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Fi IB3-18 x 8 and SEOS pure 10 kits!

post #1 of 1021
Thread Starter 
Hey guys, this was not my fault this time and I had no reason to change anything! I loved my system and it was the best ever! A member PM'd me and asked if I was still selling my subs and I said not really because he wanted to buy a few. I told him it was really a system and I would only consider it if he bought all of them and I did not want to ship 1200 pounds. Well, now I am subless so I was going to go with RE XXX's and these came along. So I am building a Baffle wall to house these in a 300 cubic foot enclosure. I need or would like suggestions from all or any for some tips. IB is new to me but with my multiple sealed eD system I had I don't expect much better except the ability to play louder at lower frequencies. More overhead! So, I have a 2100 cubic foot room, should I build a reverse manifold, line array(needs one helluva strong baffle wall), or just use the Baffle wall as the enclosure. Any info will help and ideas of where you would put these or the manifolds in my room. As you guys know I get a pretty good response with my subs going across the front stage, in the corners, both, it really does not matter with my low ceilings creating another boundary for gain!

I will update this first post with pics, graphs, sweeps, THD, etc...

Here are some pics

Edited by MKtheater - 11/17/13 at 2:42pm
post #2 of 1021
Subscribed. Cool. MK I don't know much about ib systems. So this will be a nice learning thread.I always enjoy your builds smile.gif
post #3 of 1021
Curious where your opening's will be. Never seen an IB before so I am new to them. Thought about someday doing an IB door like Krypto did in the past but not anytime soon.
post #4 of 1021
Thread Starter 
You guys decide. I was thinking either across the front bottom below the speakers or two separate ones in each front corner on the side of the screen.
post #5 of 1021
I think you typically get better frequency response when you have them spaced out on opposite sides of the screen vs all under the screen.
post #6 of 1021
Can't wait to see this!
post #7 of 1021
Thread Starter 
Yeah, I was thinking the same thing and I will build the opening to the baffle extra big that goes from ceiling to floor kind of like stacking sealed subs. I will have two 50x24 inch holes on the side of the screen! Something like that.
post #8 of 1021
Looking forward to seeing some 24"'s.
post #9 of 1021
Thread Starter 
The problem is you won't see them in action, they will be in a manifold. Of course I will take pics of them takin up floor space. I will put them next to a DR-250, wedge 10, and a 888lp for size.
post #10 of 1021
Proper IB sub system have characteristics superior to any other approach.

However, there's two primary drawbacks to typical IB builds, in my opinion. One being zero post-build placement experimentation, the other having to do with power.

Re placement;
I know it's a lot of work, but I'd examine the possibility of building the baffle wall with a modular design for front loaded array style, ... whereby gasketed section blanks, and similar sections that receive drivers, can be interchanged. Ideally this would encompass both the horizontal and vertical dimensions. Then upon time to optimize via placement, you move the drive elements accordingly.

With a manifold IB, a modular approach like that is made more difficult, but not entirely impossible.

The above, although perhaps ideal, would clearly be a lot of work. Perhaps some test boxes, or even simple selective mode cancelation calculations/guesswork, and hope for the best.

Even if you don't possess enough backspace volume for the theoretical ideal 10x VAS, it's still a continuum as you leave ideal infinite backspace, and proceed toward small sealed. Just fill the backspace with fluffy insulation (keeping it away from the immediate driver area), it'll maximize the backspace volume, .. and dampen any potential internals too.

Remember, baffle wall front stage places higher demands on rear wall acoustics than other non baffle wall systems. Effective rear wall attenuation of reflected energy is needed.
post #11 of 1021
hey bud...they are going to shake the hell out of that front wall unless you brace it with super duty construction.

this is where i would suggest you place the baffles cutouts as it will minimize lots of modes.


post #12 of 1021
Thread Starter 
Dejavu! I forgot about wanting to do this before with Fi drivers. The problem is I only will have 4 drivers now so two manifolds. The opening to the manifolds should take up most of the floor to ceiling height so I might be pretty good there and make the manifolds dead center on both sides.

Btw here are some bad pics from my phone of the theater displaced! I can't find the computer cord for my good camera. I will get good pics.

Here are my DR's sitting on the floor

My surrounds not in the final resting place

My location for the IB and baffle wall which will be behind the screen.

post #13 of 1021
Originally Posted by MKtheater View Post

The opening to the manifolds should take up most of the floor to ceiling height so I might be pretty good there and make the manifolds dead center on both sides.

I don't understand this. You're certainly welcome to make the openings as big as you like, but "take up most of the floor to ceiling height", isn't a performance requirement. The opening can be ample to encompass the driver's height, and a typical stud width would be plenty.

What's your plan with the DR cabs ...? Are they excluded, or integrated into the baffle wall?

Those surrounds are massive! I fear for the folding TV trays ... eek.gif

My surrounds are flown, yoke mounted and fully aim-able, fully adjustable fore and aft, and side-to-side movement,..such a system may serve you well too. I know ceiling height is a concern in your room. Since my room is a multi-function, non-dedicated family room, and possible seating changes, I needed full movement flexibility with my sides and rears. I've got it, .. just throwin' that out there upon seeing yours.
post #14 of 1021
Thread Starter 
Yes, the surrounds are massive and the TV trays are crying uncle. I needed a quick setup. Those will be wall mounted for an ideal 7.1 for the front seats and removable if I have guest in the back seats and make dual row 5.1.

As for the openings, you tell me what is the perfect opening for these. I really don't know, maybe 26x26 or is a square a bad idea? Maybe 26x20? This is why I started the tread early because I am new to IB. The DR's are pure awesomeness and will get put back in the loop but they will be isolated in their own box to keep out of the way of the IB(really a sealed sub).
post #15 of 1021
You will want to be very careful if you go line array. Have a look at my wall and the construction, it uses steel H beams chemically anchored to solid concrete and 2 and 1/2 inch thick baffle. Just remember that you will lose db's if the wall flexes any.

post #16 of 1021
Totally subscribed! Id never miss a new adventure from MK. As said the more strength the better on the baffle wall.
post #17 of 1021
Thread Starter 
Hey guys I am having second thoughts. What about 8 Fi IB318's? For the same price I could get even more!
post #18 of 1021
Those FI drivers are excellent as well. My only worry about the 24 is that it's brand new and it's not even been tested, I'm sure it would be great but thats a big "what if" for $2800. I think I'd have a hard decision as well! Though personally, my location makes my decision extremely easy on what to use in my HT biggrin.gif
post #19 of 1021
Someone chime in if I'm off base here, but I recall a good way to get the manifold ported into the room without wrecking walls is to use a rubber gasket to isolate the manifold from the wall, but still keep an air tight seal from the manifold to the wall.

It's been many years since I've read up on The Cult, but I thought I recall them doing that there. I wound up going with a single Maelstrom 21" sealed rather than an IB setup, so I could be talking out my arse.

That said, i really wish I could find another Maelstrom 21" used somewhere...biggrin.gif
post #20 of 1021
Thread Starter 
OK, If I were to buy 8-10 Fi IB318's which ohm would I get and how would I get a nominal 8 ohm load for my amp! I think I am shifting towards the IB318 guys. I only had 36 liters of displacement before and plenty of headroom so 5 of these would equal what I had. The best part of what I had was the rolloff characteristics.
post #21 of 1021
which amp are you planning to run?
post #22 of 1021
btw, 8 drivers of 4 ohms each can be wired up several different ways to get to 8 ohms total.

the simplest way would be to wire 4 drivers in series for 16 ohms in one group. then, make a second group just like that one. then parallel wire the two groups to get to 8 ohms net.
post #23 of 1021
Thread Starter 
I have my clone 14K.
post #24 of 1021
ah, so you have lots of flexibility in drivers and wiring configurations and aren't going to run out of power with an i.b. no matter which way you go.

if you go 8 drivers, the 4 ohm would be a good choice for wiring to the clone.

with 8 ib318's, you should be over 130db everywhere that you want to be. :-)

the inductance is probably not so good on the ib318's, but folks don't seem to report that being a problem.
post #25 of 1021
You gotta love 1st world problems hahahaha
post #26 of 1021
Thread Starter 
I think I am leaning towards this right now.
post #27 of 1021
I really like FI drivers, they are well built and of great quality. If thats the route you do go, you know you'll have a kickass setup!
post #28 of 1021
MK, wtf, you completely lost the boner with the 24's?
The uniqueness of 4x 24" has gone to hell? frown.gif

It just isn't as cool without the 24's...It almost feels like "deja vu" now.
Hey I'm just saying

Good luck and still subscribed. biggrin.gif
post #29 of 1021
I think the more drivers used with IB the more trouble your going to have keeping the baffle from flexing. .Not trying to derail your hopes but IB builds arent for the faint of heart. Make sure your construction is as sound as possible.
post #30 of 1021
I am excited to see this. I wish I could have done exactly this in my home, but I would have had to build on to the house to do it. 8-IB3-18"s on your clone will be bonkers.
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