TL subwoofer sd clarification?

[iFearFractals]

Quick question: I have been looking for an answer to for a day + (including the forum search here), but have had no luck...

If I am using two sub woofers in the t-line, do I double the Sd for calculations?

Thank you in advance.

 

[bjorno]

Hi...FYI:

b🙂

 

[iFearFractals]

Oy vey, Good grief, how did I miss that?!

Thank you bjorno

 

[iFearFractals]

Another question, if you don't mind...

Do the speakers magnets not affect the cross sectional area within the line?

example:

(using the curved corners was just the easiest way to keep the symmetry, which was giving me fits. I know they are not typically necessary).

An externally hosted image should be here but it was not working when we last tested it.

 

[GM]

Yes, they do. In this patent drawing you can see an additional plank was added between the driver, terminus to apparently rather ingeniously accomplish it: dts-20.gif gif by soho54 | Photobucket

GM

 

[iFearFractals]

Oh, very nice! Never thought of that configuration. I assume this may be one of the appeals of a daline enclosure?

Yesterday I received an email reply from Martin J. King about my cross section question, and this was his reply:

"The basket, cone and magnet will change the cross-sectional area of a TL locally. I have taken this into account a few times. But my experience has been that the changes in the SPL response have not really been that significant. At low frequencies where the wavelength of sound is so long, small local interruptions in the cross-sectional area are just not very significant."

​

 

[GM]

Not sure what you mean, i.e. the drawing is of a tapped horn [TH], which is a TL folded back on itself whereas a Daline is a BR with a TL sized vent IIRC.

GM