or Connect
AVS › AVS Forum › Audio › DIY Speakers and Subs › Adding rear subs to Home theater
New Posts  All Forums:Forum Nav:

Adding rear subs to Home theater

post #1 of 12
Thread Starter 
I'm currently building a home theater room that has a chamber at the front with 4 Fi IB3 18" subs in 2 manifolds. Since I cannot move these around I was thinking of adding a few subs in the rear to help smooth out any response problems. I have not taken any measurements of the room yet as I'm sure they will change once the room is finished. I plan to take measurements and then use room treatments to address what I can. Sound quality is a higher priority to me than sheer output.

I have a fair amount of space behind the back row seating but would prefer a couple of smaller subs. (I mean small in terms of this forum like 3-4 cubic feet not what most sane people would consider small)

Something like the LMS5400 in a smaller sealed would be nice but I've pretty much blown the budget on the theater with stuff like seating, projector etc so I have to try and keep some sanity when it comes to price. If I could keep it under $1200 or so for a couple of drivers and amplification that would be nice, but I could go a bit higher if there was a good reason.

Any recommendations that would complement the IB nicely but not be too obtrusive?
post #2 of 12
Tagged for interest.

I am in the same boat with designing a new HT with an IB up front but would like to plan for a set of subs at the back of the theater. There doesn't seem to be a lot of information on integration with IB sub set ups.
post #3 of 12
Quote:
Originally Posted by the dude 08 View Post

Tagged for interest.

I am in the same boat with designing a new HT with an IB up front but would like to plan for a set of subs at the back of the theater. There doesn't seem to be a lot of information on integration with IB sub set ups.

I have this exact same setup. 4 x 18's in the front and 2 x 18's and 2 x 21's in the rear. Mine are only placed there because of space reasons but you will need something like a DCX2496 to get everything to play properly......and some time
It does work and works very well in fact, but it's tricky getting it all setup.
post #4 of 12
You will need some measuring equipment to get it right. This seems to be of great interest to us all. I'm kinda in the same boat as my sealed subs weigh in at about 300lbs each and i have two, so they are staying where they are Lol.

I had great success with a single AUX sub placed next to my LP. Once my mic gets back from PE and my sub parts are instock i can ge all this under way with my first AUX SUB.

Looking forward to your results
post #5 of 12
Thread Starter 
I currently have a BFD but was planning on a minidsp for the IB. I could add a second minidsp for the rears if that does everything I need. I do have the omnimic and I do have everything I need for REW except my behringer 8000 mic is not calibrated.
post #6 of 12
Quote:
Originally Posted by stockmonkey2000 View Post

I currently have a BFD but was planning on a minidsp for the IB. I could add a second minidsp for the rears if that does everything I need. I do have the omnimic and I do have everything I need for REW except my behringer 8000 mic is not calibrated.

Then you're all set. DO IT!!!
post #7 of 12
Quote:
Originally Posted by stockmonkey2000 View Post

I currently have a BFD but was planning on a minidsp for the IB. I could add a second minidsp for the rears if that does everything I need. I do have the omnimic and I do have everything I need for REW except my behringer 8000 mic is not calibrated.

You should only need one MiniDSP: 1ch for each front manifold which leaves 2 for the rears.
post #8 of 12
i hate to sound like "that room treatment guy", but have you considered removing the enemy vs. beating him down?
post #9 of 12
Thread Starter 
Quote:
Originally Posted by LTD02 View Post

i hate to sound like "that room treatment guy", but have you considered removing the enemy vs. beating him down?

Yes that would be great if I could have designed a space from the ground up but much of what I had to work with was dictated to me by the existing space.
post #10 of 12
Quote:
Originally Posted by N8DOGG View Post

I have this exact same setup. 4 x 18's in the front and 2 x 18's and 2 x 21's in the rear. Mine are only placed there because of space reasons but you will need something like a DCX2496 to get everything to play properly......and some time
It does work and works very well in fact, but it's tricky getting it all setup.

How well do you think XT32 would do off a denon 4311?

room treatment is at the top of my list as well. I am just trying to make sure I have the room for subs in the rear if I want them. I am planing on a dual manifold or line array of 8 18" up front and might have the space to do another IB in the back corner or a big sealed box in the back middle.
post #11 of 12
A small sealed(s) will really help address modes in not only the front to back modes, but experimenting with elevation may mitigate any potential height modes as well. Now, you may or may not have too bad a response in your existing config. Your lateral spacing should do well, but as we've discussed before, many rooms have suckout nulls in the front to back midpoint. The modes still exist with a multisub config, they're merely excited in lesser degree.


You could approach it a couple different ways, if you think your bottom octave performance will be ample, you may pursue a bit more modest small sealed(s). Oftentimes, the FR aberrations reside up in the octave range where a decent 12" or 15" could cover your needs. However, if you really want to pursue the most ULF as possible, then by all means, go full tilt and go LMS5400, or another solid, strong performer. You're skilled enough to delay each accordingly, perform EQ in both time and freq,..both individually, and globally if needed.

Good luck

btw; those that haven't seen the build, it's a nice straight forward IB, and attn to detail across the entire build is superb
post #12 of 12
^^^^ yup, my plan is to start with 12" sealed to get things started. I was surprised at how well a BIC did the job.....
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: DIY Speakers and Subs
AVS › AVS Forum › Audio › DIY Speakers and Subs › Adding rear subs to Home theater