The fs for my subs is 41hz. The MFG says tune enclosure to 39hz. If you're not suppose to go below the fs for your sub. I'm confused!!! I have a HCCA-D2400 The high pass filter starts at 20hz and goes to 150hz (i think) but that's it! there's 20hz and there's 150hz "NOTHIN IN BETWEEN" What's the best way to set the LPF and get it a.c.a.p. ?? I'm not pickin' on ya' and there is no trick questions. You seem to be a most knowledgable fellow in this realm. so you're it!! PtP
39Hz is pretty close to the Fs.. the only real drawback to going lower than the Fs, is you lose the benefits of teh port.. you don't get the efficiency gain near the tuned frequency you would from going higher with the tuning. For example, if you tuned the port to say, 45 or 50Hz, it'd sound boomy and very craptacular, but it'd be a lot louder at the same power input.
you'll want the "HPF" (subsonic filter) set to 20Hz if that's the only real option you have. Set the LPF at 80Hz to start with, since the box is tuned a bit high. You can lower that to as much as 60Hz and see how it sounds. stop where it blends well with the mids, and hits how ya want. I cross subs low to avoid vocals bleeding to the subs with singers like Barry White and such, where they reach pretty low, and tend to get boomy if caught by the subs.
There is other options for the "HPF" but the dial isn't marked so I'll just "guess-ta-mate" See there, You ask the right people, the right questions, and you get answers even a muscian can understand! Thanks GlassWolf PtP