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Discussion Starter #101
I think the parameters aren’t really going to matter for IB use. Or are you going ported?
If you don't mind explaining what you mean, you could perhaps save me a lot of time and money! I went about going down the t/s rabbit hole as I definitely needed to know the vas (to make sure my space was large enough). Other than that, you're probably right but do I come across to you as someone who doesn't want to know the specs of every piece of equipment I touch? Lol
Also I've talked about adding 'ports' to the infinite baffle setup as was discussed earlier in the thread.
 

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Discussion Starter #103
Let’s say you find the Vas to be X vs Y - since your enclosure size is already determined, how is it going to affect your design at all?
I would either have to change this to a basement baffle or I'd change the whole plan to ported.
 

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The IB Vas guideline is merely a guideline. An IB is a sealed subwoofer with an enclosure big enough that the air spring won’t have an effect on the FR. As the enclosure gets smaller, the air spring increases, eventually causing rolloff in frequency. The smaller and smaller you go, the higher in frequency the rolloff begins.
 

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Discussion Starter #105
Thank you, Steve. That was my understanding as well, with the exception of how the box size affects the rolloff... I didn't know how those two were related! It makes sense then that infinite baffles have such a low digit rolloffs! You know, I'm having a lot of fun with this, learning everything about speakers. The other day I learned exactly how alternating current causes sound to come from the speaker via the motor effect. So cool. So as you can see, even if I did not need to find T/S parameters, it's still enjoyable to do so.

I ran into a bunch of 4x6x8s the other day purely by happenstance! I started to think how I could use them in this build. They're going to come in handy for sure!

Another thing I've been mulling over given recent events is moving this project to the actual basement... Seriously, these drivers are so HUGE. Let me also say, I never ever thought I would own these drivers. Pipe dream.
Basement Advantages:
1) Larger area, legitimately 10x+ Vas (FWIW)
2) Located right next to equipment rack and main fuse box
3) Much easier installation
4) I can turn it up LOUDER with the same amount of bass coming from my property (theory...I mean it's poured concrete...neighbors are 10ft to the left and right)

Original Space Advantages:
1) Completely hidden
2) Better distribution of bass (theory...I feel like radiating from the floor isn't optimal)
3) A lot of research has went in to using this space and it was the original intent of this thread
4) Probably more but I have to go eat dinner

Like I said, just a thought... but one that I ponder more and more the more I move these drivers around. The sheer magnitude of these... I would be remiss if I couldn't give these the power they obviously love.

Have a good evening!
 

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progressive thinking . . .
and 2 of these
6-1/2 ft. 2000 lbs. Capacity Lifting Sling for at least 1 of the manifold assembled
which you return the next day . .
same M.O. for the larger temporary strong-ties units . . .
get the simpson screws tho, they are handy to have around
also, perhaps for some physical vibration isolation in the mounting / securing mech for the manifold
Heavy-Duty Vibration Pad for Air Compressors
by Husky
or- the big boy pants kinda stuff . .
MASON
Vibration Isolation Pad, Neoprene, 800 lb Max. Steady Load, 4 in Length, 4 in Width
  • Item # 2LVP1
these cut be cut into 4 : 2 x 2

IF . . .
plan to have a 4 x pieces of say 3/8th's" all thread secured and sealed thru the manifold bottom,
protruding thru the bottom about 3- 4 inches
that slides thru the pad and then thru the brackets holding the manifold up,
the extended length / protrusion means you may not have to actually bolt the manifold tightly onto the supporting bracket,
the weight will keep it in place and
it's pretty sure you're not going to have much bounce to unseat it . .
more free floating for less vibration transmission to the structure
seems feasible . .
 
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Discussion Starter #107 (Edited)
Alright, I'm grabbing a Crown MacroTech 5000vz this weekend to replace the Behringer EP2500 now that the subwoofer plans changed. To clarify, I bought the EP2500 when I thought I'd be running a pair of IB18s, which are 600W rms each (1200w total). When these HS24s came out of left field, I now am looking at 3000W rms each (6k total).
Not sure yet how I want to run it:
3047474
3047475

Since these are dual 1.7ohm speakers, the following are my options:
0.85 or 3.4 ohm each subwoofer (stereo amplifier or two mono)
6.8, 1.7 or 0.425ohm if wired together (mono signal)

I'm thinking my only two real options are either running at 3.4 ohm stereo or 1.7 ohm mono. That would give me about the same output power I believe. Is it better to run stereo or mono? I'll have to look that up and get back with the answer. I would imagine it to be less work for the amplifier running two channels at a higher ohm versus one channel at half the ohm. Not sure though, so I'll go do research.

I do like that idea of vibration pads between the manifold and the pole/wood holding up the box. I will 100% be doing that. Thank you for that one. As I said, I've got 23 extra treated 4x6x8's, so one or two of those are going to be used to hold this bad boy up... I think. Then again, now that I am thinking (it's all I do, it's a curse), I wouldn't want something holding up the manifold that is going to warp. These are treated and very heavy, but that doesn't mean they won't warp. They certainly should warp to a lesser degree than untreated, thinner pieces of wood though. Not sure how much a steel beam would be instead but I imagine they can't be too expensive. I'll figure it out.

Today I want to figure out the exact size of the manifold, the opening, and where I need to mount it in the basement. I'm going to have the opening in the corner of the room, where the sub is currently. Only concern with coming up through the floor is covering the opening with something that a person/cat/dog won't fall through. Maybe I put a metal grate around whatever it is I use to cover the opening to further prevent accidents.

Oh, I also bought one of these for like $15. Now I can get some professional REW measurements!
3047482
 

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How have the subwoofer plans changed? I read your previous few posts and didn't see anything about changes.
 

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Discussion Starter #109 (Edited)
How have the subwoofer plans changed? I read your previous few posts and didn't see anything about changes.
Going from the original idea of IB18 subs (600W RMS) to these (3k RMS).
I bought the EP2500 when I thought I was going to be running a pair of IB18s.
Instead of buying another (which I could do), I'm just going to go with a single, higher powered amp. That's all.
(Edited post above for clarification as well).
 

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Discussion Starter #111

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+1
that is the mike stand I got, guitar Center, iirc . . .
I was also able to extend the boom using some curtain rods that were a close fit wrt diameter-wise
and DUCT TAPE . .
that enhanced the reach for mike placement slightly at the top back of the seating- YMMV
you might need a counterweight at the base as the boom extended- geometry and extended lever forces, etc.
while it might take a good 6" lag bolt , somewhat countersunk, to anchor it , a 4 x 6 as the support for the manifold
pretty sure warpage isn't an issue, but maybe some simple 1.5 x 1.5 ngle iron , 1/4" thick could be adequate and easier to anchor and drill for the all thread posts
standing by
 
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skip the angle iron , imho
the lag bolts are less expensive,
and the pads and allthread can be arranged to not any other supporting part of the structure
and the pads should accommodate any "warpage", if you think about it
 
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Discussion Starter #115
I went downstairs to take some quick measurements and to see where this manifold would be exactly. Very unfortunately, the only spot where it would really work is right as you reach the bottom of the steps and walk through the doorway. There is no way in hell I can have the manifold in the way of where we are always walking. I could try putting it to the left of the doorway, but I don't want to do that because that space is already a workout area. I wonder if I could put the manifold even further to the right of the doorway, and then kind of 'pipe' the opening out to the left, up into the living room. I think there may be time delay issues there. There is a reason I've read you want to make these manifolds as shallow as you can. Everything degrades over distance, sound no exception. It would be neat to just be able to do that, though. Like how the ductwork for the furnace is ran between the beams, and then up through vents in the floor.

So maybe less unfortunately, I think we may have to go with the original idea BUUUUTTT we can assemble the box in the basement. I'll simply cut out the area at the bottom of the steps where the recessed light is and work through there. I can assemble everything, put it on a creepy crawly, wheel it on over to that area at the bottom of the stairs. Then I'll use a multiple rope/pully system to give myself a mechanical advantage and get that sucker on up into the space. Tie to off while I secure it to the wall/floor of the space. I was thinking running a couple of those previously mentioned steel poles or 4x6 pieces of wood as shown in the pic. Hopefully the pictures help show what I'm talking about.
Here is a view from the basement, looking into the doorway, at the bottom of the steps. You can see the arrow, which is pointing to the recessed light, which is the floor of that space from original idea. Notice the manifold being in the way in teh spot I thought I'd get away with. As I said, I can't have something blocking the doorway. To the left of the doorway is the workout area.
3047500


Here is if you walk right through the doorway, starting from the previous pic.
Sensitive content, not recommended for those under 18 Show Content
3047501


Here is if you are standing at the bottom of the steps, looking through the doorway, INTO the basement. The pull-up bar should give you perspective, which is why I tried to get it in every shot. See here, the area in red is what I'd cut out, and then I'd put the pulley system way up in the ceiling above that. The recessed light here is the same one you see the back of in the pictures I took inside the sub space. Also notice the poles/wood beams could rest right there, on top of the concrete foundation. So it would take up no extra space in basement.
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Aaaaand if you walk up the stairs, turn around, here is your view. Again, see the pull-up bar, recessed light, and steel posts/beams from last pic. Honestly if you don't have your bearings about you at this point as to what is where, I'm not sure I can illustrate it any better lol.
3047509


Another thought about doing this is, I don't think I'd have to seal off the floor/bottom (where recessed light is), as it would just lead to the bottom of the steps/basement doorway. I mean, the rear waves could travel up the stairs, 90 degree turn, through the kitchen, and then another 90 degree turn into the living/tv room.

Does anybody know of a better illustrator? By that I mean a software that I can draw up a box plan. I'm using MS paint, so I'm pretty sure anything is better, but I don't know how to use solidworks or CAD stuff... I'd learn but I need to get going on cutting some wood, lol. I'd like to be able to draw an accurately scaled subwoofer box. A 24" hole should be nearly as large as a 26" box, etc. One I don't have to write next to the shapes 26", 14", etc.
 

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Discussion Starter #116
living vicariously thru you :)
btw there's an FP10000q in the classifieds
Thanks, I know. I have already messaged him, haha. If this Crown 5000 falls through, I told him I'd be reaching out again. :)
 

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Get the 14k instead, the 10000 drops off at 7hz and the 14kz drops off at 2-3hz. I know I would want the most bandwidth possible.
 

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Some details have escaped me . .
both drivers in the manifold?

and goes through the floor of the space above as pictured, pic #2,
because the passage is for the bass to get into the actual listening room . .
or up to it as it seems the 4 bys or whatever are not thru the floor (?) but are to hold it all up there
i was trying to envision something like a 4 point holding structure or 2 rails for 2 of the edges and vibe block thing
 
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Discussion Starter #119
Some details have escaped me . .
both drivers in the manifold?
Yes, dual opposed. Wait, you thought only one? Communication breakdown is occurring, which is the story of my life.

and goes through the floor of the space above as pictured, pic #2,
because the passage is for the bass to get into the actual listening room . .
or up to it as it seems the 4 bys or whatever are not thru the floor (?) but are to hold it all up there
i was trying to envision something like a 4 point holding structure or 2 rails for 2 of the edges and vibe block thing
Yes, the two 4x6 or steel beams will go through that 'floor' and be attached to the bottom of the box. I'm going to draw this out somehow.
I've gotta figure out how much wood to buy now. That's why I want to figure out a good program to draw this manifold. Wait, I can just use any old box designer... I just omit one of the sides, as that will be open to the living room. This is going to be so awesome.
 

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Discussion Starter #120
Get the 14k instead, the 10000 drops off at 7hz and the 14kz drops off at 2-3hz. I know I would want the most bandwidth possible.
I'm getting a Crown MacroTech 5000VZ. Not sure where the rolloff is there but that's what I'll have! If it falls through, I'll have to deal with a 10000q. I can't afford a 14k.
 
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