Well, you know, I really like the sound of the Aerial Stryke, but my Gawd, that puppy is big and heavy. It's made me think a lot about how to get a "monster" sub in a smaller box.
So, yesterday, in my copius spare time during lunch, I got out my copy of Unibox spreadsheet, entered some driver parameters, and I think I've hit upon an interesting solution, using the Blueprint 1203. My calculations show that in as little as an effective volume of 40 liters, a sealed box will have an Fs of about 40 Hz, but more importantly, a Q of 0.5, which is critically damped. (the Blueprint 1203 is a low Qts driver, nominally about 0.29) Now, with a straight forward shelving EQ, the response roll off can be lifted to be near flat anechoic with 8-10 dB of boost, maxing at 20 Hz. Since the in room response increases the low end some anyway, probably 6-8 dB of boost is all that should be used. Note, this is better than a comparable effort with a Shiva because of the high cone mass, large magnet/high BL product, and low Q of the Blueprint driver.
Back of the napkin calculations show this should be doable in one of the Woodstyle sub cubes I have lying around, asumming a lot of extra internal bracing- subtracting for the bracing and driver, from the nominal 61 L, should leave enough box volume.
I've got a Sumo crossover hanging around that I bought from a friend in MO- he wanted to get out of separates and get into a big receiver (I dunno, it must be something in the water there, maybe too much fluoridation), so I "helped" him out by taking it off his hands- zero feedback high pass buffer, and nice frequency options- should work for this. And there's a Marchand Basis under my bed that I need to finish assembling; that should handle the LF EQ just fine.
Power requirements calculate out to 500 - 1 kW. I knew there was a reason we've been on an Aragon buying binge the last year. Sounds like a Palladdium or 8008 would drive it handily (clips at around 600 W balanced out at 8 ohms, about 1 kW at 4 ohms- gee, the Blueprint is 4 ohms, how convenient!) Should hit about 107 dB at 20 Hz, with 45 mm p-p Xmax. A cool thing about the Sumo crossover is that it has stereo and mono bass outputs, both positive and inverted polarity, so it can bridge amplifiers into mono without any extra circuitry. If you do this with an ST or BB, be sure to strap the output speaker grounds together.
Well, when I get back from the trip next week, I think I'll have to put one of these Blueprint drivers on order.
Can anyone think of a better high excursion twelve for this concept? I'm all ears, at least for a couple of weeks.
Regards,
Jon
Earth First!
_______________________________
We'll screw up the other planets later....
So, yesterday, in my copius spare time during lunch, I got out my copy of Unibox spreadsheet, entered some driver parameters, and I think I've hit upon an interesting solution, using the Blueprint 1203. My calculations show that in as little as an effective volume of 40 liters, a sealed box will have an Fs of about 40 Hz, but more importantly, a Q of 0.5, which is critically damped. (the Blueprint 1203 is a low Qts driver, nominally about 0.29) Now, with a straight forward shelving EQ, the response roll off can be lifted to be near flat anechoic with 8-10 dB of boost, maxing at 20 Hz. Since the in room response increases the low end some anyway, probably 6-8 dB of boost is all that should be used. Note, this is better than a comparable effort with a Shiva because of the high cone mass, large magnet/high BL product, and low Q of the Blueprint driver.
Back of the napkin calculations show this should be doable in one of the Woodstyle sub cubes I have lying around, asumming a lot of extra internal bracing- subtracting for the bracing and driver, from the nominal 61 L, should leave enough box volume.
I've got a Sumo crossover hanging around that I bought from a friend in MO- he wanted to get out of separates and get into a big receiver (I dunno, it must be something in the water there, maybe too much fluoridation), so I "helped" him out by taking it off his hands- zero feedback high pass buffer, and nice frequency options- should work for this. And there's a Marchand Basis under my bed that I need to finish assembling; that should handle the LF EQ just fine.
Power requirements calculate out to 500 - 1 kW. I knew there was a reason we've been on an Aragon buying binge the last year. Sounds like a Palladdium or 8008 would drive it handily (clips at around 600 W balanced out at 8 ohms, about 1 kW at 4 ohms- gee, the Blueprint is 4 ohms, how convenient!) Should hit about 107 dB at 20 Hz, with 45 mm p-p Xmax. A cool thing about the Sumo crossover is that it has stereo and mono bass outputs, both positive and inverted polarity, so it can bridge amplifiers into mono without any extra circuitry. If you do this with an ST or BB, be sure to strap the output speaker grounds together.
Well, when I get back from the trip next week, I think I'll have to put one of these Blueprint drivers on order.
Can anyone think of a better high excursion twelve for this concept? I'm all ears, at least for a couple of weeks.
Regards,
Jon
Earth First!
_______________________________
We'll screw up the other planets later....
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