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Discussion Starter #1 (Edited)
Back in June I reached out to LTD02 for his help and knowledge in designing new enclosures for my SId4’s. They have been in Marty cubes since 2014. In my old livingroom they were fine as I had plenty of space to put them. Now moving forward to our new house and dedicated theater build. My new room was smaller than I wished but that’s ok. So in order to fit in a AT screen, false wall, and stage I had limited depth behind my screen wall, 19”. So I knew the cubes would not fit so time to rebuild. So that is where LTD02 comes in to help as always, plus many other fellow AVSers. That’s what makes this community so great.

So the maximum size I gave him was 24” W x 16”-18” D x 76 H. But let him know I would prefer as shallow as possible with my limited space. He came back with 22”W x 14”D x 75”H, perfect. :) They are 8.5 cf and 17hz tune.









Seeing my theater is almost to the screen wall I better start the new enclosures build. So made up a cut list and off to Home Depot I go. I had them make a 2 cut per sheet so I can get the wood home and manage in the table saw. Here is the wood after getting it home.





So after running the boards thru the table saw and using my crosscut jig we have all the boards ready to assemble.



Does not look like much but there is 4 big panels there too.



Cut sheets and plans ready to go.



Got both enclosure shells built and that’s enough for now.





How they sit now in garage, no the port rails are not in yet, just sitting there.

 

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space constraints can be a bug-a-boo, especially when looking for a good deep FR dig,
placement issues notwithstanding

that size would work very well in my mancave , tho the 2 THTLP's do manage about 95%+ of what there is to listen to. .

can you post any of the modeling graphs?

how will you power them?
 

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Discussion Starter #3
subbed . . .

space constraints can be a bug-a-boo, especially when looking for a good deep FR dig,
placement issues notwithstanding

that size would work very well in my mancave , tho the 2 THTLP's do manage about 95%+ of what there is to listen to. .

can you post any of the modeling graphs?

how will you power them?
I would have to ask LTD02 for the graphs. I gave him my space specs, subwoofers ( si18d4’s), and still using my inuke 3000dsp.

If I can get another si, already have a spare, I will buy a new inuke 6000dsp and use the 2 cubes for nearfield instead.
 

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Discussion Starter #4 (Edited)
Got a question. What if I added a another layer of mdf at the bottom of the subwoofer? Basically it will be a double baffle at the bottom. This would let me flush the subwoofer into the box and add strength to the woofer area. I’m still doing all the bracing but would like to flush the subwoofer. If I make the extra layer the size piece would be roughly 20” x 29” x 3/4”. This is my math is correct is less than a 1/4 cubic feet. Would this be an issue taking away from the volume? Also thinking of window bracing instead.

Here is a crude image.

 

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My rough estimate is around 9 ft^3 after port so if you take off a 1/4 cubic foot with the same port length, WinISD predicts a shift of 0.25 hz upwards. No big deal.
 

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Discussion Starter #6
My rough estimate is around 9 ft^3 after port so if you take off a 1/4 cubic foot with the same port length, WinISD predicts a shift of 0.25 hz upwards. No big deal.
Thank you, I need to learn winsid.
 

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space constraints can be a bug-a-boo, especially when looking for a good deep FR dig,
placement issues notwithstanding

that size would work very well in my mancave , tho the 2 THTLP's do manage about 95%+ of what there is to listen to. .

can you post any of the modeling graphs?

how will you power them?
This is what LTD02 ( John ) wrote when he designed it for me,

“This one is ported out the top side, so that you can take full advantage of your available height. It doesn't have to be exactly 75", half inch or 1 less won't matter. Tuning is about 17hz, internal volume is around 8.5 cubic feet net. I wouldn't go much smaller than that with that driver.

Your room is very small, so if you wanted to go with sealed, that would probably work fine too. Cabs would be pretty much the same concept, just without the port.

The ported cab will provide about 4dB more output on the low end relative to sealed, but in your room you will probably have a lot of room gain.

On the other hand, if you build the ported, you can always experiment between sealed and ported by simply stuffing the last foot of the port with something to block off the air flow or even building a, air tight cover door for the port.”
 

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Discussion Starter #10
I decided not to do the extra baffle to flush the woofer. The extra wood and time would not be worth it. So I went home and ripped 2x4’s down to 2x2 or 1.5 x 1.5 seeing I had the wood on hand and normally you can’t find them in store straight enough. I glued and clamped about half of them in one cab after work.
 

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Discussion Starter #11
Quick layout.



Bracing put in that is not dependent on the subwoofer location. Will cut sub hole first then install sub bracing.





Ripped 2x4 for bracing. Made extras incase I want to add a few more around the woofer seeing I already had my stop blocks setup on the saws.

 

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Back in June I reached out to LTD02 for his help and knowledge in designing new enclosures for my SId4’s. They have been in Marty cubes since 2014. In my old livingroom they were fine as I had plenty of space to put them. Now moving forward to our new house and dedicated theater build. My new room was smaller than I wished but that’s ok. So in order to fit in a AT screen, false wall, and stage I had limited depth behind my screen wall, 19”. So I knew the cubes would not fit so time to rebuild. So that is where LTD02 comes in to help as always, plus many other fellow AVSers. That’s what makes this community so great.
I think I need to do that very thing. What was your room cu ft? Mine is around 3300. I could stand two of them up like columns beside the sofa or in corners. I'm still pretty clueless about placement, room gain etc. I just want killer low base for movie effects.

What's the estimated weight? Understand a sheet of 3/4 MDF is around 100lbs.
 

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Discussion Starter #13
I think I need to do that very thing. What was your room cu ft? Mine is around 3300. I could stand two of them up like columns beside the sofa or in corners. I'm still pretty clueless about placement, room gain etc. I just want killer low base for movie effects.

What's the estimated weight? Understand a sheet of 3/4 MDF is around 100lbs.
I don’t know the weight yet but I will weigh them after their done. My room cu ft is 1025, lol. It’s a dedicated theater build, you can see my build thread in my signature. I had the 2 si18’s in Marty cubes but they would not fit behind my proposed false wall so I needed to slim them down. One other benefit is I’m almost doubling the internal volume with these over the cubes.
 

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teester9484 do you really need to quote the whole thing with all the images? ...:crying:

You might want to add dampening material to one side since there will be quite "deep" standing waves inside. Depending on the crossover those will have a negative impact.
 

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Discussion Starter #15
teester9484 do you really need to quote the whole thing with all the images? ...:crying:

You might want to add dampening material to one side since there will be quite "deep" standing waves inside. Depending on the crossover those will have a negative impact.
Directly from LTD02 when I asked him about lining the cabs with like I did my cubes wth eggcrate.

“1-2 polyester "Walmart" pillows placed toward the center of each cab would be best.”

So a couple of pillows it is. Will slip those up in before mounting the driver.
 

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Discussion Starter #16
Worked on one cab when I got home. Ran into an issue. While glueing in the port somehow with some clamps and the glue the back moved a little bit. To explain the photos the port is crooked. The one side is in 1/8” and other is out 1/8”. If I’m thinking correctly the port volume did not change do to give and take, right? Will it still be ok or should I build another cab seeing trying to remove wood glue and brad nails will be impossible without destroying the wood?

Here are some photos.

You can see the bottom is to the left and top is to the right.



Here is a square piece of wood for reference, total is about 1/4 inch from top to bottom, hence 1/8 on each side.

 

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Worked on one cab when I got home. Ran into an issue. While glueing in the port somehow with some clamps and the glue the back moved a little bit. To explain the photos the port is crooked. The one side is in 1/8” and other is out 1/8”. If I’m thinking correctly the port volume did not change do to give and take, right? Will it still be ok or should I build another cab seeing trying to remove wood glue and brad nails will be impossible without destroying the wood?

Not to fear, PL Premium ( PL3X ) will bridge that gap no problem. Get yourself a tube or two for a caulking gun and fill that gap up. Home Depot / Lowes / pretty much any home improvement / hardware store.
 

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Worked on one cab when I got home. Ran into an issue. While glueing in the port somehow with some clamps and the glue the back moved a little bit. To explain the photos the port is crooked. The one side is in 1/8” and other is out 1/8”. If I’m thinking correctly the port volume did not change do to give and take, right? Will it still be ok or should I build another cab seeing trying to remove wood glue and brad nails will be impossible without destroying the wood?
Port volume hasn't changed so that's not an issue. The possible issue is the side that hasn't been glued yet - Will that side sit flat on the port board? If only 1/8" off you should be good.

A little extra glue on that edge to help cover the slight gap should be fine. I would run a few extra brad nails on that line as well.

One trick I use for a "T" style piece like that is to cut blocks the same depth of the center and place those in between the port panel and whatever it's sitting on. Won't rock on you that way, remove right after gluing so they don't get stuck.


ETA: PL3, As Michael mentioned, will fill pretty large gaps, but I took the plywood in the last pic to be a scrap piece that wouldn't be part of the cab. Just there to show the offset. If that's not the case, use the PL3 to fill the gaps.
 

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Discussion Starter #20
Thanks guys. The board is there only to show the offset. There is no gap at the glued joints. It’s just crooked as you can see in the first photo. There should be no gap either when I put the front baffle on the cab.

So for safe measure I could put a bead or caulk line of PL3 on those joints just incase? I’m just a perfectionist and this normally does not happen, lol. I was about to scrap the cab and build another.
 
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