I can not seem to find the lower -3db limit on the Sonus Faber Solo. The most I am able to find is frequency response 40 -20.000 Hz. Is this anywhere close? I do see the -3db on the Polk site for the Lsis and the Rtis. And , at the risk of sounding like a dweeb, what exactly is a 'lower -3db limit' anyway? (Caution:Learning In Progress).