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[Pascal Pincosy]

Another consideration is that your overall costs will rise with the addition of each sub. Consider that you need to purchase the proper-sized amp for each cabinet. Add in the amount of time to properly mount the amps, and custom-build input panels. Then multiply for each cabinet. How much more is it going to cost you than buying one amp, a rack, and some cables? And are you really going to save setup time by doing this (per Mac's post?)

[Chris Coleman 2]

True it may not save a LOT of money or time, but there are possibly some other benefits....

Like what about using active power amps that have a built in "cone position sensor" circuit to provide true driver excursion protection + overheat protection + dynamic EQ ??  Did you ever try such an advanced power amp inside DIY LAB sub or inside a matching top enclosures ??

[Bogdan Popescu]

I use LAB's for a few years now. Could not be happier about my decision and never thinking on changing them for any tuba or other  sub except maybe for some other of Tom's creations.

Also i would not add another kilo to the weight some people here shore know why

B.P.

[Rick Powell]

www.speakerpower.net

These "plate" amps might do the trick, the 1000w at 4 ohms version looks like the ticket for a sub.  They only draw about 2 amps, too.

RP

[Tom Herr]

1000 watts per sub. Can't speak for the Tuba but that would tickle a labhorn and get you some sound but no where near it's potential. I feed my labhorns with 1 RMX 2450 or PLX2402 bridged per labhorn. Never had a driver or amp failure. Started out running them this way, and never looked back. Just make sure your processor settings are correct, especially the hp filter.

[Craig Leerman]

The LAB sub was designed to be used in large systems, where size and weight is usually not an issue (large trucks, loading docks, lots of labor, etc) It uses 3/4 Plywood, as well as heavy aluminum plates as the port covers. Expects a Lab to weigh in at 250 - 300 lbs depending on finish and grill options.

Bill's Tubas OTOH were designed to be portable! His cabinets use 1/2 plywood and were designed mainly for use by local folks who have to move their own stuff around.  While I don't know what his stuff weighs, I can tell you that your back will love a Tuba over a LAB sub anyday!

If you are playing clubs, I think  Tubas would be a good choice.  A LAB is a bit large and heavy.

In addition, some of Bill's designs have options to use 1 or 2 drivers per box. That would save some money on drivers. His TUBA SLIM with 1 X 15" per box seems to be popular.

[Chris Coleman 2]

Rick and Tom: good thoughts.. With the new bassmaxx subs being active designs, is the DIY world ready for a powered lab sub using something like a speakerpower 2ch plate amp at 1000w/ch including integrated dsp crossover ??

Craig: do you think an active tuba would be more of a hot item than an active lab ?

[Ivan Beaver]

The problem with the Speakerpower solution for subs is in the max output available.  This is not saying anything bad about them, you just have to look at the REAL numbers.  The dual 1000w module is 1000w per channel @4 ohms.  It is like 660W or so at 8 ohms.  Don't make the assumption (like I did) that you can bridge the outputs into a single loudspeaker.  The outputs are already bridged so that is all the power that is available.  For serious subs that is a wee bit shy of what is needed.  Of course it keeps them from getting overpowered.  The DSP has a limiter to keep the clipping down, but to really push the performance of modern day subs, you need more power, or possibly go to 4 ohm drivers.  In a situation such as a lab sub, the speakerpower solution might be pretty good, with a channel driving each speaker.  You would have around 700-800W /driver, which is not bad, but still shy of what you would put on it, if you were to put an outboard amplifier on it.

[Chris Coleman 2]

Ivan: very true, for 8 ohms at 800w you're only getting 80volts (instead of 88 volts from 1000w at 8 ).  Do you know of a plate amp that would be better match the Lab sub, offering 1000w into 8 ohms..?!

[Ivan Beaver]

Considering that the Lab 12 is rated for 400watts, you can add 3 to 6 dB to that figure (depends on how you want to count) and end up with 800-1600Watts as the proper power to be AVAILABLE to the speaker-not to be used continously.

The Speaker power amp would drive it pretty good, but if you want the last couple of db out of it, it would be shy.  But the limiter could take care of those small peaks and you would probably never know the difference in level-only clipping on the external amp-if allowed to do so.

The biggest issue with the Speakerpower DSP is the actual programming.  IT AIN'T your normal DSP-Far from it.  It is a TI design-so that should give you an idea.  It is FAR from being real time and can get confusing.  I know enough to barely get around on it.  But at least it keeps people from messing with it.