Hold the line on the HDP4. It's going in a Road Glide. Have we confirmed that it will fit up there? My gut says that it will not.
Nope. Not without some serious metal work.
Arc Moto 600.4 under the radio all day and he could even mount an EQ on top of the headlight. The KRC he mentioned fit in his pods with no issues then put some VO 6X9 in the lids. Would sound pretty damn sweet!