Well he asked for subs with 33mm of xmax and I just mentioned some. And I have the LMS-R Ultra in my home theater. I also am selling the SoundQubed subwoofer with 33mm of xmax in the classifieds.
If you had to have that Xmax in that budget I would do a single 15 but in a higher price bracket and proper box/power.
Usually the arguement is "well two 12s have more cone area than a 15" but if there slightly underpowered + the 15 you buy is nicer quality/more effiecent then the 15 might actually get just as loud
Could you guys give me some options for a 15" in the $650 neighborhood?. One that handles 1500 watts RMS is what I want. And I want to do a ported 3.25ft3 box tuned at 33hz. I could do 32hz or 34hz as well. I will be using a 1250 watt SoundQubed mono amp for this sub.
You can do much better then Skarbage. Look at Fi, Sundown, SSA, Adire, Soundqubed and so on. If you are going to spend up to 650 dollars buy a good quality subwoofer like one of those. Lots of options in that range for that kind of money.