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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => SR Forum Archives => LAB Subwoofer FUD Forum Archive => Topic started by: Rick on May 02, 2004, 09:26:47 pm

Title: LAB Sub sounds great
Post by: Rick on May 02, 2004, 09:26:47 pm
Hi all, Im currently working on a music festival in New Zealand.
We are building our sound system from the ground up.  

Currently I had planned to use 48 Dual 18" horn cabinets for my LF, but im interested to hear what the story is with thes LAB subs, they certainly sound great.  What sort of numbers do you think we will be needing to happly thump an audence outdoors of 5000people?  

we had also thought about surrounding the audience in bass cabinet stacks?

Just a general question here, interested to hear your thoughts, and experiences with LAB sub in situations like this

Cheers

Rick
Title: Re: LAB Sub sounds great
Post by: Tamas Tako on May 03, 2004, 03:51:23 am
Hi,

I would say it depends from the type of music, how many LAB you need for an audience of 5000 open air.

Let's talk about numbers.
if you would use 4-5 stacks along the stage with 6-8 LABs on the Left and Right side and 2-3 times 4 pieces in the front of the stage, and then you "ARC" the horizontal sub array to get a virtualy point source, you can get a quite even sub distribution.
Driving one LAB with 2500-3000 watt capable amp(this would be then the peak power), you would get a max. SPL@50m of 126dB and @100m 120dB...

Those numbers are based on my 10m measurements, and not verifyed at 50m and 100m!

However I always prefer by Rave and Techno music to increase the number of boxes and decrease the driving power to protect the drivers when tzhey should sound 10 hours long...

For normal rock, hip hop and rap or pop materials these numbers are even too mutch for 5000 people

I think the minimum quantity would be 3x or 4x 4 pieces of LABs using the "ARC" technique described above.

All the best,

Tako Tamas

Title: Re: LAB Sub sounds great
Post by: raj on May 04, 2004, 09:12:21 am
 Smile Dear Tako Tamas,
  I read about  the "ARC" technique you have described in your last post,for some

time I have also been thinking about of lab sub placement in open area,for live

programmes & dance parties.
I will be greatful if you and other friends could advise on lab sub placement

techniques , various experiments tried out , Xover frequeny etc .Some basic tips

will be useful.


ps
when I was sending this post I got the message that my cookie has expired,I had

got myself registered only a few days back on this new software of the

forum,please make my registration permanent
Title: Re: LAB Sub sounds great
Post by: Rick on May 04, 2004, 07:13:35 pm
Hey all,

I would also been keen to hear a little more about sub placement for open air dance events, and reccomended pages one the net ?

And alos, what would be the story with surrounding an audence of 5000 in hexagonal shape of bass stacks? It seems ok to me, but is there a large problem that I dont know about ?
The thing with this festival, is the idea to be different, and I this certainly hasent been done in New Zealand, and im sure it would give the ravers one hell of a thump ! We are looking at running around 70,000W for the bass stacks. I certanly think the LAB would do the trick for us.

Cheers

Ricky Owens
Title: Re: LAB Sub sounds great
Post by: Michael_Elliston¶ on May 05, 2004, 12:56:58 am
That really sounds amazing! will it be near Auckland?

I dont know about the cancellations etc if you have an array that is surrounding the audience..some one will know here.

http://www.prosoundweb.com/install/synaudcon/tt26_3/tt26_3_p 1.shtml

I live in dunedin,where nothing much happens basswise Very Happy

I do know that a solid clean 42hz sounds awesome at high spl,so having 35hz ish performance can give people a fright.

Title: Re: LAB Sub sounds great
Post by: Rick on May 05, 2004, 02:06:21 am
Yes, the idea is it to be different, and as far as I know there hasent been a festival will such a big bass rig. I ask why.., and I why not ! Of course, it would be a feedback nightmare for a band reinforcemnt situation, but for DJ's, no problem there.

We will be holding it in Hawkes Bay.
Cheak us out @ www.expuls.co.nz

Well, I think the LAB horn might just do the tick, the laser cutters are going to have fun next year cutting 70 cabinets, and assembling them all!

cheers
Title: Re: LAB Sub sounds great
Post by: Michael Strickland on May 05, 2004, 10:59:52 am
70 LAB's? Holy crap. I don't know much about arcing them, but I do know that you'll run into phasing issues setting them up as "surround sound". It's less of an issue for the tops because the wave form's are much shorter. With 50 cycles, you'll end up with HUGE nulls in places and HUGE sums in others, not only size wise but amplitude wise as well.
Title: Re: LAB Sub sounds great
Post by: Rick on May 05, 2004, 06:10:30 pm
Ha, yeah, I certanly for see problems, but am keen to hear from someone who has given this sort of idea a go.  If no, then It looks like we will might have to give it a shot !
I think being outdoors, and the stacks will be fairly spaced out, im hoping not to run into to may wave related problems.
But the phasing issues will always be there, just need to work out a practical way of working with them.
Title: Re: LAB Sub sounds great
Post by: Marjan Milosevic on May 06, 2004, 04:25:30 am
Hi Rick,

First of all it is very nice to be entusiastic but...

For driving 70 labsubs you will need at least 140 000W of power amps and for 5000 people it will be a huge overkill.

Beside the time and work needed to build them, you will spend aproximately 500 - 600$ per box plus 300$ for drivers for each Labsub, which is total of about 60K$. And that is yust subs, no mains, no amps, you know what I meen.

So we are talkin SERIOUS money.

What are you think you can use to keep up with 70 labs?

How many amps will you use for the whole system 100+ maybe???
For 5000 people ??????

Are we talkin about Motorhead outdoor concert? Or NO SLEEP IN HAMMERSMITH Festival?

For that kind of money you can rent any sound system you like. Also you will need HUGE storage place that needs to be payed too. Not to mention the work labor.

If I were you I will consider more realistic sound system.

Here at the forum you have people who has done 5000 audience with yust 4 labs (two per side), so maybe they can comment on this to.

I am not trying to discurage you but, unless you have more events, not one planed for 1,5 year from now (at least 10 BIG events per year) you will be loosing money. Investing 60K$ and make yust enough to pay the rent for the warehouse is no sence for me.

Thans  just my 2 cents
MarjanM
Title: Re: LAB Sub sounds great
Post by: Tamas Tako on May 06, 2004, 05:45:32 am
Hi,

I agree.

For 5000 people outdoors I would use maximum 20-24 pieces of LAB and that only when I need to push them 10-12 hours long with Techno or Drum&bass material. So I can drive them just with ca. half power peak and this would be OK even when it is warm and sunny out there.
For normal production 4x4 =16 pieces is enough.
I also don't prefer the subs placement around the audience. It is not easy to make sound good.

cheers,

Tamas



Title: Re: LAB Sub sounds great
Post by: raj on May 06, 2004, 10:15:12 am
  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
Title: Re: LAB Sub sounds great
Post by: Michael Strickland on May 06, 2004, 10:47:41 am
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.
Title: Re: LAB Sub sounds great
Post by: Rick on May 06, 2004, 06:23:54 pm
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
Title: Re: LAB Sub sounds great
Post by: Michael Strickland on May 07, 2004, 06:15:43 am
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?
Title: Re: LAB Sub sounds great
Post by: Too Tall (Curtis H. List) on May 07, 2004, 11:27:16 am
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


Title: Re: LAB Sub sounds great
Post by: Al Limberg on May 07, 2004, 01:03:46 pm
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!!!  Laughing  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
Title: Re: LAB Sub sounds great
Post by: Rick on May 07, 2004, 05:53:33 pm
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
Title: Al's system
Post by: andreas on May 08, 2004, 08:47:31 am
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
Title: Re: Al's system
Post by: Al Limberg on May 08, 2004, 11:41:51 am
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
Title: Al's boxes
Post by: andreas on May 09, 2004, 04:18:32 am
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
Title: Re: Al's boxes
Post by: Al Limberg on May 09, 2004, 11:04:30 am
No, you're right about that!!  Shocked  The M4 is really expensive right up till you compare what it takes to replace it.  On the other hand, in anything less than outdoor or large theatre/arena use it might be considered 'overkill'.  I am most fortunate that mine were purchase in about 1981!!  

Al
Title: Re: Al's boxes
Post by: andreas on May 09, 2004, 02:15:39 pm
Hi Al

Year i saw a figure just on the good side of 1500$, thats not really equal to giving it away i might say Shocked. An yes again overkill a 40 sqm living room, unless one desires to be utterly hearing impaired.

cheers
andreas
Title: Re: Al's system
Post by: andreas on May 10, 2004, 02:12:41 pm
Hi Al

Is there any chamber in front of the speaker before the horn starts. Or is it as I suspect, a 3 ft^3 closed chamber behind the speaker unit and the unit mounted directly to the baffle, thus having a negligible front volume ?

cheers
andreas
Title: Re: Al's system
Post by: Al Limberg on May 10, 2004, 02:31:20 pm
You.ve got it pictured right.  The Boxer fibreglass horn, when placed face down outwide of the box, brings to mind Three Mile Island and similar nuclear power plants here in the states  Shocked.  The rear chamber is actually made as small as possible by building in a 'floor' and 'ceiling' under and above the frames of the lower and upper 15s.  

Al
Title: Re: Al's system
Post by: RobertOziemkowski on May 10, 2004, 03:13:02 pm
Al Limberg wrote on Sat, 08 May 2004 16:41

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


BOXERS???

Thats too funny!

A friend had 4-18 Fostex speakers loaded in Boxers at a club(800cap, 25+' ceiling) he worked. I remeber busting him about not hearing the lows(woof) enough, so he made me stand there until I thought my chest would cave. As you said, not super sub freqs but clean and efficient.

He talked me into working the next day but neither of us were prepared for all the ceiling tiles lying on the floor!

OOPS!

Great idea to use them for sub-top fill. Another friend has(had?) 4. I wonder.........

Robert
Title: Re: Al's system
Post by: andreas on May 10, 2004, 03:17:19 pm
WOW Shocked Nuclear Speakers, might have to aquire that internet domain. I wonder how a similar homebrewed horn fitted with a single jbl 2226 (18") or 2245 (18") would perform. The difficult thing here would be to build the dam nuclear "cooling towers".

cheers
andreas
Title: Re: LAB Sub sounds great
Post by: Bogdan Popescu on May 12, 2004, 02:54:12 pm
Hi,

How many boxers for one LAB, and how do you stack them ?
The boxer's are wider than the LAB...

Thanx,
Bogdan Rolling Eyes
Title: Re: LAB Sub sounds great
Post by: Al Limberg on May 12, 2004, 03:43:32 pm
Since I typically only use the Lab/Boxer/M4 set up in outdoor or very large applications, I have been able to use the subs in a center cluster with the Boxer/M4 stacks flanking the stage each time I 've used it.  I expect if I find myself in a situation where I can't put the Labs in the middle, I'll just stack them beside the Boxer stacks.  The Boxer/M4/s90 combination is already about 94" tall so addtional height isn't a major concern.

Al