Can someone maybe put this in easy to understand terms? :)
I emailed Ken asking for a frequency response graph of the Lsi15 and received one from him. After noticing that it drastically rolled off after about 60Hz, I asked him for an for any information without spending too much time explaining it to me as I'm sure he has tons to do. He pointed me to the Speaker Specialist #11. After reading that, it seems as though there are tons of variables when plotting those graphs (lab conditions, positioning, etc.).
I guess what I still don't understand is how Polk's manual states it goes to 30Hz at the -3dB limit yet the graph from Polk shows it rolling off drastically before that.
In case this helps, here's the specifications for the graph...
LSi15 tower speaker “Full-band” magnitude response; derived from ground plane measurement over the range f <= 400Hz and free-air on-axis magnitude response @1m 2.83Vrms drive level over the range f >= 400Hz. Smoothed to 0.17th octave.
There's probably an easy explanation, I'm just lacking the knowledge and figured you all might have an excellent explanation. Plus I don't have to keep nagging Ken ;)
Thanks in advance for your responses.