Originally Posted by Absinthe

The amps all have 1.5" is free space around their circumference and 1.5" between the upper and lower amps. This allows for adequate convective cooling without supplying fans. To date, the highest temperature I've recorded has been 118F after running for over an hour. Then again, with all the sound deadener I have on the bottom, sides and top of the trunk space, the ambient temp in the trunk rarely goes above 100F

The RF amps I'm using are two channel. The smaller size (11.4" X 8.1" X 2.1") gave me more options for a staggered mount. This is the primary reason why I don't like four channel amps.