PDA

View Full Version : Box help for two Shivas



venom107
04-23-2003, 11:37 PM
Hey guys I want to tune my box to 29Hz for two shivas. The measurements for the box are:

31 inches across
14 inches high
24 inches deep

So you have any ideas or tell me how I could constuct it? Im going to build it out of 3/4 mdf so Help on this would be appreciated.

venom107
04-23-2003, 11:57 PM
I forgot to tell you that the box I want is slot ported tuned to 29Hz. I just need some measurements on how to seperate the subs and how big of a port I should use. I'm not going to any competitions so I just want the loudest daily driving subs I can get.:p

more_spl
04-24-2003, 01:07 AM
http://www.carstereo.com/help/Articles.cfm?id=31

Use the second calc at bottom.
don't put the subs in seperate chambers in ported..... a slight miscalc or cut will throw one side off... Just use one big chamber, it's ok when dealing w/ ported

venom107
04-24-2003, 11:08 AM
If one sub blows wont that cause the other one to blow also? Plus if I want to put each sub in a 2.8Cu Ft box do I just build a 5.6Cu Ft for both of them together? What are the calculations for finding out Cu Ft. I migh just build two seperate boxes so I can avoid some of these complications unless you could clear them up.

venom107
04-24-2003, 11:21 AM
Ok I figured out that I can fit a 5cube box exactly in my car so if I build a dual 12" box with no spacers and a single port I will put it in the center. Will 5 cubes be enough for 2 shivas tuned to 29Hz?

more_spl
04-24-2003, 04:53 PM
to find the EXACT internal Ft^3 of your box, use the sealed box calculator on
http://www.eatel.net/~amptech/elecdisc/spboxnew2.htm

It doesn't matter w/ this calc if you are porting it, it's close enough still....
But ya. If you want the real formula for Ft^3, it's "(LxWxH) / 1728"...
although that formula doesn't take into account for the thickness of wood you use.

I've heard from many people, and everyone agrees that the single chamber for multiple vented subs is okay to use... I questioned the fact becuz it's improper to do w/ sealed, but you will be fine w/ 1 chamber... I would assume you're ok becuz are is escaping thru port as well so not as much push-pull on the subs if one blows....... idk