Gregwor & Audiomutt's TL MSM Calculator and o/c stud spacing

[Elusive Sounds]

Hi all,

I could not find the answer on the forum so I hope it warrants a new thread.

In an MSM assembly, it is my understanding that having studs spaced at 24" o/c versus 16" o/c will lower certain resonant frequencies and therefore increase the overall TL. In the TL MSM Calculator v2.04, is the o/c stud spacing assumed or accounted for in any way? If so, should this be a user definable variable?

For example, when retrofitting an existing structure with an outside wall framed with 2x4 wood studs, one can choose different stud depths and o/c spacing for a new inner wall. The calculator shows the effect of the stud depth and air gap depth of a new inner wall, but does it also account for the fact that a 2x6 wall would typically be framed at 24 o/c while a 2x4 would be at 16" o/c? What if one were to choose to frame 2x4 at 24" o/c?

Thanks to Gregwor and Audiomutt for the calculator.

[Gregwor]

That is not a variable included in the formulas. The calculations are close to but not 100% accurate as I'm sure you understand. It is to be used to estimate how your room will perform after being constructed with immaculate detail. Also, note, not every single stud in your build will be 24 or 16" o/c.

I'm glad you're finding the calculator useful!

Greg

[Elusive Sounds]

I have a few more question about version 2.05 of the MSM TL Calculator. Figured I'd post here rather then starting another thread.

1. : When we say "We want our resonant frequency <= 1/2 lowest dominant frequency", are we talking about dominant frequencies of sounds generated in the space? For example the fundamental frequencies of kick drums, low B bass strings, etc, etc?

2. In the equations section, there is no precise definition (in words) of F1 except that it is = 55 / depth of cavity. Does F1 represent the frequency at which a coincidence dip happens? Or is it the frequency above which flanking limits the theoretical TL values at around 70db?

3. Is the 2.05 versions basically the latest evolution of the calculator found here?

http://www.mediafire.com/file/shl5c966q ... limWngFiWw

4. This may have been asked before, but would modifying the math so that the option of adding green glue between the material layers be doable in a 2.06 version?

Thanks again!