cobras with ease.
you could choose XCO1 th 18 ,or Weltersys keystone,both are tryed and proven to work verry wel.so no gambling there.
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Randy,
From what I gather from what I have read about the Bdeap, in various places, tapped horns have more LF output even without relying on the down fireing corner placement.
I'm relying on Ivan Beaver's comments, I have never measured a corner horn.
Being in the PA business, a cabinet that has to be used in a certain part of the room never appealed to me, and corner horns are too big for my living space .
Direct ceiling mounting can work as well as floor mounting as far as boundary gain, and evens out the room response as the listeners are all much more equidistant to the source.
The problem using typical rigging is the motors and bridles put the subs a rather large distance from the ceiling (probably mid point from ceiling to floor in Randy's case), so the results are far different than in the club you describe.
Does this work when coupling subs as well?
For an example, if one placed 2 Keystones next to each other, would the above extender suggestion remain true, 90"W x 45"H?
Earlier you mentioned your extenders being 15" front to back. Is the 15" from the front of the extender to the front of the Keystone or front of the extender to the end of the extender (after overlapping the Keystone)?
Also, is this easy to edit a Hornresp input to mimic an extender?
Originally Posted by weltersys
Placing the wave-guide/horn extension/barn door stack so the resulting shape looks like 1/2 of a square (the other 1/2 is mirrored by the floor) is the most effective shape in general for LF output.
Art
The extender used is 15" deep from the front of the cabinet to the front of the extender. The depth is rather meaningless, the increased frontal area is the main gain component, the depth could be 0 (180 degree wings) and you would still likely see the same 3 dB forward gain, as I did in other experiments with ported cabinets.
You can model the waveguide in Hornresp like any other horn section.
That said, there being an abrupt area difference between the normal cabinet mouth and the wings/waveguide/extender/barndoors, Hornresp is not super accurate.
Placing the wave-guide/horn extension/barn door stack so the resulting shape looks like 1/2 of a square (the other 1/2 is mirrored by the floor) is the most effective shape in general for LF output.
Art
The suggestion I made applies to all subs for LF output.
The extender used is 15" deep from the front of the cabinet to the front of the extender. The depth is rather meaningless, the increased frontal area is the main gain component, the depth could be 0 (180 degree wings) and you would still likely see the same 3 dB forward gain, as I did in other experiments with ported cabinets.
You can model the waveguide in Hornresp like any other horn section.
That said, there being an abrupt area difference between the normal cabinet mouth and the wings/waveguide/extender/barndoors, Hornresp is not super accurate.
The Zombie thread rises again - but
My fellow horn extender fans,
(how) would you add a horn extender to this cabinet?
It has a relatively short horn path, but pretty decent sensitivity and output and has a pd 186 driver:
more details here
http://www.amstudio.co.jp/pa/pakizaipdf/hk/rl118f.pdf
Regards, Ben
P.S. I have a set of 4
My fellow horn extender fans,
(how) would you add a horn extender to this cabinet?
It has a relatively short horn path, but pretty decent sensitivity and output and has a pd 186 driver:
An externally hosted image should be here but it was not working when we last tested it.
more details here
http://www.amstudio.co.jp/pa/pakizaipdf/hk/rl118f.pdf
Regards, Ben
P.S. I have a set of 4
Ben,
The answer is still the same, simply make a "wave guide" or "barn doors" as the picture in post #1 shows. The bigger, the better.
The extension can be held in place with ratchet straps or turnbuckles.
Post #8 shows what the wave guide in #1 does to the response of a pair of "C horns", cabinets very similar to yours, +3 dB (or more) with a relatively small amount of plywood.
Art
The pictures below show how the waveguide is made.
One ratchet strap goes through a slot backed with a metal plate "T" nutted to the top and bottom piece. The top and bottom pieces have two pieces of 3/4" x 3/4" in front and behind the waveguide to form the channels it fits in.
Two ratchet straps are used through slots in the wave guides.
Takes only a few minutes to set up, adds 3 dB forward SPL output with no power compression, yee-ha!
