winisd, cone excursion, subsonic filters

OK, so far whenever I model a driver/vented box combo, there is always a point where, once I add a reasonable amount of power to the driver (say upwards of 150w), there becomes a point along the Cone Excursion graph where the graph soars high above the red line which is Xmax. Now, I've managed to get this to happen at as lows as 25hz by fiddling with the design, but still, anything at 25hz or lower that goes through the amp to the drivers will apparently cause the driver to explode outwards well past Xmax in short order. My question to you is - first: how common is sound below 27Hz or so in any recorded music? I typically listen to electronic music genres that go by the names of Jungle, Drum 'n' bass, Trance, House, Hardcore, and various sub-genres thereof, if that helps. Second question: if subsonic filters are needed for pretty much any ported box design, why the hell can't I find any decent ones for sale online? Best I could find was a 50Hz second-order passive high-pass filter at Crutchfield.com, which when I apply it to my WinISD project, really screws with my overall bass performance! 3rd: how many of you are running ported/vented designs with no subsonic filter? How are your drivers holding up? Thanks in advance

Get a amp with a subsonic filter built in.

Umm, not to be an ass, but I am curious: Which question are you answering? 1, 2, or 3?

That part of the excursion graph where the excursion goes up exponentially is where the enclosure is unloading and no longer has control of the cone's motion. #1 - how comming is music at around 27 hz?? Rarely do you have music with bass this low. #2 - External Subsonic filters aren't really common because most decen't mono amps have them built in. #3 - I really just depends on your setup if you need a SSF or not. I used to push 600 watts to my JL 15W4 in a 4.3 cu ft ported box tuned to 40Hz with 112.5 sq inches of port and NO SSF...it held up fine only because the enclosure was designed to have excellent control of the cones excursion though...playing full blast the sub looked like it was barely even moving but it was pumping out some major bass I built a 2.5 cu ft ported enclosure tuned to 35Hz for my brother's 12 inch MTX sub...its getting 300 watts and no subsonic filter and its doing fine.

Use WinISD to help you make proper sub and amp selections according to your listening tastes.   Your favorite music genres will push the limits of the low end.  Electronic synthesization can be murderous on speakers if they aren't protected from the extremes.  If the sub you currently are working with is a bit short of Xmax, look for one with more excursion.  If your amp doesn't provide a SSF, look for one that does.  Don't consider using passive electronics to provide subfiltering.Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.

Decent external subsonic filters: Harrison Labs.  The PFMOD HP-Sub works well.Support the12volt.com

DYohn wrote: Decent external subsonic filters: Harrison Labs.  The PFMOD HP-Sub works well.

Didn't they make the Drag Queen?

dwarren wrote: DYohn wrote: Decent external subsonic filters: Harrison Labs.  The PFMOD HP-Sub works well. Didn't they make the Drag Queen?

Yes, and I think they still do.  They make some real interesting amplifiers (designed for competition use mainly.)

Support the12volt.com

Hey guys, thanks for all your help on this! Very informative. I am looking at the Harris Labs stuff now, looks great!