BlueSmoke - Review : Evergreen RumbleFX 3D Sound Amplifier

		Date	: Oct 1st, 2001
		Category	: Audio
		Manufacturer	: Evergreen
		Author	: Jin-Wei Tioh

Evergreen Technologies, based in Corvallis, Oregon was founded back in 1989 to provide products to "refresh" older systems, extending their useful life. It manufactures some rather interesting products, such as the Performa line of processor upgrades and the AcceleraPCI. Evergreen then branched out into consumer electronics with their RumbleFX line, starting with the RumbleFX Force Feedback Headphones which we reviewed some time back.

Now, a second audio product has been launched under the RumbleFX name, the RumbleFX 3D Sound Amplifier, a sound enhancement gadget. Evergreen proclaims that this product will "transform your listening experience from any mono, stereo or surround sound device". These gadgets used to be either only modestly effective or simply plain rubbish. Does the RumbleFX live up to its claims?

The RumbleFX amplifier comes in an attractively designed box, with an audio conversion jack (from 1/8" to 1/4"), a 10 foot 1/8" to 1/8" cable, a 110/120V DC adaptor, a brief instruction guide and the usual legal brouhaha. Destined for retail channels, that's for sure.

The amplifier unit itself looks flashy, with a dark bluish-green iMac style plastic enclosure measuring 35x130x115mm (HxWxD) along its largest dimensions. On the back of the unit are gold-plated RCA and 1/8" connectors for both input and output. The 1/8" connector's output is amplified, with the amp power (3 Watts) being on par with most sound cards. Fortunately, Evergreen also decided to provide an unamplified output in the form of RCA connectors, a very important feature if you're going to hook up the RumbleFX to amplified/powered speakers.

On the right is a 1/8" headphone output connector and a volume control dial that affects the output level through every connector. To the left sits the WOW and TruBass level adjustment dials. The lowest possible level afforded isn't zero, which is why the 3D Sound on/off switch on the unit is a Godsend on occasion. The exterior looks quite alright, so let's see what's under the hood.

Inside the RumbleFX unit is a single circuit board, with an odd empty space next to the amplifier IC. We can only speculate that the original design was based on a different chip. Besides that waste of space however, it is a very clean board with none of the dodgy wiring that is common in some consumer electronics products. Of special mention is the DC adaptor that powers the RumbleFX. The provided adaptor is a 110/120V unit that outputs 15 volts. While there doesn't seem to be a 220/240V equivalent, you can still operate the RumbleFX using a 700mA-rated DC adaptor for 12V operation. An ordinary 12V 1A multi-plug adaptor will work just fine, as tested in our labs.

As mentioned earlier, sound enhancement gadgets have a spotty past. They either worked a little magic or simply mucked things up. Generally, manufacturers aim to enhance two aspects of audio : the stereo soundstage and bass. This is achieved by stereo expansion and bass enhancement technologies. With more research into psychoacoustics, ie. how we perceive auditory information the way we do, HRTFs (Head Related Transfer Functions) have been created, resulting in a better implementation of these enhancement technologies.

The RumbleFX 3D Sound Amplifier is based on SRS Technologies' WOW and TruBass hardware. WOW improves an audio signal's image size, dynamics and immersion by inserting spatial cues. It is important to note that early bass enhancers were simple frequency boosters, similar to cranking the bass dial to maximum. This proved to be extremely ineffective in some cases, due to the limit of the speaker voice coils which simply could not physically produce such sound. Modern HRTF-based enhancers, such as the TruBass-based RumbleFX do not drive the speakers harder - they just fool your brain into "perceiving" the bass.

Sound quality is where things really start to get funky. Since WOW and TruBass type enhancements usually work better on more modest sound systems, the RumbleFX was hooked up to a Diamond Monster Sound (which lacks software treble and bass adjustment) and an Altec Lansing ACS90, a 2 piece speaker system.

Music was the first type of source material to be sampled. Songs such as Loverboy (Mariah Carey), Hit 'em Up Style (Blu Cantrell) and Bootylicious (Destiny's Child) worked wonderfully with WOW and TruBass fully enabled. The bass beats and electric guitars were accentuated very nicely, giving an overall "wrap around" immersive effect. Likewise, all the prayer songs and the orchestral version of Suteki Da Ne from the Final Fantasy X soundtrack came through great. Hadyn's Trumpet Concerto in E Flat Major required the WOW to be dialed down by half, but once there, the mellowness of the trumpet was enhanced, producing an overall nice effect. Generally speaking, sounds/music with already a fair amount of reverb present or with short to mid-length, reasonably well defined bass beats benefit the most from a full WOW and TruBass boost from the RumbleFX.

One supposed benefit of the RumbleFX is its ability to process mono into stereo. Some really old audio clips were thrown at it, and the results were a mixed bag. One annoying characteristic of WOW is that it boosts the treble, especially the higher range. Mono recordings are almost always old recordings - hisses are omnipresent and slight pops and clicks are occasional visitors. Bessie Smith's Lost Your Head Blues (1962), Billy Strayhorn's Take The "A" Train (1941) and Charlie "Bird" Parker's Bloomdido (1950) (all classical jazz pieces FYI) sounded better off with 3D Sound completely disabled. Background noise and tape hiss were over-emphasized while the songs stayed stubbornly in mono. There were some exceptions however; Louis Armstrong's Hotter Than That did turn out to be a little better sounding. But the RumbleFX's talents seemed to best suit Harold Arlen's Over The Rainbow (1939). This is a beautiful legato melody that invokes dreaminess and a sense of wonderment. The expanded soundstage with slight reverb made it most delightful to audition.

How does the RumbleFX fare in games? In Unreal Tournament, the background music definitely sounds better. However, when tested on a SBLive! equipped system, the audio positioning already done via Creative's EAX was quite mucked up by WOW. One simply couldn't tell where attacks were coming from, ie. above, below, left, right, front or back, a tactical disadvantage. Plain stereo PC and console games almost always sounded better with the RumbleFX as in the case of Sonic the Hedgehog, Super Mario Brothers and Final Fantasy IV.

While one cannot go wrong with TruBass, WOW is not as perfect. As previously mentioned, WOW amplifies the higher treble range. If your speakers and sound card lack some form of adjustment, the effect produced can sometimes be extremely aggravating. Piano and violin pieces don't sound particularly good, as can be readily demonstrated by feeding Vivaldi's La Primavera from The Four Seasons, Chopin's Nocturne in E Flat Major and Franz Liszt's Transcendental Etude into the RumbleFX. The effect of Hadyn's Surprise Symphony and Debussy's Prelude to the Afternoon of a Faun were compromised by dialing up WOW.

Moving to more modern examples, WOW didn't do much for the 3DMark 2001 soundtrack, except bringing the guitars out front and sending everything else into the distant background. Nelly Fertado and The Corrs definitely fared better with WOW completely disabled. Interestingly, metal fans might be disappointed by the RumbleFX. Otherworldly, the only heavy metal track in Final Fantasy X sounded somewhat fainter and hollow with WOW. Only the TruBass bass boost was beneficial. Sometimes, WOW produced very strange sounding effects. For instance, Race to Old New York from the Final Fantasy : Spirits Within soundtrack with WOW fully enabled sounded as if you had crawled right under the London Symphony Orchestra. Same thing goes for the Star Wars orchestral pieces.

The WOW stereo expansion doesn't work very well with headphones. By definition, headphones already give you excellent stereo separation, though the TruBass enhanced bass is welcome (probably a moot point if you use the RumbleFX Force Feedback Headphones). With better 3-piece speaker systems such as the Altec Lansing ACS45.1, TruBass helped to make some of the bass sounds less muddy and more defined. There was definitely improvement in some cases with WOW and TruBass enabled, but the improvement is not as impressive compared to that of more modest, closely spaced speakers. The TruBass enhancement on the RumbleFX works very well in almost all situations, though the upper limit could stand to be significantly increased. The WOW stereo expansion works just as well, provided it is matched with the appropriate source materials. Unsuitable material will result in all sorts of weird effects and distortions. Mono to stereo "conversion" only works well with very select source material - otherwise, it just brings out tape hiss and background noise. Evergreen indirectly acknowledges this by placing a 3D Sound on/off switch - they don't expect you to like what the RumbleFX does to everything. The RumbleFX functions well as a plain amplifier, though the inclusion of unamplified outputs is thoughtful decision on Evergreen's part. Portability is hampered by the use of a DC adaptor. To be fair however, using regular batteries as a power source is an impractical alternative due to the high voltage and current requirements. Lastly, one of the most important considerations for the end-user is the price. The RumbleFX has a MSRP of US$79.99, a tad on the expensive side. Doing some digging turned up the unit at Computers4SURE for US$55.99, a much more reasonable price tag. At this price level, the RumbleFX 3D Sound Amplifier is a must have for video game console owners. Computer users with more modest sound systems would benefit greatly as well, though those with better 3-piece speakers or who use headphones won't realize as much benefit. A safe buy so long as you know what you are getting. Highly Recommended!