Solution to the Swappable Port Dilema

[Omarvelous 10+ year member]

OK, i have devised a plan on how to make easy to use swappable ports.

I'm sure it has been done already, i just felt that i'd share it with every1 since it has been a reoccuring topic recently.

In my example I will be using a 15" XXX and 1" MDF.

Here is a diagram that i made with fireworks.

Pretty Easy to understand.

I apologize for the size of the picture, my resolution is very high, therefore not as big on my screen.

It's basically making 3 seperate sections. The modified top board piece, the port mount piece, and the port. Can be easily adapted/added to any box if you already have it created.

The port will be mounted flush with the Top board ontop of the port mount piece.

You may use tnuts and a rubber seal to ensure as minimal airloss as possible.

The port piece is given one inch around to mount with a tight and perfect fit both with the top board and the port mount piece.

Any?s Feel free to Post up and i or any1 who understands/has done this can answer.

This is how i will be doing mine for the summer.

It's much better then the other methods i have read about because

- Saves time - some suggested actually opening the box and removing port section, This way is WAY faster.

- Saves confusion - unlike the suggestions that state to add pieces, you don't have to account for any loss in volume

Admins might wanna Sticky this :thumbsupw

Click to read more...

 

[Omarvelous 10+ year member]

Oh yes she's a beauty! //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

I won't be doing this for another 3 months or more so maybe some1 will get to it b4 me.

 

[JonnyBlaze 10+ year member]

im designing something similar. im using 2 15's and the port will be on the same side as the speakers. ill post the plans once they are finalized.

JB

 

[Omarvelous 10+ year member]

im designing something similar. im using 2 15's and the port will be on the same side as the speakers. ill post the plans once they are finalized.
JB

Yea it can be done on that side.

I'd recommend however doing a double baffel.

The bottom layer mount the sub and use that as the port mount also

Then your port assembly would be flush with the top layer of the baffle which is flush/close to flush with your sub surround.

 

[JonnyBlaze 10+ year member]

let me ask you another question. i used the port area calc on loudspeakers101.com and telling it 2 15's, with 32mm xmax, which the xxx's have and tuned to 27hz, it says it needs a port area of 179"!! my port was going to be 15x4, 60sq inches. could they be right? would going that much smaller cause alot of port noise? im close to scrapping what i have so far, using your double baffle idea and putting the port on a longer edge. it dosent take me long to draw up new plans.

thanks

JB

 

[JonnyBlaze 10+ year member]

thanks for the tip //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

im still working on a new design to give me a lil more port area.

JB

 

[JonnyBlaze 10+ year member]

I don't know why people use the loudspeakers101.com calculators ... The only time they're correct is by coincidence ...
Use the calculators @ BCAE1.com, diysubwoofers.org, or use WinISD Pro 0.50a7 ...

i been wasting my time over there. just realized on the port calc, if you swap the height & width numbers, the answer shouldnt change cause the port area dosent change, but it changes alot. i knew i needed that formula in excel for a reason.

JB

 

[LoneRanger 10+ year member]

heh....

i've built several boxes with swapable ports like that....if i can find the pics i'll post them later

 

[JonnyBlaze 10+ year member]

http://24.218.132.26:81/sweeps/blazer.jpg

heres my design so far. the volume after the port and brace is 8cu feet. the port is 14x3x 13" long, which should tune it to 28hz. the shorter port will be 2.5" long and tune it to 42hz. is that going to be too short?

will port noise be a problem?

JB

 

[Omarvelous 10+ year member]

http://24.218.132.26:81/sweeps/blazer.jpg
heres my design so far. the volume after the port and brace is 8cu feet. the port is 14x3x 13" long, which should tune it to 28hz. the shorter port will be 2.5" long and tune it to 42hz. is that going to be too short?

will port noise be a problem?

JB

REAL Fing SWEET!! What program did u use?

 

[smullen 10+ year member]

REAL Fing SWEET!! What program did u use?

I was thinking the same thing..

 

[JonnyBlaze 10+ year member]

its a program called inventor. i use it for work.

i used autocad also.

JB

 

[JonnyBlaze 10+ year member]

here is a new box i just designed. its tunable from 23hz to 42hz. im going to make a plug for 27, 35 and 40 to see what i like.

JB

http://24.218.132.26:81/sweeps/blazer01.jpg

http://24.218.132.26:81/sweeps/blazer02.jpg

http://24.218.132.26:81/sweeps/blazer03.jpg