Port seems too long on winISD

[srb 10+ year member]

I'm trying to design my first box on winISD pro but I'm having a bit of trouble. The box is for a 12" Adire Brahma and I want it to be 2.25^3 tuned at 28 hz. I want to use a 8 inch round port.

WinISD says that the port needs to be 70.62 inches long. Is that correct it, seems really long.

Thanks

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[THATpurpleKUSH 5,000+ posts]

I got 70.9 inches long. An 8inch port is wayyyy too big for a single 12 in a standard ported box. I would go with 2 3's, those would need to be around 19inches long.

 

[srb 10+ year member]

Ok thanks man

 

[srb 10+ year member]

I have another noob question, and figured I would just put it here instead of start a new thread.

I figured I need my port to be 7.5 inches long. Do I add the width of the double baffle on to this so the full 7.5 inches is inside the box, or does the 7.5 just need to be the total length of the port?

 

[Ronny 10+ year member]

Total length of the port as long as it is being mounted on the outermost portion of the enclosure (end of port or flare is on or flush with the outermost wall).

Seriously, just do a 4" round port. It'll be perfect for you. I'll get you the total length needed in one second.

 

[Ronny 10+ year member]

16.25" straight tube length, Or 17.25" with the flares on.

So, really, if you can, just make the enclosure the slightest bit larger, or if you wouldn't mind the tuning being like 27.67Hz then just install a full length 4" aeroport in there. Purchase one from here: Precision Port 4" Flared Port Tube Kit 268-352

Or just buy a length of 4" I.D. PVC tubing and experiment with flaring or rounding the edges, or just keep 'er straight.

Also, if you are having the woofer and port fire back, that may be too much length/depth for you, and you can certainly side fire the port too, that of which I have had the best luck with, as long as it doesn't get choked off by the shock tower walls etc. Post up all of your dimensions you have and are planning on using, and post a photo or describe where the enclosure will be placed.

 

[srb 10+ year member]

16.25" straight tube length, Or 17.25" with the flares on.
So, really, if you can, just make the enclosure the slightest bit larger, or if you wouldn't mind the tuning being like 27.67Hz then just install a full length 4" aeroport in there. Purchase one from here: Precision Port 4" Flared Port Tube Kit 268-352

Or just buy a length of 4" I.D. PVC tubing and experiment with flaring or rounding the edges, or just keep 'er straight.

Also, if you are having the woofer and port fire back, that may be too much length/depth for you, and you can certainly side fire the port too, that of which I have had the best luck with, as long as it doesn't get choked off by the shock tower walls etc. Post up all of your dimensions you have and are planning on using, and post a photo or describe where the enclosure will be placed.

I got a 3 inch tube kit. Just got delivered today. The box i ended up building called for 3 inch cut to 7.5 to have about 28 hz tuning. Thanks for answering my question man!

 

[pro-rabbit 5,000+ posts]

3" is pretty small for that application, but it should "work" non the less.

 

[Ronny 10+ year member]

Should have went with a 4" bud, it should be fine with a 3".

How much power? For that woofer which is "capable," you'll wan't to use (two) new 3" ports because you have cut the one already.

Or, MUCH better yet, a single 4" port. It'll be more efficient too, as a single port is always more efficient than multiple ports.

 

[srb 10+ year member]

winISD said that a 4 inch port would have to be around 14 inches long. My box is only 14 inches deep and I didn't want the port to be sticking out the box that's why I used 3 inch.

The brahma should be on around 1,200 watts.

 

[pro-rabbit 5,000+ posts]

That is a part of adjusting the design to ensure you are getting the correct port area and sub/port placement for the application.

Just to give you an idea, a single 3" port would be normal for a typical 10" driver.

 

[srb 10+ year member]

That is a part of adjusting the design to ensure you are getting the correct port area and sub/port placement for the application.
Just to give you an idea, a single 3" port would be normal for a typical 10" driver.

Ok thanks. Now I know for next time. Its my first design I have done myself. The three inch should work though right? Just won't be ideal.

 

[pro-rabbit 5,000+ posts]

Ok thanks. Now I know for next time. Its my first design I have done myself. The three inch should work though right? Just won't be ideal.

It will "work" yes. Just not the ideal setup. I would just use it since you have it, then order a 4" to replace it.