Port Plug?

[btnhfan 5,000+ posts]

How do I make a port plug? I want about 32hz for daily, and about 45hz for comps.

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[Nikuk 5,000+ posts]

check out Snova's or InhumanAck's (iirc) CD site. dont have a link off hand. Good basic pictures.

Basically its a way to reduce port area (but enough to avoid chuffing).

 

[btnhfan 5,000+ posts]

It just has snova's plug. Not how to make one. Can someone who has done this help me out, or if they have any idea?

 

[Nikuk 5,000+ posts]

i've done it for three diff installs.

looking at your other thread you want 64 in^2 for 32hz daily? this means that for 45hz you're going to have more port area, same port length.

Imagine:

You have a rectangular box with a 10"x10" port opening in the middle of it. The port is 6" deep. With this port area you're tuned to 50hz.

Now, make a rectangle out of mdf that is 10"x10". Cut a hole in the middle of it that is 5"x5". Mount it in the port opening on your box. Make sure it is sealed around the seams (snug fit, insulation, whatever). You now have a 5x5x6" deep port, tuning you to 35hz.

Make sense?

To make it user friendly, you should inset the port opening the by the thickness of your plug. This way it'll be flush when plugged.

Hope this helps, I can draw some diagrams after i get out of work.

 

[Randy Savage 5,000+ posts]

This is how I did it:

Say I have a 10x10 opening for port area, and it's 10" deep. Tuned pretty high, ~50hz or so. Now, you make another port, tuned for daily. Make the opening 9.25x9.25, so it can slide right into the current opening (the wood is 3/4" thick, so 9.25 will slide in perfectly if you make your cuts good). Make it however long you have to, to get your tuning. Then, put a mounting flange on the second port (like I have in mine, so the port will sit on top of the box).

That's pretty much how I did it. My next one will have a plug, but it will be flush mountable.

 

[btnhfan 5,000+ posts]

Ahhh. Thanks a lot for that. I think I understand how to do it. Hopefully I can pull it off.

 

[btnhfan 5,000+ posts]

OKay. So far I have a port for 45hz

13x4 with a length of 14 inches.

But when I go to do 32 hz, I put in an opening of like 12x3 or 8x3, I always get a length of 27.5 inches, which I cant fit into my box. Can someone help me out with this?

 

[Randy Savage 5,000+ posts]

Yeah, that's what's tricky about it. You might have to cut down on port area, which will result in a shorter required port length.

 

[btnhfan 5,000+ posts]

Okay well I adjusted my tuning frequency to 33hz and I think I have it. The 45hz is same as above, but for 33hz, it is a 7x3 opening with a length of 10.5. Does that sound correct?

 

[Randy Savage 5,000+ posts]

What's the box volume?

 

[btnhfan 5,000+ posts]

The total volume before any sub displacement, .3, and port displacement is 4.94141.

 

[btnhfan 5,000+ posts]

Also the port is going to be made with .5 mdf, not 3/4's.

 

[Randy Savage 5,000+ posts]

21in of port is rather small. Assuming the box works out to 4 cubes net, I'd aim for at least 40 in of port.

 

[btnhfan 5,000+ posts]

Hmmmm.... Should I want more port or more box volume? Because I know that I am not giving my subs a lot of enclosure volume.

 

[InhumanAcura 5,000+ posts]

http://www.sounddomain.com/id/inhumanacura