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September 2004
Enjoy the Music.com Review Magazine
Power Line Magic From Quantum's RT800 Black Box
Review By A. Colin Flood
Click here to e-mail reviewer


  Quantum's latest product, now reduced to $999, is a black box that distinctly improves the sound, as if someone nudged the treble and the bass sliders higher. The RT800 AC source/EMF power line stabilizer is simple metal construction on the outside: about the size of a Kleenex tissue box. Two silver plates adorn each end and screws hold the unit together. It is NOT as tall, but it is as wide, as a double-bagel toaster. Though it looks as hefty as a barbell, it weighs a mere 5.5 pounds. A row of eight gray electrical sockets adorn the top: half of them marked with a green dot. The green mark indicates earth ground for hospital grade duplex outlets.

Quantum RT800 Black BoxThe back plate has a socket for a standard-size power cord and the only control knob, a small rocker switch for the QRT .

The seemingly simple black box performs some startling sonic magic. Patricia Barber's sedate and sultry live jazz CD, Companion, is redolent in delectable string bass riffs; the kind that make you nod your head in rhythm, rather than tap your feet. The disc makes you murmur to yourself "yeah, that is jazz" as you sip your golden beverage. (Man–oh, man! Did I tell you how much big ole horns bring enjoyment to movies and music?)

Quantum's black box quickly displayed its unique capabilities: the bass suddenly sang better, like a bird joyously freed from its cage. The treble sparkled. (Yes, cliché it may be, but it was as if the veil had been lifted.)  The treble was brighter, but NOT too hot or sharp. On Chuck Loeb's aging The Music Inside (1996), the black box made subtle differences sound more realistic: brushed cymbals had less of the artificial sizzle. It seemed to add darkness to the CD.

Opening notes on both CDs seemed more dramatic -- lyrical. The treble range took on a soft, gentle, edge-free quality. The mid-bass was better defined; notes are more clearly isolated and linger the nanosecond longer that makes them deliciously tempting. I couldn't really measure, but the deep bass seemed a tad more solid.

My initial impression is quite favorable: only the steep price of this audiophile tweak prevents a flabbergasted response (hey, this black box works!). My other concern is whether long term listening reveals that the box is actually suppressing other parts of the music. Is it me, or is there slightly less kick and emphasis to the bass and drums? Brass instruments, like horns, show so well on the big ole Klipsch; but with the RT800, are they slightly more polite, less of the blare that makes them so uniquely horns?

For many tweaking audiophiles, the RT800 magic will be worth it. I liked the “different difference” it made. As easy as it was to plug and unplug the black box - switching from track to track, component to component - I quickly grew to resent month-long swapping trial. Although the RT800 difference is slight, it is pretty obvious what the little unit does:

1. Change the disc and you might not notice the difference, the black box makes, but swap the black box back in again and you appreciate its bouquet.

2. This refined subtlety may slip surreptitiously by, like the moon sliding behind the clouds. You may never notice the magic the RT 800 creates until its shadow is gone.


Sade's Lovers' Rock CD blurs the line between techno and torchy jazz with its funk-heavy bass lines. Quantum's black box made the bass lines slightly quicker - tighter somehow, deeper, even - perhaps meaningful. The cymbals sparkled more (always a nice effect) and the bass dug in deeper. Long-term listening did NOT reveal an annoying suppression of other parts. Or if there was, it was NOT nearly as nice as the crisp dynamics and isolation the black box adds to music.


Behind The Curtain

Like the instructions for a "Mission Impossible," the thin brochure for the black box hides in a manila folder, beneath layers of foam, in an inner box, inside another paper-filled box. "Your mission Colin, should you choose to accept it, is to decipher the engineering gobbledygook for tweaking audiophiles as simple minded as yourself." Except for these secret instructions, the brochure is a repetition of the company's mystifying web site.

The black box is the creation of Bill Stierhout (Dutch, pronounced as it looks, "steer-hout"). He is President of Quantum and designer of the products. He got into this crazy industry through his work in pro audio and his interest in environmental health and electricity. Stierhout received a Bachelor's degree in E.E, an M.S. in Computer Science. He worked in professional audio/video/music/film recording production/post-production/broadcast industry for 25 years in studio operations, technical design, engineering, manufacturing, and technical support. His company has been in business seven years. Stierhout subs out all manufacturing in Santa Monica, near Los Angeles.

Quantum Resonance Technology, or QRT, is the material treatment process applied to the electronics. This alters the conductive properties of the component materials and is an expensive process. QRT is proprietary to Quantum and is unavailable anywhere.

"Quantum Resonance," Stierhout says, "is affected by the strength of the existing electro-magnetic fields in the home. The greater the load, or the number of appliances in the home, the greater the electro-magnetic field intensity, and the greater the EMF pollution and associated chaos/noise on the signals."

The magic of the black box, the manual says, is its ability to "affect electromagnetic fields in spaces of up to 1,500 square feet." The black box conditions the space occupied by electro-magnetic fields (EMFs) of any kind! The RT800 harmonizes and tunes existing EMFs within a radius of 35 feet. Sources of electromagnetic fields are the stuff that make up our beloved entertainment systems: amplifiers, CD/DVD players, TVs. Even refrigerators, computers, and cabling/wiring, the web site says, generate considerable EM fields.

The RT800 is a year and a half old. RT is for Resonance Technology, 800 for the 8 outlets The RT800 improves on previous models with signal enhancement/noise reduction. The small green dots on four of the outlets indicate the ground connection: standard on hospital grade Bryant duplex sockets. The black box is somewhat fragile; hence the rugged metal enclosure. The RT800 uses three (3) microprocessors and three (3) crystal oscillators. It should be plugged directly into the wall outlet, before the UPS, if one is employed. If you are concerned with voltage surges/spikes then use a surge protector ahead of the RT800. All front-end equipment as well as amplifier should be plugged directly into the unit.

Stierhout says the black box "uses two oscillator/transmitter hardware platforms to generate a small electrical field at specific frequencies to induce a qualitative change in the external fields." Two oscillators offer greater electrical signal stability/integrity, meaning greater clarity and musicality. The loudspeaker impedance load, tube or solid-state amplifiers, or 20-amp electrical service makes no difference to the unusual black box. A 30-minute warm-up period is suggested for the RT800. With the RT800 plugged into a surge protector, the black box should last a lifetime. It draws less than 20 watts of power, “more like 10 watts at 110VAC,” Stierhout says.

The biggest difference, he says, should be noticed with the pre-amplifier versus the amplifier, because the pre-amplifier draws far less current than the amplifier. Therefore, the RT800 "aligns" the signal with greater influence. The amplifier presents a greater load than the pre-amp, so it generates greater EM field. "Larger power supplies, i.e. transformers/inductors," Stierhout says, “means greater current capability, which equals greater EM fields, which means more noise. The proximity, or location, of any device to our RT800 unit increases our affect on that device. This is because the unit has small transmitters that are responsible for achieving the induced qualitative changes directly on the information (audio, video, data or power) path.” Quantum recommends plugging in both pre-amp and amp for the greatest, cumulative affect.

The manual says the black box doesn't lose the power, energy or realism of the music. My music did indeed seem to have expanded dynamic range (always a good thing). Music did indeed have more life. Yet, the video effect was NOT nearly as noticeable on my aging VHS player. How do some things somehow come out good in the end? In the beguiling Shakepeare's in Love movie, Geoffrey Rush repeatedly shrugs, "its a mystery!" Exactly how does the black box work? “It's a mystery” to me.

Jim Merod reviewed Quantum's Symphony AC Line Conditioner in August 2000. He said better power equals better music and the Symphony model added a "discernible vividness." Quantums' most popular model is the Symphony Pro EMF Stabilizer. The Pro features one (1) oscillator/transmitter platform at $599.95. There are no upgrades or modifications that tweaking audiophiles can make to the RT800 model. People interested in a local audition should contact Stierhout. He offers a 30-day money-back satisfaction product guarantee. Buyers should allow 72 hours for processing and shipping.



The updated, Roksan Caspian solid-state integrated amplifier evaluated the RT800 with my big ole horns (see the Writer's Bio for the context of all my reviews) and Aperion's slim 522D Powered Towers (coming up next). The black box clearly adds more magic to the ultra-efficient horns than it did to the more conventional, but capable, cone towers.

On a scale of one to ten, Jim Merod gave the Symphony model a 1.5 score. Despite the obvious improvements in sound quality, the price of the black box gives cheapskate me pause, especially when considering other tweaks, such as Gingko's floating Vibration Isolation Platforms or RealTraps' not-so "Mini" Traps. Other tweaks may cost less and yet give as much sonic improvement as Quantum's black box. Yet, on a ten-point tweak scale, I would have to give the RT800 a solid two – its differences are more than simple power cords or hospital grade outlets.

Normally the Enjoy the Music.com blue note score below would be a straight-line comparison to other products. When comparing similar products to each other, I award very few four and five notes – most products can't be above average, can they? High blue notes defeat the purpose and value of objective and subjective reviewers and reviews. They cheapen the value of the review for the tweaking audiophile. Since I grade products on a curve, this makes my class the toughest in the Enjoy the Music.com school.

Since I have never reviewed any form of power line conditioner before, the scorecard below reflects the above average (four notes) improvement in many areas of the RT800 black box. The black box did improve mid-bass, treble and inner resolution (with added clarity) beyond the average. I wish the simple box was more elegantly designed. Since the Quantum RT800 black box does have four blue notes in some areas, this means its over-all performance is actually quite good. My own category, Enjoyment, is above average.

The RT800 is a distinct improvement in sound quality, a "different difference" certainly, but one which the tweaking audiophile can get, if not so easily, with other system improvements. Plus, this unit is an improvement for both audio and video components. Besides, anything less than $500 buys only flimsy equipment at “sell it as quick as you can" retail chains. Therefore, I think this unit is an average value for tweaking audiophiles. I am seriously thinking of buying one.

For tweaking audiophiles, whose tweaks and improvements to their home movie and music reproduction system are already beyond a few hundred-dollars, the Quantum RT800 represents a step upward in audio and visual refinement. It is well worth considering.


Summing Up

I am reluctant to recommend something so subtle and expensive as the Quantum RT800 black box, when so many lower-cost tweaks can make such significant differences in audio quality, but the very real magic of the RT800 is well worth it for tweaking audiophiles already past minor DIY tweaks. A delightful addition.



Sub-Bass (10 Hz - 60 Hz)

Mid-Bass (80 Hz - 200 Hz)

Midrange (200 Hz - 3,000 Hz)

High-Frequencies (3,000 Hz on up)



Inner Resolution

Soundscape Width Front

Soundscape Width Rear

Soundscape Depth Behind Loudspeakers

Soundscape Extension Into Room


Fit And Finish

Self Noise


Value For The Money



Type: Power filter

Outlets: Eight hospital grade

Internal wiring: 14 gauge multi-strand silver coated Teflon

LED monitoring QRT field effect sweep rate

Two custom microprocessors

Total power available: 1,650 Watts (15A/110VAC) 
3,300 Watts; (15A/220VAC)

Current handling capacity: 15 Amperes 
QRT current (electronics): 620 Amperes

Dimensions: 5 x 5.5 x 10 (HxWxD in inches)

Weight: 5.5 lbs.

Price: $999


Company Information

Quantum, Inc.
943 Euclid Street, Ste. A
Santa Monica, CA 90403

Voice: (310) 394-4488
Fax: (310) 859-5563
E-mail: info@quantumqrt.com
Website: www.quantumqrt.com













































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