Speaker Basket/Magnet Weight and Dampening

[lsiberian]

Thank you! I am glad you mention rubber being a very effective mass loader. One of these days I am going to just coat the inside of a box with a 1/4" of plasti-dip - you know, the stuff they use to put rubber grips on tools - and see what happens. In the meantime, I think I will do something similar to what you mention, and go with Dynamat or something similar. Thanks again!

Here's some picks from my build hopefully they'll help you get some ideas. It took me several attempt to find an approach that really worked well. I used 13-ply birch, PL-Construction Adhesive, Texas Red Oak, Peel-N-Seal Roofing Material, Speaker Grill Cloth, and 4lb mineral wool.

 

[highfigh]

Okay, this helps! Sort of how a rod op dowel, when upright, can support a very heavy object, but if the same rod or dowel were horizontal (supported at both ends only) and the heavy object were tied to its middle, it would bend or break? Air inside a sealed box presses outward and sucks inward nearly equally in all directions, and it would seem the mechanical energy in the material from the driver would seek the same paths of dissipation; that is, perpendicular to the long plane of the material. So, rods or dowels for bracing would be a low material volume, high rigidity bracing solution that would work quite well. Am I on the right track there?

Yes- the panels will vibrate, more or less, at different frequencies. The dowel is like pressing a finger in the same spot- the direction of the pressure doesn't matter- you could do the same thing with a cable pulling on opposite sides. All you need to to is make the dowels reach from one side to another and glue them in place- it would require a lot more force to make two panels move than just one. If you install them so they cross in a way that you could connect them (wire and glue for dowels, glue for square or rectangular members), the braces will vibrate less and at a higher frequency, as a unit.

BTW/FYI (in case you need to build something lightweight that will support a lot of weight- when a rod or cylinder is loaded by extreme force and the length is many times the diameter, it can bend due to the opposite sides not being absolutely parallel or because of some inconsistency in the material. At some point, it will fail and the failure point around an axis is called the 'radius of gyration'. You know how pressing at the ends of a straw makes it bend? Same thing- it will bend in all directions evenly until the distance from the axis causes it to kink. A cylinder is an inherently stable shape as long as the diameter is large enough to fight against gyration.

 

[l_pad]

Here's some picks from my build hopefully they'll help you get some ideas. It took me several attempt to find an approach that really worked well. I used 13-ply birch, PL-Construction Adhesive, Texas Red Oak, Peel-N-Seal Roofing Material, Speaker Grill Cloth, and 4lb mineral wool.

Wow, that looks pretty rigid and "dead"... and probably lots of fun, too. I appreciate your helpfulness and taking time to explain things. I've got plenty of ideas now with which to craft an initial approach. Thanks again!

 

[Bizarro_Stormy]

Wow, that looks pretty rigid and "dead"...

Ummm...

That's what she said..?

 

[KEW]

Ummm...

That's what she said..?

Necrophilia and rigamortis?

 

[Bizarro_Stormy]

Necrophilia and rigamortis?

That's what she didn't say...

 

[lsiberian]

Wow, that looks pretty rigid and "dead"... and probably lots of fun, too. I appreciate your helpfulness and taking time to explain things. I've got plenty of ideas now with which to craft an initial approach. Thanks again!

At times they were fun, but I'd be lying if I said I never cussed during the build. They are built using the ideas and theories of the now deceased Chris and still living Andrew. They incorporate bi-polar, denfse bracing matrix, plenty of rock wool, and CLD theories. After discussions with an engineer in the CLD field I believe it's probably the mass that actually damps rather than the rubber.

For crossovers I currently use mini dsps though I plan to build passive boxes for the tweeter/midrange soon. Because I want to switch to Crown XLS amps. Instead of the chip amps.