Enclosure Design break-down

[Kinser]

Is it possible for one of the box wizes on here to post up a thread explaining all the elements of box design?

Things like:

Box size vs power

Box size vs port area

Port area vs sd of the driver

Power vs port area

Type of wood to use

Propper bracing

And so on..

I think it would help alot of people understand why thing are done the way they are, and it can help most of us improve our designs and scores.

Thanks for reading & any info input.

David

[Cadillac John]

Agreed.

Ill answer a few.

Box size vs power

-9 times out of 10 It is best to go with what the company recommends within reason of their power ratings. But high powered enclosures can be ran smaller then rated or low power enclosures. With the high power enclosures the box requires alot more braciing due to the high compression or extra force with in the box. When using low power with a box it is best to go at the higher/bigger side of cubes that the company recommends. But, going to large will make the woofer reach its Xmax/Xmech quicker which will result in bottoming out the coils. A small box will make a tighter bass rather than a boom from the bigger box.

Box size vs port area

-The general rule for port area is 10-14" of port area per foot. Nowadays will the Torres and RE calculators out there figureing out how much PA(Port Area) you have isnt an issue. Simply through some numbers down on paper and do simple math, if it doesnt seem right simply divide it threw the range of 10-14". With aero ports with PA per foot should be between 8-12" with the same math to double check.

Im going to skip to the wood and bracing, its late, others know more about those and the rest than I do.

Wood

-MDF is the general used wood as it is dense, strong and relatively cheap to purchase. Also is a consistent wood with little flaws. Birch is also an option, more commonly seen is the SPL, High power builds as well as walls due to its weight. It is lighter then MDF, just as dense if not more, and stronger. BUT, you need to have an eye for good, solid wood. If you just throw a few sheets on the cart you may end up with knotty, warped wood.

Bracing

- There are many ways to brace a box. 2x2's,2x4's, 45's in each corner, Dowels, All-Thread, Resin/Epoxy, Fiberglass. Mostly common is many boxes is 2x2's ran vertically and horizontally making or acting as the box is one. Side to side, Top to port, how ever your box is laid out. 45's brace the box, but not nearly as well as the others. 45's in the "pressure points" creates smoother air, which means a smoother flow or pressure of air with in the box. What I meant by pressure points is below or behind the subs, as that is wear the airflow is strongest and most disrupted by the 90 within the box. Dowels are used in SPL oriented boxes as it supply's the lateral suport of 2x2's with out the disruption of air as it is a smooth surface. All thread serves the same purpose as a 2x2 or dowel, but people see metal being stronger than what wood can be. Resin, Epoxy, and Fiberglass need to be used with any of the options before it. They will offer support on the walls, but if the walls of the box flex to much they can crack. SO all your time spent and money didnt go to much.

SO in the long run of how you brace your box, do it well. Or you may have to do it again. Your box can never strong enough, so the stronger you can make it the greater number and response you recieve out of it.

[Kinser]

Thats great! Thanks for taking the time to write that up!

Any one else feel free to chip in and add some more info

[RAM_Designs]

Required/minimum port area is in no way dependent on box volume, assuming the excursion of the sub is not limited by the size of the box or power being used.

[Kinser]

Hey ryan,

Could you elaborate on that?

[Skullz]

This is something that is well worth every penny for all the information contained inside.

http://www.parts-express.com/pe/pshowdetl.cfm?&Partnumber=500-035

[TRTC360]

I have a feeling this thread is gonna go down hill very fast.

[Kinser]

This is something that is well worth every penny for all the information contained inside.

http://www.parts-express.com/pe/pshowdetl.cfm?&Partnumber=500-035

Ive got a copy, there is a TON of info in there but i am still left with questions at the end of the day.

For instance:

If my port is too small ill suffer from port noise, if my port is too big..? Then what?

Why does a burp box have so much port area?

Thats the kind of things im keen on understanding.

David

[Joe X]

This is something that is well worth every penny for all the information contained inside.

http://www.parts-exp...tnumber=500-035

Ive got a copy, there is a TON of info in there but i am still left with questions at the end of the day.

For instance:

If my port is too small ill suffer from port noise, if my port is too big..? Then what?

Why does a burp box have so much port area?

Thats the kind of things im keen on understanding.

David

Play with the Richard Small's estimate for minimum port area.