OK. yes I could be diving into one-big-waste-of time but I thought I'd ask first rather than just play ignorant...!
I read the review on Sound and Vision:
http://www.soundandvision.com/content/test-report-yamaha-ysp-2200-digital-sound-projector
And Brent Butterworth came away impressed, and even more so when he decided he mention this:
"Since I just had to know, I ran a quick frequency-response sweep on the YSP-2200’s sub output and found that it crossed over at 400 Hz and was high-passed below about 50 Hz, no doubt to protect the little woofers. It also produced about 10 watts maximum to the sub. For a lark, I tried piggybacking a 12-inch active sub, set for very low low-pass, to span the missing octave-plus with great effect. I’d recommend this adaptation to anyone planning a “serious” YSP-2200-based system.)"
Now, he doesnt' illustrate how he does this but from digging around, I think I would run the sub-output from the bar, to a line-level input to a sub and line out to the sub included with the Soundbar.
I am just wondering if covering anything from ~20hz-~50hz would be worthwhile? I am curious because I don't even know if the amp in the soundbar can do anything below the 50hz cut off and from what google has told me, there isn't any info about anyone that had tried.
Interestingly enough, the SoundandVision test report also illustrates this:
But from my running a few frequency sweeps, I don't hear any drop from ~50hz-13khz
My test was:
There is solid audible tone from what I could hear in my setup and I would think this totally invalidates the graph.
Have patience with me, fellas,I'm learning!