Posted by Wayne Parham [ 70.242.199.195 ] on December 11, 2007 at 16:37:14:
In Reply to: 12Pi plans posted by joe p on December 11, 2007 at 11:28:08:
I'm actually sending the v1 plans. The v2 plans are done for the CNC machine but the plans for DIY (without dado grooves) aren't quite done yet. They'll be ready in a few days.
Actually, with the ice storm in Tulsa, most everyone is out of power and it will probably be sometime next week. I went to Texas to work remotely from a hotel. So I think probably you should count on us having the plans ready by the end of next week. Drop me a line and remind me and I'll send you the v2 plans then.
As for comparison with Fitzmaurice boxes, they are really in two different leagues. No comparison is really fair. The Fitzmaurice boxes are smaller so they're easier to carry. If you're doing smaller gigs, they're more than plenty. But if you're doing stadiums or outdoor gigs, you just can't get the Fitzmaurice boxes to keep up with the 12π's. We've optimized them as much as I think is possible, and that's what sets the 12π apart from every other hornsub I've seen.
At the last Prosound Shootout, we measured the Fitzmaurice Titan 48 and the 12π (v1). At 800 watts, the 12π was 10dB louder all the way up to about 60Hz. Above that point, the Fitzmaurice box starts to come closer (with a brief peak at 70Hz where it is only 3dB below the 12π) but the average output is still 6dB lower from 60Hz to 100Hz.
Remember that adding boxes connected in parallel decreases impedance, so you can expect 6dB when running a pair of boxes if the voltage level remains constant. But if you compare at a constant power level, you only get 3dB more from a pair of boxes. Both are relevant and both things are worth considering.
When comparing equal volumes and equal power levels, say two Fitzmaurice boxes to match size of one 12π, you're looking at about 6dB difference in SPL below 60Hz and 3dB difference from 60Hz to 100Hz. Comparing at equal power like this means the 12π gets 800 watts and the pair of Titan 48's gets 800 watts, 400 watts a piece. Now if you increase power to each Titan 48 to 800 watts, so the pair are getting 1600 watts - twice as much power as the 12π - then the Fitzmaurice boxes are closer, being only 3dB lower than the 12π up to 60Hz and roughly equal above that.
The bottom line is you'd need more real estate for Fitzmaurice boxes to equal the sound output of 12π hornsubs. You'll need three or four Titan 48's to match the output of a single 12π below 60Hz. Also, there is less response ripple from the 12π and distortion is much lower too. The 12π is more efficient, uses push-pull drive and has the cooling plugs to keep the motors cool, all of which put it in another league.
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