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I have a question about a post stemming from SPL Neon's question about how and why larger boxes are generally louder than smaller boxes. Someone on there said that in order to align the backwave from a speaker radiating out of a traditional ported box (90 degrees out of phase), simply build baffles which are 1/4 the wavelength of the Fb (tuning frequency) of the port. SO...if that is true...does this make sense?
Say I have a ported box with a 35Hz tuning frequency. Therefore, I should need a baffle approximately 8 feet long seperating the speaker itself from the port? So in escense, the actual design of this box turns out looking as if it's a bandbass box, correct? With a "port" seperating the speaker from the true port???
-------------------- 1994 Ford F-250 7.3L Powerstroke Diesel Super Cab Long Bed 33" Mud Terrains Yeah, it's big, and yeah, it's got balls. Posts: 876 | From: Decatur, IN | Registered: Apr 2002
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well the whole idea of a larger box creating higher spl is the physics of air pressure. with 2 or more containers all connected and sealed to the outside, air pressure would be greatest in the smallest container. with the passenger compartment of the car being one container, and the enclosure being the other, with the sub and port as the pressure piston. pressure would be greater in the box if it were smaller than the passenger compartment, increase box size or decrease passenger compartment size and air pressure shifts a little, build a sub wall with the box bigger than the passenger compartment and you've got a lot of spl.
Posts: 33 | From: u.s.a | Registered: Sep 2003
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posted
I wasn't asking about box size, I am asking about box design . Also, is it supposed to be 1/4 the wavelength from the speaker bottom plate or the speaker voice coil to the inside of the port or the outside of the port??
-------------------- 1994 Ford F-250 7.3L Powerstroke Diesel Super Cab Long Bed 33" Mud Terrains Yeah, it's big, and yeah, it's got balls. Posts: 876 | From: Decatur, IN | Registered: Apr 2002
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posted
I think you are all misunderstanding me...I don't mean a 1/4 wave enclosure (transmission line) I mean what was mentioned in another post about a ported box with 'waveguides' that force the internal soundwaves to travel farther than normal, aligning the backwave with the frontwave (well...360 degrees behind). I think this is supposed to be what a snailshell box is? Help me out.
-------------------- 1994 Ford F-250 7.3L Powerstroke Diesel Super Cab Long Bed 33" Mud Terrains Yeah, it's big, and yeah, it's got balls. Posts: 876 | From: Decatur, IN | Registered: Apr 2002
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i understand what ur talking about, but u have it a little bit wrong. u have pretty much the correct reasoning behind it (theres also a little bit more to it), but the design u suggested in ur first post isnt quite right. the box isnt gonna turn out anything like a bandpass. if u have yahoo messenger i can show u. chris_lee292000@yahoo.com
-------------------- as real as it seems, the american dream, aint nuthin but anotha calculated scheme, to get us locked up, shot up, back in chains, to deny us of the future, rob our names - Pac Posts: 179 | From: washington | Registered: Apr 2003
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wow!!!! sorry, i completely forgot about this thread. yes, i have msn messenger. sorry again, i'll add u right now
-------------------- as real as it seems, the american dream, aint nuthin but anotha calculated scheme, to get us locked up, shot up, back in chains, to deny us of the future, rob our names - Pac Posts: 179 | From: washington | Registered: Apr 2003
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posted
[B]Quarter wave only works in a 2 dimensional plane, have tried it, don't waste your time, this is a 3 dimensional world
-------------------- Canadian Street Max 1-2 record holder 152.5 db's PROUD MEMBER OF TEAM GATES Posts: 433 | From: Fort Saskatchewan | Registered: Dec 2002
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