Internet Info 1997 December/Internet_Info_CD-ROM_Walnut_Creek_December_1997.iso/faqs/rec/answers/AudioFAQ/part2

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Subject: FAQ: rec.audio.* Systems 5/97 (part 2 of 13)
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Summary: Answers to common questions about audio equipment, selecting,
  buying, set-up, tuning, use, repair, developments, and philosophy.
X-Last-Updated: 1997/07/31
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Archive-name: AudioFAQ/part2
Last-modified: 1997/7/31
Version: 2.12

9.0 High Fidelity Systems
    People frequently use the term "Stereo" to refer to a sound
    reproduction system. To be more accurate, we will use the term
    High Fidelity System to refer to a pile of equipment including
    at least one source, at least one amplifier, and at least one
    speaker. Common sources are turntables, CD players, tape
    players, tuners, and receivers.

9.1 What is a receiver?
    A receiver is a tuner, power amplifier, and preamp combined. A
    common receiver has inputs for a turntable, a CD player, a tape
    deck, and perhaps one or two other sources. It has selector
    switch(s), tone controls, and a volume control. A receiver may
    have outputs for two speakers, or for more.

9.2 What is a tuner?
    A tuner is a radio reception device which can not drive
    speakers. Sometimes, the radio in a tuner is higher quality
    than the radio in a receiver. A tuner may or may not receive
    the AM broadcast band, but 99.999% will receive the FM broadcast
    band. Some also receive short wave bands, frequencies used
    for long-distance rather than for local commercial broadcasts.

9.3 How should I go about selecting a system?
    If you're looking to buy something, the first step is to figure
    out what you can spend. If you're looking for a whole system,
    this gets tricky, because you have to allocate amounts for the
    different components. The most popular current rule-of-thumb
    for a single source system (speakers, amp, 1 something-player)
    is to divide the money about equally among the three parts. If
    you want several players, you'll have to decide whether they are
    all equally important, and so deserve the same amount of money;
    or whether some are less important, in which case you can spend
    less on them and put the savings elsewhere.

    This rule isn't hard-and-fast. It's just meant as a starting
    point so you don't have to listen to every possible combination
    of equipment. If you are building around a CD player, you might
    spend a bit less on the player and a bit more on the speakers.
    If you are buying turntable (or something else which plays by
    physical contact) on the other hand, it might be good idea to
    put a bit extra into the player. The reason for this is that if
    you skimp on the turntable, then when you come to buy a better
    one you may find that your records have been worn out by the
    cheap player. If you skimp on the speakers, on the other hand,
    then when you can afford better speakers the music will still be
    there on your records.

    Another perspective says that you should spend the most you
    can on your source, as the sound can never be better than
    what you get off of the record/CD.

    See also 12.1, 12.2, and 10.1 for information on what to listen
    to and what to listen for when evaluating speakers, turntables,
    CD players, tape recorders, and systems in general.

9.4 How can I improve the sound of my stereo?
    The cheapest improvement you can make, and perhaps the most
    effective, is to position your speakers carefully and correctly.
    See 13.1, below. This will improve the frequency response
    flatness, making it easier to hear every instrument and voice.
    Setting speaker position correctly can also improve the
    three-dimensional recreation of a stereo image.

9.5 Do I want a combo system or separate components?
    Combo systems used to be cheap jokes; that's not always true
    now. Some sound very nice; there are even some made by
    "audiophile" companies, and they sound even nicer. They've got
    lots of advantages. They take up less space. The controls tend
    to be well-integrated, especially if they are remote-controlled.
    Therefore, they are easy to operate; this can be a major plus if
    some of the people who'll use it are afraid of, or not very good
    at, technology. Also easy to set up, and don't leave millions
    of wires dangling all over everywhere.

    If you do go for a combo, get a brand name; either an audiophile
    company, or a good "consumer electronics" company. Brand-X
    combos are generally overpriced and unpleasant. If possible,
    buy it where you can listen to it first, such as a "real" hi-fi
    shop. Mid-range hi-fi shops sell combos, as a way of
    introducing beginners to quality sound.

    In most good combos, the speakers are the weak link. If you do
    go for a combo, you can almost always improve the sound
    drastically by buying a set of better speakers. Better speakers
    start in the $100-$200 price range. Some of the best combos
    come without speakers, forcing you to do this. A good combo
    with replacement speakers will give you very pleasant music.

    Sounds good, you say, so why do people bother with components?
    Well, you can get better sound with a component system -- but
    usually at the expense of convenience and size. A good
    component system will normally require a mixture of boxes from
    different makers to get the best results, so you've got to spend
    more time listening to things. However, if you listen to your
    music seriously, then the performance of a component system is
    the reward for that extra work.

    Components are harder to set up and operate. However, as noted,
    you can get better sound. You also get more flexibility. If,
    for example, you decide you want a better CD player, you just
    replace the CD player. With a combo system, you've got to
    replace the whole system. If your component tape deck breaks,
    you can remove it from the system and take it in for repair or
    replacement. With a combo, the whole system has to go in for
    repair or be replaced.

    When you want to add some new recording medium to your system
    (laserdisc, VCR, DAT, DCC, MD, ...), if you've got components
    you just go buy the appropriate box. Many combo systems do not
    have places (or many places) to attach extra bits, so again you
    could be looking at replacing the whole thing. With a component
    system, you can add a turntable; most modern combos can't cope
    with turntables any more. Do you have a record collection?

    If you're really not sure, components are the safer bet; if
    you're going to make a mistake, that's probably the better way
    to be wrong. But, if you're sure that a combo would be best
    for your needs, it can be a totally reasonable choice.

    Now, some people may be tempted by one-maker 'component sets',
    particularly the modern, miniature ones. They tend to be
    equivalent to combos. Most use non-standard connections, rather
    than the normal twin phono plug, so that it's likely you can't
    swap or add components anyway. Even where they use standard
    interconnects, they may rely on non-standard interconnections
    for control purposes. In a few cases, they also rely on sharing
    power, with a power supply in only one of the boxes and the rest
    taking low-voltage connections from that. And, no one maker
    makes the best everything. By default, assume that they will
    have the same disadvantages (and most of the same advantages) as
    combos. If it's important for it to work with "standard"
    components from other makers, be sure to ask before you buy.

    One-maker 'component sets' are also often of lower quality than
    true individual components.  Component sets are designed for
    convenience and appearance, rather than sound quality.

    And, if you're in doubt, go for separate components.

9.6 How can I get better FM radio reception?
    A. Use a (better) antenna. (See 9.7 and 9.8 below)
    B. Use a (more) directional antenna. (See 9.7 and 9.8 below)
    C. Aim your directional antenna. Rhombics are ungainly to move,
        but Yagis and dipoles are small enough to point right at
        the station. With the dipole, to tune in a station to
        the East, run the antenna North-South. With a Yagi,
        point the individual elements North-South with the
        smallest element on the East end.

9.7 How good are these compact FM antennas?
    For receiving, small is ugly. The bigger the antenna (all else
    equal) the better. Of course, all else is never equal, but
    these fancy, expensive mini antennas tend to be awful. Some
    compensate for their small receiving structure with a small
    antenna signal amplifier. However, the quality of that
    amplifier is often no better than the quality of the amplifier
    in your tuner or receiver, so the antenna just gives you a
    stronger signal, complete with stronger noise.

    All of that said, some compact FM antennas can work better than
    a simple dipole in some situations. Some have an internal
    amplifier, which helps with weak signals if the input stage in
    your receiver is poor. Some are directional. Some aren't. If
    possible, be sure that whatever you buy can be returned for a
    refund if it doesn't work out well for you.

9.8 What makes the best FM radio antenna?
    Although there is no "best" antenna for everyone, one of the
    most directional is the "rhombic". Being very directional, this
    antenna can select one weak station out of many strong ones, or
    one group of stations originating from a general direction.
    In addition, very directional antennas are good at reducing
    multipath interference, a problem which is more severe in
    cities with tall buildings.

    This antenna is very long, and made up of four pieces of wire
    with feedline at one end for antenna connections and a resistor
    at the other for termination. Rhombics for FM broadcast band
    use are at least 15 feet (4.5 meters) long, but can be made
    fairly narrow, less than 3 feet (1 meter) wide. A more narrow
    antenna will be more directional. A longer antenna will give a
    stronger signal.

    Another very directional antenna is the "yagi", which looks just
    like a common TV antenna. You can even use a common TV antenna
    as a very good FM antenna. The FM and TV bands are very close
    together. It has the advantages of being cheap, directional,
    and easy to rotate.

    One of the simplest and easiest to make antennas is the folded
    dipole, made from 300 ohm twin lead. It is approx. 58" long.
    This antenna is surprisingly good for receiving signals in a
    moderately strong signal area. Folded dipoles come with many
    tuners and receivers as a standard accessory. They are also
    available for approximately $2 at audio and department stores.

    Whatever antenna you have, you can often get it to work better
    for specific stations by moving it. In the case of the folded
    dipole, sometimes it works better vertically, and other times it
    works best horizontally. Sometimes, you can get that one
    elusive station to come in perfectly if you bend the two ends of
    it at funny angles. Don't be afraid to experiment. One
    warning. As atmospheric conditions change, the best antenna
    placement may also change.

    An excellent reference book on antennas is printed by the
    American Radio Relay League (ARRL). It is called The ARRL
    Antenna Book. Currently in its 17th edition, it is a 736
    page large, illustrated paperback which includes a disk
    of MS-DOS software. It costs $30 plus s/h. It has fairly
    complete antenna theory, practical information such as
    charts, drawings, comparisons, and tips on construction
    and adjustment. ISBN 0-87259-473-4. The ARRL is founded
    and chartered as a non-profit organization to better
    amateur radio, and antennas are a vital part of amateur radio.
        American Radio Relay League
        225 Main Street
        Newington CT 06111 USA
        203-666-1541

    Also useful:
        Practical Antenna Handbook by Joseph J. Carr
        Tab Books #3270/McGraw Hill - ISBN 0-8306-3270-3

9.9 What about power line conditioners?
    Each home and each outlet has slightly different power line
    impedance and power line noise. Each amplifier is affected by
    power line impedance and power line noise differently. Power
    line conditioners try to reduce this line noise. Some also
    change the power line impedance in a way which is supposed to be
    better. We will leave it to your ears to decide if these
    devices help the sound of your system enough to justify their
    expense.

9.10 How can I reduce vibration sensitivity?
    Some complain that heavy foot falls will cause skipping or more
    subtle sonic problems with CD players or turntables. If you
    have these problems, there are a few different things which you
    can try to reduce the problem. One is to add weight to the rack
    which holds the equipment. Heavier things move slower. If you
    can get the motion slow enough, it won't cause sonic or tracking
    problems.

    Another solution is to add rubber or elastomer (Sorbothane)
    cushions under the CD player or turntable. This might make it
    better, but might also make it worse. Experiment.

    A third solution is to increase the coupling between the rack
    and the floor using spikes, which concentrate the weight on
    a very small area. Another way to increase the coupling between
    the rack and the floor is to use a plastic adhesive like HoldIt,
    sold under the UHU trade name in office supply stores.

9.11 What equipment can I buy that is 100% made in the USA?
    There are many lines of equipment that are carefully hand
    crafted in the USA. Unfortunately, these systems are usually
    the high-end ones. Some US companies also make gear in the
    far east. When in doubt, ask. Some US audio manufacturers are:
        Adcom (some made in Japan)
        Audio by Van Alstine
        Audio Research
        California Audio Labs (CAL)
        Carver (some made in Japan)
        Jeff Rowland
        Krell
        Mark Levinson
        McCormack
        McIntosh
        Parasound
        Proceed
        PS Audio
        Spectral
        Sumo (Power amps, preamps, CD transports, D/As)
        Waida

9.12 Should I buy "xxx"? Which is better: "yyy" or "zzz"?
    We can provide facts and opinions (and you get to decide which
    is which :-), but we can't recommend if, or which way, you
    should jump, because we don't know what your priorities are.
    (That won't stop us from trying, though!) For example, if you
    are considering a used item at a low price vs. a new one at a
    higher price, one of us might say "go for the new one because
    of the warranty", when another would say that you can fix it
    yourself if it breaks. They're both right.

    This also applies to speakers. One may have very good, flat
    bass, but only go so low, where the other may go lower, but
    have less flat frequency response. Which is better? Depends
    on the buyer. Good speakers are carefully designed to
    achieve a balance of performance that matches the priorities
    of the designer. Some designers put much of their budget into
    appearance. Some designers put their budget into very high
    efficiency. Others strive for the smallest box which can
    deliver an acceptable low frequency performance. Do you
    really want people on the network making that decision for you?

9.13 What is Surround Sound? Pro Logic?
    In an effort to make movie soundtracks more dramatic and
    engaging, Dolby Labs created a signal encoding which encodes
    more than just two channels of audio onto the stereo signal.
    Many popular receivers and home-theater systems include the
    required circuitry to decode these signals. These components
    are referred to as Pro Logic, Dolby Pro Logic, or Surround
    Sound components. Very few audio recordings contain this
    encoding, but it is very common with movie soundtracks and
    some network TV programs.

    Best Surround Sound reproduction requires five separate
    speaker systems, but some improvement is claimed from a
    surround sound receiver and three speakers over two speakers.
    In its best implementation, surround sound will give a fuller
    sense of being in the middle of the action. The quality of the
    image is a function of the recording, the broadcast quality,
    and the choice of reproduction components.

    For more information on surround sound, get:
        The soundtrack comes after you...
    which is available by anonymous FTP from ftp.csn.org as:
        /Laserdisc/ld03

9.14 What do they mean when they say "It sounds warm?"
    There are many subjective terms used to describe slight
    differences in frequency response, distortion, noise, etc.
    Thanks to Bruce Bartlett and Pro Audio Review, we present this
    Sound Quality Glossary.  This glossary puts a meaning behind
    many different, common terms.  There is no guaranty that people
    mean the same thing when they use these terms.  However, these
    definitions give insight into why a system sounds the way it
    does and may also help bridge the communications gap.

    Airy: Spacious. Open. Instruments sound like they are
    surrounded by a large reflective space full of air. Good
    reproduction of high-frequency reflections. High-frequency
    response extends to 15 or 20 kHz.

    Bassy: Emphasized low frequencies below about 200 Hz.

    Blanketed: Weak highs, as if a blanket were put over the
    speakers.

    Bloated: Excessive mid-bass around 250 Hz. Poorly damped low
    frequencies, low-frequency resonances. See tubby.

    Blurred: Poor transient response. Vague stereo imaging, not
    focused.

    Boomy: Excessive bass around 125 Hz. Poorly damped low
    frequencies or low-frequency resonances.

    Boxy: Having resonances as if the music were enclosed in a
    box. Sometimes an emphasis around 250 to 500 Hz.

    Breathy: Audible breath sounds in woodwinds and reeds such as
    flute or sax. Good response in the upper-mids or highs.

    Bright: High-frequency emphasis. Harmonics are strong relative
    to fundamentals.

    Chesty: The vocalist sounds like their chest is too big. A bump
    in the low-frequency response around 125 to 250 Hz.

    Clear: See Transparent.

    Colored: Having timbres that are not true to life. Non-flat
    response, peaks or dips.

    Crisp: Extended high-frequency response, especially with
    cymbals.

    Dark: Opposite of bright. Weak high frequencies.

    Delicate: High frequencies extending to 15 or 20 kHz without
    peaks.

    Depth: A sense of distance (near to far) of different
    instruments.

    Detailed: Easy to hear tiny details in the music; articulate.
    Adequate high-frequency response, sharp transient response.

    Dull: See dark.

    Edgy: Too much high frequencies. Trebly. Harmonics are too
    strong relative to the fundamentals. Distorted, having unwanted
    harmonics that add an edge or raspiness.

    Fat: See Full and Warm. Or, spatially diffuse - a sound is
    panned to one channel, delayed, and then the delayed sound is
    panned to the other channel. Or, slightly distorted with analog
    tape distortion or tube distortion.

    Full: Strong fundamentals relative to harmonics. Good
    low-frequency response, not necessarily extended, but with
    adequate level around 100 to 300 Hz. Male voices are full
    around 125 Hz; female voices and violins are full around 250
    Hz; sax is full around 250 to 400 Hz. Opposite of thin.

    Gentle: Opposite of edgy. The harmonics - highs and upper mids
    - are not exaggerated, or may even be weak.

    Grainy: The music sounds like it is segmented into little
    grains, rather than flowing in one continuous piece. Not liquid
    or fluid. Suffering from harmonic or I.M. distortion. Some
    early A/D converters sounded grainy, as do current ones of
    inferior design. Powdery is finer than grainy.

    Grungy: Lots of harmonic or I.M. distortion.

    Hard: Too much upper midrange, usually around 3 kHz. Or, good
    transient response, as if the sound is hitting you hard.

    Harsh: Too much upper midrange. Peaks in the frequency response
    between 2 and 6 kHz. Or, excessive phase shift in a digital
    recorder's lowpass filter.

    Honky: Like cupping your hands around your mouth. A bump in the
    response around 500 to 700 Hz.

    Mellow: Reduced high frequencies, not edgy.

    Muddy: Not clear. Weak harmonics, smeared time response, I.M.
    distortion.

    Muffled: Sounds like it is covered with a blanket. Weak highs
    or weak upper mids.

    Nasal: Honky, a bump in the response around 600 Hz.

    Piercing: Strident, hard on the ears, screechy. Having sharp,
    narrow peaks in the response around 3 to 10 kHz.

    Presence: A sense that the instrument in present in the
    listening room. Synonyms are edge, punch, detail, closeness and
    clarity. Adequate or emphasized response around 5 kHz for most
    instruments, or around 2 to 5 kHz for kick drum and bass.

    Puffy: A bump in the response around 500 Hz.

    Punchy: Good reproduction of dynamics. Good transient response,
    with strong impact. Sometimes a bump around 5 kHz or 200 Hz.

    Rich: See Full. Also, having euphonic distortion made of
    even-order harmonics.

    Round: High-frequency rolloff or dip. Not edgy.

    Sibilant. "Essy" Exaggerated "s" and "sh" sounds in singing,
    caused by a rise in the response around 6 to 10 kHz.

    Sizzly: See Sibilant. Also, too much highs on cymbals.

    Smeared: Lacking detail. Poor transient response, too much
    leakage between microphones. Poorly focused images.

    Smooth: Easy on the ears, not harsh. Flat frequency response,
    especially in the midrange. Lack of peaks and dips in the
    response.

    Spacious: Conveying a sense of space, ambiance, or room around
    the instruments. Stereo reverb. Early reflections.

    Steely: Emphasized upper mids around 3 to 6 kHz. Peaky, nonflat
    high-frequency response. See Harsh, Edgy.

    Strident: See Harsh, Edgy.

    Sweet: Not strident or piercing. Delicate. Flat high-frequency
    response, low distortion. Lack of peaks in the response. Highs
    are extended to 15 or 20 kHz, but they are not bumped up. Often
    used when referring to cymbals, percussion, strings, and
    sibilant sounds.

    Thin: Fundamentals are weak relative to harmonics.

    Tight: Good low-frequency transient response and detail.

    Tinny, Telephone-like: Narrowband, weak lows, peaky mids. The
    music sounds like it is coming through a telephone or tin can.

    Transparent: Easy to hear into the music, detailed, clear, not
    muddy. Wide flat frequency response, sharp time response, very
    low distortion and noise.

    Tubby: Having low-frequency resonances as if you're singing in
    a bathtub. See bloated.

    Veiled: Like a silk veil is over the speakers. Slight noise or
    distortion or slightly weak high frequencies. Not transparent.

    Warm: Good bass, adequate low frequencies, adequate
    fundamentals relative to harmonics. Not thin. Also excessive
    bass or midbass. Also, pleasantly spacious, with adequate
    reverberation at low frequencies. Also see Rich, Round. Warm
    highs means sweet highs.

    Weighty: Good low-frequency response below about 50 Hz.
    Suggesting an object of great weight or power, like a diesel
    locomotive.

COPYRIGHT NOTICE
The information contained here is collectively copyrighted by the
authors. The right to reproduce this is hereby given, provided it is
copied intact, with the text of sections 1 through 8, inclusive.
However, the authors explicitly prohibit selling this document, any
of its parts, or any document which contains parts of this document.

Note: My e-mail address in this FAQ is "Spam-Blocked".  Remove "xyz" to use.
--
Bob Neidorff; Unitrode Corporation  |  Internet: [e-mail]
7 Continental Blvd.                 |  Voice   : (US) 603-429-8541
Merrimack, NH  03054-0399 USA       |  FAX     : (US) 603-429-8564

Note: Unitrode Corporation has openings for Analog and Mixed
Signal Design Engineers in Merrimack, New Hampshire.  If
interested, please send resume in confidence to address above.