VHD4.21 · Overview
VHD4.21 ACTIVE - part number KVV 987 333
VHD4.21 PASSIVE - part number KVV 987 336
Introduction
The VHD4.21 is a high output, high definition ultra low frequency active subwoofer system. Through the use of
proprietary amplifier technology, a precision manufactured state of the art woofer component and the innovative
implementation of a high efficiency, twin chamber acoustic design, the VHD4.21 delivers tight, fast, controlled bass
response at very high output levels. The system establishes new performance standards for an active powered
subwoofer that can only be achieved through the integration of new amplifier and power supply topologies,
transducer designs and electronic control technologies.
Originally designed as part of a VHD system it is voiced for live music but also excels in the field of club and dance
music. In any situation it works very effectively, operating down to 28Hz, alongside other VHD products, the SL range,
or as an incredible stand-alone subwoofer that can complement any other manufacturers systems.
Application
The Ultimate seismic Subwoofer to add to any KV2 Audio or third
party manufacturers system.
• Large scale live music and playback performance
• Dance Clubs and Nightclubs where Music comes first
• Hire and Production
• Large Concert venues
• Cinema
• Fixed installation
• Easily incorporated into multiple system projects with VHD, SL, ES
and ESR
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Electronics
The VHD4.21 Active Bass Module consists of two purpose designed Very High Definition enclosures, one active and
one passive, each containing two custom designed 21“ woofers. A Low Q design has been applied to attain the
optimum speaker loading, enabling a high sensitivity of 109dB 1w/1m. Running at close to 100% efficiency on any
voltage from 160 to 270 Volts, the amplifier for the VHD4.21 is a revolution in electronic engineering, utilising a huge
bank of capacitors as a power store. This unique and innovative new power management system enables the onboard
amplifier to deliver peak output levels of 14 kW, whilst operating at a modest constant power consumption of 3.5 kW
from a16 A circuit. The VHD4.21 Active Module represents proven KV2 Subwoofer Amplifer technology that has been
consistently improved over the last decade to provide maximum control over the movement of large mass speakers.
The end result is a fast, dynamic, Very High Definition subwoofer, truly capable of reproducing the articulation in a bass
guitar, whilst also extending down to 28Hz.
