Jump to content
Second Skin Audio

Is it possible to build a box that will sound good ported and sealed?


Recommended Posts

I want to build an enclosure that will have a removable external port that bolts on to the enclosure. It will normally be run sealed since I prefer the sound quality of a sealed enclosure. I also sometimes compete so I would want to be able to have the option to run ported. 

 

Is it possible to build an enclosure that sounds good sealed and gets loud ported?

I'm guessing I will need to oversize the enclosure for being sealed while it's a little on the small side for ported to give a happy medium.

 

The subs I will be running are 4 sundown U15 v1s. If that matters. Subs will most likely be firing up while the port faces forward and it will be going in a extended cab pickup. 

 

Feasible at all?

Link to comment
Share on other sites

  • Replies 22
  • Created
  • Last Reply

Top Posters In This Topic

If your ported box is to compete is has to be optimized for doing that, no happy medium but you can close the port  and have the volume reduced with a low density material like blocks of stryofoam to run sealed and that should work.

 

Also sub selection is very important, that can excel on ported and work well in sealed, you know sounds not so easy.

Link to comment
Share on other sites

Ok so let's say the enclosure is optimized for being ported. Instead of splitting the difference I make the enclosures to ported volume specs. Does it still sound good being .75ft3 oversized per woofer and sealed. The displacement of the woofers is about .25ft3 and they want 3ft3 for ported 2ft3 for sealed. 

So I run the subs regular for sealed that gives me an enclosure that is only .75ft3 oversized per woofer. Then run inverted while ported and external port that gives me a true 3ft3 per woofer. Then it's just about tuning which having external port I can make multiple ports and see which frequency my cab peaks at and optimize from there. 

 

Does this sound like it could work?

I really do trust you judgement. I think you've designed like 5 enclosures for me in the past from my first sa8 enclosure to my enclosure for dc lvl 3 15s that I took first place with so I know you know what your doing. Thanks for all the help in the past btdubs appreciate you Joe X 

Link to comment
Share on other sites

You can always change the internal volume without turning around subs or compromising the box size, you can do the following, use an adapter for ported and another for sealed:

 

adapter.png

 

The adapter for ported (left) doesn't take any internal airspace, the adapter for sealed (right) takes up internal volume.

 

 

 

 

Edited by Joe X
Link to comment
Share on other sites

That's a great idea I thought about making some cubes to go inside of the enclosure but didn't like that idea at all. This idea I like. 

 

I was thinking similarly that's about how I would want the external port to go on.  So I would make one adapter to take up space for sealed and the other would be for ports. I figure I can build several ports to fine tune and find what works best. (I may need some help calculating my ports Joe.)

 

Thanks for the great idea. 

I'm going to start drawing some plans and crunching some numbers so I can have an idea of how much MDF I need and hopefully soon I can get a day off to travel for supplies. 

Edited by DizzleDizzle
Wording
Link to comment
Share on other sites

The block to take away volume needs not to be wood ( heavy )  you get a block like this:

 

https://www.homedepot.com/p/Tileco-16-in-x-16-in-x-6-in-Concrete-Foundation-Block-166F/202622809

 

For like $10, they are very light weight and available in any size and shape.

 

Back to your design your first two steps are learning about the rules of the categories you wish to compete and get a cheap  SPL meter, SSA makes one, you really need these Before any designing takes place, With box designs for daily applications there is some flexibility regarding it's specs  but competition boxes are absolutely unforgiving and if it is not near perfect you will lose every time the moment you get in any half serious competition.

 

 

 

Link to comment
Share on other sites

So the local shows where I compete don't really have any rules that I'm aware of. It's kind of a free for all. Highest spl wins mic on dash and last time I was in one it was off music. There was another one I participated in don't remember much since it's been a couple years. I believe it was db drag style and on test tones but also pretty much a free for all. 

 

I planned to try to keep it below window line and that's about it. If I do travel to compete which I doubt will happen I will probably build an entirely new enclosure. Just want to be able to get loud in local shows. 

 

I'll be honest with you here my real goal I'd like to aim for with the ported section of the box is to move the maximum amount of air. I had 2 DC lvl3 15s I could float a paper towel in the window. 

I figure since I'm going in a little bit smaller cab and effectively doubling cone area I can get closer to that hair trick I've always wanted. If this is unrealistic well that's ok but I still want to do a box that I can play sealed and also throw a port on to get a little louder/move some air. 

Link to comment
Share on other sites

Looking at your subs specs,  given that is an ext cab its really a ported wall you are building not just some box, the difference between ported and sealed is 4 cubic feet and that is a lot of volume to correct, similarly the port needs about 200 square inches of port area, so a fairly big port, the most you will be able to do is build an external adapter to change it's length a bit for retuning. 

Link to comment
Share on other sites

Well the dimensions I have to work with are 25"(26 to window line)x63.75"x20" this gives me a little over 15.6 cubes to work with.

 

I still plan to invert the subs when running ported to gain some airspace, this buys me a full cube so let's say I have to make up for 3 cubic ft instead of 4. Well that's still a lot but I'm also thinking the subs will still do ok being in a slightly oversized enclosure when sealed. Maybe .25 cubic ft per sub oversized not sure if this is too much. So that will leave 2 cubic feet I have to take up when running sealed. Still a good amount but I think I can easily make an adapter to take up 2 cubes no biggie.

 

The port problem may be a bigger deal though. I don't have a lot of space to vent.

I have the area above the center console between seats. Not sure how much while staying below window line.

I also can vent through the center console I don't have any problem redoing it to accommodate for a port if that's possible.

Then I have the space behind each seat towards the floor which would be more of a wedge shaped area. 

 

I have no idea what 200 sq. In. of port looks like but I'm thinking I can definitely make this work.

Unless it's just something so impractical it's not worth trying to make it work. In which case I'll just build a quick sealed box to get the subs out of the house and into the truck beating. Then I'll work on figuring up a ported box to run with.

 

 

Link to comment
Share on other sites

Just to give you an idea 32x63x20, is 12 cubes 32Hz 200 square inches of port area, double .75 all around wood.


Even then 3.35 net per driver is what you want to do to gain efficiency, in that case:


33.25x63x20 is 13.4 cubes 32Hz 200 square inches of port area, double .75 all around wood. This what gives you the performance edge. And it's a wall.


 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Recently Browsing   0 members

    • No registered users viewing this page.
  • Who's Online   1 Member, 0 Anonymous, 272 Guests (See full list)




×
×
  • Create New...