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Post by mpotoka on Mar 12, 2007 17:31:17 GMT -7
I really really want to build an IB so that I can demo it to potential clients. My theatre is 17x21.5x7, so about 2600 square feet. First row is about 12' from one of the 17' walls. The only location I have for a manifold is if I mount it in the bathroom connected to the theatre (in the front left corner) I would be mounting the manifold above the crapper--so I would ideally like to use 2 12" drivers in an "innie" type of box so that the backs of the drivers don't haver to be exposed, and that it can be a small-ish enough box that people don't crack their head on it when they stand up from doing their business. The bathroom is 420 cu ft so I think that it is big enough? I also don't want to be spending gobs of money on drivers since I plan on selling this house within a year.
So, if I got 2 ascendant audio 12s giving me about 2.96l of displacement, would that allow me to go say, 105DB at 15hz in my room? Any suggestions? Thanks so much
Mike
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Post by ThomasW on Mar 12, 2007 17:54:02 GMT -7
o, if I got 2 ascendant audio 12s giving me about 2.96l of displacement, would that allow me to go say, 105DB at 15hz in my room? Nope not a chance. You can model the output of a given number of drivers at a particular frequency and SPL using one of the freeware programs like WinISP Pro or Unibox. Given the rather unique installation you describe, I recommend waiting until you don't have to place the manifold over a toilet...  |
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Post by mpotoka on Mar 12, 2007 18:08:17 GMT -7
I know I know--I realize that I have to make some sacrifices. Now I do have an Earthquake Supernova Mark V that I'm using right now. Would I at least gain a nice amount of "boost" in displacement? Or is it tough to try and use an IB along with a conventional sub?
Could I get 95DB at 20 HZ? Oh yeah, I'll go get UniBox or something...
I lust after building an IB though! Over a toilet or no--what if I did 2 15s for 4.6l of displacement???
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Post by mpotoka on Mar 12, 2007 19:27:43 GMT -7
What if I just installed a single Ficaraudio Q18 in the wall instead of a box? Would I gain anything over just putting it in a box?
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Post by ThomasW on Mar 12, 2007 20:25:49 GMT -7
Given the particulars of their individual performance characteristics, I think it would be difficult to integrate a vented cube sub with an IB.
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Post by htnut on Mar 12, 2007 21:44:05 GMT -7
If you were careful with placement you might be able to reduce some of the dips in your room modes.
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Post by mpotoka on Mar 13, 2007 5:24:01 GMT -7
Ok--I also have a furnace room to the side of the theatre. The theatre is on the end, then there is Bathroom, Furnace Room, Hallway along side of it. The hallway door ends at the theatre in the back part of the room. But this furnace room is next to the bathroom and I don't care what I showed in there. If I put 2 or even 4 18s (mach 5s) would that work alright, being basically directly to the left of the seating position?
What is the Vas for the 18s? I'd have to measure that room to see if it was big enough
Mike
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Post by ThomasW on Mar 13, 2007 7:56:25 GMT -7
The T/S parameters for the Mach 5 drivers is on their website www.mach5audio.com/index-2.htmlThe 10X Vas recommendations are just that recommendations, not something that must be strictly followed. The MJ18 are a good low cost option, but they have modest Vd. The yet to be released newer 18"s from Mach 5 or the Fi .Q18's, might be a better choice if you want to use the fewest number of drivers. |
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Post by mpotoka on Mar 13, 2007 15:59:54 GMT -7
Sorry to ask such newb questions... but what exactly is Vd? Could you point me to a good source that explains what all those parameters mean? I read yours about Qs but haven't found a good consice "Parameters for Dummies" type thing.
I ordered Vance Dickeson's book on speaker building, hoping that it will enlighten me some. I also ordered a BFD after reading part of your article on explaining it (which was very well written and easily understood!)
I guess budget is the biggest factor right now, 4 Mach5 18s cost the same as 1 FI Q18. This is a temporary house for me so when I move and build the "real" theatre, then I'll be a bit more concerned with Vd (depeding what it is)
As far as location is, there is no issue being on the side of the listening position?? The furnace room has a good 350 cu ft after subtracting the furnace etc. Would I want the manifold to be open above ear level or below, or at?
I'm just guessing there would be a bit of wind produced--making me think low is good?
Thanks again
Mike
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Post by ThomasW on Mar 13, 2007 18:14:00 GMT -7
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Post by PeterW on Mar 13, 2007 19:09:19 GMT -7
You will get greater dicplacement with 4 mj 18's than with 1 fiQ18.
about 1.77 times more dicplacement.
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