Port ?

[malandrin4o8 10+ year member]

Does a the port have to be L shaped or can it just be straight l. For example port needs to be 17" long and sub box depth is 24.

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[adulbrich 5,000+ posts]

Can be straight

 

[adulbrich 5,000+ posts]

Not that it pertains to this too much, but high-peak narrow-bandwidth burp boxes have ridiculously short ports. DD Belgium's looks to be about 3", lol:

dB-drag SS NW project 2012 from "Team DD Belgium" - SPL & Streetbass - Talk Audio

 

[twizt3dfuc]

I've actually never had the need to do an L lol

Sent from my Nexus 6 using Tapatalk

 

[hispls 5,000+ posts]

Not that it pertains to this too much, but high-peak narrow-bandwidth burp boxes have ridiculously short ports. DD Belgium's looks to be about 3", lol:
dB-drag SS NW project 2012 from "Team DD Belgium" - SPL & Streetbass - Talk Audio

A slot port along a wall like that actually gains half the port width in effective depth.

 

[Buck 5,000+ posts]

That box looks like a dog house.

Ya, you can do just a straight port. When doing a slot, half the ports width needs to be taken off the end of the port because the surrounding walls extend the port basically.

 

[adulbrich 5,000+ posts]

A slot port along a wall like that actually gains half the port width in effective depth.

Can you explain that more? I'm very interested, actually

 

[Buck 5,000+ posts]

Can you explain that more? I'm very interested, actually

There is a % of the port width that still acts as port length. I forget the % exactly but if a port is say 5" wide, up to say 5.5" width can still be considered port length.

Same with flared aeros or kerfed ports.

 

[adulbrich 5,000+ posts]

There is a % of the port width that still acts as port length. I forget the % exactly but if a port is say 5" wide, up to say 5.5" width can still be considered port length.
Same with flared aeros or kerfed ports.

Cool, thanks!

 

[hispls 5,000+ posts]

Can you explain that more? I'm very interested, actually

Looking straight on at that "box" you posted, the right hand wall is part of the "port". While the baffle side is short, the long side still holds a column of air against it. SO to figure out the effective port length, you take the depth of the shorter side and add half a port width.

Or in other words. Sketch up a top view of that box, then draw a line at a 45 degree angle from the back of the baffle (right at the edge of the port) extending to the right hand wall of the port... that is the port volume/length that the speaker/box "sees".

Or in other other words. If that "port" was in the center of the box, it would need to extend about a foot deep into the box to load the same as it is now due to the driver's side wall. I tried to sketch it up in gimp but it's saving in some oddball file format. LMK if you don't follow I'll boot up windows and use Paint.

 

[adulbrich 5,000+ posts]

Looking straight on at that "box" you posted, the right hand wall is part of the "port". While the baffle side is short, the long side still holds a column of air against it. SO to figure out the effective port length, you take the depth of the shorter side and add half a port width.
Or in other words. Sketch up a top view of that box, then draw a line at a 45 degree angle from the back of the baffle (right at the edge of the port) extending to the right hand wall of the port... that is the port volume/length that the speaker/box "sees".

Or in other other words. If that "port" was in the center of the box, it would need to extend about a foot deep into the box to load the same as it is now due to the driver's side wall. I tried to sketch it up in gimp but it's saving in some oddball file format. LMK if you don't follow I'll boot up windows and use Paint.

Thanks, that was a great explanation! Good to know