im new to this forum so i want to start off by saying hello to everyone! for the last few days ive been reading over all the posts regarding DIY subs. it seems that building a sub using tempests or shivas is the way to go. (there are some beautiful ones on this site BTW) my questions is, how would a properly designed and constructed sub, using one tempest(ported or sealed) with a 380w rythmik amp(open to suggestions for different amp), stack up vs. a 15" velodyne (or similar sub in this price range) here are the specs from the website: CHT-15 15" - Forward Firing Subwoofer (12.7" piston diameter) Frequency Response: 23-120 Hz +-3 dB High Pass Crossover (6 dB/octave slope): 80Hz or 100Hz Low Pass Crossover (12 dB octave, 48 dB ultimate): 40Hz-120Hz (adjustable) Auto On/Off Dynamic Power: 750 watts RMS Power: 300 watts Magnet: 70 oz. Voice Coil: 2 1/2" copper Inputs: Line-level and speaker-level Outputs: Line-level and speaker-level Crossover bypass: Subwoofer Direct Cone: Reinforced fiber Cabinet (H/W/D): 21" x 18.5" x 22.75" Weight: 83 lbs. Warranty: 2 years (parts & labor) Finish: Black vinyl Are tempests THAT good? (overall quality and spl are important) i could build one for 400 bucks(can) and this sub costs about 1000. sorry for rambling on but should i take a chance, or just bite the bullet and buy a sub? to make a long story short, will a tempest outperform a sub similar to the velodyne? thanks in advance for any opinions or advice.