BAR NONE! THIS IS THE VERY BEST WOOFERS WE HAVE EVER USED IN 30 YEARS OF SPEAKER BUILDING BELEAVE ME WE USE(ALL THE BIG NAME) THE BEST IN OUR SPEAKER BOXES!,THESE SPEAKERS GO LOWER, SOUNDS HEAVEY BIG BOOM AND VERY MUSICAL,WITH A 31 BAND EQ ITS THE ONLY ONES OUT THERE THAT WILL RESPOND WHEN MOVEING THE 25HZ AND 31HZ POINT OF A 31 BAND EQ. SEEING AND HEREING SOLD ME,THE OTHER BIG NAME SPEAKERS ARE OLD AND MADE BEFORE CD'S AND ANY OTHER MEADUM WOULD ALLOW YOU TO GO DOWN TO 20HZ ,SO THEY JUST WANT RESPOND IN THOSE RANGES ,TALK TALK JUST TRY EM AND SEE FOR YOUR SELF, BOYD OWNER B and B SOUND,