ProSoundWeb Community

Please login or register.

Login with username, password and session length
Advanced search  
Pages: 1 [2] 3   Go Down

Author Topic: Lab sub questions (impedance & using 1 per side)  (Read 12060 times)

Winston Gamble

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 848
Re: Lab sub questions (impedance & using 1 per side)
« Reply #10 on: May 12, 2008, 12:21:47 pm »

Matt F Castle wrote on Sun, 11 May 2008 09:58

Thanks for the reply Silas,

Could you expand a little on what you've said and qualify why one per side is not worth bothering with and why 2 per side is not recommended?  What are the "special circumstances" 1 pair (L/R) would be ok?  


I think the comments are in regards to what the lab sub is designed to do/be. It's not that one per side won't work, it's that one or even two per side won't produce what they were designed for. Horn loaded subs work best in groups, and the Lab sub was designed to used in blocks of four. Less than that will give lesser performance and then the whole value vs. performance equation may start to favor a smaller simpler to build design.
Here is graph I got off of the Fitzmaurice site that illustrates the effect of multiple hornloaded cabs on performance. (note that the graph is a generic representation, not actual measurements)
" target="_blank">http://i91.photobucket.com/albums/k309/lifeloverwg/ArraySPL.gif
"This SPL chart of a generic horn sub shows what happens when you stack (multiple cabs). Response flattens and extends deeper as more cabs are added to the pile. Response flattens when any speaker types are stacked, but only with a horn does extension also go lower."

Good luck, Winston.
PS. We have one Lab Sub per side at our Church. They were built by one of our members who was going to use them in a small sound company that never got off the ground. They work just great for our needs, but many simpler to build designs would work to cover our 350 capacity room as well.....

Gary Perrett

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 298
Re: Lab sub questions (impedance & using 1 per side)
« Reply #11 on: May 12, 2008, 10:43:01 pm »

It seems to me to be a question of "if your serious" about low end performance. If you are, then get the power, and build the numbers... since 4 is awesome', 6 is 'serious', and 8 is "devastating"! When I first built a (l) LABsub, I laid it down behind the car (outside) and hooked the system to it. It is a "competition" system meant to be run @ SUPER LOW impedance...for LF reproduction power...even @ the LABsub's impedance for one cab it was clearly "thumping" 2 blocks away and could be "felt" 4 blocks away... off response".( I soon added a second and it was...well we HAD to have 2 more...and so on.  We have used 6 outdoors(mono block), with "canned" music for an outdoor "pro" lazer light show, it was palpable...you could feel the thump that far away. Note: it seems implausible, but that was all done with a single "Digam" 5000 amp... a one rack space 17 lb amp...That was (by the way) outdoor, all day and night, and it was HOT... That amp even ran on a 150' 16 gage extension cord. Granted not to full potential, and not that day, but it also seemed to work no matter what the speaker... but I digress...

The LABsub's in the configuration they were designed for, finally gave me the low end I had been dreaming of. I have a system in my house and car, and I too wanted to match the impact of the home, and car systems. ( the home system incorporates a "Sunfire" truesub, and Infinity RS1's. I think now... my "house(BAR INSTALL)" system, sounds BETTER than both my "everyday" systems.

Proper numbers, sufficient power, good Edison supply... and you will FEEL the difference... ( Oh and DSP processing like the Driverack 260-4800, or other Pro processor) and it's ADDICTING!

Gary
Twilite Zone Productions
Logged
We the few who have done so much, for so long, with so little, now feel we can do everything with nothing...

Matt F Castle

  • Jr. Member
  • **
  • Offline Offline
  • Posts: 58
Re: Lab sub questions (impedance & using 1 per side)
« Reply #12 on: May 27, 2008, 07:13:10 am »

Hi,

Thanks to everyone who’s replied, all appreciated.

Currently having trouble finding the Lab12 drivers this side of the pond (UK), they seem to only send them over when people order them… so it’s a 4 week wait for the next container to arrive….. and thus this is prompting me to double check some things to make sure I’ll be using within there limit’s as it looks like it’s a long wait if you need replacement drivers over here.

So just a couple more questions, hopefully someone will be able to help me with:

While I fully understand that the design is aimed at 3 or 4 boxes in a stack, budget & storage only allows for 2 boxes to start with (the idea is to expand over time....). so is there a definitive answer to the following to help with running them in less than ideal numbers:

How much power can one Labsub per side handle safely (single Labsub essentially, 38hz HPF?)?

How much power can a pair (block of 2 Labsub’s) handle and will 2 together allow a slightly lower high pass filter to be used?

Will a pair of drivers in a single Labsub be within the drivers 400w cont. / 800peek (each) thermally and excursion wise when used singly and high pass filtered at 38Hz?

When matching power amps what impedance should I be looking at (one box per channel)?

Has anyone any advice for checking the drivers are sealed properly when they are mounted and should any extra steps be taken to seal them in (eg some form of sealer sandwiched between the drivers and the mounting hole)?

Lastly, in one of the poll’s (what amps do you use for your Labsub’s), people seem to be using QSC PLX3402’s.  As that is what I currently have available for power:  How are people using these with there lab’s (one Labsub per channel, stereo? ) and how well do they do driving them?

Cheers

Matt
Logged

Marjan Milosevic

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 681
Re: Lab sub questions (impedance & using 1 per side)
« Reply #13 on: May 27, 2008, 05:33:13 pm »

Can you please answer some questions for me?

so...

What are the application you will use them?
How often you will use them?
Do you have a proper transportation?
Are you aware how big and heavy the are?
What are your current boxes?

I will try to help you after you give me those answers Smile

And they can be ordered from here:

http://www.thomann.de/gb/search_dir.html?sw=LAB12&x=0&am p;y=0

They have them on stock and can be at your door in a week or less.

Regards
Marjan

Matt F Castle

  • Jr. Member
  • **
  • Offline Offline
  • Posts: 58
Re: Lab sub questions (impedance & using 1 per side)
« Reply #14 on: May 27, 2008, 06:35:23 pm »

Hi Marjan,

Application will mainly be live bands, but with some DJ use (and music playback between bands on bands gig's usally).

How often, good question.  Can't really answer properly.  I'm a small operation just finding my feet and clients.

Yes I have transportation and I am aware how big & heavy they are they are.

Current boxes are single 18's, front loaded reflex.  Labsub will ether be used below these or more likly instead of (depends on avalible amps and how they work together etcetc).

Btw: Thomann only have the one driver in stock and couldn't give me an idea when they will be able to source more, so probably in the same container my UK based supplier is waiting for (who had a better price).

I'm already commited the pair, so i'm  really after some facts about how well they work one per side and what I can/can't get away with power wise.  I know there not ideally to work that way, but it's a long road to having 4 to stack together and power properly so I'm starting at the start and hopfully will be there in a year or two!

Cheers

M
Logged

Marjan Milosevic

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 681
Re: Lab sub questions (impedance & using 1 per side)
« Reply #15 on: May 27, 2008, 09:34:43 pm »

From my experience (i do have 4 lab subs) you will be better with 2x18 boxes.
One lab per side dont have a noticeable advantage over good 2x18 box.
They are PITA to move.
To load it in a van you need 2-3 people. Yes it is doable by your self but at the load out time 2-3 a.m. and a few drinks no one will help you. It is around 120kg.

Please reconsider again.

While it is good to have it for a personal satisfaction i really dont think it is a practical box for a starter in the bizz.

I can not justify the building if you only do small indoor parties for 2-300 people.

Al thou i am very pleased to have them, from a business point of view i dont think i have made a wise decision when builded the Labs.

It is very complicated build and for the money you will spend on two Labs you can build two very good quality 2x18 boxes.

Matt F Castle

  • Jr. Member
  • **
  • Offline Offline
  • Posts: 58
Re: Lab sub questions (impedance & using 1 per side)
« Reply #16 on: May 28, 2008, 05:46:47 am »

Hi Marjan,

Thx for the reply.  As I have said I'm committed to building a pair (wood, drivers etc.. on order).  It is a bit of a personal thing having been reading about them on here for the past few years and probably not the wisest choice from a business point of view. This is a chance I am willing to take.

As for the size and loading in/out, sometimes I have found that can actually be a help.  I've worked with Turbo TSW718's in the past (similar weight box, similar dimensions, but don't think there as deep) and there size actually makes them easier on the back to stack/unstuck using a little bit of GCSE physics to pivot them rather than a straight lift.  That all goes out the window if there’s stairs involved but that’s another thing.....

As things stand at the moment I’ve 4 x single 18's and there a discontinued product so I most likly can't pick up any more.  So will need to ether by all new to upgrade (so 4 x double 18's to make it worth while).  The current ones probably don't have much resale value and they also work with the smaller system I have.  So the conclusion I came to was to ether look at a pair of efficient, higher spec double 18's or look at something horn loaded.  And having looked around at what is available ex-hire it's still cheaper to go with a pair of Labsub's than buy used good quality (eg Turbosound 718's or EAW's etcetc) so from that point of view the Labsubs make more sense.  Although the resale might not be as good.

Which brings me back to my questions about using a pair (one per side and as a centre cluster of 2) and how much you can/can't get away with power, HPF wise.  Was there ever a design document or posts that state the limitations/spec of the design when used in different configurations, that would make a good sticky or page on the documentation site.

Cheers

m

Logged

Josh Billings

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 949
    • http://www.mindboxmedia.com/soundsystem
Re: Lab sub questions (impedance & using 1 per side)
« Reply #17 on: May 28, 2008, 08:38:16 am »

yorkville ls1208

About the same price to build a LAB, smaller, lighter, and 2 according to a few people will be louder than 1 LAB, not a crazy amount, but they will be louder + they will have a resale value and easily reconed (single 18" driver i believe).

Check em out, i might of went this way if i didn't start down the LAB Route

I think you can get them cheaper if you shop around
http://www.musiciansbuy.com/YORKVILLE_LS1208_SUB_1X18_1200WR MS.html

-Josh Billings
Logged

Marjan Milosevic

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 681
Re: Lab sub questions (impedance & using 1 per side)
« Reply #18 on: May 28, 2008, 11:12:44 am »

I wonder one thing.
You are willing to build a pair of the most complicated subs on earth, and dont even consider building 4 2x18 boxes, but rather look at the used pro boxes.
I was also aware of the size prior to building. But when they was completed they turned a lot bigger that i would imagine.
Here is one picture to get the size idea.
index.php/fa/16046/0/

Marjan Milosevic

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 681
Re: Lab sub questions (impedance & using 1 per side)
« Reply #19 on: May 28, 2008, 11:13:45 am »

And here is another one
index.php/fa/16047/0/
Pages: 1 [2] 3   Go Up
 

Page created in 0.053 seconds with 18 queries.