The fishy sub-port

[TroelsM]

So this is probably not New in Any way, but at least its not used in Any designs I have seen.
Goal is to make a port with a Nice big flare and have control over all dimensions.
The example here is 32cm long and 200cm2 at the end and 50cm2 in the middle. It can be simmed in hornresp as a horn.
The cavity is used to make room for a classic handle cutout.
First test says it works and no farting noise with 12" woofer at 250w.

What do you think?

Kind regards TroelsM

 

[Brian Steele]

If I remember what I've read about vents correctly, that's basically the ideal vent shape to reduce compression effects.

 

[GM]

Yeah, back in the '50s the R-J speakers used similar for vents IIRC and for in front of drivers for BP apps. Freddy has periodically posted about them.

GM

 

[papasteack]

Hi, can you show or explain more ?

I see a cavity, ok. Inside it, i see a handle. Where is the speaker ? What is this kind of oval stuff ? Do you have a schematic ? is that just a reflex port ? I don't see where it is flared on photos... Sorry, it interest me, but i don't understand what is shown
Damien

 

[David Morison]

It's a variation on a slot port (commercial example pictured) with the central divider/brace shaped to give a flared port profile to help manage airspeed/chuffing and also do double duty as the back box for a handle which would otherwise use up more space within the box. The pics don't show that last panel of the port which would be a flat place across the top of what is shown already.

HTH,
David.

 

[TroelsM]

Hi.

Davis is correct. It is a modification of a slot-port.

I'l try to post more prictures when I get on with the project.

Kind regards TroelsM

 

[kipman725]

pretty cool idea, how did you curve the ply?

 

[TroelsM]

Its 4mm, 3-layer play. Bends very easy in one direction. Its just glued and nailed to the centre-piece of 16mm ply.

I think it could do even smaller bend-radius, but haven't tested.

The 4mm becomes very stiff when its curved.

TroelsM

 

[papasteack]

So simple ! I'm surprised i didn't see this before !
Thanks !

 

[kipman725]

Its 4mm, 3-layer play. Bends very easy in one direction. Its just glued and nailed to the centre-piece of 16mm ply.

I think it could do even smaller bend-radius, but haven't tested.

The 4mm becomes very stiff when its curved.

TroelsM

could you show the hornresp inputs for your simulation of this port?

 

[TroelsM]

Im using something like this.

Its basically a 6th order BP. Maybe not the best solution, but I wanted to try something new.

Kind regards TroelsM

 

[kipman725]

Great thanks