Dual 15" subwoofer ?

[Jonniebravo]

Hello Guys....I've got 2 15" Tempest-X 15" drivers and I'm ready to build, but I need some Info. My plan calls for both 15's In the same box, 48"W X 28"H X 20"D,the box will be sealed.The sub will be used In my home theater for movies and music.The drivers will be mounted on each end of the box with a Internal volume of about 14cu/ft, accounting for bracing. My questions are:what effect will the drivers have on each other,being loaded In the same box and will mounting them in a opposed position have a negative effect. The last question is,should I use two independent amplifiers because the Tempest-X drivers have dual 8ohm voice coils and will result In a 2ohm load which my 1000 watt PE plate amp won't handle.....Thanks guys

Jon

[David_D]

You could wire both coils parallel and then each set in series. This would present an 8 ohm load to the amp.
As for the rest, I'll let the Gurus' chime in.

[Jonniebravo]

Thanks...I had pondered that Idea,but I think It would result In a loss of sensitivity....Jon

[Blktre]

How about the Behringer Ep2500 and a FBQ2496?

[Bent]

dual 15" RL-p's, Adire ADA 1200 watt plate amp (in repair)

[Jonniebravo]

The Behringer Ep2500 Is an viable option. Bent that's a nice design and a great looking sub. What I purpose to build will be on the order of what you have there,accept due to the layout of my theater, my sub needs to be wide instead of tall. If someone could answer the question's about loading both sub's In the same cab and the effects of the drivers firing at opposite ends of the box, that would be of great help.....Jon

[Bent]

One of the issues with two drivers in one box, is if you cook a voice coil, you will counter-drive the dead driver and have severely reduced output, not to mention that there will be a certain frequency that the dead driver will behave like a passive radiator.
At enough power, this could oil can both drivers (no big loss on the burnt one, but it would take the good one out too.) Unless they were wired in series, then it would just get really quiet.

That being said, I use a common chamber in mine, with about 8 pounds of stuffing. Mine is 22"x22"x approx 50" on the base. It is doubled up 3/4" mdf all around with a 1/8" oak ply skin. I calculated 8 ft^3 net volume after bracing. Mine is a tad more than 300 pounds with drivers installed, my amp is outboard.
You may want to reconsider you calcs - 14 f^3 at your dimensions seems large.

Drivers on opposite ends of a box that size will not be a problem, look up Tubzilla on Thomas' pages, there's one with dual 15" BP-1503's on the top and bottom.

[Jonniebravo]

At the calculations(48"x28"-30"x20") for Internal volume,It appears pretty close,About the size of a small table.Each 15" Tempest-X driver requires 200L(7cu/ft) sealed to provide an F3 of 26Hz. If there's another approach or design that will render something like this performance, let me Know.....Jon

[shame302]

You could wire both coils parallel and then each set in series. This would present an 8 ohm load to the amp.
As for the rest, I'll let the Gurus' chime in.

i did this and temporarily powered them with my bash 500. i originally had only one tempest and ran it at 4ohms with this amp. i built another tempest just like it and rewired the bash. it powers them wonderfully. i built the same subs for a buddy of mine and he is powering them with the ep 2500. i gotta tell you, at twice the cost and 4 times the power, there really isnt much differance between the subs output. im sticking with the bash. im super impressed with it.

only differance here would be that i have 2 passive sub enclosures. i cant comment on how 2 subs in one enclosure will be different.