Hsu Research VTF-15H MK2 & VTF-3 MK5 HP Subwoofer Preview

Hsu Research is one of those brands all Audioholics should be familiar with. Established in 1991 by Dr. Poh Ser Hsu, the company has been building high value subwoofers for better than two decades. To be sure, this is an impressive feat for an internet direct company. More than a couple subwoofer manufacturers have fallen by the wayside in that time period (Epik and eD being recent examples), and the market is undoubtedly tough thanks to competitors like SVS and Power Sound Audio. As of late, chatter on the forums has been suggesting that Hsu is starting to lag behind the competition a bit. There is some truth to that: the current lineup is getting a little long in the tooth, while others seem to be continually pushing the envelope with new models. With the release of the VTF-15H MK2 ($899 + $109 shipping) and VTF-3 MK5 HP ($799 + $99 shipping), Dr. Hsu may have just silenced those critics in one fell swoop.

The Design & Features

Unlike the outgoing models, the VTF-15H MK2 and VTF-3MK5 HP are very similar on paper. Both subwoofers feature a new 15” fiberglass reinforced driver built on a cast frame and boasting a much heftier motor structure than the old VTF-15 woofer. The new VTF-15H and VTF-3 both also feature the same amplifier, rated at 600W RMS continuous, and 2000W RMS short term, which is a bump up from the old 350W continuous / 1400W short term amplifiers in the outgoing models. Where the designs diverge is enclosure volume. The VTF-3 MK5 HP’s enclosure measures in at 24”H x 17.25”W x 21.5”D and sports a 4” diameter port plus an additional 3” diameter port. The VTF-15H MK2’s enclosure is both wider and deeper at 24”H x 18”W x 26”D, and boasts a pair of triangular ports stated to be comparable to dual 4.5” diameter round ports. As you’ll see below, this gives the VTF-15H MK2 an extra helping of low end power relative to the VTF-3 MK5 HP.

  

The VTF-15H MK2 (left) and VTF-3 MK5 HP (right).

In terms of feature set, both new models have the basics for integrating the subwoofer with a system lacking bass management. A phase switch is on board along with a variable (and bypass-able) crossover knob with settings ranging from 30Hz to 90Hz; the crossover slope is stated to be 24dB/octave. The VTF-3 MK5 HP and VTF-15H MK2 are also notably variable tune subwoofers. By blocking one triangular port on the VTF-15H, tuning is dropped from the native 22Hz down to 16Hz. Meanwhile, blocking the 3” port on the VTF-3 MK5 HP drops the tuning point from 22Hz down to 18Hz. In order to further shape the sound, these subwoofers boast a “Q Control”, the effects of which you can see below.

Frequency response of the VTF-3 MK5 HP with both ports open. The three curves show how setting the Q control affects the response.

The Numbers

As you might deduce from the use of identical drivers and amplification, as well as similar enclosures, the performance of the new VTF-3 MK5 HP and VTF-15H MK2 are relatively close. Both feature a frequency response of +/-2dB from tune up to above 200Hz. In terms of output capabilities, we’ll let the CEA 2010 charts (reported at 2 meters, RMS) do the talking:

CEA 2010 Reported Output Date by HSU scaled to 2 meter (RMS)

These numbers are substantially higher than the outgoing models, particularly in the case of the VTF-3 MK5 HP, which practically doubles the performance of its predecessor.

Analysis & Summary

In case you’re tempted to stop reading in order to compare Hsu’s latest and greatest to your favorite subs, we’ll save you some of the trouble: The output numbers above indicate that the VTF-3 MK5 HP will be breathing down necks of subwoofers like the mighty SVS PB13-Ultra and Rythmik FV15HP. In fact, judging by Hsu’s numbers, both the VTF-15H MK2 and the VTF-3 MK5 HP have adequate output to achieve our Bassaholic Extreme certification (in both of their respective tuning modes to boot). Given the pricing of these subwoofers at $899 and $799 plus shipping respectively, we’re duly impressed with what Dr. Hsu has achieved here. Needless to say, we’d like to get these bad boys on our test bench pronto.  In the meantime, HSU has just put the ID subwoofer market in checkmate.

Unless otherwise indicated, this is a preview article for the featured product. A formal review may or may not follow in the future.