A little long but hopefully this helps.


Review: By Brian Mitchell, CEO eCoustics.com

Three Subwoofers Face Off: SVS 25-31PCi, HSU Research VTF-3, and Axiom Audio EP-350 Subwoofers

Each of these subwoofers proves you don't have to spend a lot to get low frequency bass effects for movies and music. But does spending more guarantee better performance?

First impressions: These are heavy
Let's start out with my first impressions. Both the Axiom and HSU are familiar looking cubed shaped sub boxes, while the SVS uses a tall cylinder design with a downward firing subwoofer. All three employ a 12-inch subwoofer driver, and have internal amplifiers. The Axiom is the lightest and weighs in at 39 lbs, the middleweight is the SVS at 65 lbs, and get out the forklift for the HSU -- it's 85 lbs!

Let's look at the manuals
The SVS comes with the most comprehensive and professional looking manual. It contains diagrams, setup advice and explains how to use a SPL meter (not supplied) to properly calibrate your unit. The HSU manual consisted of stapled together pages, had no diagrams, although it did offer setup tips with an accompanying CD of test tones and music. The Axiom manual had no setup tips, but it gave a definition of each feature in English and French.
+1 SVS, 0 HSU, 0 Axiom

Connections, knobs and switches
Each subwoofer has volume controls, variable crossovers, phase switches, line-level in, high-level in/out, and auto on power settings. The HSU and SVS both have external cross-over disable/enable switches, while the Axiom does not. Lastly the HSU is the only sub with a 20Hz/25Hz switch to change the tuning. Don't worry if you don't know what all that means. Each sub has all the connections you need for home theater or stereo use. As recommended by the manufacturer's, each sub was connected with one 75 Ohm RCA cable from the receiver's subwoofer-out jack to the subwoofer's line-in jack.
+1 SVS, +1 HSU, 0 Axiom

The Setup
Each sub was calibrated at 75db using the test tones on the AVIA Guide to Home Theater DVD setup disc. A BetterCables.com 8ft subwoofer cable was used. Subwoofer crossovers were disabled for Dolby Digital movies (allowing the receiver to manage low frequency settings), and enabled for stereo music (allowing the sub to control settings).

Music time
I threw everything from classical to jazz to hip-hop to rap at these subs. Each sub performed remarkably similar at the same listening levels, but I would give the advantage to the HSU on classical music because it seemed the most accurate. The SVS gets the nod for rap and hip-hop music as it produced tight loud bass that literally shook the room. The Axiom performed admirably, but was least impressive of the group.
+1 SVS, +1 HSU, 0 Axiom

Movie time
Using these subs for movies is really where they shine. The SVS not only shakes the room, it will rock your entire house. Explosion scenes and crashes will be felt as well as heard with the SVS, without a hint of distortion. The HSU will also shake-up a room, and produces quick clean bass, but it didn't seem as realistic for movies as the SVS. The Axiom again did not add any more realism for movies, but it wasn't that bad, just overmatched.
+2 SVS, +1 HSU, 0 Axiom

How low can they go?
Just for fun I played with some low test tones to see how each sub performed. The HSU easily won the battle, in playing the lowest audible frequencies below 20Hz, but it also caused the most room resonation. I can't fault HSU for that. The SVS was second in this test, and the Axiom was last. It should be noted that most sound below 25Hz was felt as vibrations more than it could be heard in these tests. Low frequency tests are more for manufacturer bragging rights and sales literature, then a true measure of subwoofer performance.
+1 SVS, +2 HSU, 0 Axiom

Is bigger better?
The SVS is the largest and tallest, and could easily be mistaken for a floor standing speaker. The HSU and Axiom subs are about the same sized cube boxes and can be easily hidden in a corner. If you have the space, I'd get the SVS. If you want a less obtrusive looking sub go with the pricier HSU. If that is too much money then get the Axiom. No matter what your decision you won't be disappointed with any of them.

Final Thoughts
If you haven't figured out already, the SVS emerges as the winner of this face-off. You'll also be surprised to learn it is the least expensive of the group! It just goes to show you that more expensive doesn't always mean better. At just $549, the SVS is the best bargain in bass.

(All can be bought online)
SVS 25-31 PCi - $549
HSU Research VTF-3 - $849
Axiom Audio EP-350 - $620

Remember I am just one man with one opinion. If you own any of these products, or have a comment or question feel free to add your thoughts below.

Brian Mitchell
Founder & CEO
eCoustics.com







Sunfire amps & processor Sammy 50" Crown amp 2-SVS SS Maple Ultras, Axiom 60s,22s,150cc, QS8s