With the VX21PRO from the VISION PRO series ESX offers an SPL subwoofer of the superclass. Resilient up to 6,000 watts RMS and 12,000 watts of music power. Alone the key data of this giant are more than impressive and let the SPL fans fall into ecstasy:

Features:
Mighty Aluminum Basket with high stability - a must with this with these mighty dimensions
4 x 150 oz Quad Magnet Driver with a total weight of 17 kg
Double Stitched High-Roll Foam Surround, which allows a very high excursion of the cone
Fiberglass reinforced Paper Cone with an effective surface of 1662 cm2
6-layer Nomex Spider, which ensures a good and long-lasting cone
8-layer 10 cm (4”) Voice Coil (Made in the USA), which was wounded with copper sheathed
ribbon aluminum wire, 80 mm high and is thus very light and efficient
Voice Coil Former made of black anodized aluminum
+/- 23 mm linear stroke, +/- 35 mm X-Max
Integrated 10 mm2 speaker cables with 1,5 m length

Specifications:
53 cm (21”) SPL Subwoofer
Power Rating 6000/12000 Watts RMS/Max.
Impedance 2+2 Ω
SPL up to 160 dB
Installation depth 335 mm
Installation diameter 495 mm

ESX VISION VXP104