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[Bill Abel]

Hi All,

I've reading these forums for some time now. I've gone back through the postings, and can't fine a definitive answer.

What's the amount of power a single LAB cabinet wired in parallel can safely handle. I realize the Lab12 specs at 400 watts rms each. But, from what I've read it seems with a horn loaded encloser with a sealed rear chamber, the power capability really increases.

Bill

[Ivan Beaver]

Bill Abel wrote on Sat, 23 October 2010 09:40

Hi All, I've reading these forums for some time now. I've gone back through the postings, and can't fine a definitive answer. What's the amount of power a single LAB cabinet wired in parallel can safely handle. I realize the Lab12 specs at 400 watts rms each. But, from what I've read it seems with a horn loaded encloser with a sealed rear chamber, the power capability really increases. Bill

And as with any other enclosure there is no "definitive" answer.

The answer will depend on a lot of variables. And the "power" ratings are not always based on actual power and burning up the voice coil.  Overexcursion and physically tearing up the cone is another popular way to tear up drivers-even though the voice coil may be fine (not burnt from power).

The "power" the coil will take remains the same (more or less) but the excursion at a particular freq will be reduced (untill you get down to a particular point) due to the sealed small enclosure.

So at some freq you may be able to "push" more level due to the fact the the cone would not be moving as far and therefore will not tear itself up as easily.

The electrical impedance will also rise with a horn loaded enclosure (at some freq) so therefore the cabinet can handle more VOLTAGE, but the POWER would still be the same.

This works if you think of your amplifier as a voltage source (which it is into a loudspeaker) and NOT a power source (which it DOES NOT deliver a particular power into a loudspeaker.

It delivers a voltage and the RESULTING power is a combination of the voltage delivered and the impedance of the loudspeaker at a particular freq.

And then you run into the whole dynamic range of the signal.  Some sources are much more demanding (heating wise) on a loudspeaker-even though the meters on the amps may not be getting as high as sources that have a higher dynamic range and therefore produce less heating.

So add all that together and come up with a number to describe how YOUR usage of the cabinets may be-and you will have your answer.

But with so many variables-there is no way to come up with a simple single answer.  Sorry.

[Josh Billings]

I'll give you as simple of an answer as i can.

I've used 1,400 watts per cab and been pretty happy with the results and had minimal driver failures (it has happened though). The music we do is very compressed DJ Playback stuff though.

If you're doing live music you can probably bump this up to 2,000 watts fairly easily.

But best answer is...it all depends

-Josh

[Silas Pradetto]

Properly limited and high passed a LAB box will handle 2000 watts peak no problem. I've powered mine with IT8000s for years with no driver failures.

Lately I'm using IT5000HDs, and I'm not seeing much, if any, level decrease between the 8000 and the 5000 at limit. In a side-by-side comparison it might be noticeable, but the dB or two difference probably isn't enough to matter. If you're running your system that hard, you need more subs anyway.

If you're doing electronic music, stick to the RMS level of the drivers or less, and use a proper high pass filter.

The thermal rating of the voice coils won't change no matter what box the driver is in, and will be the limiting factor for very low crest factor music (techno, dance, dub, etc).

[Bill Abel]

Thanks,

Bill

[Jeff Bailie]

I have been running labs off Plx3602's for almost 3 years. 2 labs for every 1 plx3602

I have had 1 driver failure.

The failure I believe had nothing to do with how much power I was giving it. I believe it was from over excursion.  I have had my high pass filters set at 33 hertz, 24dB BW Slope for over 2 years. Probably a bit low for labs running at high output.

The connection point where the lead meets the frame severed at the solder point.  I have re-soldered it. The driver still works fine.

I do expect to see some more driver failures because of my crossover settings.

I think the point of my post is that proper gain structure set-up, limiting, and crossover settings are whats most important. I don't use the full power of my 3602's before I hit my set limiters anyway.  

Even the RMS could be to much power if your high pass is too low...

You know, I don't know why i ever post. Everyone else has already nailed it down in lesser, and more scientific words.

oh well. here's a picture!