JL audio play,s very clean at loud level,s in a small box.Another brand to consider would be JL Audio, they are superb for the highest-quality drivers.
What size of sub are you considering?
Thanks for your input. I am considering 15 inches in a 3 C.F boxI would say that TC Sounds is a "better" brand than Dayton, but I would definitely recommend both. Another brand to consider would be JL Audio, they are superb for the highest-quality drivers. A good budget friendly solution that competes with the Ultimax is the Stereo Integrity HT drivers. The Creative Sound SDX subs are also impressive.
What size of sub are you considering?
I modeled the ultimax 15" in a 3 ft cu box and the f3 is 33 hz. qtc about .87. If you could build a larger box you will get better extension and transient response. Beware of exceeding x-max with high power though.