Potential issue that measures 2"x 8"

[liquisonic]

Hello good folks,

I posted this on another forum, but no-one has replied.
So either I am proposing something that is so out of whack that nobody wants to touch it, or they just don't give a rodent's ringpiece about IB subs..lol...

What I am starting with is two SI DS4 18s I picked up on closeout, the specs in attachment. (power handling listed as 1200wrms)

Will build manifold that can accept an additional two to six 18"drivers if SPL is inadequate.
First amp is a a Behringer INuke 6000 DSP utilizing limiter, x-over, EQ and whatever else is needed.

The space (front left corner~ish) has been tested by ear switching sub and listening position, all is good.

Here's the thing:
There isn't enough room to place between wall and first 2x8 joist, as the wall is 8" away from the foundation.
There also isn't room between the 1st and 2nd joist, this position blocks upper left corner of the projection screen.

So question:
As long as I allow for the added volume of the joist in manifold design, can it be placed around it? Basically straddling the joist?
Complete manifold opening will be sealed to the basement ceiling/main floor, including sealing around said joist.
The joist will not interfere with the physical operation of the drivers whatsoever.

Additional information gladly provided...

Cheers
-Steve

[ThomasW]

Hi,

Not to worry, there are no issues if there's a stud integrated into the manifold.

Keep us updated as your project progresses

Regards,
Thomas

[liquisonic]

Thanks much Thomas, it's these 'little things' that always seem to creep into my projects, and I just need a little reassurance before I carry them out, that what I am doing doesn't throw the whole thing for a loop. So thanks again.

Will be documenting the project along the way, stay tuned for the details..

Side note: I was reading up a little more on the manifold vs line, and am just wondering if the smaller opening of the two, does what? Load the drivers a bit? (my assumption).

Anyway, I'm on the train now, let the psychosis begin! ...HAHA..

[ThomasW]

Nov 8, 2016 18:18:55 GMT -7 liquisonic said:

Side note: I was reading up a little more on the manifold vs line, and am just wondering if the smaller opening of the two, does what? Load the drivers a bit? (my assumption).

I'm not sure I understand the question. A line array has an opening for each driver. A manifold has a single opening.

[liquisonic]

My apologies, I posted during an election-night party whilst the booze was flowing like water!

Wrong terminology, I should have said a "lengthwise" opening manifold instead.

Also, I'm openly admitting that I am very new to all of this, so if I make yet another mistake, call me on it (please describe how I'm mistaken though, if you would  )

Couple pics:
Here is the lengthwise opening, IB that has a much larger opening vs total SD:


That manifold design differs from using a rule-of-thumb clearance for downfire sub, which is suggested somewhere on this site.
My design will be loosely based on the following, which is in a documented project:

While the opening vs total SD on this may be greater, it seems that it's a lot less than what's in the first pic..
The space needed for this latter type is all I can incorporate, so I was wondering what differences in response these two designs might have. (??)

Many thanks. 
Cheers
-Steve

[ThomasW]

No worries we all started out as n00bs...

No issues at all with the opening being larger than Sd.

Understand that IBs are a very forgiving type of design, this means there are very few hard are fast rules. Think of most things posted as guidelines.

Eric's project is a good one to follow since it's so well documented