VTF-2 MK4 Subwoofer (Discontinued)

New Q Control and Hybrid Tuning Give Unprecedented Bass Control

The new VTF-2 MK4 takes advantage of the new technologies we developed for the VTF-15 H -Hybrid tuning variable Q, sealed operating modes – making this one of the most flexible subwoofers we have offered to date, catering to virtually any audiophile’s preferences.
With the added Q control and sealed mode options, even higher sound quality is now possible. Unlike most of it's competitors, the VTF-2 MK4 comes in an expensive custom satin black paint.

Harnessing the unique Variable Tuning Frequency port technology (VTF), each port uses the air generated from the long throw woofer to dramatically boost the deeper frequencies. The VTF-2 MK4 succeeds down to a very deep 18 Hz with one port open (in maximum extension mode).

The reason for variable tuning is that all subwoofer designs, especially consumer-level subwoofers, involve tradeoffs in design. You cannot have a small subwoofer that goes very low, plays very loud and costs very little. Traditionally, the engineer decides what tradeoff he or she thinks is best for the consumer. The consumer has to take it or leave it.

The VTF-2 MK4 changes all that. It allows you, the user, to choose the tradeoff. If you enjoy music that is loud but does not have much deep bass, set the VTF series for maximum output. That way, you get maximum dynamic range with the lowest distortion. If you like music with deep bass, set it for maximum bass extension to reproduce the deep bass accurately. You can even switch between the two modes depending on what you play. That means effectively you get a subwoofer that can play loudly, and can play low, all in one, at a reasonable price!

VTF-2 MK4 Frequency Response Curve - Ported (1 port open, 'EQ1')

Freq Response Curve with 1 Port Open, EQ1

VTF-2 MK4 Frequency Response Curve - Ported (2 ports open, 'EQ2')

Freq Response Curve with 2 Port Open, EQ2


CEA 2010 Measurements (1 Meter, Peak)

VTF-2 MK4 One Port Open:

Tone Burst Center Frequency (Hz) Maximum SPL CEA 2010 Rating
16 103.7  
20 108..7 111.0
25 110.9
31.5 113.4
40 115.7 117.4
50 118.1
63 118.5
80 118.3

VTF-2 MK4 Two Ports Open:

Tone Burst Center Frequency (Hz) Maximum SPL CEA 2010 Rating
20 107.1 112.1
25 113.0
31.5 116.2
40 117.8 118.9
50 119.5
63 119.3
80 118.8


Industry Reviews

"The benchmark to which other under-$1,000 subwoofers must be compared"

Read Full Article

Gary Reber, Widescreen Review, June/July 2013


"The VTF-2 MK3 subwoofer achieves the kind of bass home theater buffs crave"

Read Full Article

Mark Fleischmann, Home Theater Magazine, March 2007


Customer Testimonials

"I just got my HSU VTF-2 MK4 sub in today and had all evening to play around with it. I love this thing!! It hits lower than my Polk PSW505, and it seems effortless in comparison. I like how tight and accurate the notes can hit. This has been a great investment for my home theater.

Most people buy new audio gear for use with music or movies. I tend to play games a lot more, but I believe that great audio equipment is just as important when it comes to getting the most out of a games soundtrack. Mass Effect 3 sounds so much better with my HSU providing the low frequencies.

Thank you, Dr. HSU, for an amazing product line! I will be back for more in the future! "



"I bought your VTF 2.4 and I have to say, not only am I impressed but every single person who has heard it so far has been in awe. "



"I just wanted to say that anyone looking for a great quality sub, HSU should on the top of your list. We have had a VTF3mk2 since forever now ( I think 2003-2004). Anyone that comes over to watch a movie (we have front projection setup) is just amazed at the bass. I've had some higher end stuff over the years having been around music for some time ( DJ in my younger years ) but it continues to impress me. She's held up well over the years and in two different homes. I have it matched with Axiom M80 package. I'm also in Canada, we bought our sub from some place in Canada years back, Supertek I think. I don't think they exist anymore?

My only regret is that I don't have more of them! I'd love to upgrade mine now but it's not in the cards (both of us with health issues - long story and bad luck) But honestly, I love my Sub, one of the best audio purchases I've made in my life. Actually, it's rare to have any product these days that you can actually be proud of."



Error: Data not available (103)
In-stock: Error: Data not available (103)
Regularly:$ Error: Data not available (103)
MSRP:$ Error: Data not available (103)
S/H:$ Error: Data not available (103)
Error: Data not available (103)

$ Error: Data not available (103)

Data not available (103)

Return to Previous Page

Product At a Glance

Amplifier Power (RMS) 1000 W Short Term, 250 W Continuous
Hybrid Tuning 18 Hz Ported, 25 Hz Ported or Sealed
Low End Extension (+/- 2 dB)

17 Hz (1 port open)

22 Hz (2 ports open)

Woofer Down Firing 12 Inch
Q Control Range 0.3 - 0.7
Crossover 30 - 90 Hz, Bypassable
Crossover Slope 24 dB/Oct
Phase 0°/180°
Inputs Line Level (2), Speaker Level (2)
Power Outlet Requirement 300 W, 120/240V
Enclosure Dimensions 20 12" H x 15" W x 22" D
Dimensions with Feet & Amp 22 12" H x 15" W x 2234" D
Weight 64 lbs
Warranty 7-years on Woofer, 2-years on Electronics
Designed and Engineered in the U.S.A.


Quick Set-Up
Owners Guide

Requires Adobe Acrobat Reader