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Subject: FAQ: rec.audio (part 4 of 4) Newsgroups: rec.audio,rec.music.info,rec.answers,news.answers From: neidorff@uicc.com Date: Tue, 26 Jul 1994 21:06:38 GMT Archive-name: AudioFAQ/part4 Last-modified: 1994/6/20 Version: 1.17 16.0 Wire More than any other topic, speaker cables and equipment interconnects seem to use up rec.audio bandwidth echoing the same theoretical arguments, testimonials, and opinions. Controversy can be stimulating, educational, and also amusing. Please try to keep postings aimed at one of those three goals, and avoid the insults and emotion. Also, try to avoid echoing a common position or principle, as described below. 16.1 Do speaker cables matter? To avoid confusion and repetition, here is some terminology. Cables are connectors attached to wires. Wires generally have multiple conductors optionally surrounded by a shield and outer insulating covering. Cables can introduce noise into the signal, act as a filter (and thus change the frequency response of the system), and provide nonlinearities from improper (intermittent/loose) connections to or between the connectors. It is quite scientifically conceivable that some cables do cause a difference in sound, because of the differences in DC resistance, interconductor capacitance, and connector attachment alone. The effects of exotic conductor weaving and materials are not so well established. In general, these effects (once we eliminate DC resistance), seem to be small. However, if your system is at least fairly good, then some folks have observed (although not in an experimental, double-blind sense) significant differences in system performance with different cables. The effects are said to be quite system specific; the only real guideline is to try them and see which ones seem to sound better in your system. Roughly speaking, the price ranges for speaker cables is low (under $1/ft), medium (under $6-8/ft), and high (up to $100/ft and more). Try to arrange it so you can trial such cables; at several hundred dollars per set, experiments can be expensive. In any system or experiment, it is essential that the differences between cables be separated from the differences between connectors. You should have an EXTREMELY solid connection between cable and speaker. Speakers operate at very low impedances, so that bad connections will create significant artifacts or signal losses at any power level. For example, if the connection has a linear resistance of just 1 ohm, the speaker damping factor will be dramatically reduced, making bass muddy. If the connection contains imperfect metal oxides, then a slightly rectifying junction will block the signal, producing compression, distortion, and other non-linear effects. There are many magazine articles on cables with various perspectives which are worth reading, including: "Speaker Cables: Testing for Audibility" Fred E. Davis Audio, July 1993, pgs. 34-43 16.2 What speaker cables are available and how good are they? There is a wide range of speaker wire available, ranging from 30ga zip cord (~$.10/ft) to exotic wires costing over $300/ft. The material used ranges from copper to oxygen-free copper (OFC) to silver. (There are a bunch of others as well.) Oxygen-free copper is probably NOT any different from common copper in sound. If you hear a difference between two cables, it is not a difference between oxygen-free and common copper. Resistance may be significant for speaker cables. The higher the resistance, the more the cable will affect the sound, all else equal. The resistance characteristic of metals is called resistivity. The resistivity of copper is 1.7 microohm-cm. Silver is very slightly lower, 1.6. Gold is a bit higher, 2.4. Silver and gold are different from copper in other ways than resistivity. Gold does not oxidize in normal environments, so gold contacts will not need periodic cleaning and will not create rectifying junctions. Silver will oxidize, but the oxide of silver is conductive, so oxidized silver will still make good contact. Copper oxide is a bad conductor. Oxidized copper contacts may insulate, may conduct, or may rectify. Copper is a bad material for cable terminals, but this may or may not mean anything for the conductor itself. 16.3 What can I use for budget speaker cables? First, a few words on terminology. Wire is sized by AWG or BS gauge number. Larger numbers represent smaller wire. AWG 40 (also called 40 gauge) is as fine as human hair. AWG 12 is 2mm or .081" diameter. Some wire is classified as solid, because it contains one strand per conductor. Other wire is called stranded, because it consists of many strands per conductor. Stranded wire is far more flexible than solid wire. Most wire is made from drawn copper. Some wire is sold that is claimed to be made with a process that produces oxygen-free copper. Oxygen-free copper has a different metallurgical structure than common copper and may or may not conduct current better. Some critical listeners have reported excellent sound from large diameter solid copper wire, such as home wiring "Romex 12-2". At least one expert has said that common 18-gauge solid copper hook-up wire sold by Radio Shack also works very well. Also recommended on a budget is Sound King wire, a 12 gauge oxygen free copper stranded cable. This is available from MCM Electronics for $.39/ft. The scientific literature indicates that small gauge wire generally sounds worse than large gauge. Resistance-related effects of the cable can be eliminated by using at least 12 gauge wire, particularly for long runs. Of course, shorter runs are always preferred, because they come much closer to the ideal zero-length wire, with no resistance, no capacitance, no inductance, and no change in signal. 16.4 What can I use for budget speaker connectors? The worst connectors are push-down, or spring terminals. Screw terminals with solid copper wire are much better. Gold-plated binding posts and gold spade lugs are inexpensive by audiophile standards and are extremely stable. Binding posts with spade lugs can be tightened to get a very good mechanical joint, and may offer the lowest electrical resistance of any connector. Gold plated banana plugs and jacks are very good speaker terminals. Good ones are more expensive than gold spade lugs, however, they also provide a bigger area of contact, and are more convenient when you must frequently reconfigure the system. Banana plugs should be periodically monitored for corrosion and loss of spring tension. Monster offers a banana-plug connector with an expanding center pin that forms an even better connection than common gold banana plugs. At approximately $25 per pair, the Monster banana plugs aren't a budget connector. All else equal, connectors with gold surfaces are better than connectors with any other surface. This is for two reasons. First, gold is extremely inert, meaning that unless gold is exposed to very harsh chemicals or harsh vapors, it will not corrode or oxidize. It will remain a pure, low-resistance conductor. Second, gold is quite soft, so that if a gold-plated connector is squeezed between two metal surfaces, it will deform slightly to fill scratches and voids, giving a very broad, low-resistance contact area. Corrosion of connectors is often a problem. Gold-plated terminals and connectors somewhat avoid this problem; problems with other connectors can be mitigated by unplugging and replugging the connector on a regular basis, cleaning the contact areas with a pencil eraser, or by using a contact enhancer such as Cramolin or Tweek. When you use a contact enhancer, be very sure to follow the directions, and avoid spreading enhancer about your equipment. 16.5 What about interconnects, such as the cable between tuner and amp? Line-level interconnects conduct smaller signals than speaker cables; the typical signal ranges from -2V to +2V (the CD output standard) with currents in the microamps (the corresponding values for speaker cables attached to a largish power amp might be -70V to +70V and currents of many amps). Line-level interconnects can be divided into single-ended (or unbalanced), and balanced interconnects. Home audio is almost always single-ended interconnects. Single-ended interconnects almost always use a form of the RCA connector (or phono plug). RCA plugs form fair to poor connections that degrade with time as corrosion works into the metal-metal contact and as the spring tension of the connectors relax. Gold-plating reduces the effect of corrosion and locking RCA connectors solve most of the mechanical problems. However, these premium phono connectors are rare and expensive. For example, a gold-plated Vampire locking RCA plug costs approximately $23/pair. If RCA connectors weren't a de facto standard, we'd recommend against them. Unbalanced interconnect wires vary in geometry, material and price. Cheaper wires have a single conductor (normally stranded) and a shield and cost $.20-$2/ft. Medium (complexity and price) wires have two conductors (often arranged as a twisted pair) surrounded by a shield and cost from about $3-$20/ft. Exotic wires have all sorts of geometries and materials (such as stranded silver conductors, or ribbon cable braided around a core, or in one extreme case, a tube filled with mercury!). Prices may be as high as $200-$300/ft. Balanced interconnects have three conductors: two for the signal one for ground, and additionally a shield. The standard connector for balanced cable is the ITT/Cannon XLR connector, which is quite good mechanically (they lock). Equivalent connectors are also available from Switchcraft, Neutrik, and other vendors. If you have to run cables longer than 12 feet or 4 meters, the greater noise immunity of balanced interconnects is often a good idea. For this reason, balanced connectors are standard equipment in professional installations such as studios, public address systems, and broadcast stations. There is not much variation in balanced cables. The three brands mentioned above are known to be rugged, high quality and moderately priced. Slightly weaker imported connectors are | available, but they aren't dramatically cheaper. Better | connectors are also easier to assemble and have a more durable | cord strain-relief. For most systems, the most important aspect of a cable are the mechanical reliability of the connectors; in particular, the joint between connector and wire, and the joint between connector and socket. Typically, interconnect cables are short. It is worth getting just the right length; cables often come in .5 meter increments. With quite good systems, some people observe differences in sound between various interconnects. This is quite system-specific and the same advice as given above applies: try several brands. Most good dealers will loan interconnects for home evaluation. In cables where the shield does not carry the signal or ground, the shield is normally only connected to ground at one end. In systems where there are significant differences between ground levels on various components, it may make a difference which way such cables are connected. Typically, the end where the shield is grounded should be at the source of the signal. Often, such cable has arrows on it pointing in the direction of the signal flow. In any case, try both orientations. There are many objective reasons why cables might cause differences in sound by interacting with the drivers in the signal sources as well as by providing non-linear effects in the RCA connector. Most of these effects are again related to interconductor capacitance and resistance, and the quality of the shielding provided by the "shield" conductor. In balanced cables the quality of the "twisted pair" inside the shield is also important. One might note that a shield protects from only capacitively coupled interference, and not from any magnetic field interference. The twisted pair in a balanced line provide some magnetic rejection, as does steel conduit. However, steel conduit has other characteristics which make it undesirable for audio in general. 16.6 What about Phono Interconnects: Phono interconnects are part of the link between a cartridge on a turntable and a preamp (or head amp or receiver). They are a special case of line-level interconnects because the signal is much lower, typically 1 to 50 millivolts. They are also intended to operate into a higher impedance, typically 47K ohms, and form part of the capacitive load for the cartridge. The low signal levels mean that the shielding of the cable, and the presence of a separate drain/shield are more important, as is a good ground. A separate solid ground should come along with the cable as a separate lead co-routed with the cable. In addition, the low signal levels make a good solid connection to and through the connectors MUCH more important, because of the greater sensitivity to low-level nonlinearities. Wire capacitance is often ignored in line-level interconnects; however, in a phono interconnect, it may constitute half of the total capacitive load of the cartridge. Obviously, then, two cables with significantly different capacitances should sound differently. In this sense, the "right" cable for one cartridge may be too low or high in capacitance for another cartridge. For low-impedance cartridges (most moving coil cartridges), the wire must have low resistance to prevent cartridge unloading and frequency-dependent signal loss. In addition, as the signal levels are quite low, shielding is important. Unfortunately, copper shields do not block stray magnetic fields, so in the case of phono cables, careful routing may be even more effective at reducing hum than special wire. 16.7 Is there really a difference in digital interconnects? There are now three kinds of digital interconnects that connect transports to D/A converters: coax, plastic fiber (Toslink) and glass fiber (AT&T ST). In theory, these should sound EXACTLY the same (bits are bits). However, this assumes good circuit design (in particular, the clock recovery circuits of the DAC, and careful consideration of electronic noise) which may be compromised because of cost considerations or ignorance. Note: different signaling schemes are used on plastic and glass fiber. In any case, some people claim to hear a difference; of those who do, most seem to prefer the glass fiber. However, the technology of fast digital data transmission in consumer electronics is evolving very quickly now. Any specific recommendation should be treated with suspicion until the industry matures. 16.8 Can I make very good interconnects myself? Yes. You will need to be the judge of whether or not they are as good as $100 interconnects, but it is easy to make interconnects that are better than the $2.00 set which comes with new equipment. There are two necessary ingredients: two-conductor shielded cable and RCA connectors. There is a lot of debate over what is the best cable, but in general, the lower the capacitance per foot, the better. Choice of insulation is harder. There may be an advantage to polypropylene or teflon over polyester or rubber, but even that is debatable. If you are buying wire from an electronics distributor, some have successfully used Belden 1192A microphone cable. It is rubber insulated, so very flexible. Another recommended cable is Belden 8451. This is a polypropylene cable with foil shield. Finally, consider Belden 89182. This is foamed teflon insulated, so very low capacitance, and foil shielded. If you plan to make a long cable, this low capacitance cable may be the best choice. There is also a variety of RCA connectors available. A good connector would be gold plated and machined to tight tolerances. A poorer connector will not fit as well, will make poorer contact as the connecting surface oxides, and will lose its springiness with use. When wiring the cable to the connector, use one wire for signal, (the tip of the RCA connector) and one wire for ground (the shell or outer conductor of the RCA connector). Some cables use a foil shield which is difficult to solder. These cables typically have a drain wire parallel to the foil which can be used for soldering. Others use a braided shield. Regardless of which type of wire you have, connect the shield or the shield drain wire to ground on only ONE SIDE. This will stop noise picked up by the shield from causing ground noise. It can be a touchy job soldering RCA connectors. Before you use your new cables, check with an ohmmeter or a continuity tester to make sure that you have not accidentally sorted the signal and ground leads together, either with a stray drop of solder or a loose wire strand. 17.0 The Press 17.1 Which magazine should I read? Which ever one you like. None are absolutely objective. Here's a list of some common ones: Audio Amateur ($20/yr 4 issues) (Do-it-yourself) Box 576 Peterborough NH 03458 USA 603-924-9464 Audio Critic (US $24/yr 4 issues) (High-end) PO Box 978 Quakertown PA 18951 USA 215-538-9555 or 215-536-8884 Audio Magazine (US $24/year 12 issues. Mid-fi) Subscription Office: PO Box 53548 Boulder CO 80321-2548 USA 800-274-8808, 303-447-9330 Editorial Office: 1633 Broadway New York, NY 10019 212-767-6000 Audio Observatory (US $15/year 12 issues) 22029 Parthenia Street West Hills, California 91304 Audiophile (High-end, High-$$$ Buying Guide, Blind reviews) Haymarket Trade & Leisure Publications Ltd 38-42 Hampton Road Teddington, Middlesex, TW11 0JE, UK +44 81 943 5000 US Inquiries should go to: Eric Walter Associates Box 188 Berkeley Hts NJ 07922 USA 201-665-7811 Audiophile Voice 2001 Palmer Ave Suite 201 Larchmont, NY 10538-2420 USA Bound For Sound (US $18/yr 12 issues) (High-end) 220 North Main St Kewanee IL 61443 USA 309-852-3022 Car Audio and Electronics ($19.95/year 12 issues) Avcom Publishing Ltd 21700 Oxnard Street Suite 1600 Woodland Hills CA 91367 USA 818-593-3900 CD Review (Music Reviews; all tastes, only CDs.) $19.97 per year 12 issues PO Box 588 Mount Morris IL 61054 USA Glass Audio ($20/yr 4 issues) (Do-it-yourself, tubes) Box 576 Peterborough NH 03458 USA 603-924-9464 Hi-Fi Choice (Mid-end. Comparative reviews with graphs, tables, and subjective commentary; 'Buying Guide' section) Dennis Publishing Ltd. 14 Rathbone Place London, W1P 1DE, UK +44 71 631 1433 Hi-Fi News and Record Review (Mid-end. Good new record reviews) Subscriptions Department Link House Magazines Ltd 1st Floor Stephenson House, Brunel Centre Bletchley, Milton Keynes MK2 2EW, UK Hi-Fi World (Friendly, lower-mid-end magazine) (reviews and "how things work" articles) Audio Publishing Ltd 64 Castellain Rd Maida Vale London W9 1EX, UK +44 71 266 0461 In Terms Of Music (Emphasizes music reviews, new) PO Box 268590 Chicago, IL 60626 USA 312-262-5918 International Audio Review (US $38/yr, 12 issues?) 2449 Dwight Way; Box 4271 Berkeley CA 94704 USA Positive Feedback (US $25/yr 6 issues) (high-end) Oregon Triode Society 4106 N.E. Glisan Portland OR 97232 USA 503-235-9068 Sound Practices (US $20/yr 4 issues) (Do-it-yourself) Box 180562 Austin, TX 78718 (512) 339-6229 Voice/Fax 72411.533@compuserve.com Speaker Builder ($25/yr 6 issues) (Speaker projects) Box 576 Peterborough NH 03458 USA 603-924-9464 Stereophile (US $35/yr 12 issues) (High-end) 208 Delgado Santa Fe NM 87501 USA 800-238-2626 or 505-982-2366 Stereo Review (US $6.97/yr 12 issues. Lower end/mass market) Subscription Office: PO Box 52033 Boulder CO 80323-2033 USA Editorial Office: 1633 Broadway New York, NY 10019 212-767-6000 The Absolute Sound (US $46/yr 8 issues) (High-end) Subscription Center: Box 6547 Syracuse NY 13217 USA 800-825-0061 Editorial Office: 2 Glen Avenue Sea Cliff, NY 11579 516-676-2830 The $ensible Sound (US $20/yr 4 issues) (Mid/High-end) 403 Darwin Drive Snyder NY 14226 USA 716-681-3513 or 716-839-2199 What Hi-Fi (Mid-end; comparative, subjective reviews) (contains it's own buyer's guide with recommendations) Haymarket Trade & Leisure Publications Ltd 38-42 Hampton Road Teddington, Middlesex, TW11 0JE, UK +44 81 943 5000 US Enquiries should go to: Eric Walter Associates Box 188 Berkeley Heights NJ 07922 USA 201-665-7811 17.2 Which reviews are better? Some reviews are so colorful and exciting, that they make great journalism and fun reading. Lets ignore these for now, even though they have their place. Beware of reviews from magazines that advertise the same product. The likelihood of bias is too high. Unfortunately, that rules out 99% of the reviews in magazines. Stereo Review has a bad reputation for loving everything made by every advertiser. Even high-end journals such as Stereophile and The Absolute Sound can be influenced. A classic example of misleading reviews occurs with equipment submitted to a magazine for review. The manufacturer may send the editors a carefully built, adjusted piece for review. The magazine will honestly rave about it. The manufacturer will then send the design off-shore for more economical manufacture and assembly, and the quality will suffer. Lower quality components will be substituted for prime parts. Adjustments will be made to wider tolerances or will not be made at all. The design may be completely changed to make it more manufacturable. You will unknowingly get a completely different piece than reviewed. Home auditions with one or two candidates from each of a few dealers are your best guide to be sure that you get what you want and pay for. 17.3 Is Consumer Reports right? Consumer Reports is the most objective testing lab we have ever found. Unfortunately, they are also the world's least specialized testing lab. They market their testing to the average consumer. The average consumer will not hear some of the subtle differences which audiophiles hear. For that reason, Consumer Reports ignores issues that others feel vital. Consumer Reports also insists on basing their audio testing predominantly on lab measurements. Although lab measurements do tell many differences between devices, interpreting lab measurements for best sound is difficult or impossible. For example, it is very hard to compare two speaker frequency response curves and tell which will sound better. Some $3000 speaker frequency response curves look worse than some $600 speaker curves, even when tested in the same setup. On the other side of the issue, Consumer Reports has improved its test methods, and will continue to improve. Expect the accuracy of their reviews to improve with time. The Consumer Reports frequency-of-repair data base is larger than any similar data base published and can be trusted as well as any statistic. 18.0 Retail 18.1 Should I use an up-scale retail store? This is probably the best place to listen to gear in a controlled environment, next to your home. This is the best place to find expensive, high quality gear. This is the place which is most likely to have a good policy on home trials and a liberal return/upgrade policy. This is also likely to be the most expensive place to shop. One exception to this is that these stores have the ability to sell demos, returns, and discontinued gear at very advantageous prices. Some up-scale dealers will negotiate price on large systems or expensive purchases. It never hurts to ask. There are definitely better and worse local hi-fi stores. If you find a really good one, it is probably worth the extra money to buy from them, rather than from discounters. A really good store will not push you to buy what they want to sell. A really good store will allow you to take your time with your decision. A really good store will not distort the truth in describing equipment. A really good store will help you get the most out of your purchase by showing you how to set it up. They will tell you what placement works best for the speakers. (Don't believe them if they tell you to put them anywhere.) A really good store also selects their lines carefully. They don't want dissatisfied customers or warranty returns any more than you do. A really good store will also have technical equipment and/or skilled technical people that can perform tricky adjustments correctly, such as cartridge and tonearm alignment. Due to the nature of the customer, a hi-fi store in a shopping mall is likely to use high-pressure sales techniques. They know that the majority of their customers are distracted easily by 299 other stores. Most of their sales go to customers that come in for 3 minutes, select something, and leave. There are exceptions to this, of course, but if there was a good generalization, it would be to look elsewhere. There are stores in large buildings, small buildings, private homes, shopping plazas, and every other conceivable venue. Search from among these to find one that meets your needs and fits your style. 18.2 Should I use a discount store? If you need to listen carefully before making up your mind, discount stores can be very frustrating. If you know exactly what you want, then this can be a great place to save money. Don't expect knowledgeable sales help or after-sale support. Be sure to ask about the warranty (see 19.1 below on warranties). 18.3 Is it right to negotiate price? Most people feel that it is fair to negotiate. Some feel that it is fair to lie in negotiating, as the sales people frequently lie to you also. Others think that lying to get a lower price is an immoral practice. It may even be illegal, an act of fraud. Some people feel that if you negotiate over price, you encourage stores to mark prices artificially high, so that the stores have room to negotiate. Others feel that in negotiating, you are asking the store to accept a lower profit, or asking the sales person to take a lower commission and are directly hurting them. 18.4 How can I negotiate price effectively? A great source of information on this topic is available from books on buying a new or used car. However, some very helpful general tips include: Know the competition and the dealer. Know the gear. Know the prices available elsewhere. Believe in your research, not their words. Stand your ground. Be nice to the people but hard on the deal. Be prepared to walk away if they won't agree. Expect their lines and prepare responses in advance. For example, expect the dealer to claim that the Nakamichi deck is the best cassette deck on the market. Be ready with a reply such as at that price, you can buy a DAT machine which has better frequency response, lower signal to noise ratio, etc. 18.5 It sounded great in the store. Is it great? Never let anyone else pick stereo for you. Especially not speakers. They all sound different, and you don't need a golden ear to hear the differences. Listen for yourself and ignore what the sales people say. If you are still unsure, ask the sales people to let you take the gear home for a home trial in exchange for a large deposit. Home auditioning takes 99% of the risk out of store auditions. 18.6 Do sales people try to trick the customer? Some do and some don't. Some will treat unpleasant customers badly and treat friendly people well. Most sales people aren't wealthy. They sell stereo to make a living. If they can sell you a more expensive piece of equipment or a piece of equipment with a higher profit, they will make more money. Usually, this figures into everything they say. Some sales people claim to be altruistic. Some sales people really are open and honest. They may starve with this approach, or they may have a nice enough personality, a good enough product line, a good enough store behind them, or enough technical background to overcome this "limitation". 18.7 How can sales people trick the customer? Often, a customer will trick him or herself without help. We are often swayed by appearance, sales literature, position of the equipment in the show room, and our own desire to buy what others will like. Some times, the sales person will actively try to push a particular piece of equipment by demonstrating it against another piece of equipment which is inferior or defective. Some sales people will demonstrate a set of speakers while simultaneously driving a subwoofer, even though they are not telling you this. With the subwoofer, it probably will sound better. Some sales people will demonstrate one set of speakers louder than others. Louder almost always sounds better. Most stereo buyers go into the store, spend a few minutes selecting what they want, lay down big bucks, and leave. They don't need to be tricked. They don't listen carefully. They trust the sales person's choice as best in their price range. For non-technical reasons, these people are the most likely to be satisfied with their purchase. 18.8 What should I ask the sales person? What do you want to know? Seriously, the best questions are those which the sales person can answer without distorting the truth. Don't ask a sales person to compare their brand to a brand they don't sell. Don't ask "how good is the ...". Ask questions of fact. Here are some questions you may want to ask: If I don't like it can I return it for a full refund? Can I try this out at my home in exchange for a deposit? What does the warranty cover? For how long? What do I need to know to set this up for best sound? Do I get a manufacturer's warranty with this? Where do I take this to get it repaired under warranty? Where do I take this to get it repaired out of warranty? 18.9 How do I impress the sales person? Why would you want to? You have money and he doesn't. 18.10 How do I get the best service from a sales person? Be honest with the sales person. Set some reasonable request and ask them to meet it. For example, say that you will buy this if you can try it at home first and listen to it side-by-side with a piece from another store. Alternately, say that you saw the same thing at store Z for $xx less, but you will buy it from the guy if he will match the price. 19.0 Miscellaneous 19.1 What do I need to know about warranties? Warranties have a few basic components. The first is the term of the warranty. The second is what is covered. The third is who supports the warranty. The fourth is what restrictions. Term is fairly self evident. What is covered is more detailed. In audio electronics, typically everything is covered with a "parts and labor" warranty. Often mechanical components such as tape heads are covered by different terms, such as shorter terms on labor and longer terms on parts. Likewise, speaker warranties vary widely, from unconditional with no term limit to a basic 30 days parts and labor. Some warranties come from the manufacturer. Others come from the dealer. Still other warranty support is available with certain premium charge cards. A common restriction on some warranties is that the equipment is not covered unless it is sold by an authorized dealer. A few dealers have lied about being authorized dealers. Equipment sold by an unauthorized dealer is almost always sold completely legally. This unauthorized dealer may, in fact, be fully authorized to sell, but not authorized to sell manufacturer's warranties. In buying gear this way, dealers can get it cheaper, and provide the service themselves. This kind of gear, with a full warranty from the dealer is referred to as gray market equipment. Manufacturers discourage buying from these gray market dealers, but the risks are fairly low. If the dealer is local and well established, the risks are minimal. If you buy equipment mail-order, a dealer warranty may be a pain in the neck, especially if you have to ship the gear to the dealer more than once to get it fixed correctly. Then again, some factory service requires shipping gear far away at your expense, too. Frequently, home audio equipment is sold with a warranty restriction that if the gear is used commercially or in any profit-making enterprise, then the warranty is void. This is to protect the manufacturer from having to frequently repair equipment meant for light service. Professional audio equipment often comes with very liberal warranty terms, such as lifetime parts and labor. Professional gear takes heavy use and severe wear from constant transportation. It is expected to be able to take this abuse. All gear, electronic and mechanical, is known to have three principal failure modes: abuse, infant failure, and end-of-life failure. In addition, a few of the failures occur at random. Infant failure occurs in the first fifty hours of use, and is the principal responsibility of warranties. Infant failure is frequently caused by defective parts or a design defect. Abuse failure is that caused by a person who pulls a cable too hard, bangs the equipment on the table, pushes the controls too firmly or too fast, or does anything else which the manufacturer did not expect. These are the gray areas of warranties. They do not represent a manufacturing defect in the manufacturer's eyes, but they do leave you with a broken device. To get the best chance of coverage against this kind of failure, select a brand or a dealer with a very liberal warranty policy. End-of-life failures are rarely covered by warranty. Tape heads have a finite, calculable life, as do rubber rollers, speakers, cables, batteries, bearings, and motors. The life of some of these components can be extended by intelligent care. For example, the life of common rechargeable batteries can be extended by good recharging practice. Likewise, some cleaners can dry out rubber, and will lead to premature failure. Don't expect warranty support for any of these problems, and if you get it, feel lucky. 19.2 What is blind testing? Non-blind? Double-blind? If you want to compare pieces of equipment, recordings, or people, you could run an experiment. You could select an experimenter to initiate various trials, select some subjects to listen to the sounds, and then ask the subjects questions about what they hear. However, if you want meaningful results, it is necessary to set up the experiment correctly, and ask the right questions. One of the major problems with any experiment is that the subjects may become aware of the experimenter's hypothesis and allow this awareness to influence their behavior. One technique for preventing such bias is to keep the person who conducts the experiment unaware of the hypothesis of the research. Unfortunately, experimenters invariably form SOME hypothesis of what's going on, and these hypotheses affect how they deal with subjects. A more reasonable solution involves allowing the experimenters to know the true hypothesis but somehow keeping them ignorant of the specific experimental condition of each subject. This is known as a Partial Blind Experimenter technique. An example of this is that the person running an experiment knows that the main experimenter wants to determine which connecting cables are best at signal carrying, but would not know which cables are being used at any given time during the experiment. It is also important for subjects not to become aware of the experimenter's specific hypothesis. Subjects often become highly responsive to any cues, intended or unintended, in the research situation that suggest what they are supposed to do to appear normal or "to make the study come out right." This problem can be present in judgment experiments, particularly those in which each subject is exposed to more than one variation of the stimulus. Such a procedure, by its very nature, increases the probability that the subject will begin to guess which aspects of the experiment are being systematically varied by the experimenter. Many studies avoid this problem with what is called a Blind Subject technique. Using this approach, subjects are not told specifically what the hypotheses are. Additionally, subjects are not told what specific experimental conditions they are in. For example, a subject might be told that he/she is supposed to determine which stereo system sounds better, when in fact the experimenter wishes to examine which color or appearance of the same components looks better to subjects. When both a Partial Blind Experimenter technique and a Blind Subject technique are used at the same time, this is called a Double Blind experiment. Double Blind experiments have higher probability of producing statistically valid results than Partial Blind Experimenter alone, Blind Subject alone, or other techniques. Double Blind experiments are highly recommended. 19.3 Where can I get a service manual for brand XXX? The most reliable source of supply is the manufacturer's sales office in your country. 19.4 Where can I get good repairs on brand XXX? 19.5 How can I take 115V gear over to a 230V country or vice versa? Some equipment is available with an international power supply, which can be rewired by any serviceman to either power line voltage. If you expect to be moving abroad, look for this kind of equipment. Often, the same model is available both as US only and as International. Some equipment will be rewirable and won't say it. Adcom amps are known to be rewirable. If you know that your gear is limited to one power line voltage, you can order a new power transformer for that receiver, CD player, amplifier, or tuner which will be wound differently. Contact the manufacturer's local service center. This can be very expensive. A new transformer for a 40 watt receiver would wholesale for under $25 but cost $75 from a service center. Another alternative is to buy a power transformer that will convert 115V to 230V and vice versa. This is only practical for smaller gear. Larger power amps require prohibitively massive and expensive transformers. Also, the addition of a transformer may hurt the sound quality. Here are some common transformer models and 1992 list prices. Power ratings are total line current multiplied by line voltage (2A at 115V is 230 watts). Larger transformers cost more. Some of the costlier transformers are constructed with plugs and jacks for immediate use. Those marked * have wire leads and need safe connections to be used. Before spending money, check into other things about audio in the new country. Broadcast frequencies are slightly different in some countries than in others, so a receiver or tuner bought in one country may not be able to receive some or all of the stations in another country. The US separates the AM broadcast band frequencies by 10kHz while the UK uses 9kHz. Similarly, the US separates FM stations by 200kHz, where the UK has stations on a 50kHz spacing pattern. It MAY be very simple to modify a receiver from US to UK spacings, but may not. Last, but not least, some equipment will NOT work well on 50Hz power. Step Down (230V in, 115V Out) MagneTek/Triad N1X* 50 Watts $11.83 Stancor P-8620* 50 Watts $14.16 MagneTek/Triad N3M 85 Watts $29.95 Stancor P-8630 85 Watts $43.65 MagneTek/Triad N6U* 200 Watts $25.72 Stancor P-8632 200 Watts $51.80 MagneTek/Triad N5M 250 Watts $42.60 Step Up (115V In, 230V Out) Stancor P-8637 85 Watts $43.10 MagneTek/Triad N150MG 150 Watts $49.46 MagneTek/Triad N250MG 250 Watts $54.69 Stancor P-8639 300 Watts $55.51 The Stancor and MagneTek Triad lines are carried by large electronic distributors. 19.6 Are there really good deals in country XXX? 19.7 How do I find out how much an XXX is worth? There is a "Blue Book" for used audio equipment called "Orion Blue Book-Audio". This guide lists both a wholesale and a retail value for most audio gear. Orion Research Corporation 1315 Main Avenue Suite 230 Durango CO 81301 USA 303-247-8855 Last I knew a guide costs $169. Each Nov, a new book is printed. After June, the old book is discounted. If you need a single quote from the Orion Blue Book, send a polite request to: al@qiclab.scn.rain.com and you may get a quote back by e-mail. 19.8 Do people really hear those differences? Who knows? They sure think that they do. 19.9 Why do people disagree on what is the best sound? There are at least three different measures of what is "Perfect Sound". All three have advocates, and all three are right, in their own way. In general, whether they admit it or not, most listeners fit into one of these three preference groups: 1. It must sound like live music. These people know what voices sound like in person, they know what instruments sound like without any amplification, and they have heard orchestras perform unaided by sound systems. They want to accurately reproduce that sound. 2. It must sound like the recording engineer wanted it to sound. The recording engineer listened with extremely good equipment to the sound coming out of the microphones, and mixed them together for what he, at that time, felt was artistically correct. It may not have been the same as live, but it was exactly what he wanted. In the extreme, people like John Fogerty used to audition his final recording mix in his truck to see how it would sound through a common, lousy stereo. 3. It must give me the most pleasure. No matter how good or bad live sounds, no matter what the recording engineer intended, if buy some equipment will give me more listening pleasure then it must be the best. With these three perspectives, it is clear that no one system will satisfy everyone. Add to that confusion the variable that everyone likes a different kind of sound, has heard live music under different conditions, and has a different idea of what the engineer intended. There is an enormous range of possibilities. Another set of reasons is that people look for different things to be right. Some want strong bass; others want male voices to sound like male voices; others want violins to sound like violins. Systems rarely do everything equally well. Speakers (in particular) are compromises. Look for the speaker where the designer had your priority first. You are perfectly right to select speakers based on YOUR personal taste. Confounding the situation further, we all say the greatest things about the stuff we already bought. To do otherwise would be to admit that we are either stupid or deaf. Still another reason is that most people haven't heard enough variations. Until you hear a system that can truly reconstruct the three-dimensional accuracy of a stereo image accurately, you may never realize that it is possible. Some excellent recordings contain enough information that with a good enough system, you can hear up-down, in-out, and left-right distinctions very clearly. However, we will never experience this until we are fortunate enough to hear such a fine recording on a very good system. Finally, some of us really can't hear much difference. We aren't deaf, but we don't have a well trained ear, don't know exactly what to listen for, and may even have slight hearing deficiencies, such as bad sensitivity to high frequencies which comes with older age, or hearing damage from listening to loud sounds (machinery, rock concerts, etc). 19.10 How do I contact the manufacturer of XXXXX? How do I get repair service on XXXXX? How do I get replacement parts? Some magazines publish lists of contact phone numbers for the manufacturers of equipment. In the US, Consumer Reports has a small listing in each issue and a more comprehensive listing in their March issue. Also, Audio Magazine has an exhaustive listing in their October "Equipment Directory". In Europe, look in "What HiFi?". You can find many addresses by reading ads in hifi magazines. You can also find out by asking at your friendly local hifi shop, especially if you've built up a relationship with them. There is a book called the "Electronics Industry Telephone Directory". It comes out yearly and is available in some libraries. Many reps from parts distributors pass them out for free. If you want a copy and are willing to pay for it, call Harris Publishing, 800-888-5900 or 216-425-9000. The directory of the Electronic Industries Association is similarly useful. You can reach the EIA at 202-457-4900. A good source for parts and service is often the manufacturer's repair center. The best way to locate one near you is to look at the literature which came with your equipment when it was new. Failing that, see the ideas mentioned above in 19.10. There is an old list of addresses and phone numbers called "Music Equipment Mail/Phone List". This is posted periodically to news.answers, and contains many addresses of equipment manufacturers. This list is also periodically posted to some music newsgroups. If you don't see it posted at your site, you can get a copy by sending a request to its maintainer, rsk@gynko.circ.upenn.edu (Rich Kulawiec). 20.0 Network Protocol 20.1 What are the other newsgroups on audio and music? rec.audio.pro: This newsgroup is dedicated to professional audio. It includes discussion on record production, studios, studio equipment, DJ equipment, recording concerts, sound reinforcement, mastering, mixing, special effects, and other topics which might apply to audio professionals. If you are a home audio buff but like tape recording, you can find good advice here. rec.audio.high-end: This newsgroup caters to audiophiles and serious music lovers who are interested in discussing the subtle differences between expensive equipment, the nuances of selecting the best cables, the love and lore of LPs, and other details of audio that are inaudible to the untrained ear. rec.audio.car: This newsgroup supports discussion on different brands and models of car stereo, and also is an open forum for talk about car stereo installation, speaker selection, custom crossovers, and the special noise problems which occur in cars. 20.2 What network mailing lists are out there which aren't on usenet? There is an informal group of people interested in using DAT recorders to record "Grateful Dead" concerts. These people call themselves "Dat-Heads" and have a daily E-Mailing List. To subscribe to this list, send a message to: DAT-Heads-Request@fuggles.acc.Virginia.EDU asking to join the mailing list. There is also a general turntable chat mailing list. To subscribe to this list, send a message to: analogue-addicts-request@vortex1.exeter.ac.uk asking to join the mailing list. 20.3 Should I post a question about "XXXXXXX"? If it is related to professional audio, take it to "rec.audio.pro". If it relates to very expensive audio equipment or a request for opinions on subtle sound differences, you might want to take it to the newsgroup "rec.audio.high-end". If it's related to car audio, there's rec.audio.car. Otherwise, if it isn't addressed in the FAQ and it isn't a question for one individual, do it! 20.4 How can I suggest a change to the FAQ? Send an E-Mail message to neidorff@uicc.com and explain your suggestion or correction in detail. 20.5 Where is the FAQ for rec.audio archived? This FAQ is available by ftp from rtfm.mit.edu in /pub/usenet/news.answers/AudioFAQ To get the entire FAQ from this archive, you need to get all four of the following files: part1 part2 part3 part4 20.6 What does FAQ stand for? FAQ stands for "Frequently Asked Questions". It is assumed that a FAQ also contains FGA or "Frequently Given Answers". The newsgroup rec.audio has very few FGAs due to the personalities involved and the nature of audio. For that reason, this document is called a FAQ. 20.7 Why did I get a bitter reply when I posted a simple opinion? Some feel that rec.audio is populated by people with very strong opinions. The whole audio industry is filled with opinionated people. However, for the most part, these people like voicing their opinions and reading others. What may have sounded like a severe rebuttal may have instead been an outlet for the other person's frustrations or a challenge to you to "play the `rec.audio' game" and back up your words with some spirit. Be sure to stay light when reading rec.audio. Otherwise, you are likely to take yourself and everyone else too seriously. 20.8 Can I post a "FOR SALE" notice on rec.audio? In general, yes. Usenet is not for commercial purposes, so if you are a store or other retail operation, this is the wrong place for your advertisement. If you have some used gear or something you bought and don't need, feel free to post it. If you see an advertisement for a store that has a great deal, AND people had been asking about where to buy that item cheap, you might want to tell the readers on rec.audio about it. However, try to avoid commercializing. Something like: Pete's Audio has JVC PS992 for $435, which is 40% less than anywhere else; If interested 202-555-1212. should be fine. Try to avoid posting their entire price list, or using too many superlatives. If commercialism leaks into Usenet, it could materially hurt us all. When posting something for sale, have a concise but complete subject line. Come to think of it, this is good advice for any post. Here are some good examples: Subject: 4Sale Power Amp PS 352 $500 San Francisco area Subject: 4Sale Carver 100W Receiver nearly new Subject: 4Sale Stereophile Back Issues 4/88 to 6/92 Think about who you are willing to sell to before you post. If it is fragile or heavy, you may not want to ship it, so you may restrict to people who are close enough to pick it up. Use the Distribution: header to restrict your posting area. If you will only sell to people in Texas, don't distribute it to Australia. Check with your system administrator if you aren't familiar with the options you have for Distribution. Different sites have different restriction codes available. Distribution headers don't always restrict distribution, so it is still a good idea to include the target area in the Subject. Anyone buying or selling needs to understand that Usenet contains no mechanism to protect the buyer's money or the seller's property. There is a frequently posted message "A Guide to Buying and Selling on Usenet" which talks of other issues on the subject. This is posted to news.answers as well as other newsgroups. It is also available by ftp from "rtfm.mit.edu" in "/pub/usenet/news.answers/radio" as file "swap-guide".