I know the Polks are rated at 4ohms, and my Pio Elite outputs at 8ohms, but do you think there is ample power for these speakers from the Pio? or am I missing out by not having an external amp? LSi15's fronts, LSiC center, FXI-A4 surrounds. Anybody have this combo? just curious as to what settings you use also. Has anybody done any easy "tweaks" to the Polk speakers? I heard of people stuffing there port hole to get "better" bass response, and to replace the metal jumper with regular audio cable, does this really have a noticeable effect to the sound? Anyway, your thoughts are appreciated.