Well the subs specs recommend the sub be tuned to 40hz, but i helped my friend build 2 enclosures for these subs. The first enclosure was around 4.2 cubes tuned to like 31 hz, we both loved the response from this box but decided to go a little bit bigger and higher with the tuning. The second box was around 4.5 cubes tuned @ 35 hz defently louder but also slight peeky..The low end IMO just could of been better, but overall we liked the subs, the pair of 12's were getting around 1200 watts rms a piece becasue we had 2 1200d's strapped to them and they sounded great