Post the links. I have a customer using this head unit with subwoofers and I heard no such problem. The EQ may only go down to 40 Hz but that is not a limitation of the frequency response on the pre-outs. I have 1 5500 refurb in stock.Something like the x5500 would be perfect, doesn't have to be a new unit, could be used or refurbished. Like the 7" screen. But I just did a quick info hunt on the x 5500 and stats on pioneer that there's a software glitch to where it does not play bass below 40hz in subwoofer eq settings.