Need help designing a home theater subwoofer

Presume you mean this. šŸ‘ šŸ˜Ž

And what's wrong with folded horns and big obelisks straight our of the movie 2001? Huh? (*)

IMHO, the intersection of the WAF and DIY sets is zero.

Honey, here's the new amp for the living room...sure... it 19"x20"x8", it's flat black, has handles on front and back... and a bright BLUE LED... Oh, did I say it's two amplifiers... you see, they're "mono". Oh, before you keel over, did you see the new speakers I'm making in the garage?

In this hobby, heck, just being a plain audiophile, it helps to have a very understanding wife, or make her enjoy the music with you. For example, there is no coffee table in our living room... it would smear the audio imaging. It also makes it easier to walk around.

OP: has your fiancee thought about the cables to your "woofer table"?

OP: Just thinking out of the box... err... table...

All of your calculations are awesome, but fundamentally the concept may be flawed once she realizes there will be some cables on the floor of the room. How about just building a large but shallow woofer box, mounted on the wall behind the flat panel TV? How about using an array of 5 or 6 inch drivers instead? You can always add drivers are your budget allows.

(*) When non audiophile visitors chez nous see the Maggies, they are confounded. I tell them they are communication antennas to establish subversive radio transmissions with Ming Of Mars... then I point out to the amplifiers and last the tube amp. They would not believe they are speakers... Mon Dieu! Maybe if I put a Bose sticker on them.. eh?

OP: back to your regularly scheduled thread....
 
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And what's wrong with folded horns and big obelisks straight our of the movie 2001? Huh? (*)
In mine and all my friend's audio 'world' way back when, nothing; have even had at one time an L-C-R setup with three of the single dual 15" 70 Hz horn cabs/large horns perched on top in my Avatar with not only zero WAF issues to date, but some used them more than I did since nothing else did 'their' music anywhere near like they enjoyed at the live concerts, dance halls we frequented.
 
I
And what's wrong with folded horns and big obelisks straight our of the movie 2001? Huh? (*)

IMHO, the intersection of the WAF and DIY sets is zero.

Honey, here's the new amp for the living room...sure... it 19"x20"x8", it's flat black, has handles on front and back... and a bright BLUE LED... Oh, did I say it's two amplifiers... you see, they're "mono". Oh, before you keel over, did you see the new speakers I'm making in the garage?

In this hobby, heck, just being a plain audiophile, it helps to have a very understanding wife, or make her enjoy the music with you. For example, there is no coffee table in our living room... it would smear the audio imaging. It also makes it easier to walk around.

OP: has your fiancee thought about the cables to your "woofer table"?

OP: Just thinking out of the box... err... table...

All of your calculations are awesome, but fundamentally the concept may be flawed once she realizes there will be some cables on the floor of the room. How about just building a large but shallow woofer box, mounted on the wall behind the flat panel TV? How about using an array of 5 or 6 inch drivers instead? You can always add drivers are your budget allows.

(*) When non audiophile visitors chez nous see the Maggies, they are confounded. I tell them they are communication antennas to establish subversive radio transmissions with Ming Of Mars... then I point out to the amplifiers and last the tube amp. They would not believe they are speakers... Mon Dieu! Maybe if I put a Bose sticker on them.. eh?

OP: back to your regularly scheduled thread....
Haha!

She thought about the wire on the floor. The couch, wall and cabinet are literally 12-16in from the table. I said I would poke hole under the cable for the cable to get out from under the carpet, she was fine with this, and even suggested we only let the cable on the carpet.

The amp, while quite noisy, will probably be inside the same cabinet as the av receiver, or behind the couche, or maybe downstairs with only the speaker cable to the subwoofer. We’ll see when we get there.

The big shallow box would have been a good idea if I didn’t install a huge tv wall mount rack on the wall. I once thought of doing this behind the couch, as we have a 8 foot long table, 6in deep, ~40in height. I could have gone with a 8in not more. Which give me between 13 and 17 cubic feet.

Didn’t really think of array, but we don’t see this type of arrangement often recommended. I don’t know a lot about this hobby, and don’t know a lot about stray either.

What’s the Maggie’s?

I’ll get a Bose sticker to put ont my table too! šŸ˜‚
 
?? Dual (2) 15UM-22 in ~141.58 L = ~0.96 Qtc using the only sealed math I know whereas Hornresp (HR) computes it as a 1.0 Qtc, so no audible difference, just included it for completeness.

Using 'my' math: 150 L for a single (1) 5UM-22 = 0.743 Qtc.

For an optimal 0.707 Qtc = ~177.5 L, so x2 (dual) = ~355.1 L.
 
What’s Pipe OH?

Edit: never mind, saw the link GM privided.
rabbit hole of awesome, but bring carrots šŸ‘šŸ¼šŸ‘šŸ¼šŸ˜ once your sucked into the fun your trapped (no bass trap puns intended).

-( random sketch)
 

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Between 0.707 - 1.0 with how much being very room dependent, where the speaker and you are and how 'intense' the audio is, i.e. the more noticeable the lower the fundamental since the lower the frequency the wider its bandwidth (BW), ergo the more it impacts the 'quality' of the higher frequency speaker's performance and one reason why folks are often very 'picky' about a speaker's performance in their acute hearing BW to point where they often prefer not to have a speaker go very low.
 

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Basically, one sub that goes very low. Others that goes 60hz.

Not necessarily. It can also be a bunch of small cones, in parallel, acting as a Big Woofer. You get "fast" (*) and accurate bass.

The more cones you put in, the larger the surface area... you can really get pretty deep that way. The flip side is that it does require quite a bit of power and likely dedicated amplifiers. Most likely class D - low pass filtered and high damping factor.

Check out Phil Jones' latest endeavor... this is the guy behind the Acoustic Energy AE1 (**). Note how his bass cabinets are all built around multiple small drivers:

https://www.pjbworld.com/cms/

(*) Yeah, I know.... but as a Maggie (Magnepan) owner, I appreciate bass that has no overhang and can track the rise and fall times without having to push a heavy cone around.

(**) I got two pairs of them... handsdown, still the best small monitor the World has known, and still current.
 
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I

Haha!

She thought about the wire on the floor. The couch, wall and cabinet are literally 12-16in from the table. I said I would poke hole under the cable for the cable to get out from under the carpet, she was fine with this, and even suggested we only let the cable on the carpet.

The amp, while quite noisy, will probably be inside the same cabinet as the av receiver, or behind the couche, or maybe downstairs with only the speaker cable to the subwoofer. We’ll see when we get there.

The big shallow box would have been a good idea if I didn’t install a huge tv wall mount rack on the wall. I once thought of doing this behind the couch, as we have a 8 foot long table, 6in deep, ~40in height. I could have gone with a 8in not more. Which give me between 13 and 17 cubic feet.

Didn’t really think of array, but we don’t see this type of arrangement often recommended. I don’t know a lot about this hobby, and don’t know a lot about stray either.

What’s the Maggie’s?

I’ll get a Bose sticker to put ont my table too! šŸ˜‚

(0) Magnepans... very few audio brands have a nickname... Maggies are one. ;-)

(1) Buttkicker, Aura Bass Shakers. Put those on your couch. Assuming you are on a concrete floor and not a second, or above, apartment with a wooden structure. Bass without all the hassle.

(2) Whatever you do, need to take into account leakage into other rooms, floors. Mounting on a wall is awesome for space, but it will shake that wall mightly.

(3) Can you open up the walls? How about building the cabinets into the walls, in NA that would be 16" between studs, so you ought to be able to build a nice box, about 13" x 60" x 3 1/2" and still have it insulated from the studs themselves. That will hide the whole thing, but it will still transmit a lot of vibration to the structure no matter how well you insulated - reasonably so.

(4) Imagine.. a whole wall filled with 60 5" drivers... do it on two walls... "Arrays" are not often "recommended" because they are expensive ( BOM is high ) and most people have no clue what clean bass is all about, so they go for boom boxes with an overripe, inaccurate, BOOM, BOOM, sound: exactly what the LFE in movies is all about. šŸ˜› . The Dead's Wall Of Sound was, IMHO, the best example of an array...

(5) You can trade volume for power and equalization.

(6) How about four 7' by 10" Mini Pipe Ohs? I've been thinking of building something like that this next spring.

(7) If you put a Bose sticker it will mean Deep Bass Nowhere.... I mean, I once had an OTR, two actually.... Odyssey Type R.... take an Odyssey, put Bridgestone sport tires, put in an OEM ITR sticker -minus the Integra part- and suddenly you got an OTR... So, I understand the power of "sticker engineering". šŸ™‚
 
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Between 0.707 - 1.0 with how much being very room dependent, where the speaker and you are and how 'intense' the audio is, i.e. the more noticeable the lower the fundamental since the lower the frequency the wider its bandwidth (BW), ergo the more it impacts the 'quality' of the higher frequency speaker's performance and one reason why folks are often very 'picky' about a speaker's performance in their acute hearing BW to point where they often prefer not to have a speaker go very low.
Oh I see. So a qtc of 1 will play much louder those lf. That’s why you were saying this.

But I think that the box will be way too big in order to have a qtc of 1 to play those low frequencies.

I’m a bit stuck in all the limitations I have: size, budget, waf, etc.
 
(0) Magnepans... very few audio brands have a nickname... Maggies are one. ;-)

(1) Buttkicker, Aura Bass Shakers. Put those on your couch. Assuming you are on a concrete floor and not a second, or above, apartment with a wooden structure. Bass without all the hassle.

(2) Whatever you do, need to take into account leakage into other rooms, floors. Mounting on a wall is awesome for space, but it will shake that wall mightly.

(3) Can you open up the walls? How about building the cabinets into the walls, in NA that would be 16" between studs, so you ought to be able to build a nice box, about 13" x 60" x 3 1/2" and still have it insulated from the studs themselves. That will hide the whole thing, but it will still transmit a lot of vibration to the structure no matter how well you insulated - reasonably so.

(4) Imagine.. a whole wall filled with 60 5" drivers... do it on two walls... "Arrays" are not often "recommended" because they are expensive ( BOM is high ) and most people have no clue what clean bass is all about, so they go for boom boxes with an overripe, inaccurate, BOOM, BOOM, sound: exactly what the LFE in movies is all about. šŸ˜› . The Dead's Wall Of Sound was, IMHO, the best example of an array...

(5) You can trade volume for power and equalization.

(6) How about four 7' by 10" Mini Pipe Ohs? I've been thinking of building something like that this next spring.

(7) If you put a Bose sticker it will mean Deep Bass Nowhere.... I mean, I once had an OTR, two actually.... Odyssey Type R.... take an Odyssey, put Bridgestone sport tires, put in an OEM ITR sticker -minus the Integra part- and suddenly you got an OTR... So, I understand the power of "sticker engineering". šŸ™‚
(1) wooden structure. But I’m in a house. No basement.

(3) opening up the wall. Too intrusive. Also, we think of moving in the next 2-3 year. Doesn’t worth opening the walls. And I just finished (last year) renovating the living room/kitchen. Do not want to open them up again.

(4) doesn’t it what PA drivers are for? Lighter cone to move around?

(5) I have plenty of power and equalization for this project, I think.

(6) don’t know what 7’ 10ā€ ohs is.

(7) was a joke. Not much of my friends would get the joke anyway.


But I think I’ll built that dual opposed driver in ~150liters with either mx15 or um15 and will see what I want to improve for the next one.