Peak power is when a certain tone is reaching "1400" watts. human ears are only able to detect RMS.
So, that 300 watt sub needs to be paired with the correct amp that wont over do it. I'm not going to search for you, but go to your local audio store and tell them what sub you have and what amp would be good for it.
probably a mono channel amp, so go ask best-buy or whoever you go to, they'll tell you.