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Ok Melon....
Just because I think you are about ready for this, I present Gary Pimm's W Box, cardioid emission pattern subwoofers. The larger cavity is filled with Levi's chopped up and pressed into 3/4" thick sheets. These things equaled a thunder storm that was playing outside in transient attack, SPL and sheer terror inducement. Just thought the AN15's should have some worthy friends to play with. God's just think, 8 15 inch drivers in one room and two channels........ he he he he !!!!!!
Bud
Just because I think you are about ready for this, I present Gary Pimm's W Box, cardioid emission pattern subwoofers. The larger cavity is filled with Levi's chopped up and pressed into 3/4" thick sheets. These things equaled a thunder storm that was playing outside in transient attack, SPL and sheer terror inducement. Just thought the AN15's should have some worthy friends to play with. God's just think, 8 15 inch drivers in one room and two channels........ he he he he !!!!!!
Bud
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Yeah I can do that.
I have 12x10", and 8x12" coming, so I reckon I could do something crazy with them. Maybe 6x10 per side in slot loaded open baffle and 4x12 per side in one of them W thing a ma jigs.
I could possibly order some 15s as well if these drivers turn out to be good.
1.5.5 - 10hrs vs 100hrs
The plot is 1/24 Octave, hence the ripples
Quite a pronounced improvement with break in
I am going to change the crossover from 1.5.5 to just 1.5. Once I change it to purely 1.5way I may not need bass boost
Black is 10hrs
Blue is 100hrs
The plot is 1/24 Octave, hence the ripples
Quite a pronounced improvement with break in
I am going to change the crossover from 1.5.5 to just 1.5. Once I change it to purely 1.5way I may not need bass boost
Black is 10hrs
Blue is 100hrs
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Hey Melon, the +5dB to +8dB bump in the response centered around 300 Hz is pretty close to what would be predicted by something like MJK's sims. I used his horn sims for a similar mass-loaded OB idea, and then abandoned it because it's basically going to operate as a partial horn-load. (Basically it's a compression cavity and short throat coupled to a very short horn with a very wide flare!) It may be OK when used with 48dB filters in DSP, but not so good when using first order slopes... and since I favor the 1st order variety to keep the time coherence... well... that's where I gave up on the mass loading.
Making the hole smaller will increase the mass-loading and extend the lower end, but is very likely to increase the size of that mid-bass peak.
If you really want to keep the mass-loading, then you would be wanting to use a tank network to tame that peak.
For my tastes, I prefer to sacrifice the increase in extension in favor of keeping max efficiency and linearity in the response prior to any filtering. YMMV, but you may want to try the woofers with no mass loading. My bet is that you would subjectively like it better than the mass-load even if you can get that bump perfectly dialed out with the eq.
Great project, keep it rolling!
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