What are you using for subsonic filtering?

[Ricci]

I'm wondering what everyone uses to filter out the lowest freq's from their subs? Specifically I'm looking for something that is variable and can be set lower than 16hz and preferably around 10-12hz. I'm thinking that a Linkwitz-Riley 24db slope would be best.

[brent_s]

What are the specifics of the sub?

Pesonally, I just use common sense with the sub/main calibration and application of the volume knob. I've never run a rumble filter on any of my DIY subs. My sub amp is rated down to 3hz at full power so electronics rolloff doesn't seem to be a factor. To the best of my knowledge, I've never bottomed a driver. FWIW, I rarely listen to movies at Reference level, finding -10 below reference to be much more comfortable, but even when I run through demos of the big bass scenes in M&C, WotW, Incredibles, U-571, etc at reference level, I get no bad noises...at least from the sub; the room/house structure is a different story.

-Brent

[Mike P.]

If you decide you do want a varible subsonic filter, there is the Reckhorn B1 from Creative Sound, about $90 shipped.
http://www.creativesound.ca/details.php?model=B-1

Info on the unit is here.
http://www.reckhorn.com/index.php?ln=en&prod=b1

[Ricci]

The Reckhorn looks OK. I'm just trying to weigh my options. I've got a couple of projects coming up and I'm not going to be tuning super low like some people do, so I think it would be in my interest to provide some kind of overexcursion protection. The Elemental designs unit looks pretty good but it still hasn't been released.