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[Art Welter]

Art, I appreciate all the good info.  Do you have an approximate weight for your cabinet design, presumably loaded with a 18SW115?  This is something I would consider.
Thanks,
Greg

The Keystone sub made with Aruco plywood (about 15% lighter than Baltic Birch) loaded with a BC18SW115 weighed 150 pounds.

The BC18TBW110 costs (a lot) less, is slightly more efficient, but has slightly less output potential and weighs 8.3 pounds more.

[Greg_Bell]

The Keystone sub made with Aruco plywood (about 15% lighter than Baltic Birch) loaded with a BC18SW115 weighed 150 pounds.

The BC18TBW110 costs (a lot) less, is slightly more efficient, but has slightly less output potential and weighs 8.3 pounds more.

Art, thanks so much for the info.  I'm gaining a little confidence with my kludge of a solution, and it is an improvement over my prior system.

Maybe I ought to start a new thread for this question, but I picked up a bag of Roxul batting for another project, and I remembered a line I read where putting more damping in a cabinet made the cabinet appear bigger to the speaker.  Since the Kilomax wants a bigger cabinet, could I increase my safety margin of operation by putting in additional damping?
Thanks,
Greg

PS - I'm humping gear 3x a week, and I don't mind lifting 70 lbs, but I just calculated my rolling rack at 160 lbs.  I can do a curb single-handed, but steps are a two man job.  All the self-powered solutions seem to be 150 lbs, and Orbit Shifters are 185.  Performance certainly comes with a price.

[Tim Weaver]

The batting inside a cabinet will only let you fudge the numbers a couple of percent. Not enough to get a "bigger box" so to speak.

In the old days you would calculate the size of an empty box. Then you would brace it internally, then add batting to "make up" the space you lost with the bracing.


Yes, performance costs! In weight and in money.

It sounds to me like you need a ramp!

[Tim McCulloch]

PS - I'm humping gear 3x a week, and I don't mind lifting 70 lbs, but I just calculated my rolling rack at 160 lbs.  I can do a curb single-handed, but steps are a two man job.  All the self-powered solutions seem to be 150 lbs, and Orbit Shifters are 185.  Performance certainly comes with a price.

Levers (ramps) and wheels.

The household movers have "curb ramps" or "walk boards".  There are some folding ramps for wheel chair use, too.

I've moved a lot of heavy stuff by my own grunt labors when I was younger and I regret every bit of it.  I'm now one of the Old Guys that told me to not work that way 30 years ago, so I'm telling you to not do what I did.  Seriously.

[Greg_Bell]

The batting inside a cabinet will only let you fudge the numbers a couple of percent. Not enough to get a "bigger box" so to speak.

In the old days you would calculate the size of an empty box. Then you would brace it internally, then add batting to "make up" the space you lost with the bracing.


Yes, performance costs! In weight and in money.

It sounds to me like you need a ramp!

The 3" thick Roxul is 2 pcf density, so that's pretty hefty stuff.  I bought a bag of it to (loosely) create a blockoff plate where a woodstove's SS liner enters the chimney flue.  I'm going to have a lot left over.  Maybe I'll ramp up GOBO production instead.

[Greg_Bell]

Levers (ramps) and wheels.

The household movers have "curb ramps" or "walk boards".  There are some folding ramps for wheel chair use, too.

I've moved a lot of heavy stuff by my own grunt labors when I was younger and I regret every bit of it.  I'm now one of the Old Guys that told me to not work that way 30 years ago, so I'm telling you to not do what I did.  Seriously.

I hear ya!  Message received!!

It turns out a Teeter Hang-Up is in my rehearsal space.  If I can force myself to use it 3X a week, I stay in pretty decent shape.  If I don't do spinal/core maintenance, I can't stand up straight.  These days I exercise only in self-defense.  I try really hard to find good techniques for lifting.

I process a lot of firewood.  This year it was nine cords with almost no help.  My mantra is that if it's hard to do, I'm doing it wrong.  But there still seems to be a correlation between sounding like a box of Rice Crispies getting out of bed and the number of birthdays I've had... 

[Tim McCulloch]

I hear ya!  Message received!!

It turns out a Teeter Hang-Up is in my rehearsal space.  If I can force myself to use it 3X a week, I stay in pretty decent shape.  If I don't do spinal/core maintenance, I can't stand up straight.  These days I exercise only in self-defense.  I try really hard to find good techniques for lifting.

I process a lot of firewood.  This year it was nine cords with almost no help.  My mantra is that if it's hard to do, I'm doing it wrong. But there still seems to be a correlation between sounding like a box of Rice Crispies getting out of bed and the number of birthdays I've had... 

Yep.  I remember when Snap, Crackle & Pop were heard at the breakfast table, not at bedside...

[Art Welter]

Art, thanks so much for the info.  I'm gaining a little confidence with my kludge of a solution, and it is an improvement over my prior system.

 Since the Kilomax wants a bigger cabinet, could I increase my safety margin of operation by putting in additional damping?

Greg,

Light fill in a sealed cabinet increases apparent volume.
Light fill in a ported cabinet reduces output level, so will reduce the "safety margin". The fill material also is a good insulator, trapping the heat that makes voice coil impedance rise, causing "thermal compression". The harder the cabinet is pushed, the less output it produces.

The reversed drivers in TH magnet vents are close to outside air, reducing voice coil temperature and thermal compression.

Art

[Greg_Bell]

Greg,

Light fill in a sealed cabinet increases apparent volume.
Light fill in a ported cabinet reduces output level, so will reduce the "safety margin". The fill material also is a good insulator, trapping the heat that makes voice coil impedance rise, causing "thermal compression". The harder the cabinet is pushed, the less output it produces.

The reversed drivers in TH magnet vents are close to outside air, reducing voice coil temperature and thermal compression.

Art

Art,
This is a really important distinction and caution.  Thank you ever so much.  There are a few areas where I know what's going on, but no one is ever going to see evidence of that in a subwoofer forum - at least not for a long time!!   

[Brian Dill]

You know, one of my great concerns is weight.  We play venues with steps occasionally.  But if these things have wheels built in, then the 137 lbs kind of goes away.  Do you have any trouble with curbs or steps?

No issues whatsoever. The 137 lbs. seems effortless with the wheels.

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