View Full Version : internal volume with or wihout port section volume?

07-02-2005, 03:43 AM
this MAY sound noobish but......when calculating the internal volume of a ported box, is there any relivance to knowing the volume without the port section?? or just measure all internal area for the net volume?

EX. my box is 6.4 cubs total.....internal chamber withthe sub is 4.4cubs and the rest of the area where the port starts to the opening of the port is 2.0cubs. all for my xxx15

just wondering if 4.4cub area had any relavancy or is it just total internal volume that should be counted as the "box's volume".

07-02-2005, 03:58 AM
The internal volume, the 4.4 cubes, is considered the "box size," the rest is the port size. 4.5 cubes I believe is what RE recommends for SQL, so you should be good as far as your box is designed. What is your port tuned to? Should be a good setup

07-02-2005, 02:55 PM
thats also a good question....the box is supposed to be tuned to 34Hz but we had to redisign the box while we built it because we didnt realize the design was for a 12 until we had to cut the wood. either way.......it should be good....

Mr. Loki
07-03-2005, 08:19 PM

will help find what your tunned at and so fourth.

07-03-2005, 08:53 PM
So when a manufactor recommends 3.25 cu. ft. for a ported box, they're not including the port volume?

Mr. Loki
07-03-2005, 08:55 PM
depends the quality of the company. some just dont give 2 sh*ts. I would say experiment and see what you like the best.

07-03-2005, 08:56 PM
So when a manufactor recommends 3.25 cu. ft. for a ported box, they're not including the port volume?


When calculation box volume...NET volume is what is given. NET box volume is the INTERNAL volume AFTER port displacement, sub displacment, etc. Remember when calculating port volume to account for the .75" of MDF that is also part of the port ;)


Mr. Loki
07-03-2005, 09:17 PM
How is that tru for example

3.25 ported at 26hz will be the same as 3.25 at 38 hz under stand what I am asking/saying?

07-03-2005, 09:19 PM
the 3.25 @ 26Hz is gonna be a bigger box.

Mr. Loki
07-03-2005, 09:23 PM
exactly what I was getting at so example a company said 3.25 at 26 hz isnt going to be the same as 3.25 at 38hz