Are there any adverse effects to tuning a port to the Fs of a driver? (1 Viewer)

[Mike Dr]

I'm playing with various designs for a future tempest sonosub and am just wondering what i should tune my port to. In LSPCad the differences seem very minor.. I'm using 214 liters for the volume, a 4" port and 0% stuffing.. changing tuning frequency doesnt change the curve too much. any ideas?

 

[Mike Dr]

anyone?

 

[Greg Monfort]

FWIW, I tune most subs so that Fb ~ = the lowest frequency expected, so for HT and organ music, 16-18Hz, jazz/symphony ~27Hz, R&R/etc., ~30Hz, and adjust cab volume to give me closest slope of the rolloff I want.

If it were an HT sub for me, I'd be looking at 300L min/~17Hz Fb.

GM

 

[Kerry Hackney]

Mike,

One of the reasons some people tune their subs below Fs is for better control of the driver. For example if you tune your sub to 22 Hz and you have program material that is at 18 Hz the port will completely unload the driver and you could have a bottoming problem. Cone motion is at a minimum at the tuning frequency and then quickly increases as you go below it.