Ascendo The21 Sub Pro-Passive Sealed Subwoofer

The21 SUB PRO PS unparalleled output and uncolored sound, the measured test results we publish translate perfectly to realized performance.

ASCENDO’s policy is to be completely transparent and publish measurements done by independently certified third-party labs to provide factual data, thereby enabling informed, educated decisions. The The21 SUB PRO subwoofer is so far above and beyond the competition in every aspect; refined musicality, tightness, and output levels suitable for a 21"" driver. It is also engineered to operate perfectly in sync (in phase) with our Infrasonic subwoofers; The24 PRO, The32 PRO, The50 PRO, The80 PRO when there is a desire to reproduce movie content below 20Hz with the same authority, precision, and musicality.
Compared to conventional subwoofer motor concepts, the ultra-modern double-gap motor of this custom-made 21" driver with two outer and two inner voice-coils enables more linear travel and much faster directional changes with higher sound power and significantly lower power compression.

• Speaker Type: 21" forward-firing, dual gap motor structure with 2 inner and 2 outer voice coils, neodymium motor
• Xmax: 18 mm excursion each direction (36 mm linear), voice coil remains in homogeneous magnetic field for linear, low-distortion performance
• Passive / Active: Passive
• Recommended Amplifiers: 1 channel DSP + amplifier required. Minimum recommended: 109 Vrms, 154 Vpk, 27.3 A (equivalent to 3000W @ 4Ω) with correct RMS & peak limiting and compression settings
• Recommended ASCENDO Amplifiers: Additional external 1CH DSP with AIA2-6004; DSP4-10K2
• Principle: Sealed
• SPL (Peak / Half Space 2π): 139 dB @ 63 Hz (peak)
• Frequency Range (Measurement Data):
  • 55 Hz – 500 Hz / -3 dB
  • 28 Hz – 500 Hz / -15 dB
• Efficiency: 97 dB / 1W/m
• Power Handling: 4000 W
• Impedance: 4 Ω
• Air Volume Displacement: 2.88 L (compared to 1.76 L for standard 21" cinema subwoofer)
• Directivity (H x V): 360°
• Input Terminal: Neutrik
• Enclosure: Internally braced birch ply and MDF
• Width: 23.62" | 600 mm
• Height: 43.31" | 1100 mm
• Height with Feet: 44.29" | 1125 mm
• Depth without Grille: 14.57" | 370 mm
• Depth with Plug: 14.57" | 370 mm
• Weight: 112.44 lbs | 51 kg
• Finish: Structural paint black
• Custom Colour Options: Piano lacquer, color of choice, matte or other finishes upon request
• Shape Customization: Upon request
• Mounting: Floor standing with feet
• Included: Supplied with front cover as standard