Hello. I'm Dave.

[Gregory East]

4 slims: Add 6dB to the dual chart rough enough, add a conservative 20dB for 1000W of power, add 12dB if you can corner load, add 3 dB for v-plate,

50hz @ 95+6+20+12+3 = 136dB 1m/1000W

I don't even know if that's possible.

[dave_clancey]

Brilliant, Mr. East! I'm up for amp recommendations, it would seem.

[doncolga]

If you're using Eminence 3012 lf or Lab 12, those can go to 50 volts max, so an amp that will do that or more.

I believe the formula is Volts =SquareRoot(Watts * Ohms)

I try to not exceed 40 volts to my boxes but I have them limited at about 47 volts. I did a 4000 sq ft room last weekend for a birthday/ballroom dancing event with just my two bigger T30's and didn't go over 15 volts and up to about 112 dB C weighted on the dance floor, so I had plenty of headroom. I had them V plated and wall loaded. Very consistent coverage through the room. Had the room been bigger and I'd had more time, I probably would have used all four.

I've done Rooms A and B here a couple timse with just the two 18's wall loaded.

http://www.marriott.com/hotels/event-pl ... iverfront/

Another tip: If you're using Lab12's you may want to consider installing the reducer panels as soon as the inner chamber is put together. Things are a little easier to access that way. Later is certainly doable however. That's how I did mine.

My 18's are really easy to move with a hand truck for tip and roll and for stairs. I also keep a caster board under them and roll on that when it's flat all the way.

[dave_clancey]

Great info, Donny. Seems like 4 will handle the room, and will run along nicely with a moderate amp. How far from the dance floor was the wall and your v-plated pair?

[doncolga]

Great info, Donny. Seems like 4 will handle the room, and will run along nicely with a moderate amp. How far from the dance floor was the wall and your v-plated pair?

For the most recent the center of the dance floor was maybe 20 feet away. For the T18s in the bigger room the wall was probably 30 feet away from the center of the dance floor.

[dave_clancey]

Built four at 16". Wondering what the *actual* impedance of the cab is. The amp will provide at 2ohms - the engineer fellow at Crown says the 2ohm rating is real, stable and reliable. Can I run all 4, and confidently, achieve 2 ohms or better?

[Bruce Weldy]

Built four at 16". Wondering what the *actual* impedance of the cab is. The amp will provide at 2ohms - the engineer fellow at Crown says the 2ohm rating is real, stable and reliable. Can I run all 4, and confidently, achieve 2 ohms or better?

Which amp do you have? 4 labs one one side will take a pretty powerful amp to run at 50 volts.....

Why not run 2 per side?

[Tom Smit]

Built four at 16". Wondering what the *actual* impedance of the cab is. The amp will provide at 2ohms - the engineer fellow at Crown says the 2ohm rating is real, stable and reliable. Can I run all 4, and confidently, achieve 2 ohms or better?

IITP

Which amp do you have? 4 labs one one side will take a pretty powerful amp to run at 50 volts.....

Why not run 2 per side?

+1

[Gregory East]

Built four at 16". Wondering what the *actual* impedance of the cab is. The amp will provide at 2ohms - the engineer fellow at Crown says the 2ohm rating is real, stable and reliable. Can I run all 4, and confidently, achieve 2 ohms or better?

Which amp do you have? 4 labs one one side will take a pretty powerful amp to run at 50 volts.....

Why not run 2 per side?

A smaller amp running cool, running forever, I'd choose that over a pricey amp giving its all.

[dave_clancey]

Thanks. This one is an XLS1500.

[Bruce Weldy]

Thanks. This one is an XLS1500.

Not nearly enough to run 4 on one side....

Two a side is marginal at 50 volts.....but doable, just no real headroom.

[dave_clancey]

I have a pair. Would bridged mono be sufficient for 2, you suppose?

[Bruce Weldy]

I have a pair. Would bridged mono be sufficient for 2, you suppose?

I run an XLS1500 bridged to power two T39s with 3012LFs limited to 56 volts with a fair amount to headroom.

The 1500 just doesn't have enough juice to run your subs to full output of 50 volts running one per channel or two per channel. I would bridge both amps and run two off each. You must use a limiter as you'll have more than enough power and don't want to smoke the drivers.

The other option would be to sell the two 1500s and go to an XTI4000. Personally, I'd keep 'em as I already know that it works well.

[dave_clancey]

Thanks. 'Did just that through a Driverack and they really do have quite a bit to offer, now. On with the hunt for a gorgeous amp for my tops. need a 1200/2400 peak rms at 8 ohm. Not an inexpensive proposition, I'm afraid. Thanks to all you fellows who chimed in. They really are quite nice. I think they'll do just fine.

[Bruce Weldy]

need a 1200/2400 peak rms at 8 ohm.

wow....what are you running for tops?