posted
i am looking for some good advice on what box to build for my 95 burb. i am running 3 mojo 12's with 2 4kw's powering them. i am looking for a good daily box tuned fairly low. my max external dimensions are 48w x 20h x 20deep. i would like subs and port up.
posted
i can't remember, do those amps have a subsonic filter?
-------------------- World Record-Loudest SPL in my driveway Team Powermaster/XS-Power Hifonics Amps, Kicker subs-The way it should be Zensky....World Domination at It's Finest www.zensky.com Posts: 3252 | From: Columbus, OH - formerly FL | Registered: Oct 2003
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and no shiz on the dimensions there camaro kid LOL. i am not sure of the port size, so if y'all could help with that, i would appreciate it. i would think i can do 4 inches wide by whatever long within the 48 inch width. and length of it i have no idea.
quote:Originally posted by slimshader: yes the amps do have a subsonic filter.
and no shiz on the dimensions there camaro kid LOL. i am not sure of the port size, so if y'all could help with that, i would appreciate it. i would think i can do 4 inches wide by whatever long within the 48 inch width. and length of it i have no idea.
try not to go over a 1x9 ratio. the closer to even, or round, the better.
-------------------- World Record-Loudest SPL in my driveway Team Powermaster/XS-Power Hifonics Amps, Kicker subs-The way it should be Zensky....World Domination at It's Finest www.zensky.com Posts: 3252 | From: Columbus, OH - formerly FL | Registered: Oct 2003
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posted
d-bass--- thanks for the info and by 1x9 ratio, do you mean dont make it like 2x18 or 3x27 or 4x36? in other words try to get the dimensions closer to say 4x12 or 6x6?
what happens with the long narrow ports? too much noise? or turbulance? just curious.
i think 8.5 cubes will be the size gross internal. what would be the vent length if i went with 5x20 vent and wanted it tuned around 33-35hz range?
posted
download WinISD and play with that program to get a design that you like. the camaro kid posted a link in this thread.
and yes, you understood what i meant about the ratio
-------------------- World Record-Loudest SPL in my driveway Team Powermaster/XS-Power Hifonics Amps, Kicker subs-The way it should be Zensky....World Domination at It's Finest www.zensky.com Posts: 3252 | From: Columbus, OH - formerly FL | Registered: Oct 2003
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posted
the reason is that there is more portwall surface area, causing friction against the walls, increasing the inertial force. A port doesn't tune based on the volume of air, it tunes based on the inertial tendency of the air. hence, temperature and shape of port changing tuning. An object at rest, stays at rest unless acted upon by an unequal and opposite force. the more portwall surface area, and the rougher, the more friction against the wall, and more tendency not to move. a circle has the least circumference/perimeter to crossectional area ratio. multiply that by length, and there you go. Also, having a larger perimeter to crosssectional area means that there is more port mouth and throat lip, which increases the air speed and turbulence. thus, port noise, imbalance of speed through the port--detuning, and spot-point velocity issues
-------------------- World Record-Loudest SPL in my driveway Team Powermaster/XS-Power Hifonics Amps, Kicker subs-The way it should be Zensky....World Domination at It's Finest www.zensky.com Posts: 3252 | From: Columbus, OH - formerly FL | Registered: Oct 2003
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