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[raj]

  Hi
I think using70 nos of lab subs ,that too in hexagonal arrangement     DOES NOT

MAKE SENCE.
With 16 LAB SUBs +8 Servodrive SPL-td1Tops properly used ,you should be

able to Blast the open area for 10000 people,leave alone your requirement for a

crowd of 5000

[Michael Strickland]

I just realized one other thing. Perhaps Mr. Rick is not aware of the high sensitivity of the LAB sub compared to a standard front loaded dual 18". The LAB is approximatly 9 dB more efficient, which means you'll need less than half of them to match up to X number of standard dual 18" cabs.
So if you've been to other events that used, say 70 SB 1000's, about 24-30 LAB Subs would be equal to that, assuming the same ammount of power is feeding them.
Not to mention less "time slur" from having tighter stacks.

[Rick]

Thanks to all for their comments, this is what I wanted to hear !

The number of 70 was the origonal plan for dual 18" horns, but it sounds like I should go for around 24 LAB's.  
I wont complain about that ! less storage as someone mentioned, and less cost.  I think I will go with that.

I have beeen looking over the plans yesterday and converting everything to milimeters from inches, fun...!

Well, I will keep you upto date on my progression.

Keen to hear any other storys about live dance/techno performences using the LAB's

Cheers Guys

Rick

[Michael Strickland]

Storage and space are just a few advantages of the LAB.
Others include fewer cabs to buy/build (duh), fewer power amps to buy, less rack space taken by the amps, quicker load in time, quicker load out time, less weight (both in speakers and amps), smaller footprint on stage, less cabling....
Why doesn't everyone have these things?

[Too Tall (Curtis H. List)]

Rick wrote on Thu, 06 May 2004 18:23

Thanks to all for their comments, this is what I wanted to hear ! The number of 70 was the origonal plan for dual 18" horns, but it sounds like I should go for around 24 LAB's.   I wont complain about that ! less storage as someone mentioned, and less cost.  I think I will go with that. I have beeen looking over the plans yesterday and converting everything to milimeters from inches, fun...! Well, I will keep you upto date on my progression. Keen to hear any other storys about live dance/techno performences using the LAB's Cheers Guys Rick

Hi Rick,
If you want to put more into this system you might consider beefing up the bass region just above the LAB subs.
The LAB subs work up to around 80Hz, but if you cross them lower say around 60Hz you are in better shape.
   For an out door system my friend Al Limberg uses dual 15" mounted on a horn about 1 meter deep with a small closed chamber behind the drivers. The box operates completely in the range where the horn is working making them very efficient, extremely punchy and tight with very little harmonic distortion. Above that he uses Community M-4 midrange horns and then high frequency horns above.
   For an outdoor system being totally horn loaded and having every driver only work in the range where the horn is working (no using a too short horn and then eqing in the bottom) pays large dividends in sensitivity and sound quality.
   The down side is this system is large and a visual mess compared to some tiny (in comparison) Servodrive td-1s flown over LAB subs ground stacked.
   OTOH it will pin the ears back on a td-1 system. A "clean" version would be to fly Community Air Force cabinets, but for 5k people that would be overkill and then some.
   If you want to play with putting subs out in the audience my feeling is 5k people are too few to make it worth doing. The only time I can remember it being done was by Pink Floyd and it was indoors. They put sub boxes under the seating in arenas (10k to 20k seating). They were crossed over very low (even for a sub) and only used for effects like the explosion when the plane crashed into the stage on the "Dark Side of the Moon" tour.
   For any kind of music a bad idea until you are trying to cover more like 50k outdoors and are using delay towers. At that point you delay the subs right along with the rest of the tower.
   One thing to keep in mind. If you don't hurt anyone, have the equipment and time experimenting is a good thing even when some people tell you what you are doing won't work. Nothing like finding out yourself. You might even learn something new. Just remember it works the other way too. When you hear someone like TT talking about arcing your subs give that a try too.

Too Tall

[Al Limberg]

Visual mess!!!!  Harrumph!!!  And this from the guy who is kind enough to provide the woodshop and his woodworking expertise!!  I'll have Christine and Bruce and John at Community bombard you with spam for this!!!    I sure won't argue with the size and portability aspect - I assure you that a top box containing an M4, an s90 2" and associated drivers built from 3/4" ply is no picnic to load into any van, truck, or trailer. (if you'e keeping score, that's a trap box 30" wide front, 15" wide rear, 43 1/2" tall and 45" deep! - the double 15 shares the same footprint but is 49 1/2" tall). On the other hand, when you find yourself in the middle of a nice little festival running 100db at FOH and you see the meters on the M4 amp peaking at 10 watts, it all seems a little more worth while.  Add to that the fact that each time I load and unload an M4 I know the alternative is a dozen twin 12" front loads and all the associated amps and cables,blah blah blah they would require.
And if you think its big now, just wait till I score those PC264s for the 2"!!!!

Al(I may be old and oversized, but I can pack 2 quarts into a 1 quart jar) Limberg

[Rick]

Cheers too tall, nice bit of info !

The big idea is to build everything here in NZ, basically is will save a crap load on shipping (which aint cheap), so hopefully I only have to import the drivers.

Cheers all

[andreas]

Al.

You should not happen to have a picture and a drawing and could spare a little time discussing your midbass horn with us?. It might be a tad to big for mig living room but I'd like to get a few general idears.

cheers
andreas

[Al Limberg]

Hi Andreas,
My lo-mid boxes are not totally home-brewed.  As a Community dealer back in the 70s and 80s, I purchased 6 horn flares that they called 'Boxers'.  The were based on the premeise that they provided the fibreglass flare and the box plans and we provided the box and labor to build them.  The original cabinet was designed as a rectangular ported low end cabinet using your choice of either 2 15s or 2 18s. It was 60"h x 30"w x 45" d.  As life works out sometimes, they just never got built.  I originally purchased the Bowers on about 1982 and when I closed my retail store in 1989, they followed me home. I moved them from location to location over the next 13 years until the summer of 2002 when it became apparent, with the birth of the LabSub project, that I would need a source to bridge the gap between the subs and my M4 midrange units.  I dug a Boxer flare out of my garage and took it out to Too Tall's shop and started messing with the idea of using it for a low mid.  A little playing around showed that the flare would fit (barely) in to a cabinet with the sme footprint as I had made for my M4/s90 2" combos.  With some help from a couple much more knowledgeable speaker-designer types from here, I proceeded to build the boxes and load them with some JBL 15s that were available for just over 'free' at their tent sale.  Thru the input of the folks here and some just plain good luck I suspect, they turned out very usable - we aimed for a solid response from 80-300hz and Praxis tells us we managed to get exceptional results from about 75 to 1200 with the low end EQ-able down to 40 if necessary. (As a matter of fact, I used the boxes as my low end until the Lab 12 drivers became available.
While I don't know where one would find additional Boxer flares, for what it's worth, the depth of the 'horn' is 36" from front lip to baffle and 45" is th eoverall depth of the box.  It is unported but still stands 49 1/2" tall and 30" wide.  The actual holes in the speaker baffle are 13" in diameter with the speaker chamber somewhat less tha 3 cubic feet.  I used JBL 2035H drivers.

Al

[andreas]

Hi Al

Sounds good, the 2235 is really a nice driver i recon, I have a couple of it's bigger brother the 2245 which are playing paperweight at the moment. I am just trying to get some idears how to bridge the gap between the labsub and a CD midrange horn with the 10" jbl 2012 as seen on the Pi forum. Your system, however might be a wee overkill. I might try something with a couple of jbl 2226 I have in my mains at the moment.

The M4 looks really impressive, I bet the arent cheap?

cheers
Andreas