ported clamshell help/build

[Colin - STAPUFT]

The smaller you make that from the back, the lower the tune. That is where it "chokes" up. I would think that 3.5" is too small. I think mine was 4.5 or so at the smallest and my box is smaller than yours with less speakers- that means my tune is higher than this would be.

Why not put the subs as close to the front as possible? Then you have all the room in the world (a good 12" at least) in the back to play around. You could make it whatever you wanted (say- the same distance from the back as the distance from the top and bottom baffles). If the tune seems too high, just scab on another piece of wood on top of your baffles and shorten up the gap. That would effectively lower the tune. ...OR... put some bolts in there, and have those "scab" pieces attached to the baffle where you can loosen the bolts and pull them to the front of the box for a higher tune or slide it to the back of the box for a lower tune. BOOM! on the fly adjustable port.

Oh yeah, I am seeing it now. This is like a crazy 1/4 wave tapped horn blow through hybrid. MADNESS!!! MADNESS I say!!!

[irpirate]

The smaller you make that from the back, the lower the tune. That is where it "chokes" up. I would think that 3.5" is too small. I think mine was 4.5 or so at the smallest and my box is smaller than yours with less speakers- that means my tune is higher than this would be.

Why not put the subs as close to the front as possible? Then you have all the room in the world (a good 12" at least) in the back to play around. You could make it whatever you wanted (say- the same distance from the back as the distance from the top and bottom baffles). If the tune seems too high, just scab on another piece of wood on top of your baffles and shorten up the gap. That would effectively lower the tune. ...OR... put some bolts in there, and have those "scab" pieces attached to the baffle where you can loosen the bolts and pull them to the front of the box for a higher tune or slide it to the back of the box for a lower tune. BOOM! on the fly adjustable port.

Oh yeah, I am seeing it now. This is like a crazy 1/4 wave tapped horn blow through hybrid. MADNESS!!! MADNESS I say!!!

ahah, this design is turning out unintentionally crazy, i like.

the mounting depth of the subs is almost 7 inches. if i raise the front too much ill hardly have an angle on the clam/subs. fucking toyota give me a couple more inches T_T

generally how much room is needed from the back of the sub to the wall?

[irpirate]

brb 20-25 minutes. getting mind fucked from thinking about this for so long in the last couple days xD

[irpirate]

wooh cigs n coke! alriteyyy.

back to work how much does the angle affect how everything sounds. i remember in neo frogs post "lets talk acoustics" he was wondering why there was on cancellation or something. if i angle them facing each other too much will there be cancellation? if theres only a small chance ill raise the front a bit more and edge the subs closer a bit. also would 2 inches from from the bottom of the sub to the wall be too close? time to load up torres and figure out port length!

[irpirate]

ok im getting ahead of myself.. need to figure out displacements first. if i split the ports do i need to calculate them separately for each side or can i add the volumes for each side and figure from there? any one know how to do thickness of walls on google sketchup?

*edit - aw shieettt. gotta do thickness before i draw everything out TT

[irpirate]

sorry guys, im kinda slow with sketchup :/

[irpirate]

goddamnnit. messed up. ima stay up and work on this, guessing pretty much everyone went to sleep already lol. ill post it when im done. nite everyone! thanks for taking your time to help <3

[AMI CUSTOMS]

Since you are tuning like a ported box, the distance of the opening of port needs to be the min distance from any surface like the back wall. So in the first design you had 7 inch wide port with distance to back wall 3.5, you need at least 7 inches or it will be holding the woofers back and causing issues. And you would want your subs as close to the front as possible, if you mount them all the way back to where the port starts those 4-6 subs won't be adding to the pressure output hardly at all. Nice design and just looks like a ported clam to me, where you coming up with this 1/4 wave hybrid madness....LOL

[Colin - STAPUFT]

^ this.

[irpirate]

so i had all this typed out and smd crashed on me...typing out x2.

okayy, so ive run into a problem. i added the thickness of the wood and figured out the internal volume for the box. issue is the subs are getting less than one cube each. port seems way too big, 19 per cube after port displacement. this pic is with a port of 36x7.

the front panel now is 8 inches tall on top and bottom, 9.5 inches including wood thickness.

i know that these things cant be modeled after ported boxes but thats all i have to go off of right now. should i just give them that little space? or should i tune high and hope that the clam will drop the tuning alot cuz its pretty long and narrow? this is all with a port size of 36x7.

i ran some calculations with port sizes of 36x6 and 36x6 and these both seem to work out better although it makes me worry about port noise. after all displacements the 36x6 i get around 1 cube for each sub. 36x5 i get about 1.15. all this is based off tuning to 33. im guessing in the end im probably gonna be tuning a bit higher because the clam should drop the tuning quite a bit more than colins. port wise right now im leaning towards the 36x6.

here are all the tuning variations. to get the volume of each i just put in arbitrary numbers to match with the volume i had calculated.

36x7

36x6

36x5

as far to the front it is!!!! and the idea was to do a ported clam, although a "crazy 1/4 wave tapped horn blow through hybrid" does sound kinda sexy l o L