VTF-3 HO Subwoofer with Turbocharger

"in my opinion, the best subwoofer HSU Research has ever designed"
Secrets of Home Theater and High Fidelity

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The next generation of high output (HO) subwoofers is here. They are optimized for reproduction of low bass at high levels with low distortion. We achieved this level of performance by using several patent pending and patented technologies - our bent port technology, turbocharger technology, and the use of a woofer with a patented linear motor.

The lowest bass comes from the port. You need large ports to move lots of low bass without port noise or compression. With the HO, we went to dual 4" ports, which nearly doubles the port size compared to the VTF-3 Mk 2.

Adding the patent pending turbo doubles the port area for extended bass mode, allowing the VTF-3 HO to move as much air as four VTF-3 MK2 models in extended bass mode with the same level of port noise. 

The patented linear motor used in the HO has an extremely low distortion over its full operating range. This complements the low distortion, high output low bass afforded by the patent pending bent port and turbo technologies.

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Low bass output in vented systems come from the port(s). High levels of low bass require a lot of air to be moved. If the port's crossectional area is not large, air velocity gets very high, resulting in turbulence (port chuffing) and compression.

For a given enclosure volume, putting in a larger port means a longer port length to tune the port to the same frequency. In order to fit two 4" ports into an enclosure the size of the HO, we need to bend the ports. However, if not bent properly, the bend will cause premature onset of turbulence, negating the purpose of going to a larger port.Our patent pending bent port technology ensures that our bent port performs as well as a straight port equivalent.

Adding the patent pending turbo dramatically increases the low distortion low bass. With our previous VTF technology where the bass extension of the subwoofer is achieved by tuning the subwoofer 1/3 octave lower by cutting the port area in half, we achieved lower extension at the expense of maximum output with low port noise and compression. In the extended bass mode, the air now has to be squeezed through half the port area, doubling the air velocity. Port turbulence occurs at a much lower level. The turbo technology eliminates this deficiency by allowing both ports to remain open for the extended bass mode. Hence with the turbo, the HO can move the same amount of low turbulence air as two HOs without turbo. This represent a dramatic cost and space saving.

Industry Reviews

"in my opinion, the best subwoofer HSU Research has ever designed.."
Dr. John Johnson, Secrets of Home Theater and High Fidelity (March 2006)

VTF-3 HO Turbo At a Glance

Amp Power (RMS)
500 Watts
Bass Extension (max extension mode)
16 Hz
Bass Extension (max output mode)
22 Hz
Woofer size
12 Inches
Dual flared 4 Inch
Bypassable 24 dB/Oct, continuously variable 30 - 90 Hz low pass filters
speaker level (2), line level (2)
21.5”(h) X 17”(w) X 25”(d)
Ship Weight
93 Lbs
Power Outlet Requirement
600 Watts
7-years on the subwoofer, 2-years on electronics



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For Owners

Owners Guide
Turbo Owners Guide

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