Keystone Sub Using 18, 15, & 12 Inch Speakers

What about a stepped version of the Keystone to eliminate angles?
It's response would be different, my guess it would have more pronounced odd order resonances that would ring for a longer time period.
Cylinder Vs Cone.png

At minimum, a reshape/resize of the exit would be required to make the response similar.

Art
 
what about adding that "acoustic denim" thing inside the walls
to mitigate the resonances like on TL's and BP's designs
i know that will cost maybe 2db or 3 but that is collateral damage
pursuing a simpler build process

people will need to double their cabinet count if any to reach the same
SPL as the original design..

Want an easier build....pay the price with less SPL
So.... make more cabinets!
but i guess many folks will pay the price if the build is going to be 90 degree panels inside
 
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I used straight cuts for my panels when I built mine. Around the smallest panel of the horn (top panel of the horn) there is a lot of pressure building up, I dont remember if I used regular wood glue or polyurethane glue but it broke. I didn't use screws, only small nails from my nail gun. Screws+glue would probably be fine. Should be ok as a first project, just prepare accordingly and think about the steps beforehand, and/or proceed slowly. Good luck!

This is good to know, as most builds I've done have been nothing but PL adhesive and brads. I'll be sure to use countersunk screws wherever possible!
 
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Does the vibrating air really get messed up so terribly dufferent if you change the csa at the ends of sections instead of taper it throughout? I’m sure someone can find decent results either way
If I follow, Danley once made a point of backing me up when I stated that a bend must always be expanding or it will act as a low pass filter, though sometimes referred to (in error?) as bass trap.
 
This is good to know, as most builds I've done have been nothing but PL adhesive and brads. I'll be sure to use countersunk screws wherever possible!
I'm way too impatient to use screws everywhere, but with the keystone for sure I would use screws for the small top panel of the horn where it meets the baffle and second horn panel. Maybe a brace somewhere if I got the impression it was a bad fit (due to my impatience when cutting it) and would risk vibrate loose I would screw it down too. Otherwise I would only use brad nails and glue for 99% of the build. Finishing countersunk screws with putty is a nightmare IMO also.
 
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So in a TH bends must expand ...can't be 90 degree turns like in TL's...otherwise what you gain you loose getting less bass out ....
Holly frijoles batman!!
What about the turns in all my tapered pipes? There’s a bump in the crossectional area in each corner full of air that’s just ‘stuck’ there essentially. But theres a ‘smooth decrease’ in the pipe shape through the turn if you ignore those and just measure off that tilted panel
 

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I'm way too impatient to use screws everywhere, but with the keystone for sure I would use screws for the small top panel of the horn where it meets the baffle and second horn panel. Maybe a brace somewhere if I got the impression it was a bad fit (due to my impatience when cutting it) and would risk vibrate loose I would screw it down too. Otherwise I would only use brad nails and glue for 99% of the build. Finishing countersunk screws with putty is a nightmare IMO also.
Screws weakens construction; better to use glue blocks, Titebond 3 or similar, though if still wanting screws, then stagger them.
 
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