3.89ft3 (slightly bigger than standard 4th for 8" full range driver)
tune to 31hz
I get 3" port 2.56" long
I get 2" port .61" long
is this right ?
tune to 31hz
I get 3" port 2.56" long
I get 2" port .61" long
is this right ?
Yes, as GM notes, the calculations come out closer to 32 Hz, but what's 1 Hz?
😀
However, many (most?) calculators use end correction factors for one end flush mounted and the other end free. Not sure how Horn Response works. With that in mind, a 2" hole in a .75" or .625" wall may still be close to 32 or 31 Hz, but difficult to adjust the "length".
The Loudspeaker Design Cookbook also references a (conservative) calculation for "minimum" vent diameter, based on driver Sd and Xmax. For an 8" driver, a 3" port might be a better choice.
😀
However, many (most?) calculators use end correction factors for one end flush mounted and the other end free. Not sure how Horn Response works. With that in mind, a 2" hole in a .75" or .625" wall may still be close to 32 or 31 Hz, but difficult to adjust the "length".
The Loudspeaker Design Cookbook also references a (conservative) calculation for "minimum" vent diameter, based on driver Sd and Xmax. For an 8" driver, a 3" port might be a better choice.
Yeah, don't know anyone can discern 1 Hz anywhere in the spectrum.
HR does same: 0.732 IIRC.
Don't have the LDC, but this is the one I got from Altec:
dv min. [cm] = [[20*Vd^0.5]/Fb^0.25]/10
Vd [cm] = [Sd*Xmax/10]