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[Art Abrahams]

I hope I've got the right section! If not please direct me...

Hello All!

I'm new here so allow me to introduce myself:

My name is Art Abrahams and I am involved in a few aspects of the music business; primarily as a luthier. I also work for a music festival. Our show happens early August, caters to about 10,000 guests and has 5 concurrently running stages featuring predominantly electronic music. The stage I represent is considerably more varied as we run the gambit from single DJ's  right up to 11 piece bands with horns -even a a group of acoustic marimba players this year.

One of the unique things about this event is the fact that it's held on private property and because of this, our stages are permanent installations built from steel, concrete and heavy gauge timbers. This coming year my stage director is planning a major renovation. Allow me to present our current stage:

http://www.flickr.com/photos/66542224@N08/sets/72157627562724812/

The amphitheater and stage were built in 2005 as was the main roof, which has grown and evolved over the years. The shot with the system on it is the rig we ran this year. That wall of sound contains 8 Labs and 12 shop-built Martin WSX clones. (the two SBT's were not actually in use). The stage itself is 17 feet from the front poles to the back; 12 feet of which I think will be useable for what I am about to propose.  It's currently just over a meter high an will probably be raised a bit. For argument's sake let's say the useable depth for volume is 1 meter. Now the really clever out there already know where I'm going with this: HORNS IN THE FLOOR!!

We've dreamt for years of a stage with no visible bass. Since we're going to redo the floor and foundation, why not get SERIOUSLY purpose specific! I've been tasked with the initial feasibility study and cost analysis. To do this I need to work through a significant portion of the design to get an accurate handle on component costs.

As far as horn construction goes, there is one overriding issue for any design: Flooding. Every year the pit spends at least a month under water (often right up to the stage floor). For this reason, concrete and quite possibly bricks and mortar will be the materials of choice. As far as stability and performance go I can't think of a better material; flooding or not. Many of you have already seen this:

http://www.royaldevice.com/custom.htm#THE%20REAL%20TOTAL%20HORN

I want to do that on a larger scale.  With MORE horns... (My dream would be to have a TRW-17 fan unit(s) in a large center cavity -but that's at least $20k)

 So there's my project, in a nutshell...

I'm here for as much input as I can get! Considering how massive, unique and just down right potentially cool this project is, I want to involve as many minds as possible. If speaker-builder  forums are anything like the guitar-builder forums I frequent, then I know there's an unlimited resource of passionate, opinionated and brilliant minds out there that just love to geek out on this kinda stuff...
At the moment I'm reading everything I can get my hands on and would GREATLY appreciate any recommendations. I'm also trying to scrounge up an old PC to learn hornresp and whatever other apps I can find. Again any recommendations or help in this direction would awesome (are there any mac platform simulators out there?)  Beyond my own education, I'm looking for ideas! Open your minds and engage that lateral thinking. There's no limitations due to cabinet size here so go crazy! We can zig-zag in any direction, run horizontally across the stage... This is dance music so the lower the better -I'm thinking at least a mid-bass and bass design with a possibility of adding the fan unit to get right down to 5Hz.  Where I REALLY need the help is with the industry 'shorthand'; my theoretical knowledge is growing rapidly so I'm looking for real world experience: Driver recommendations, crossover/protection and such -reading ad copy is one thing, but what are you actually using out there in the field? Also design ideas: Bigger horns with bigger/multiple drivers or smaller horns and more of them? These are the opinions I'm after.

I've been looking at every horn design I can find, thinking of what would be the most efficient use of space. I was initially thinking of designing a pair of front loaded horns that could be nested in pairs (think yin-yan or pisces). Most recently I've been considering a tapped horn with a single fold; much like this design, but without the bend at the mouth (the mouth would just flare past the driver).

http://forums.klipsch.com/forums/t/149697.aspx

The idea would be to orient these on their side, mouth to the front of the stage with access panels to the driver(s) for insertion/removal and at the bend for cleaning. (Any sediment deposited by the water will need to be hosed out)..  One could fit a lot of these under that floor!

Cheers!

art...

[Doug Fowler]

Read the rules, fix your display name. Thank you for your cooperation.

[Ivan Beaver]

Have you actually looked at the output specs of a TRw17 fan?  And what it would take size wise for an enclosure?

Yes it may go low-but not very loud at all.

And certainly not up in the "regular sub range for live music".

How much live music goes as low as the fan is intended to operate-ie single digit numbers?

You would do much better to use products that have high output in the intended range of the music being produced.

[Charlie Zureki]

Have you actually looked at the output specs of a TRw17 fan?  And what it would take size wise for an enclosure?

Yes it may go low-but not very loud at all.

And certainly not up in the "regular sub range for live music".

How much live music goes as low as the fan is intended to operate-ie single digit numbers?

You would do much better to use products that have high output in the intended range of the music being produced.

   +1

   and while it's great to "hide" the subs, make them "tamper-proof", and as Ivan say's "go low", and not in the "regular sub range for live music"... is building this thing really practical?   

    This kind of structure has a high cost of manpower and materials, not to mention that the structure may need to be isolated (de-coupled) from the surrounding earth as to prevent energy losses through unintended transmission.   And, then, there's the possibilities of neighboring business & residential complaints from low frequency energy transmission.

   Hammer

[Brad Weber]

Don't know what kinds of acts you deal with but no matter how cool or how nicely done you did something like that are the bands and performers simply going to perceive anything like that as an unknown DIY approach and be asking for something known anyways?

I'm also not clear on how you plan to put anything in the floor.  You mentioned concrete construction and the front of the stage looks solid so how did you plan on installing anything in the stage floor?  And having mucked out some pit at amphitheaters, if you get flooding up to the stage every year then you would definitely have to remove all drivers and cabling at the end of each season and would probably have to get in there and clean out the 'horn' before each season to get rid of the mud, animal nests, leaves, etc. that may end up there.

Also keep in mind that the installation you referenced was a listening room, therefore no live sources in the room.  You have a very different situation with performers and microphones on stage.

[Charlie Zureki]

Can you provide some more information.

   For What?  What more information do you need?
    Hammer


    He...eess gone!   That Vincent Mason must have been a ghost.....  

[Lee Douglas]

   For What?  What more information do you need?
    Hammer

Sig Spammer? 

if you get flooding up to the stage every year then you would definitely have to remove all drivers and cabling at the end of each season and would probably have to get in there and clean out the 'horn' before each season to get rid of the mud, animal nests, leaves, etc. that may end up there.

I would think this would be a big deterent.  And as Brad mentioned in the same post, the design you mentioned was in a finite space.  In open air everthing is quite different.  If I were to seriously persue this in any fashion, I would plan on doing a whole lot of modeling in the virtual world first.

[Stu McDoniel]

I hope I've got the right section! If not please direct me...

Hello All!

I'm new here so allow me to introduce myself:

My name is Art Abrahams and I am involved in a few aspects of the music business; primarily as a luthier. I also work for a music festival. Our show happens early August, caters to about 10,000 guests and has 5 concurrently running stages featuring predominantly electronic music. The stage I represent is considerably more varied as we run the gambit from single DJ's  right up to 11 piece bands with horns -even a a group of acoustic marimba players this year.

One of the unique things about this event is the fact that it's held on private property and because of this, our stages are permanent installations built from steel, concrete and heavy gauge timbers. This coming year my stage director is planning a major renovation. Allow me to present our current stage:

http://www.flickr.com/photos/66542224@N08/sets/72157627562724812/

The amphitheater and stage were built in 2005 as was the main roof, which has grown and evolved over the years. The shot with the system on it is the rig we ran this year. That wall of sound contains 8 Labs and 12 shop-built Martin WSX clones. (the two SBT's were not actually in use). The stage itself is 17 feet from the front poles to the back; 12 feet of which I think will be useable for what I am about to propose.  It's currently just over a meter high an will probably be raised a bit. For argument's sake let's say the useable depth for volume is 1 meter. Now the really clever out there already know where I'm going with this: HORNS IN THE FLOOR!!

We've dreamt for years of a stage with no visible bass. Since we're going to redo the floor and foundation, why not get SERIOUSLY purpose specific! I've been tasked with the initial feasibility study and cost analysis. To do this I need to work through a significant portion of the design to get an accurate handle on component costs.

As far as horn construction goes, there is one overriding issue for any design: Flooding. Every year the pit spends at least a month under water (often right up to the stage floor). For this reason, concrete and quite possibly bricks and mortar will be the materials of choice. As far as stability and performance go I can't think of a better material; flooding or not. Many of you have already seen this:

http://www.royaldevice.com/custom.htm#THE%20REAL%20TOTAL%20HORN

I want to do that on a larger scale.  With MORE horns... (My dream would be to have a TRW-17 fan unit(s) in a large center cavity -but that's at least $20k)

 So there's my project, in a nutshell...

I'm here for as much input as I can get! Considering how massive, unique and just down right potentially cool this project is, I want to involve as many minds as possible. If speaker-builder  forums are anything like the guitar-builder forums I frequent, then I know there's an unlimited resource of passionate, opinionated and brilliant minds out there that just love to geek out on this kinda stuff...
At the moment I'm reading everything I can get my hands on and would GREATLY appreciate any recommendations. I'm also trying to scrounge up an old PC to learn hornresp and whatever other apps I can find. Again any recommendations or help in this direction would awesome (are there any mac platform simulators out there?)  Beyond my own education, I'm looking for ideas! Open your minds and engage that lateral thinking. There's no limitations due to cabinet size here so go crazy! We can zig-zag in any direction, run horizontally across the stage... This is dance music so the lower the better -I'm thinking at least a mid-bass and bass design with a possibility of adding the fan unit to get right down to 5Hz.  Where I REALLY need the help is with the industry 'shorthand'; my theoretical knowledge is growing rapidly so I'm looking for real world experience: Driver recommendations, crossover/protection and such -reading ad copy is one thing, but what are you actually using out there in the field? Also design ideas: Bigger horns with bigger/multiple drivers or smaller horns and more of them? These are the opinions I'm after.

I've been looking at every horn design I can find, thinking of what would be the most efficient use of space. I was initially thinking of designing a pair of front loaded horns that could be nested in pairs (think yin-yan or pisces). Most recently I've been considering a tapped horn with a single fold; much like this design, but without the bend at the mouth (the mouth would just flare past the driver).

http://forums.klipsch.com/forums/t/149697.aspx

The idea would be to orient these on their side, mouth to the front of the stage with access panels to the driver(s) for insertion/removal and at the bend for cleaning. (Any sediment deposited by the water will need to be hosed out)..  One could fit a lot of these under that floor!

Cheers!

art...

I would can the whole perm sub idea and work on a point source sub location for the subs you have.
Pour a concrete slab off to one side and put all the subs on it.  If you dont want to see them cover them with a big blanket of some sort that will pass air.   Just my idea anyways.

[Jeff Robinson]

http://www.livesoundint.com/lab/lab/messages/archive3/125096.html

The Labsub has >10' throat length. If you're happy with the performance of 8 you'll need the same mouth area (~56.25 ft^2). Concrete is a good material for horns, but is unforgiving of design/layout errors. Please consider the "power alley" you will get with a horizontal array. I remember a guy built a variation of the LABSUB for his church in a straight throat version but don't remember enough to refine a Google search.
 
I'll have to dig up my Excel file that lays out the throat flare when I get back home next week (I'm at Schneider factory automation school this week in North Carolina). If you want a different design you're on your own. There are 2 basic horn design methods: pick a woofer and run the math to determine the optimum design or pick a flare rate (cutoff frequency), back chamber volume, throat area, length, mouth area, etc to develop the Thiele/Small specs and have a custom woofer built (the history of the Labsub was Tom Danley got a consensus of desired characteristics and did the design work, I did some minor confirming that the volume and throat could be folded to fit in the cabinet).

Jeff Robinson

Found it on the web:
http://www.geocities.ws/loudspeakerguru/LAB_Horn.xls

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