ok. well i listened to it some more today, and im having some issues.
1) the woofer claims 3" usable throw. im assuming this mean, without bottoming out. well 3" = 76.2mm. cut it in half, and you get 38.1mm one way. my BTL was rated at 26mm of xmax. i cannot get this woofer to move nearly as far as my btl without introducing a not so pleasant mechanical noise. it almost sounds like a very light bottoming out (not the full on slapping sound). only thing i could compare it to would be like this:
but imagine it spinning at the speed of the excursion, if that makes any **** sense lol. i dont know whether its a loading issue with the enclosure or what. maybe the woofer just has a super tight gap, and its just the coil rubbing against the gap. i really dont know. im not completely familar with trying to diagnose subwoofer sounds lol. the btl has a similar sound, but it was much less noticeable. this noise is only really noticible when you pop the hatch and are looking at the sub from 2' away, but i can replicate it and hear it up front if i really push on it.
currently on even less gain on the kx2500.1, i can only turn it to 60/80 (depending on song, some i can go higher, around the 64 range) before i get the noise, while the btl would take it all the way up to 70 (where the gain is set for) and not really show any signs (mechanical noise would be there but very light).
although i cant move the sub nearly as much without it starting to sound bad, at the current level its on, it gets louder than the btl on the upper notes. in the current box, the btl was not very good at producing the upper freq's, it was a low end monster though. the hdc15's low end is not nearly as bad as people say. at least not in the 4.5^3ft @ 33hz its in right now. im honestly surprised with it considering its FS. im assuming it will pick up even more as it breaks in.
i will be building another box sometime soon with a different orientation. sub up, port back, as well as making the box deeper, to give more room for the motor and basket assembly. currently the motor is about 7" from the second port wall. that should be enough, but it never hurts to try something else.
heres some pics and videos. the sound that the woofer is making is inaudible in the videos and is covered up by my rattling panels, and bumper
. i will try to get a better video of the noise that it makes another time. btw, photobucket
FUCKED the videos up. if anyone knows a place that can link videos like photobucket does, but NOT compress them as shittily as they do, please let me know so i can reup them.