View Full Version : Box design for 2 15" BTLs(will send $6 paypal)
07-06-2008, 11:28 PM
2 15" Fi BTLs(Old Design)
Sub up, Port Back
i want it to look like this.
3.5" on the front for the amplifier
7.5" on the back for the kinetik hc2400's
want it tuned at 35 hz after displacement
07-06-2008, 11:54 PM
07-07-2008, 01:27 AM
(this is outside dimensions when using .75" MDF)
port: 70 sq inches (port opening...i used 4"x17.5" but Id go with a more square port shape) and 15.25" long will get you just above 31Hz...If you want it higher you'll need to shave off some inches...
And this will end up being approx 6.7 cubic feet without subs in it (6.4ish i believe with them in it)...but I would add plenty of bracing onto this...
07-07-2008, 01:42 AM
the port will be on the upper back part of the box, thats my problem, i need to bend the port in order to make it longer.
come on i need someone to design me a box for this.
07-07-2008, 01:44 AM
I can whip something up real quick on sketch-up...one sec
07-07-2008, 02:03 AM
Ok, here it is...simply follow those demensions I stated above and use the 4"x17.5" port I used for that...
And there ^ is the port for this, this will avoid the subs it would run into otherwise...youre going to have to cut a bit more MDF than usual to make it turn downwards...and start the port fairly high on the box to keep from having to make another turn in the port...simply measure the port (from the CENTER of the port) to 15.25" to get 31.2Hz...but actually u can make it shorter because you want it around 35Hz...so I would make that port around 12-13" or so for a bit higher tuning and it will be what youre looking for..
07-07-2008, 02:09 AM
and at the turn in the port...a 45 degree insert might be wise to help out air flow and to keep the port as one-width'd as possible (a turn like that in a slot port is wider at the turn...with the 45 degree insert in the corner the change is less severe..)
Also..try and round-over the other corner of the turn so its smooth and also round-over both ends of the ports...
07-07-2008, 02:24 AM
And here's the port dimensions for ya since im feeling so giving tonight :)...this will give you a 13" port length which should be a good portion higher than the 31.2Hz that the 15.25" would give you...Though you may want to make it even another inch or so shorter to make it closer to 35Hz...if its for daily...this port will be great, but if it has to be 35Hz on the nose...PM me me and I can do the real math and get that 35Hz on the nose..
And it will give you a 70 square inch port opening, which should be plenty o' port...
PS: remember the 45 degree angle insert is a good idea (it would go on the inside of the port in this last pic in the top/highest corner) and also make sure to round all of the corners on the port..
07-07-2008, 02:47 AM
thanks alot pioneer saturn.
do you need to add half of the port height to the port length when you make a 90 degree turn?
also the depth is only 20"
the depth of that port is 8", subs are 15", it will hit the subs
07-07-2008, 02:53 AM
No and good catch haha, you can actually start the downwards turn immediately going into the enclosure...so the face of the enclosure its on will be part of the port now...just make the turn-down immediately and make the 9.75" dimension in the sketch-up an 13.25" instead because you loose 4" in the first part of the port with it like this...
07-07-2008, 02:56 AM
or should i just do sub up port up?
07-07-2008, 02:57 AM
You could definitely do that...just not as much success going sub up port up...Ive seen a handful of people do it and werent too happy with it....it wont be horrible by any stretch but a good bet when doing a setup like this is sub up, port back...
07-07-2008, 03:03 AM
Here are the new port dimensions to keep it from going into the subs...
Shoot....the 5.5" dimension should really say 4.75" because that side of the port will be the side of the enclosure and is already accounted for that way...
07-07-2008, 05:06 PM
And if you need a list of sheets to cut for this I can assist...but will have to be later when I get home..