Ok, I've got a DIY Adire Tempest sub using the "Adire" alignment. I've been using it for a little while, but I never actually tuned my home theater properly. Here are my questions... First of all, in the manual for the "Rava" sub that Adire sells (and uses very similar parts to mine) it says: "From your processor’s sub output, run an RCA cable to the RCA line inputs of Rava. Additionally, if you need additional gain on the LFE channel, a simple “Y” jack to run the LFE input to both the left and right channels will give you a “free” 6 dB of gain." (page 5) http://www.adireaudio.com/Files/RavaManual.PDF Is this something I want to do? I love bass. Would it be worth it to get this extra 6 db of gain? (I've got the same amp that this sub contains). Second, I'd like to figure out if my sub is actually performing as it should be. Adire has free files for "LspCAD" that...um...model the way the sub sounds. http://www.adireaudio.com/miscellaneous/software.htm So how do I go about taking these readings? I've got a digital SPL meter. I'm thinking that I should sit in my standard position and play a series of test files with the sub at different HZ and then record the data (I've already made a test CD). I'll combine the data to make a rough graph, and compare that to what I've gotten from the web. But then how loud do I play these test files in the first place? What do I set the gain and crossover to? Viewing the Tempest files in that LspCAD program, there's a graph of "Half Space (2pi) SPL at 1m distance". What does that mean? Half Space? There's another graph of "SPL in room and cabinet". Can I assume that's what I'll hear in my listening position? (the in-room part). Newbie question: What is Impedence? I see it spike on this Tempest graph... Thanks. Jonny K.