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Chapter II
: Electric - Whether you are building a house or music system, a solid foundation is critical. For my listening room foundation, two things had to be really right - the acoustics and the incoming power. Luckily with my new construction, I am the only house fed from a new pole transformer and I have my own exclusive 50kVA step-down transformer on my property. Also, in my rural location I’m ten miles from the nearest industrial factory with its electric pollution so I am starting with pretty decent power. Power line noise can wreak havoc with audio. Its treatment has spurred an entire power conditioning industry. As most of us have, I’ve tried many power conditioners from pure filters to regenerators. Most power conditioners offer some improvements—lower noise, blacker backgrounds, cleaner sound, less grunge—but I’ve never found the silver bullet that could be used for all my equipment, even the power amps. Most will act as current limiters to compress amplifier dynamics. Well, my power search is officially over. I’ve arrived at balanced power. 
The concept is amazingly simple. If you have ever worked with electrics in the U.S., you know the three wires black, white and ground. Black is at 120 volts, the neutral white is at zero volts and the safety ground also at zero. Our unbalanced system is simple and works well for most equipment from light bulbs to washing machines. When dealing with sensitive audio circuits amplifying the output of a .6 mV phono cartridge, we need far better tolerances and noise control however. For audio applications there is a lot wrong with traditional unbalanced wiring. The hot leg can induce hum, the wiring can act as an RF antenna and the ground wire often is not exactly at zero volts, which will serve up some nasty ground loop problems. It gets worse. Components plugged into outlets don’t just pull current, they feed back current, grunge and noise into the line which spreads into the audio signal. Your computer in another room is trashing your audio signal through the power line. Balanced power solves virtually all of these potential ills. In its simplest form, it’s an isolation transformer with a center tap that instead of delivering 120V (black wire) and 0V (white wire) over two lines delivers +60V (black wire) and -60V (white wire). The voltage potential between the two wires is still 120 volts so the equipment is happy - with one enormous advantage. The two lines are in opposite electrical phase (180 degrees out of phase to each other with respect to ground) which cancels out most noise carried on the line. My chosen Equi=Tech provider estimates a 16dB reduction in noise with a corresponding 16dB increase in dynamic range.  
"…there is never any voltage or current present on the ground reference in a balanced power system. Transient voltages and reactive currents which normally would appear on the neutral and ground wires are also out of phase and likewise, sum to zero at the ground reference thereby canceling out AC hum and noise. A balanced AC power system works the same way as a balanced audio circuit but with higher amplitude. Both balanced audio and balanced AC incorporate phase cancellation or common mode rejection to eliminate noise."

I got hooked on balanced power several years ago with the Furman IT-20 on the entire front end of my system. But even that 20-amp 80lb monster would restrict power amp dynamics.  I waited and saved up planning for my new room to splurge on what I consider the state-of-the-art power system. The Equi=Tech Model 10WQ wall cabinet system is a 300 pound monster that looks like a circuit breaker panel on steroids.  Inside are 10 x 20-amp circuits wired with oxygen-free copper and custom EMI/RFI filters. These RF filters pick up where common mode rejection tapers off to add an additional 30dB of noise reduction from 100kHz to 2 GHz.  There's a lot more to be said about balanced power and I am planning a future review of the Equi=Tech system.

The wiring from the Equi=Tech breakers runs directly to Oyaide R-1 outlets, each with the Oyaide WPC-Z face plate for static protection and electromagnetic shielding. All of the ten gauge Romex runs were kept short and away from any metal, ducts and other wiring. I also made sure that the entire wall behind the equipment rack was free of any other house wiring except of course for the equipment outlets. Finally, all components are fed from the new Walker Audio SS Velocitors which use a deep cryogenic process to treat the Silent Source wire, IECs and Synergistic Research Tesla outlets. Two of the Velocitors are special custom high-current units designed to handle the massive draw of the Tenor 350 amps. How or why do Velocitors work? I don’t have the foggiest. I do know about a modified Q.R.T. circuit from Quantum Products Inc to 'align the electricity on a sub-atomic level'. Other than that, I have no idea and Lloyd Walker ain't talking.  As Srajan said in his review, "... it excels at speed, dynamics, jump factor and release… The Walker adds speed and thereby rhythmic elan. I don't believe it subtracts anything." The new SS version maintains the original virtues with now even more dimensionality, weight and expansion (especially depth) of the sound field. Since this is no active filter, it mates well with my previous Furman and new Equi=Tech balanced power systems. Finally all power cabling from the Velocitors to critical components are the outrageously good Silent Source Music Reference power cords.

Lighting: Having the cleanest electric doesn’t matter if it is corrupted in the room by noisy dimmers. There are endless on-line discussions about quiet dimmers for listening rooms but this was one controversy I'd skip. Since my critical listening is exclusively in the dark, the type of dimmers played little role in my decisions. For me, the issue was the convenience of remote dimming. Listening to vinyl in the dark requires a trip to the turntable every 15 to 20 minutes. Getting up, walking to the door, raising the lights, changing the record and then back to the door to lower the lights really messes up my mood. To solve the problem, the ceiling spots were split into three zones. One of the zones has small nearly pin spots over the turntable and four similar spots wash the bookcases containing my records. The house has an integrated Control4 home automation system with all switches and dimmers individually controllable. This allowed a small program for remote control of the spots. A push of a single button on the remote ramps up the pin spots to 50% output and another push turns off the light over ten seconds. Simple, elegant and no electrical noise.

I did make a few concessions to the physical appearance and functionality of the room versus ideal acoustic performance. A perfect room would be sealed with no sound energy getting in or out. This perfect room would probably not have recessed lights. Aside from the holes drilled in your acoustic shell, they also tend to vibrate and rattle but in the end I wanted the look of recessed lights. I used some heavy lead tape and foam sheets to dampen potential vibrations on the lights. To test the installation, I played some music with loud deep bass and listened for rattling, securing some loose trim with silicon sealant. No rattles to date.

Back to listening in total darkness. I highly recommend you try it. It’s more than just a quirky listening preference. Your brain processes not just sound but the visual inputs as well. With the lights on, the brain sees the speaker and the audio equipment and therefore logically interprets that you are listening to artificially reproduced sound. Turn off the lights and now your brain processes information from only one input, your ears. Since you do not see the speakers, your brain can suspend disbelief and process the sound as if the music was real. Visual cues actually produce disproportional distractions because more brain power is used to process visual than audio inputs. Without visual stimuli, the sound becomes far more real. I've tested this with countless people from audiophiles to iPod listeners and virtually all prefer the darkened room. If you have never done it, try it. It’s a free tweak. It might be a little disconcerting at first but once you relax, you will have found a neat little upgrade.

HVAC - For HVAC, I spec’d out twice the number of exhaust and return vents normally required for a room this size. One of the limitations of my previous listening room was that tubed electronics, especially amps, made the room uncomfortably warm. At an extreme, my old Tenor OTLs brought the room to 85°F in less than two hours – with the air conditioning on. While there were some ultra-quiet in-line solutions, I chose a DIY approach. The front exhausts are vented inside the ceiling TubeTrap soffit. The exhaust air just silently leaks from the soffit into the room. For the rear, I wrapped both the exhaust and return ducts in a heavy rubberized insulating material to minimize flexing, noise and vibrations. Then I stuffed a foam filter inside all the ducts, with the foam extending several feet into the ductwork. Undoubtedly it does reduce the airflow but with the extra capacity built into the room, it’s not an issue and even at full blast, the noise level is very acceptable.

Room Design (furniture)
- Each table, chair, light, plant, literally anything in your listening room has an effect on the sound. Eliminating everything between you and the speakers dramatically cleans up the soundstage by reducing reflections. Designed as a dedicated room, the lack of furniture presented no problem, just a single love seat for listening. Yet even the fabric type and chair design can alter the sound. Tight fabric stretched on a large sofa can reflect the sound and in some instances act itself as a passive radiator. I might be crazy and anal but for now, I’m not going to experiment with sofa fabrics.

The rear of the room is one area where a sonic compromise was made relative to functionality. Rather than a tube trap augmented back wall, I have a built-in bookcase for my record collection. It’s extraordinarily rigid, made from 3/4" MDF screwed, glued and braced wherever possible. It was built on-site as a complete unit and weighs a ton, literally. The absorptive /diffusive balance is achieved by the irregular surfaces caused by the records, books and other knickknacks. I 'tuned' the bookcase by ear with reflective and absorptive panels placed on the sides of each shelf and on the rear areas not covered by the records and books. Still I had a slight glare so I moved a few absorptive panels and three Argent Room Lens Helmholtz resonators and placed them between the bookcase and my listening seat. This final tweak cleaned things up nicely. Although not particularly attractive, it works.

Another slight compromise was made with the carpet. Wool carpet appears to be the preferred choice for listening rooms. According to those in the know, the individual fibers of natural wool are random length within the material. This tends to smooth out the sound, allowing the room to be less harsh and more natural. For budget reasons, I settled on synthetic carpet. With carpet being one of the last home building installations, by the time we were ready to pick out carpet, the reality of cost overruns hit hard and we needed to cut back. Wool might have an acoustic advantage but it is far more expensive than synthetic carpet. I ended with a medium density carpet on a 40-ounce (7/16" thick) fiber pad. Finally I added an inexpensive wool area rug between my listening seat and the speakers.

Location of the equipment rack - With a room perimeter of almost 100 feet, I had several options of placing the equipment rack. One consideration was against the back wall behind the speakers, which are pulled out into the room almost nine feet. This would have been a big mistake and I’ve seen it many times even by some otherwise very knowledgeable audiophiles. Equipment located behind the speakers mucks up imaging and the soundstage. The hardwood and metal pieces will reflect the sound unevenly, affecting the imaging and soundstage.  The other reason at least for me goes back to lights-off listening. Staring at a bunch of blinking lights in a darkened room ruins the effect I’m trying to achieve. With the rear wall a fixed bookcase, the equipment was destined for a sidewall. One of those backs to an HVAC room with its electric noise; the other sidewall to concrete. Easy decision. Just plopping the racks randomly on a sidewall doesn’t work either due to the nature of bass peaks and troughs especially along walls. I found a resonance node along the sidewall to minimize the acoustic energy and its effect on the components. Think of it this way. Nobody in their right mind would place their turntable in a corner and aim their subwoofer at the table. That is what you're doing in effect unless you find a suitable location. Finding a quiet node is not just for vinyl lovers. A tip many years ago from Albert Von Schweikert suggested that all electronic equipment should be placed in an area along the sidewall with minimum standing waves. This is especially true for vacuum tubes and vinyl. Additionally, all electronics should be kept away from room-boundary intersections because these are vulnerable to bass peaks. Therefore as a rule, I always keep the critical components on the top shelves away from intersections of floor and wall.

Starting Point speaker set up
- To design my room treatments, ASC had to perform acoustic tests requiring a fully-functional system with the speakers positioned as well as possible in a bare acoustic shell. The conventional wisdom of speaker setup is to form an equilateral triangle. While it’s a  good starting point, my experience is that an exact equilateral triangle forces the speakers too far apart, breaking down the tight center image and producing too much of a headphone effect with the individual sounds coming too much from each speaker. I shoot for slightly less width where the distance between the two speakers is approximately 80 to 90% of the distance from the speaker to the listener. Building a dedicated room allowed unlimited placement flexibility for both the speakers and the listening area. I started with the speakers and listening position about one-third into the room. This is a good general starting position for neutrality and minimizing room resonances. Ultimately, I ended up with the speakers approximately 37% from the front wall and 29% from the sides. There is no exact way to predict this short of painstakingly incremental movements of both the speakers in the horizontal and vertical axis and the listening chair. Unless the speakers are specifically designed for wall placement, always pull the speakers out into the room. It definitely improves every aspect of performance, allowing them to effectively bloom with a much smoother frequency response. Of course, all this is only applicable to custom-purposed rooms where design and wife acceptance factor (WAF) are no issues.

Simultaneously with floor position comes the speaker toe-in angle, another setup consideration that's crucial to good sound. Get it right and the imaging will holographically snap into place. Wilson’s setup instructions are very specific. Adjust the toe-in so you can just barely see the inside walls of the speakers from your listening seat. I’ve had many Wilsons from CUBs to X-2s and have experimented with every possible toe-in angle but always come back to their recommendations.

While it might appear obvious, your listening position should be equidistant from both speakers. Otherwise the sound from the speakers will have different arrival times resulting in distortions and loss of the delicate cues that collapse the holographic imaging we cherish. Also, I don’t believe it's possible to maximize speaker performance for multiple seating positions. It’s difficult to get past the ray-like nature of highs and the resonant mode problems of lows. When you try for a compromise of multiple positions, your soundstage will never be right in any. Go for one perfect position and let the chips fall where they may for the others. Now that we are past some of the design basics, subsequent chapters will dive into the somewhat more technical areas of room acoustics.

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