Hi, I'd like to start by saying that this would be my first foray into building anything for home audio. Actually, more like my intro to higher-end home audio in general, since I'm still working on getting a half-decent receiver (half-decent being anything other than my Panacrapic HTIB/DVD player that has HDMI out, but stereo input!! ARGH!). I do have some knowledge, since I'm the kind of guy that researches stuff on the net for days, weeks when I get interested in a topic; cars, trucks, knives, home audio, etc. So I have learned a lot about placement, subs, box design, receivers, and even a little bit about the T/S parameters. I'm still confused as all hell by WinISD though.That being said, I started looking into building a T-Line SonoSub as a project. I looked around online, found all sorts of plans like the Dual Shiva Sonotube sub, the El-Pipe-o, etc. It's all very cool, but there's a few questions I have about the whole thing.
1. 12" drivers with 12"Sonotubes. Assuming that I'm NOT building a box at the bottom ala
Super Shiva Sub are there any problems with stuffing a 12" driver on the bottom of say, an 18" tube? To hit a desired low Fs (did I get that right? peak, aka resonant frequency of the whole assembly?), a tube would have to be 8, 9, 10 feet long. Could I use a shorter, fatter tube instead of a longer, narrower tube?
2. Tuning frequency. What should I be looking at for a HT application? I'm really not sure how this works. If I'm using say, the Dayton drivers that have an Fs of 22hz, should I tune for 20hz? 18hz? What would I end up with? I heard of tuning below the driver's Fs to take advantage of the enclosure's bass boost below the driver's ability. How fast does the dB drop off after the Fs? If I tune for 30hz with a 22hz driver, would I get good bass/LFE down to 22hz or say, 26hz? Very confused
3. High Pass Filters. I read about having the driver becoming "unloaded" at very low Hz, lower than Fs, and damaging it? And therefore using a HPF to cut off anything below that point. Is this a common practice? Is this something I should be worrying about?
Thank you for all the reading, hopefully you can help a newbie out!
