Posted May 3, 201015 yr I'll never do this, it's for 2 SMD 18's in 8 cubes with 15.375 sq. in. of port per cube. Would it work, the port wrapped around the box? It's 1*123, so 123" of port area. Would there be port noise, not enough back pressure, or crappy air movement? I forgot the brace for the bolt. If the port was 1:4 it would be tuned around 30hz, says a port calculator.
May 3, 201015 yr I am not sure what i am looking at?Can you dumb it down and tell me where the port is on your sketch?
May 3, 201015 yr The port is going all around the front of the box......Very interesting idea...Never seen this done before. The only thing i can tell is that it would need some significant bracing, which would also block some port area and potentially give you some port noise.......But i could be wrong....NEVER seen this done before. Port noise or not, it would be worth it to try it out. Edited May 3, 201015 yr by 4runner
May 3, 201015 yr Author The port is the blue area. It's a free-floating box inside a box, held by 12 bolts. The port is 1" wide x 123" long, it wraps around the front of the box. It's like having two slot ports, only there are 4, top/bottom & both sides. Besides the width being more than the height, the top & side views would be the same:____________________________________| _________port______________________| ||| ||| (bolt) (bolt) mag/VC/surround ||| ||| ||| __________________________________|||___________port______________________
May 3, 201015 yr interesting.I bet it would lose some stability. Maybe flush the bottom and use sides and top with some bracing down the middle of all ports.It could be fun to try.
May 3, 201015 yr Author Edit: I suppose I'd have to make this thing to find out. It works the same for 2 12's, 2 15s, etc. If using 1" MDF and 1" spacing, 2 12's would be 87" of port area which is about 2.75 cf3 each with 16 sq.in. of port per cube. Edited May 3, 201015 yr by RE XXXv3
May 3, 201015 yr Author I thought it would add stability, 12 metal bolts should be a lot stronger than MDF.
May 3, 201015 yr I thought it would add stability, 12 metal bolts should be a lot stronger than MDF.Good point!Get on it man.
May 3, 201015 yr if u gonna try it, make it more than 1" tall height-wise.I don't know if the air can be felt ALL the way around the opening but allowing only 1" height all the way around is asking for port noise.I'd do at least 3" clearance and make sure the internal box is 3" from the back of the design as well.
May 3, 201015 yr Author 8 cubes = 1" port width16 cubes = 2" port width, but the box is too long to keep it above 30hz. With 2 18's in 16 cubes the tune would be 24hz, if you're keeping the same port area. You couldn't make it taller & wider becuase the port area would change, thus needing even less than 2" port width.It might work in a 4-18" setup, maybe a wall. I'll draw something up. 4 18's, 3" port width, and 33 cubes (8.25 each) = 528 PA, exactly 16 sq.in. per cube.
May 3, 201015 yr interesting enough design. but i can see port noise coming from it. may be a sufficient amount of port area, but it's so thin. if possible i'd redo the dimensions of the box to add more port area without there being too much of it. but definitely thinking outside the box
May 3, 201015 yr I'd personally make a test enclosure for 1 10. smaller, less money spent (just in case)... great idea ... anythings possible.
May 3, 201015 yr Author 24hz if you keep 3" of port clearance from the back wall, doesn't mean you need the port that long, right?4 18's would be 504 PA (16 per cube, 3" port width) & 7.875 cf3 each, and with nearly zero port length it equals 35hz, but there wouldn't be room for bolts, so like, 5" port length for 16 or 24 bolts, but it'd probably be better if the port length equaled the length to the back of the magnets, just so air doesn't go directly from the subs into the port. I'm sure with 4 18's, it would hit the back wall purdy goood. 3" port width seems like there wouldn't be any noise, it's kind of like having one 18" with the port taking up two corners of the box, like having two seperate slots only they are connected, which is even better. It's an L-bent 20.5" x 6" port. Having even displacement for the air to get out of the box should add to air flow, no matter what part of the back wall it hits it's going to follow along that wall to get out.
May 3, 201015 yr i toyed with a similar idea not to long ago, but i just could not get the port area ratio the way i felt it needed to be.
May 3, 201015 yr i toyed with a similar idea not to long ago, but i just could not get the port area ratio the way i felt it needed to be. I've toyed with the same sono tube idea. lol
May 4, 201015 yr looks like a really cool idea. I say go for it, who knows you might change the way we build boxes forever...im tuned in
May 4, 201015 yr Author That's what I was daydreaming about.... LOL. If I make this box and it doesn't work it's like -$300. The tune would probably also be wayyyy off from what I wanted. It also is only good if you want a completely square box. It'd probably be better to have one big port in the middle and the subs on the outside.
May 4, 201015 yr Author It doesn't work for one or two 10's or one 12. It works for one 15"/1" port width if it's in 4.66 cf3 (15.98 per). It works for 2 12's with 87" PA but only if the subs get 2.75 cf3 each, and even then the port is 1" wide (15.8 per). It works for 2 15's, 1" port width, if using 7 cf3, it's 15 sq.in. per cube. It works for 4 10's/1" port width if each sub gets 1.57 cf3 (15.92 per).
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