Four 18" Fi IB Woofer Build Thread

[NickTF]

Well guys construction started last weekend and as of this weekend I’ve managed to:
1. Cut out and laminate the .75" MDF to 23/32" OSB making the baffles, the sides, and the bottoms.
2. Cut out the two holes for each of the pair of manifolds. Each manifold will consist of two 18s one firing at the other. The opening into the room is roughly 22" x 13 3/4" for each. As you can see from the pics a water pipe prevented my original intention of mounting the woofers in the center of the room in one manifold. I'm sure I could have used an elbow to turn down the water pipe but no thanks, that's just asking for trouble if you ask me.

I have an appointment with a cabinet maker this Monday for him to use his router to cut out the holes for the woofers. I am not really interested in buying a router and circle jig considering I probably will never use it again so I figured that's the best way to go. Unfortunately I was a bit retarded in construction of the first baffle and didn't think to keep the nails out of the way of the circle that needs to be cut. Me and the cabinet guy should have a blast with that one, ha. If we can't get it to work I will just create another baffle.

My plans are to actually build the boxes piece by piece under the crawlspace. With the way the TJI joists are it will be easier that way. I thought about taking two .5" pieces of plywood or OSB and making the TJIs like a normal joist and putting the box up to the bottom like most do but decided against it. It shouldn't be that hard with a buddy and two mechanical jacks that don't sink over time like hydraulics. I planned to mount each baffle board in between my floor joists and then use liquid nails, nails, and screws to fasten the baffles to the inside of the TJI top and bottom pieces (figured on using nails to fasten them in place quickly then drill and screw them into place permanently. I will use the mechanical jacks to give them support on top of what the nails and screws offer till the liquid nails has ample time to set. Once the liquid nails is set and the two baffles are in place the sides and bottom will be fastened on the same way. Finally, I plan to wedge a few 2 x 6s under each manifold to give the hoists a little relief in supporting this weight (estimated to be 120lbs in each enclosure).

Considering the baffles are only 23" wide I'm quite sure there will be no flex at all in this 1.5" total thickness baffle face. Further, the sides and bottom are the same laminated construction so I would think they'd only go to help the rigidity. If the house falls down (and it's possible from 29 liter of displacement and around 3600 watts, ha ha) these enclosures may be the only thing left.

As you can see the crawlspace is completely conditions which is why I chose this area. The holes in my floors right now have air coming from the crawlspace right now that's the exact same temperature as the interior of my home. Simply a no brainer in back wave containment choice!

Well all this being said feel free to comment. Pics are below.

I simply can't wait to get this up and running. It's funny looking at these four 18" woofers with their rather large surrounds and 30mm xmax and thinking "hmmm, is this a bit on the side of overkill" ha ha.

Once again one can see why I chose this back wave containment area, the entrance is right in my finished garage!



More of my handy dandy redneck body builder clamping system, ha ha. I imagine between the nails and the 150 lbs on top this should be sufficient. Comment if you think otherwise though.



Side shot of the side pieces. The bottoms and baffles were constructed the same way! Construction includes a spread of Titebond II on both the OSB mating face and the MDF mating face. The boards were then laid on top of each other and held as I drove in the 1.5" long nails (quite difficult to hold until the first nail is driven in as the boards want to slide all over the place!!!). After nailing about 30 nails in each the baffles were placed on my garage slab, hammered all over including over the nails again with a sledge hammer, and then placed under the weights.



Just a shot in the crawlspace from the left opening.



The offending water pipe!



The big mess I made!



More mess!



All cleaned up now! I will be seeking some fancy cover solutions for the two openings in the floor. My mother is an interior decorator and has some ideas but any suggestions from my follow IBers are appreciated! I'm not interested in cold air returns, I want something along the lines of a nice wooden register accept larger to cover the 13" x 22" hole. Each one of the openings yields about 1845 square centimeters which is a bit less then the 2420 which would be required for no effects on sound quality. Judging by my previous posts and Thomas's replies I’m guessing this won't have any noticeable impact on sound quality.

[NickTF]

Well just got back the baffles from the router guy. Unfortunately because of my stupidity the router hit a nail in one of the baffles and went crazy. He came up with a custom solution by using some oak pieces to create a face for the front of the woofer to mait to and it fits pretty snug. Now there is some minimal space (about 1/16" - 1/32") between the OD of the woofer gasket and the inset groove so I'm thinking a nice thick bead of silicone should close that gap in this piece. All the other pieces came out perfect for mounting of the woofers from the back. I will be using oak straps that he supplied as well to fasten the woofers from the back.

[NickTF]

Well here are some pics of the straps i'm using to mount the woofers, a total of seven on each. I only got one done last night because I did not have the 100% true fit philips bit for the screws I was using and was getting a bit tired of the bit popping out of the screws. Hope to get the rest fastened to the baffles tonight if I have some time. Plan to build the boxes in place this weekend!!! The straps are isolated from the woofer gasket with foam weather stripping to isolate and also provide additional clamping force.

[ISLAND1000]

My guess is you'll receive low frequency response right through the floor as well as through the vents. Nice pictures, interesting project. Amazing what a guy is willing to go through to get a little . . . . hi def Dbl for his Low THD Hz . Don't let the WAF see that.

[NickTF]

ISLAND1000 wrote:

My guess is you'll receive low frequency response right through the floor as well as through the vents. Nice pictures, interesting project. Amazing what a guy is willing to go through to get a little . . . . hi def Dbl for his Low THD Hz . Don't let the WAF see that.

Yeah, I suppose anything is possible but hopefully there will be good isolation between the crawspace and the interior of my house.

It's been a good amount of work and i'm only about 60% there. They say things worth doin usually require lots of work though

WAF factor? Well, not for me yet, a few candidates in the running but i figured I'd get all of this done before that happens that way all she sees is two nice decorative grates in the floor

[NickTF]

Kudos to Scott! Woofers are pretty tuff! I tested them in 2 ohm stereo (just two at a time) on my plx3602 and they never really bottomed out with even the lights on the amp clipping part of that may be the high crossover I was using internal to the amp just for testing which was 100hz and i'm guessing a shallow slope. that's 1800 watts into each!!!

[jwhite8086]

looks like its going to sound and feel very good are you going to build a larg box down there.
I cant wait till I get my own house.

[NickTF]

jwhite8086 wrote:

looks like its going to sound and feel very good are you going to build a larg box down there.
I cant wait till I get my own house.

Two boxes actually, one for each cut out in the floor containing two 18" woofers in each box facing each other. The box's external dimensions will be about 16 3/4" (between the floor joists) and 26" wide.

[NickTF]

HOLY COW!!! THIS IS THE MOST AMAZING THING I'VE EVER HEARD IN A HOME!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! :P :P :P :P :P
If you can't tell I’m incredibly excited, ha ha

I have not yet equalized anything and the sound produced by these 4 18" woofers is beyond phenomenal. I've been searching from something that is able to both give me the details of bass guitars and harmonics generated by rhythm guitars while being able to produce infrasonics, kick drums, etc., all at terrifying levels with amazing clarity, and I've finally found it. The clarity is unreal, but not as unreal as the weight and quality of the bass. SPL? TOO MUCH FOR MY HOUSE!!!!!!!! Watching transformers is now an exercise in brutality, but not at all overbearing like my previous high quality DIY box setup, like things are really really happening and creating natural sounds in my living room. My DIY setup was impressive, this IB setup is 4 times as tactile as it was and understand that the DIY box setup moved about 3 times as much air as a velodyne 18" model at 20hz (tuning of the DIY setup). The IB is louder, cleaner, and realer. I honestly just can't describe it but being all the hard work that went into it I was simply ecstatic to hear the results!

Building the box in place under the crawl space wasn't too bad but I'd suggest if you're not a bigger guy and have a bigger friend at your side that you consider building the box outside (I’m about 200lbs and so is my buddy who helped, made things a lot easier moving around the baffle boards with the woofers in place in the crawlspace). I ended up with some gaps, some as large as 1/4" by building in place and being far from an expert wood worker but having sealed them up with caulk from the inside and outside air is not leaking through these areas. And if it is then it's not anything I’m noticing with the amount of output coming from this system. I did manage to bridge adjacent floor joists also to prevent any horizontal movement in them. Even at higher levels there is almost no vibration in the manifold boxes at all, simply amazing!!! The house however is another story but it seems to be all coming from sound pressure. Pretty much everything moves on every surface of the house when things get cranking, ha ha!!!

Once I EQ this setup and calm down from the overall excitement it's generated I will report back with a more detailed review of the system.

Anyone on the verge of going with anything other then an IB just do yourself a favor and pull the trigger. I just can't imagine doing anything else. Sure you could build a behemoth ported box utilizing four 18" woofers and have even more output but I assure you that you will not be able to use it considering this IB can produce more spl then my new construction very well built home can tolerate!!!! My living room is 22 x 12 but opens up to the entire living area (kitchen, dining room, entrance) to the house and has a 10' vaulted ceiling. I estimate the volume to be around 3000 cubic feet but it's quite a bit more considering the rear opening. My home is very very very well sealed however as it breaths through a hepa filter filtration system, something my home builder does so this may have some influence on my results.

[NickTF]

Just in case anyone's interested here is the link for my old DIY setup which i'm comparing the IB against!

http://www.hometheatershack.com/foru...stem-sale.html

[jwhite8086]

Mann thats really great I'm happy for you. Merry Christmas

[NickTF]

jwhite8086 wrote:

Mann thats really great I'm happy for you. Merry Christmas

Thanks man, you too!!!

Quite a Christmas present indeed.

Sorry if I missed this...what do you have them low-passed at?

[NickTF]

DevilDriver wrote:

Quite a Christmas present indeed.

Sorry if I missed this...what do you have them low-passed at?

He he, 1hz. I'm sure it's more like 8 or so they start rolling off because of the hardware limitations in the SMS1 EQ I use which i've updated with recent software to prevent distortion or 20hz roll off issues.

NickTF wrote:

He he, 1hz. I'm sure it's more like 8 or so they start rolling off because of the hardware limitations in the SMS1 EQ I use which i've updated with recent software to prevent distortion or 20hz roll off issues.

Hmmm...that would be the high-pass (although I take it you don't actually have a high-pass in place, aside from the hardware rolloff). I was talking about a low-pass filter, ie. 60 Hz, 70 Hz, 80 Hz, etc. and at what slope.

[NickTF]

DevilDriver wrote:

Hmmm...that would be the high-pass (although I take it you don't actually have a high-pass in place, aside from the hardware rolloff). I was talking about a low-pass filter, ie. 60 Hz, 70 Hz, 80 Hz, etc. and at what slope.

Sorry, ha ha, had a few drinks when I was writing my reply!!! Tis the season for consumption of happy drinks, lol. In any event they are crossed over at 80hz from my reciever which I think is 24db/octave but not sure on that.

No, the SMS1 allows you to place the infrasonic filter as low as 1hz but i'm sure there is no difference between setting it at 5 or 8 or so hz because of the hardware roll off.

[Ricci]

What I want to know is... have you stuck your head down in one of the manifolds while playing the pod emergence scene yet?

[NickTF]

Ricci wrote:

What I want to know is... have you stuck your head down in one of the manifolds while playing the pod emergence scene yet?

Ha ha, no thanks, I value my hearing, lol. Just standing by the manifolds though during music makes you vibrate, ha!!!

[Avus_M3]

Has anyone seen private parts (the caller on the woofer)?


"Ooooohhhhhh Hooowwaarrrddd!!!!!!!!"

[NickTF]

Avus_M3 wrote:

Has anyone seen private parts (the caller on the woofer)?


"Ooooohhhhhh Hooowwaarrrddd!!!!!!!!"

Have a lady friend coming up tonight, maybe Private Parts will find it's way in the DVD player..........."now just sit right there, yeah, that's it now hold on".................

[thxgoon]

NickTF wrote:

Have a lady friend coming up tonight, maybe Private Parts will find it's way in the DVD player..........."now just sit right there, yeah, that's it now hold on".................

Lol! Nice job man!!!

[Avus_M3]

NickTF wrote:

Have a lady friend coming up tonight, maybe Private Parts will find it's way in the DVD player..........."now just sit right there, yeah, that's it now hold on".................

Well??? How did it go? or what?

[NickTF]

Avus_M3 wrote:

Well??? How did it go? or what?

The house is still here, although I need to start applying some sound deadening techniques to a few light fixtures. As far as the lady friend, yeah, she enjoyed the vibrations bllllbbbblblblblblblblblblblblblb ha ha

[avaserfi]

Everything looks great - have you taken any measurements yet?

[NickTF]

avaserfi wrote:

Everything looks great - have you taken any measurements yet?

No, can't say that I have. I don't have anything to measure total SPL with like a Rat Shack meter. I have my SMS-1 but it can only be used to measure frequency response up to 90db or something close to that. My subjective measurement though says loud, really loud, ha ha