Need driver advice.

[Rolyasm]

Trying to to a modified IB, if it is big enough. The theater room is about 1700cf. Behind the wall where the screen will be is a room about 500cf. It is used as storage now and is carpeted with a hinged door. Not airtight at the moment. The plan was to put one 15" driver on each side of the center channel, below the screen, facing into the room. I looked at TC sounds, but not sure if there is something on par, but less expensive on the market. Thanks in advance for any suggestions.

Roly

[ThomasW]

https://www.ficaraudio.com

The .Q18" is great for IB's

[Rolyasm]

Looking at the VAS on the Q18, I see it is 268. If I use two of the drivers, my room space isn't close to the "rule" of at least 4 times the VAS. As the room size is decreased, wouldn't I have to build more of a sealed enclosure? If so, is the hinged door (regular entry door) with carpet on the floor going to be enough of a seal? I just wanted to make sure you read the room size of 500 cf correctly before I jump in. If you think it will work, I'll do it. Also, the subs would be on the same wall as my mounted screen. Will this most likely cause movement in my screen?
Thanks
Roly

[Dennis H]

That's 268 liters for the Q18 or about 9.5 cu.ft. You have plenty of room volume.

[ThomasW]

What happened to the 4 drivers in the riser?

If you put them in a manifold there will be no more wall shake/screen shake than a box sub at the same location.

[Rolyasm]

This project is for a friend. My subs are up and doing great. Sometimes I wonder how I ever had a normal 12" boxed sub, so thanks again for the help on that first project. So 1) you are not concerned about the volume of the room and the VAS, etc. ? A boxed sub would sit on the floor, not touching the wall, while I was planning on mounting these in a manifold array. The way I envisioned it was creating a "solid wall" with MDF and ply wood, secured to the wall below/behind the screen. So 2) this doesn't create any vibrations on the front wall?
Thanks.
Roly

[ThomasW]

So 1) you are not concerned about the volume of the room and the VAS, etc. ?

Do you not understand the math Dennis provided?

A 500 cu ft space is 26 times summed Vas of 2 drivers

A boxed sub would sit on the floor, not touching the wall,

The energy off the driver will cause the wall to vibrate

while I was planning on mounting these in a manifold array. The way I envisioned it was creating a "solid wall" with MDF and ply wood, secured to the wall below/behind the screen. So 2) this doesn't create any vibrations on the front wall?

If a manifold is used 'heroic' construction isn't needed for the wall.

[Rolyasm]

Thanks,
I must have skipped right over Dennis' reply. Just didn't see it. Sorry. Appreciate the reply.

Roly

[Rolyasm]

Looking at the Q18, the only ohm rating I see is .7 or 1.4, so I am assuming that is for one or 2 voice coils. If I am using the Behringer 2500, what setup would be optimal for running the drivers. If I wanted to use the second amp channel for another project, would I need to run in series, or do you think the amp could take that low of a load if I ran parallel? It looks like the amp is only stable to 4 ohm. I don't have to use the other channel for another project, I just thought the option would be nice.
Roly

[ThomasW]

Scott at Fi will custom configure (build) the drivers for IB use when that application information is included with an order. This includes a slightly softer surround and creating a SVC driver. I think two drivers in series would be a ~4 ohm load (double check this with Scott)