diy lab 12

[Relic1Golf]

I know this thread has been done to death so Ill keep it short. I want to build a ported subwoofer for a living room size 10'x16' with a 14' ceiling using a lab 12 driver, content being 60% movies and 40% music. Im down to 2 designs one being 3.25ft3 tuned to 24hz for high spl and lower group delay. the LF roll off would be right at or close the the Fs of the driver. the 2nd would be 2.4ft3 tuned to 22hz for extended LF?

 

[GM]

Well, movies tend to have a lot more deep bass while music, not so much, so a larger cab tuned low for movies seems the choice, but the potential problem with any of these is that the vent will be excessively long to get a large enough diameter vent to handle its high power handling capability.

GM

 

[Relic1Golf]

I seen that too, I figure a 3.35ft3 (95L) ported cabinet tuned to 24hz will have an f3 of 23.7hz and still be within xmax at 300w. the port length will be a little longer than 14in with a 90deg bend.

 

[Relic1Golf]

I fat fingered the keyboard, the 2nd design should be 3.4ft3 with a 22hz tuning frequency. after negotiating with my girlfriend Im lucky to have a 2nd room for music and my sealed subwoofer would go there. the main area would be closer to 80% for movies, would there be a problem if the f3 is higher than the tuning frequency?

 

[GM]

As a general rule, the F3 is always higher than the tuning frequency in a 'sub' app since a max flat alignment tends to sound 'boomy' in room, so not sure what you're asking.

Regardless, the room normally will add some low end boost, so tuning a bit below Fs is common to get a more shallow rolloff before it steeply rolls off, with an extended bass shelf alignment [EBS] being a popular one, but requires a larger cab [7+ ft^3 net] than you can currently 'afford'.

Since this driver has a low Fs & Qts, there's no need to tune it below Fs in a small vented alignment.

GM