I've been lurking around and doing quite a bit of research with the goal of building one helluva sub for my finished basement. We use it to entertain, watch movies, etc. so the sub will be used as part of a 7.1 system that is 70/30% for tv/movies / music. I am not an audiophile, but getting there. I am a musician and music educator. Sound quality is very important to me.
I am decently handy. I already have the enclosure designed and partially built: 9 cu. ft. (8.5 after bracing) MDF rectangular shaped, originally with the Dayton HF390 15" and SPA 500 plate amp in mind.
I am hesitant to continue as originally planned because I have some concerns. With my box partially built, (base, sides, and back) I am having the following issues:
Though the freq. response should be incredible with my design, unfortunately it puts the driver at 19mm xmax at 25 hz. This is with a 500 watt signal. At 300 watts, it puts the driver at only 15mm xmax at 25 hz. So...is this a legit concern? Should I consider the 15" Ultimax driver instead? For the price, nothing can really touch the freq. response of the HF390, but I can't afford to replace the driver if it is driven past its limits.
Also, how much more cu. ft. can I expect to "falsely gain" when I insulate the box? I have heard conflicting ideas as to how much the drivers performance is actually affected by acoustical polyester, insulation, etc. I appreciate your help in advance.