View Full Version : I need help with a box design

12-15-2002, 07:06 PM
I need some help deciding if i should use a sealed box or ported. I know sealed will have better sound quality, in theory, but i am also after SPL. How big will I have to make the sealed to get some good SPL for two Shivas? What size would you recommend for ported tuned to 30hz, and how big do the ports have to be to get 30hz? The boxes have to fit in the trunk of a '93 Cutlass.

What kind of DB do you think i could hit in the ported compared to the sealed, assuming both boxes are made properly with the right cubic feet with an MTX 8100D amp pushing them? I know you cant give me an actual number because there are so many factors, but if you could just give me a range that would be cool.

Do you think a JBL 1200.1 would be better then the MTX for these subs?

Holla Back

12-15-2002, 11:20 PM
No i dont have an amp yet. If the MTX is too big what do u think about the JBL 1200.1 with the gain turned down? Is that still too big? I would like to get a high output amp because i would like to upgrade to Brahmas in the future and i am only 15 so i only have a limited income so i can't be swtiching amps all the time. Or, what about the MTX 6500? Do either one of these have a subsonic filter? Do you have any personnal recomendations for an amp?

Also that 650 RMS is per sub right? Each coil can handle about 325? What do you think about a 10" Brahma instead of two 12" Shivas?

The dimensions are: Height-14" Width-44" Deep-39"

Do you have any idea what kinda DB these could hit with a ported box tuned to 25hz?

12-16-2002, 12:10 AM
i would not mind giving it up all as long as it is for a good purpose and is actually gonna make a difference in performance. I have to have enough room though for a JBL 1200.1 and two MTX 4202 amps. If you want some pics of the trunk let me know and i can get you some.

12-16-2002, 12:35 AM
OK. sounds great.
So the divider just goes straight down the middle then to seperate the chambers?
Also, if i decide to change the width to make it a little smaller can i just add it to the depth or is this gonna throw the tuning off?

Does a flared port mean it has a lip on the outside so it will install flush against the box? Do i just use PVC for the port and run it straight back 22"?

Sorry for all the questions, but i am only 15 and on a limited budget so i want to get everything right the first time. Yuo are really helping me out and i appreciate your time. :)

12-16-2002, 12:51 AM
Alright. That sounds a like it will fit in my space a little better...just one last question. Where should i put the ports? And, these latest dimensions will leave me enough room for my three amps, correct?

I will probably use this setup and i will let you know how it works when i get all my stuff.

thanks alot.

12-16-2002, 01:05 AM
ALright. I should be able to make 1 of those 3 work.

Where should i put the ports at?

12-16-2002, 01:12 AM
Won't really make any diiference which corners then?