Dayton Audio Ultimax UM15-22

The  Ultimax UM15-22  is a 15" (38cm) subwoofer from Dayton Audio. This unit is specially designed to move a huge amount of air and produce clear, precise bass that is a sign of powerful sound. It will give you a peak power of 800 watts RMS and features two 2-ohm 2-layer copper coils. The design of this subwoofer also includes two linear stiffness spiders that limit any distortion and ensure a flawless music experience. And that's just the beginning of the ultimate subwoofer experience that awaits you with the Ultimax UM15-22.

• 15" (38cm) subwoofer
• Moves enormous amounts of air!
• Over 1-1/2" total diaphragm travel
• 800 watts RMS power
• The latest in subwoofer technology
• Two linear stiffness spiders limit distortions and rocking modes
• Two 2-ohm copper voice coils with 2 layers
• Large ventilated pole piece and ventilation under the spider

• Closed 87 liters,  f3 of 35 Hz with an alignment of 0.707 Qtc
  
• bass reflex 170 liters  tuned to 18 Hz with two 10cm diameter and  66cm long ports for an f3 of 22 Hz. Larger housings and lower tuning frequencies are possible.

• woofer series: Ultimax Series   
• Load capacity (RMS): 800  watt
• Load capacity (max):  1,600 watt
• Impedance (Z) : 2 + 2 Ohm double voice coil
• Sensitivity:  86.5 dB @ 2.83V/1m 
• Frequency response: 15 - 1,000 Hz
• Voice coil diameter: 63.5 mm
• DC resistance (Re):  3.4 ohm
• Voice coil induction (Le) : 1.31 mH
• Resonance frequency (Fs): 19.5 Hz
• Mechanical quality (Qms): 2.40
• Electrical quality (Qes): 0.59  
• Overall quality (Qts): 0.47
• Moving mass (Mms):  279.4 g
• Suspension compliance (Cms) :  0.24 mm/N
• Membrane area (Sd): 814.6 cm²
• Displacement volume (Vd): 1.548 cm³  
• Force factor (BL): 15.4 Tm
• Equivalent volume (Vas) : 224.3 liters
• Maximum deflection (Xmax): 19 mm
• Cone/diaphragm material: Nomex  membrane
• beading material:  rubber
• Voice coil wire material:  copper
• Voice coil mold material:  aluminum
• Basket / frame material: cast aluminum 
• Magnet material: Ferrite
• Outer diameter:  388 mm
• Total depth: 226 mm
• Cutout diameter: 350 mm
• Mounting holes: 8