Transmission Line SonoSub - Design Questions?

[veovius]

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!

 

[TLS Guy]

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!

No you can not make the enclosure shorter. Lp determines Fp. The volume of the pipe is related to the VAS of the driver.

You can buy George Auspurger's software from Audioxpress. WinISD is not the correct software for your project.