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LAB12 [message #69751] Sat, 08 October 2011 13:12 Go to next message
themilford is currently offline  themilford
Messages: 66
Registered: May 2009
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I need a pair of subs for the studio I work at... and I have a line on a pair of Eminence Lab12 driver for below cost.

I know the ThreePi Sub uses a similar driver... can I use the stock LAB12 in this application.

Also, is this a passive sub? I would like to use an outboard amp like a Hafler P3000.
Re: LAB12 [message #69752 is a reply to message #69751] Sat, 08 October 2011 13:23 Go to previous messageGo to next message
Wayne Parham is currently offline  Wayne Parham
Messages: 18787
Registered: January 2001
Illuminati (33rd Degree)

Yes, the LAB12 will work perfectly in the three π subwoofer. Our OEM version is different only in that the pole piece is machined to accept a cooling plug. This is only really necessary for the 12π hornsub. The three π sub can use either woofer.

Re: LAB12 [message #69753 is a reply to message #69751] Sat, 08 October 2011 13:30 Go to previous messageGo to next message
themilford is currently offline  themilford
Messages: 66
Registered: May 2009
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Thanks wayne... we won't be pushing them that hard anyway. It's a recording studio and the room has a nice neutral sound... so it' merely for extending the LF for our monitors (Genelec)

I'm going to be adding a pair of TwoPi bookshelf to the control room soon and wonder what the best way to tackle switching the frequency point on the subs would be. switching between a set of powered Genelec monitors NS-10s and the Two Pis. The NS-10s and TwoPis will be run on a Dynaco ST-70 and we have a Hafler P3000 to run the subs.

What do I do for a crossover?

Oh, and can I get plans?

THANKS!
Re: LAB12 [message #69755 is a reply to message #69753] Sat, 08 October 2011 16:31 Go to previous messageGo to next message
skywave-rider is currently offline  skywave-rider
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I'll leave the x-o for Wayne to respond to, but we run a Genelec 7070 sub with Four Pi mains. The mains are not high passed, so I parallel the main CR out to the main monitor signal chain and the sub. For me, using a sub with alt. mon nearfields in pointless, because I want to hear the limited low end un-enhanced. When I want full range I use the mains. We have shitty NS10s for nearfields as well.

Using a Bryston 4B on mains.

If you want to arrange switching on sets of monitors, you might look into the Coleman stuff.
http://www.colemanaudio.com/swtchr.htm
Re: LAB12 [message #69756 is a reply to message #69755] Sat, 08 October 2011 16:55 Go to previous messageGo to next message
themilford is currently offline  themilford
Messages: 66
Registered: May 2009
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Thanks for the reply.

This will sound a bit immature but we want subs because the Genelecs have developed a bit of a buzz that goes away when we use the roll-off. I think one of the woofers is damaged... So until we get that fixed we'll use the TwoPis with the subs... but also since the head engineer is reliant on the Genelec monitors it would be nice to have the option of using them with the subs doing bass duty until we suss the problem or he becomes used to the PIs..

The NS10s are only there for clients that want them... we never use them otherwise.

but as you can imagine the roll-off point would be different with each set of speakers. how to deal with this? Do I need one of those little boxes with the knob to set the frequency and dB-slope? what's the most affordable option?



Re: LAB12 [message #69757 is a reply to message #69756] Sat, 08 October 2011 17:07 Go to previous messageGo to next message
skywave-rider is currently offline  skywave-rider
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There are a lot of products that do this sort of thing now. See you at AES on the 22nd. Laughing

PS: Looks like your first priority is fixing your main.
I got away from Genelecs, never liked them. I used to own a pair. In the studio we have 1031s for surrounds. To each his own. I would promote 3 or 4 Pi monitors as mains, for a fraction of the price and better performance. I would call them the smart guy's Augspurger. Razz
Re: LAB12 [message #69758 is a reply to message #69757] Sat, 08 October 2011 17:43 Go to previous messageGo to next message
themilford is currently offline  themilford
Messages: 66
Registered: May 2009
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I actually have an unbuilt ThreePi kits... I was going to use them for Keyboard monitoring/PA in our rehearsal room and for stage monitors for the synths when we tour/gig.

The TwoPis sound so nice... not sure how loud they go for monitoring... I figured we'd put them behind the desk against the back wall for an ear-level "psudo-soffit" application.

THe Genelecs aren't going anywhere The owner likes them too much. They need to be fixed but we are broke. I'm willing to help out and build shit for free but I won't sink money into anything that's not mine... when and if the studio devolves the subs would be mine... if I sunk that time and money into the Genelecs I would be giving my money away. I'm generous with my time but I don't have the capital to invest.

So, Back to crossover. how can I get a variable frequency and slope low-pass box? Stereo would be nice. Even if it had 3 "preset" switches that one could set up for three different speakers. Shouldn't this be a common item?



Re: LAB12 [message #69759 is a reply to message #69758] Sat, 08 October 2011 19:07 Go to previous messageGo to next message
skywave-rider is currently offline  skywave-rider
Messages: 104
Registered: May 2009
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You could build one up passively.

Or you could go cheap active, such as: Use the LF portion of a Behringer CX3400. About $100.00.

It will sum L&R out with variable low band x-o starting at 44 Hz. You could use the crossover in that to send a filtered signal to the satellite monitors, or you could go the blending route, and split your mon out to both the main amp and the CX3400. Done.


There's probably a lot of other options out there if you want to use your Hafler and not buy a plate amp (with built in x-o.) However, the Behringer is cheap and their recent build quality is good.

PS: Build up those 3 Pi kits and put them in your own studio.
Re: LAB12 [message #69760 is a reply to message #69759] Sat, 08 October 2011 23:03 Go to previous messageGo to next message
Wayne Parham is currently offline  Wayne Parham
Messages: 18787
Registered: January 2001
Illuminati (33rd Degree)

I've send the plans for the three π subwoofer.

As for crossovers, there are a lot of options. The Behringer would work, as would the Rekkhorn sub crossover or the Pyle crossover. I wouldn't use the Pyle crossover unless it were modded though, so if you don't have time to fool with it, go another route. But if you upgrade it as shown in the link above, it's sneaky good sounding.

Definitely don't high-pass the mains; At least, don't high-pass them above the Helmholtz frequency. There's no harm limiting the out-of-band content, but we want woofer sound sources blended, so don't high-pass at 100Hz or anything like that. It's a good thing to do in prosound, and maybe the itsy-bitsy satellite speakers need it but none of mine do.

Just low-pass the subs. If they're to be setup as flanking subs (stereo, one sub per main, about 2 feet away in each dimension) - then low-pass on the high side, like 80Hz-100Hz second-order. If all you have is a fourth-order unit, let it run up to 120Hz or 150Hz. The subs should sound very muffled, but you should hear the deepest part of male voice coming out of it. We want that part to smooth the room modes at the high-end of the modal region. If they're more distant subs, then low-pass lower, around 50Hz-60Hz. The subs should be smoothly blended, and you should not be able to tell they're on.
Re: LAB12 [message #69762 is a reply to message #69751] Sun, 09 October 2011 08:33 Go to previous messageGo to previous message
themilford is currently offline  themilford
Messages: 66
Registered: May 2009
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Awesome! thanks for all the help. I think I'm getting my brain around this.

Would this work as a crossover?:
http://www.rolls.com/product.php?pid=SX45
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