The original Storm 5 spec was -3db at 15Hz. It certainly seems that way from the response. My point is that it had good extension below 30Hz. Couldn't get great volume of course, started to compress at about 95DB, unlike the dual 400's. No phase issues, both subs (next to the L and R speakers), pretty much mirror the response of the L and R in their respective positions. That's just their output in my room. I have no DSP. I'm surprised audysee doesn't flatten out that curve a bit more actually. It does with the REL.