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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.
Just been doing frequency response measurements with the open baffle.
There has been a massive improvement in bass response with these drivers after about 100 hrs of playtime. I now have to change the crossover
I never would have expected such a dramatic change.
There has been a massive improvement in bass response with these drivers after about 100 hrs of playtime. I now have to change the crossover
I never would have expected such a dramatic change.
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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Need to work on sealing the CS2.3 clone, or maybe they need more loading.
At this point in time I don't see much difference. I will keep working on it
At this point in time I don't see much difference. I will keep working on it
Yeah I did, there was virtually no measurable difference.
I am going to get some sealing compound and see if that changes things.
If that does not help I will make the holes smaller
I am going to get some sealing compound and see if that changes things.
If that does not help I will make the holes smaller
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!
This is the response of the standard OB without loading. Initially I used 1.5.5 to get a flat response. It seems that bass response of the 10 has improved significantly in addition to the 15s. I will rework the crossover
I wonder to what degree driver parameters plays on the outcome. A weaker motor woofer like the Alphas might stand to gain more from the loading than the AN15's.
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