how many ways to hook up a subwoofer

lonemountain:  You are talking about professional applications and not what's being discussed.  See 2:20 on link: The best way to connect a subwoofer (youtube.com)

 BTW: I have several systems, both HIFI and professional and I know what you mean.  They are all connected differently and speaking for myself, the difference is an audible improvement if connected as described in the video!  Try it!  This video will clarify my post.   Thanks for your input.

Paul McGowan on "High Level" sub connection

Well, my subs (JL Audio) do not have a speaker (high level) connections, only RCA or XLR inputs, and I am going direct from my Lumin X1 to my mono blocks (no preamp). I did not want to use a Y adapter.

So, I purchased a Jenson ISO-Max unit that converts speaker outs (high impedance) to XLR (low impedance). Seems to work very well.

ozzy

@ellajeanelle    +1.

A requirement is having a subwoofer that has a 'high level input'. Connects from the output of the amp. This way it will respond to the character of the amp. If the amp is punchy you'll get that punch. If you run it from the preamp you will bypass the amp and NOT get that punch.

This was a VERY noticeable improvement in bass quality! (thanks Paul McGowen)

You can run a wire from the back of the Amp to the 'High level input' OR (my preferred method) go from the speaker with a short wire to the High level input.

Don't worry, the high level input just needs a tiny bit of signal and puts NO strain on the amp. The sub amp does all the heavy lifting.