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System Setup
How to get the most out of your system
 

 
SETTING UP A HIGH END SYSTEM
by anthony chiarella

The pursuit of the absolute sound regarded by many as a pursuit reserved for the affluent. This characterization is both unfortunate and untrue: I have heard cost-no-object systems that sounded terrible, and I have heard modestly priced systems convey the essence and emotion of music. Achieving musical realism in the home depends upon selecting the proper hardware and optimally installing it in the listening room. Equipment choices are based upon variables such as budget and personal listening biases. (The component reviews published in The Absolute Sound will prove invaluable in the selection process.) On the other hand, the rigors of system setup apply whether your budget is $2000 or $200,000.

Speaker Setup and Listening Position

The best-sounding rooms have high ceilings, solid floors, and walls that are neither overly reflective (i.e. mirrored walls or expansive windows) nor inordinately absorptive (shag carpeting, wall tapestries) and are rectangular in shape. If you are making a first purchase of High End equipment, start by determining which area of your home will serve as the listening room. Note its contents (furniture, carpets, entrances, windows, construction) and relate these particulars to your dealer. (Hint: If your salesman is not concerned with these details, ask for someone else to help you.)

Once the room has been chosen and the equipment selected, the location of the various components must be decided upon. To simplify logistical issues, start  by determining where the speakers will reside.  Plan to place the speakers along either of the room's shorter wall. In order to achieve the best sound, measure the length of the wall behind the speakers and divide by 3: this number represents the approximate distance between the side wall and the speaker. (For example, in a 12-foot wide room, each speaker would be 4 feet from the closest side wall.) See Figure 1.

The speakers should also, with a few exceptions, be located at least 3 feet from the rear wall: closer placement will reinforce bass and affect midrange clarity; bringing the speakers farther out into the room will improve imaging at the expense of bass power.

Following the preceding instructions allows the speakers to be "roughed in."  Imaging and frequency balance should now be optimized by auditioning familiar recordings. Select a piece of music with a full frequency spectrum to adjust tonal balance, and a female vocalist (Jennifer Warnes's Famous Blue Raincoat [Cypress 661 111-2] and Marni Nixon's Nixon Sings Gershwin [Reference Recordings RR-19] are excellent for this purpose) to achieve image focus.

Assuming your speakers are both accurate and capable of adequate bass performance, playback of full-frequency recordings should indicate any tonal inbalances. Here is a useful guideline for all speaker types: Placing the speakers farther away from room boundaries (rear and side walls) will lighten frequency balance and reduce bass power, while situating the speakers closer to room boundaries will augment bass response, adding weight to the sound. Because dynamic and planar speakers differ somewhat, the adjustments techniques for each type are discussed separately.

Dynamic speakers offer great placement latitute. Experiment by moving speakers; (1) Backward and forward while maintaining a constant distance to the side wall; (2) closer together and farther apart without changing the distance to the rear wall; (3) diagonally, at various angles, into and out of the corners. If the initial speaker locations were determined as per the preceding instructions, movement on the order of 1 foot or less should be sufficient to correct most tonal aberrations.

Planar speakers radiate a significant proportion of their energy to the rear, and therefore must be kept  at least 3 feet from the back wall. While the relationship between room boundaries and tonal balance is the same with planars as it is for dynamic speakers, I would advise against attempting to augment the bass performance of a dipole radiator by moving it closer than 3 feet from the rear wall, otherwise, dipolar cancellation effects might compromise the sound. On the other hand, I recommend decreasing the distance between the speaker and side wall to improve weight and fullness. Of course, as with dynamic speakers, locating the speakers farther away from room boundaries can cure boominess.

For all speakers: While bass and lower midrange response can be smoothed through variations in speaker placement, this technique often has little impact upon mid and high frequencies. Anomalies such as brightness, dullness, hardness, softness, and the exaggerated projection or recession of vocals are generally the result of rooms that are either too reflective or too absorptive. The addition of plush furniture, heavy draperies, thick carpeting, wall hangings, and acoustical damping products can tame room reflections which impart a bright or forward quality to the sound. Conversely, a tendency toward muffled or recessed sound will be counteracted by the removal of these energy attenuating materials; Again, experimentation is necessary in order to achieve the best results.

Once the placement that yields proper tonal balance has been determined, proceed to adjust image focus. When you listen to the vocal recording previously selected, the voice should appear to emanate from a fixed location at the center of the soundfield. If, however, the voice seems to come directly from one of the speakers, or if the vocal image is bloated and diffuse, further speaker adjustment will be necessary. Toeing in the speakers, that is, aiming the cabinets or panels toward a point at the center of the listening position, is the most effective method of focusing an image. In your zeal to centralize the voice, take care not to compromise the width of the soundstage. The stereophonic effect places instrumental images across the soundfield. Ideally, the collection of images should extend from one side wall to the other. The requirement of precise centerfill must be balanced against that of a realistically expansive soundstage.

As with tonal adjustments, varying speaker location can improve imaging. Of course, when moving speakers to optimize image quality, verify that frequency balance is not affected. With patience and persistence, the techniques herein described will unlock the true potential of your sound system.  Here are some additional rules for dynamic and planar loudspeakers:

For dynamic speakers: If your speaker or stand includes screw-in feet or spikes, place a bubble level on top of the speaker cabinet and manipulate the feet to assure that the speaker is level. To quickly improve the image quality of dynamic speakers, toe the speakers in or out until the front panel, or baffle, is the only vertical surface visible from the listening position (the vertical side walls of the cabinet should seem to disappear).

For planar speakers: Planars are less tolerant of extreme toe-in than are box speakers. The toe-in process with planars should be accompanied by a  variation in the distance between the panels and those walls of the room (the side walls) which flank the speakers. Some planars (i.e. Magnepan and Apogee) are mirror imaged; that is, the drivers of the left and right speakers are at opposite ends of the panels. Placing tweeters to the outside will improve apparent stereo separation but, unless the listener is very far from the speakers, image focus and bass response are improved when the speakers are placed with the tweeters towards the inside edge of the panel.



Turntables

The performance of any turntable is dependent upon resonance control, geometric accuracy, and speed stability. Other than recommending that the  audiophile purchase an easily readable strobe disc to verify proper rotational speed, the issue of speed stability will be not discussed here. There is, however, much that the system owner can do to optimize his record playback equipment in terms of the other two parameters.

Resonance Control: The listening room can prove a hostile environment. In addition to coping with the vibrations created by its own motor and suspension system, a turntable must deal with the structure- and air-borne energy propagated by the playing of music through the loudspeakers. The first guideline, then, is to place the turntable as far as possible from the turbulence created by the speakers. Locate the turntable on a far wall or around a corner (keep in mind that turntable-preamp interconnections, especially with low-output moving coils, should be kept to 4 feet or less in order to minimize noise).

Structure-borne vibrations are dealt with both by the turntable's suspension system and by the support upon which is situated. Wall-mounted shelves and free-standing tables, specifically designed for turntables placement, are commonly available. A proper structure will serve to insulate the turntable from external energy (speaker vibration, footfalls, etc) and evacuate any residual energy within the turntable system. I will not deal with the technical aspects of isolation and evacuation, as they are beyond the scope of this article, but I refer interested readers to a publication by George Merrill (owner of Underground Sound, Memphis, Tennessee) entitled, "How To Set Up and Tune Your Turntable and Tonearm," (Available from Underground Sound, 2125 Central Avenue, Memphis, Tennessee 38104-5495; 901-272-1275) which comprises a primer on the subject of resonance control. I would, however, be remiss if I did not stress the importance of locating the turntable and its support near a load-bearing wall. The outer walls of the home and those interior walls used to support the weight of the building (i.e. those walls sharing the same vertical plane as the house's support beams) are inherently the most stable and solid areas in the structure, and provide the points of turntable anchorage that will be least interactive with external resonance. If pressed to choose between wall shelves and tables, I would say that wall shelves offer the best combination of desirable physical properties at the lowest cost, especially if you have the luxury of an available wall space located both on a load-bearing wall and out of the soundfield.

Geometric Accuracy: A turntable system includes a plinth or base, a rotating platter, a cartridge tracing the record grooves, and a pickup arm to hold the cartridge as it traverses those grooves. The first requirement in the accurate retrieval of information from the LP storage medium is that the system components be level - in order to minimize the effects of gravity. Ideally, the turntable support, plinth, and platter should all be level. Start with the support. Place a bubble level on the support's top plate.  Proceed to level the support along this line, then rotate the level 90 degrees and repeat the process. If either your support or turntable does not incorporate a levelling mechanism, use paper, cardboard, or coins as shims to achieve level. After the support platform has been levelled, center the turntable on top of it. Now place the level (or levels, it is better to have two and place them at right angles to each other) and assure that the plinth is paralleled to the horizontal plane of the support surface. Finally, place the level on the platter and verify that it is level. If your turntable has a spring suspension, now is the time to ensure that it is properly adjusted, neither riding too high above the plinth nor bottoming out against it. For turntables with dished platters, such as those by Well-Tempered, only the inner 3 inches of the platter surface will be flat; place the level so that it rests within that 3-inch area.

Pickup Arms and Cartridges

Once all functioning parts of the turntable are leveled, the pickup arm/cartridge adjustments can be made. Tracking force (a/k/a downforce) and tracking angle should be set with the assistance of accurate gauges. Ortofon made a lovely, inexpensive tracking force gauge, but it is no longer available. The Shure gauge is a fine alternative. For adjusting tracking angle, the Dennesen Soundtractor and DB Systems Alignment Gauge are recommended. Vertical tracking angle, azimuth, and anti-skating are normally set without the use of gauges. (Note: the Signet Cartridge Analyzer, allows precise azimuth adjustment, and VTA can be optimized with the use of an oscilloscope; however, most audiophiles will neither have access to these devices nor will they have the expertise to use them. The alternative procedures described in this section will allow a high level of adjustment precision without the need for such test equipment.)  All deal with the angular relationship of the stylus to the record groove. It is helpful to remember that the objective of the turntable system is to decode groove modulations in exactly the same manner as they were encoded on the master disc by the lathe and cutter head.

To adjust vertical tracking angle (VTA), view the cartridge from the side as it is tracing a record. The arm, and particularly the cartridge mounting plate, should be parallel to the record surface. Using this position as a starting point, audition the system with both string and vocal recordings. Move the VTA adjustment up and down until a natural balance between bass, treble, and vocalist image height is achieved. See Figure 2. Azimuth refers to the perpendicularity of the stylus to the record surface as the cartridge is viewed head on; that is, at a 90-degree angle to the view used to measure VTA.  Improper azimuth adjustment manifests itself as channel imbalance. If azimuth is correct, the angle between the stylus and the record will equal 90 degrees on either side. To adjust azimuth, rotate the arm in the direction of the largest angle (that one more than 90 degrees). If your pickup arm has no azimuth adjustment, use small washers as shims between the top of the cartridge and the bottom of the cartridge mounting plate.  See Figure 3.

For those who do not wish to rely on the visual procedure described above, a simple apparatus can be constructed which will allow you to use the "null position" method of azimuth adjustment. The null method assumes that by reproducing an identical signal through both channels, inverting one channel, then combining the inverted and non-inverted signals, perfect channel balance (and by extension, correct azimuth) will yield zero output. Materials required include: one pair of female-female RCA barrel adapters; one pair of stereo RCA interconnects; one "Y" connector, two male-one female, and a second "Y" connector, two femal-one male. Sever either the right or left interconnect, remove the insulation and invert phase by reversing the hot and ground conductors, insulating the new connections with electrical tape to assure that no short exists in the line. The stereo interconnect pair will now consist of one in-phase wire and wire modified to invert phase.  Disconnect the turntable wires from the preamp and connect the female-female barrel adapters to the male ends of the pickup leads. To the other end of the barrel adapters, attach the stereo interconnect (with one inverted channel), followed by the two female-one male "Y" adapter. Finally, connect the female end of the two male-one female "Y" connector to the open male plug, and attach its two male ends into the preamp's phono input. Playing a mono record, you should notice a large decrease in output. Adjust azimuth until you find the position that produces minimum volume.

The final adjustment is for anti-skating or, as the British call it, bias.Ostensibly, anti-skating force should be identical to tracking force, but variables such as stylus shape can cause a discrepancy between these two settings. With the record spinning, place the needle on the grooves and, while viewing the cartridge head on (as for azimuth), note any deflection of the stylus/cantilever assembly in relation to the cartridge body. See Figure 4. If the cantilever points toward the center of the record, reduce the anti-skating force. If the assembly pulls outward, increase anti-skating. Cartridge mistracking and an imbalance between right and left channels are audible indications that anti-skating force has been set improperly.

One last tip: If your arm is supplied with multiple counterweights, use that combination of weights which allows the arm to apply the correct tracking force with the counterweight as close as possible to the pivot point, as this setting will, through a process of dynamic destabilization, allow the most unhindered tracking of warped records.

Electronics

Modifications and accessories aside, there is little rigor that can be employed in the optimization of electronics. In terms of equipment placement, the concerns expressed in the turntable section of this article apply here as well; keep the electronics out of the soundfield, on platforms that isolate/evacuate vibration energy.It is, furthermore, important to situate your electronics in such a way that the power amp is as close as possible to the speakers, thereby minimizing the length of speaker cables. If a long run of interconnect (over 6 feet) is used between the preamp and power amp, shielded cable can be used to reduce EMI/RFI-induced noise. Equipment supplied with XLR interconnecting facilities generally sounds better when operated in the balanced mode, especially when using long cable runs.

With vacuum tube electronics, bias the output tubes as per the manufacturer's instructions. As the characteristics of tubes change with age, perform rebiasing periodically, and replace tubes when necessary (usually 1-2 years of use for output tubes and 2-3 years for preamp or driver tubes).

The recent proliferation of line conditioning devices is testimony to the impact of AC power upon the sound quality of audio components. While a line conditioner might prove to be a worthwhile purchase, a high quality AC receptacle can improve the quality and consistency of current supplied to your system, and do so for negligible expense. Hospital-grade ("green dot") receptacles are available from your local electrical supply house, generally for less than $15. Warning: AC receptacles should only be installed by qualified personnel.

Sound quality of amps, preamps, and CD players can be dramatically enhanced by assuring correct AC line polarity. This procedure requires the use of a multimeter and of "cheater plugs" that lift the earth ground from three-conductor power cords by converting three pronged plugs (consult the manufacturers of your components regarding limitation in warranty coverage which might result from operating their products without the benefit of earth grounding). Disconnect and shut off all components. Set the multimeter to the "AC Volts" position. Connect the positive lead to a metal part of the power amp's chassis and the negative lead to an earth ground, such as the retaining screw of your AC receptacle's wall plate. Turn the amp on, allowing a minute or so for the amp to stabilize, and measure the voltage. Now, turn the amp off and reverse the polarity of the power cord. Turn the amp back on and compare this voltage reading to the first. Install the power cord with the plug orientation that yields the lowest voltage measurement.

Optimize electrical and signal integrity  by keeping interconnect lengths as short as possible, and assure that all connections are solid, made with clean contact areas, and that heavy wires are strain-relieved so that chassis-mount and wire connectors are not overstressed by the weight of the cables.  It is advisable to keep tuners and CD players at least 3 feet from preamps in order to minimize the interaction of these source components with sensitive amplification devices. Finally, routing signal-level wires away from AC power cords will minimize hum and noise.

CD Players

Some of the techniques discussed in the preceding pages can improve the performance of CD players. Transports benefit from a stable, isolated support platform as described in the turntable section of this article. Additionally, a weight placed on top of the transport (caution: do not block air vents) can reduce chassis resonance, improving clarity and detail. Correct AC polarity is especially important for digital hardware. When listening to records, turning off your CD player minimizes digital interference, thereby enhancing Analog sound quality.

The burgeoning accessories market has been a boon for CD enthusiasts. Disc stabilizers, edge treatments (CD Stoplight, for instance) ferrite chokes, digital line conditioners, and an abundant variety of digital interface cables allow the audiophile to extract maximum performance from his or her CD system.Those "tweaks" that are applied to the CDs themselves, rather than the players, are generally inexpensive enough to encourage audiophile experimentation. But be forewarned: Some CD treatments will not work in all players. When in doubt, ask your dealer for advice. On the other hand, modifications to CD hardware, such as transport or clamping-device revisions, tend to be more expensive, often require the services of a professional technician, and may void the manufacturer's warranty. Proceed with caution.

There are currently four categories of digital interconnects: plastic fiber optic, glass fiber optic, standard 75-ohm coaxial, and AES/EBU. Of these, plastic fiber optic cables have the narrowest bandwidth, followed by coaxial, AES/EBU, and glass fiber optic. There seems to be a correlation between wider bandwidth and improved digital information retrieval. If your transport and D/A converter are equipped to handle multiple interfaces, investigate all options.

The procedures outlined in this article constitute a common-sense approach to system optimization. I would recommend implementing one change at a time in order to determine the impact of that technique upon the system's sound quality.

Tinker. Experiment. Explore.
 And please keep in mind that audio is your hobby: Enjoy it!  It is my fondest wish that the advice in this article encourages you to gain a greater familiarity with your equipment - and that you might, as a result, more fully appreciate the ability of fine stereo systems to transport the listener to the original performance space.



 


 
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