First, I agree with av_phile,
I've tried this one, and I ended up with a pair of burned transistors on my amp. An ECE friend told me this is a case of mismatch. Subwoofers usually require a whole lot of power to be driven and average amps can't handle loads this high. Kahit sa impedance point of view na lang, usually subs are rated at 4 Ohms and amps, usually at 8 Ohms. MISMATCH!
Bro Raycor,
meron namang nakalagay sa box ng targa subs ng box volume at kung anong box type, you may have missed it. It's also on their website.
www.daiichi.ph. But that's the price of DIY, experimentation.
ALL IN ALL, if you have budget constraints, and may not be that knowledgeable about DIY powered subs, I would suggest buying a powered sub na lang instead of building one. Suggestion? Daiichi ASW-10DR, 4,250 pesos only, with dual 10" drivers, isobaric 4th order, freq. resp. range: 5Hz-300Hz. Mahihirapan kang gumawa ng sub that would cost less than that and could perform as well. Just my thoughts.