Usenet 1994 January/usenetsourcesnewsgroupsinfomagicjanuary1994.iso/answers/AudioFAQ/part3

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Archive-name: AudioFAQ/part3
Last-modified: 1993/11/23
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12.0 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.

12.1 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.

12.2 What is a tuner?
    A tuner is a radio receiver which can not directly connect to
    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.

12.3 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.

    See also 9.1, 9.2, and 11.1 for information on what to listen
    to and what to listen for when evaluating speakers, turntables,
    CD players, tape recorders, and systems in general.

12.4 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.

12.5 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.

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

12.6 How can I get better FM radio reception?
    A. Use a (better) antenna. (See 12.7 and 12.8 below)
    B. Use a (more) directional antenna. (See 12.7 and 12.8 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.

12.7 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.  They tend to have an
    internal amplifier, which helps with weak signals.  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.

12.8 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.
    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 16th edition, it is a 736
    page large, illustrated paperback.  It costs $20 plus s/h.
    It has fairly complete antenna theory, practical information
    such as charts, drawings, comparisons, and tips on construction
    and adjustment.  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

12.9 What about power line conditioners?
    Each home and each outlet has slightly different power line
    impedance and power line noise.  Each amplifier is effected 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.

12.10 How can I reduce vibration sensitivity?

12.11 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
        Waida

12.12 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?

13.0 Listening Rooms and Houses

13.1 How should I place speakers in my room?  What size room is best?
    You are after two important, distinct goals: flat frequency
    response and good three-dimensional image.  At your disposal is
    the room size, the room shape, speaker height, speaker
    placement, listening position, and room treatments.  Even though
    good speakers are essential to good sound, room effects are also
    extremely important.  In many cases, the differences in room
    effects will be more noticeable than spending twice as much on
    speakers!

    For smoothest bass response, a listening room should be as large
    as possible, have dimensions as unrelated as possible, and
    should be optimally damped.  Although nothing is ever ideal,
    there are a few room dimension ratios that are better for
    listening rooms:
        Height        Width        Length
        1        1.14        1.39
        1        1.28        1.54
        1        1.6        2.33
    If your room isn't shaped like that, don't worry.  These
    effects are not major.

    Also for smooth bass response, woofers should be at distances
    from the nearest three room boundaries that are as different as
    possible.  In some cases, the line dividing the listening room
    into left and right halves must be considered a room boundary.
    Also, for smooth bass response, the listener's ears should be
    at distances from the nearest three room boundaries that are
    as different as possible.

    All of this is essential because a wall near a speaker boosts
    the bass from that speaker at some frequencies.  If a speaker
    is the same distance from three walls, then some frequencies
    will be emphasized much more than others, rather than slightly
    more.

    For best three-dimensional image, a listening room should have
    good symmetry about the plane between the two speakers.  This
    means that if one speaker is in a corner, the other speaker
    must be in a corner.  If this symmetry is not right, the first
    reflection from the wall behind one speaker will be different
    from the first reflection from the wall behind the other speaker
    and critical parts of the stereo signal will be damaged.

    Also, no large object should block the path from speakers to
    listener or from speaker to speaker.  Speakers should be
    elevated so that tweeters are at listener ear height.  The
    distance between speakers should be no greater than the distance
    from each speaker to the listener.  Finally, the tweeters should
    be aimed at the listeners.

    A normal box-shaped listening room with bare walls will have
    "slap echo" which will reduce intelligibility.  A good cure is
    randomly-placed wall hangings consisting of small rugs spaced
    an inch or so away from the wall to increase sound absorption.
    Another cure is convex-shaped art objects on the walls to
    disperse harmful reflections.  If money is available, commercial
    room treatments such as "Tube Traps" and "RPG Diffusers" are
    also valuable, but many of the benefits of these exotic devices
    are available with simpler techniques.

    As a general rule, in a good room, speakers and listener can be
    close to room boundaries with minimal adverse effects.  In a bad
    room, a good strategy is to place both speakers and listener as
    far away from room boundaries as possible.

    An excellent starting point for speaker placement is to measure
    the listening room diagonal dimensions.  Divide that measurement
    by three.  Put each speaker that distance from a corner, on the
    room diagonals.

        I-----------------------------------I
        I                                   I
        I                 L                 I
        I                                   I
        I        S                 S        I
        I                                   I
        I-----------------------------------I

    Place your listening position midway between the two speakers
    and approximately half way from the speakers to the wall.  Be
    sure that there is nothing in the "triangle" formed by the
    listening position and the speakers.

    Try this and then move things 12" (30cm) at a time to see if
    you can improve the sound.  Your ears will be a better guide
    than any commonly-available instruments.  To keep track of
    what you are doing, take notes.  To remember exactly where
    you put the speaker on the floor, a practical trick is to
    mark the floor with a sewing needle and thread.

13.2 How do I wire a house for sound?
    A fundamental principle of physics is that the farther a signal
    travels, the more the signal will be degraded.  Translate this
    to mean that the shorter the wire, the better.  Understanding
    this, the idea of running speaker cable between  every room of
    the house isn't as attractive as it first seems.

    If you still decide to wire your house for sound, you should do
    it at the same time you're wiring for telephone and electricity.
    It is possible to wire a house after the walls are closed, but
    it becomes very difficult.

    It is economical to use common house wire (Romex, UF, NM, etc)
    for speaker wire in the walls, but this may violate building
    codes.  Check with an electrician or inspector first.  It will
    also confuse future electricians, so label the wire clearly, all
    along its length.

    If you want to make your house like a recording studio, it is
    best to use the techniques of recording studios.  When studios
    run long lengths of sound cable from one room to another, they
    drive the cable with 600 ohm line amplifiers.  They also use
    shielded, twisted-pair cable.  They only connect the shield at
    one end of the cable.  Finally, they use balanced inputs at the
    other end of the cable.

13.3 Where can I read more about listening room construction and tuning?
    "Building a Recording Studio" by Jeff Cooper
        Mix Bookshelf
    "Handbook for Sound Engineers"
    "The Master Handbook of Acoustics" by F Alton Everest
    "Sound Engineering 2nd Edition" by Don and Carolyn Davis;
        Howard W. Sams & Co. (C) 1990
    "Good Sound" by Laura Dearborn
        Introductory, but clear and accurate
    "Sound Recording Handbook" by John M. Woram
        Howard W. Sams & Co. #22583
        Excellent General Reference
    "Audio Technology Fundamentals" by Alan A. Cohen
        Howard W. Sams & Co. #22678
        Overview of Audio Theory
    "Introduction to Professional Recording Techniques"
        by Bruce Bartlett
        Howard W. Sams & Co. #22574
    "Modern Recording Techniques" by Hubar and Runstein
        Howard W. Sams & Co. #22682
    "Sound Studio Production Techniques"
        by Dennis N. Nardantonio
        Tab Books

| 13.4 What is white noise?  What is pink noise?
|    "White noise" is characterized by the fact that its value
|    at any two different moments in time are uncorrelated.
|    This leads to such noise having a flat power spectral
|    density (in signal power per hertz of bandwidth), and is
|    loosely analogous to "white light" which has a flat power
|    spectral density with respect to wavelength.
|
|    Pink noise has flat power spectral density per PERCENTAGE
|    of bandwidth, which leads to a rolloff of -3 dB/octave
|    compared with white noise.
|
|    There are many reasons for using pink noise in audio testing.
|    One is that music has an average spectral content much closer
|    to pink noise than white noise.  Another is that pink noise
|    can be readily measured with constant Q bandpass filters and
|    naturally leads to flat plots on logarithmic frequency scales
|    - which correspond to the equally tempered musical scale.
|
|    Pink noise is often used with 1/3 octave band filters to
|    measure room acoustics.  This idea has merit since 1/3 octave
|    is a convenient number near the limit of our ears ability to
|    detect frequency response irregularities, and because
|    averaging measurements over 1/3 octave bands smooths out the
|    numerous very narrow peaks and dips that arise due to
|    standing waves in rooms.
|
|    Another term you'll hear about is Gaussian noise - this is
|    noise with a Gaussian amplitude probability density.
|    Gaussian noise has the amazing property that linearly
|    filtering it preserves its Gaussian amplitude density and
|    that sums of Gaussian random variables are again Gaussian.
|    The two terms shouldn't be confused.  It is possible to have
|    Gaussian white or pink noise.

14.0 Recording
    There are more different recording systems available today than
    ever before.  Digital and analog are both available to the
    consumer.  With the advent of consumer digital recorders, used
    pro analog recorders are becoming available for surprisingly low
    prices.  Now may be the time for you to buy a microphone and
    recorder and make your first!

14.1 What is DAT?  What is its status today?
    DAT (Digital Audio Tape) is currently the standard professional
    digital format for 2-track digital recording.  DAT had a
    short-lived consumer presence, but never "made it".  As digital
    recorders have no tolerance for clipping, using a DAT recorder
    takes a slightly different knack.  The results can be worth it,
    however, as DAT format offers the same resolution and dynamic
    range as CDs.  DATs record for up to 2 hours on a tape, and can
    run at three different sampling rates:  32 kHz, 44.1 kHz
    (for CD), and 48 kHz (the DAT standard).

14.2 What is DCC?  What is its status today?
    DCC is Philips' attempt to modernize the regular cassette.  DCC
    decks can play analog cassettes, and can record new Digital
    Compact Cassettes.  They use stationary heads (DATs use rotary
    heads as do VCR's), and although they are digital, they use
    lossy compression to fit all the data on the cassette.  Although
    DCC sound quality is far better than the 1960 standard cassette,
    the DCC does not have the sound quality present in DAT or CD.
    DCC may be a good choice for consumers who want to assemble mix
    tapes for cars or walkmans, but is not suitable for any
    professional applications.  As of December 1992, DCC is very
    new, DCC equipment is very expensive, and the ultimate future of
    DCC is not assured.

14.3 What about writable compact discs?  What is the status today?
    Recordable CD's are available, but are very expensive.  Blank
    discs sell for approximately $35 each, and the recorders start
    at around $6,000.  These units are mostly used by recording
    studios and other audio professionals.

14.4 What is the best cassette deck under $200?

14.5 What is the best cassette deck under $400?

14.6 What is PASC?  Can I hear the effects?
    PASC (Perceptual Audio Sub-band Coding) is a data-compression
    algorithm.  It increases the length of recording that can be
    stored in a given number of data bits by eliminating sounds that
    the developers' research claims can not be perceived by human
    listeners.  Its most important component is the omission of
    quiet sounds that occur at the same time and near the frequency
    of louder sounds.  It provides up to a 4x increase in the length
    of recordings a given digital medium can hold; this is essential
    to allow full-length digital recordings on DCC (and on MD, which
    uses a different compression technique).  It is not necessary
    to translate CD data to analog before compressing it using PASC,
    nor the reverse, but today's DCC decks do not have digital
    inputs or outputs.

    You CAN hear PASC, but it is very difficult, since it is not
    a distinctive noise (like a hiss) nor a consistent diminution
    (like a notch in a speaker's response), but a broad,
    uncorrelated dropout in a changing collection of sounds that
    are masked by sounds that you can hear very easily.

    Since it is lossy, repeated PASC recording will cause
    progressive loss, and this signal damage may become easily
    noticeable.  This is a side effect that recording companies
    hope will have the effect of discouraging piracy via DCC.

14.7 What is SCMS?  Can I hear the effects?
    SCMS (Serial Copy Management System) is a copy-protection system
    intended to stop rampant piracy of commercial recordings to
    digital tape.  SCMS allows the home taper to copy from a CD to a
    digital tape, but prevents anyone from digitally copying that
    new digital tape.

    You CANNOT hear SCMS.

14.8 How can I bypass SCMS?
    There are professional devices used by engineers to manipulate
    the digital bitstream, but they cost several hundred dollars and
    are not cost effective for consumers.  If you need to make
    perfect digital copies of digital copies, buy a professional
    digital recorder.  Pro models do not have SCMS, are more durable
    than consumer recorders, and may have better quality electronics
    than consumer models.

14.9 What's this about a tax on DAT?
    Every digital audio tape recorder and every blank digital tape
    sold in the USA is priced to include a "premium" or "tax".  This
    tax is collected by the US Copyright Office and distributed to
    the recording artists and record companies that own the
    copyrights to commercial music.  These fees are supposed to
    repay them for lost royalties.

    Many believe that this "tax" is illegal, because it represents
    an assumption that the buyer will use the recorder and tape to
    violate    a copyright, and not to record their own works.  A
    founding principle of the USA legal system is that everyone is
    assumed innocent until proven guilty.

    If you believe that this law is unjust, write your elected
    representatives.

14.10 Is it legal to copy an LP, CD, or pre-recorded tape?
    In the US today, it may be legal to copy LP's, CD's, etc. for
    your own private use (such as to copy a CD to play on your
    walkman).  UK law specifically prohibits this, but it is almost
    never enforced.  It is definitely not legal in the US, UK, or
    almost anywhere else, to copy these sources for commercial
    purposes, or to give the copies to others.

    It is as of yet unclear whether you own the rights to sell
    or give away a copy of a recording if you made the copy on media
    which was sold with an included digital audio tax.

14.11 How do I clean and demagnetize tape heads?
    First, a caution: DAT recorder tape heads are VERY fragile.
    Before cleaning the heads on a DAT recorder, get specific
    recommendations from a very knowledgeable source that is
    intimately familiar with DAT head cleaning.  In the internet,
    a good source is the DAT-Heads-Digest FAQ.  For more information
    on DAT-Heads-Digest, see section 20.2, below.

    To clean tape heads, use pure isopropyl alcohol and lint-free
    swabs.  Wipe the metal parts of the transport with alcohol
    (DON'T wipe the rollers!) and allow them to dry.  Throw the swab
    away after use.  Be exceedingly careful when cleaning the heads
    on a DAT.  DAT heads are notoriously easy to misalign by
    incorrect cleaning.

    Practical tape head demagnetizers are available for under $10.
    Try to find one with a plastic coated tip.  If you can't find
    one which is plastic coated. you can slip a drinking straw or
    plastic tube over the tip for the same effect.  This plastic
    will prevent the demagnetizer from scratching the head.

    Before plugging in the demagnetizer, remove all tapes from your
    working area and unplug the recorder.  Hold the demagnetizer
    away from the recorder as you plug it in.  Slowly bring the tip
    of the demagnetizer up to the tape head and slide it back and
    forth across each tape head for five one-second strokes.  Then
    pull it away from the head slowly and go on to the next.  After
    demagnetizing the heads, use the tip on each metal tape guide
    with a similar five strokes.  Last, slowly pull the demagnetizer
    far away from the recorder and unplug it.  Recording engineers
    use a demagnetizer before each recording session.

14.12 How do I adjust a tape recorder for best results?
    Adjusting a tape machine for best results usually requires
    special equipment and test tapes.  Unless you know what you're
    doing, leave it for a pro.  If you are serious about doing it,
    buy the service manual for your particular tape recorder.  It
    will list a detailed procedure, as well as describe the correct
    test tape and tools.

    As for setting of record levels, it is best to experiment with
    different levels on different tape brands.  Different
    formulation will reach saturation for different levels.
    Generally speaking, the transients on a Chrome tape should peak
    at about +6 dB above 0, though some formulations can take
    significantly hotter signals.

14.13 Where can I get new pinch rollers or drive belts?
        Projector-Recorder Belt Company
        Whitewater WI USA
        800-558-9572

14.14 What is a good rubber (pinch) roller cleaner?
    Teac RC-1 available from
        J&R Music World
        59-50 Queens-Midtown Expressway
        Maspeth NY 11378-9896 USA
        800-221-8180 or 718-417-3737
    Tascam Rubber Cleaner RC-2 available from:
        Tape Warehouse
        Chamblee GA
        1-404-458-1679

14.15 How can I program a recorder to tape a radio broadcast?
    Radio Shack and Panasonic make a clock/radio/cassette that can
    be set to record at a specific time.  Radio Shack also sells 120
    minute cassettes, which can be used for 60 minutes per side.
    The recorders are not high quality, and the long tapes are
    fragile, but it works.

    You can buy "appliance timers" at hardware stores that will
    start and stop an appliance at a specific time.  Radio Shack
    sells fancier versions of the same thing for more money. Gadget
    freaks love "X-10" control systems.  These can be configured to
    do the same thing.  All require a recorder that can be left in
    RECORD mode.  Such recorders are identified by a "TIMER" switch
    on the front panel.  Many cassette decks have a TIMER switch for
    use with timers.

    Memorex sells a "CP-8 Universal Remote" with a built-in timer.
    Available for approximately $90.00 from either:
        Crutchfield
        1 Crutchfield Park
        Charlottesville VA  22906 USA
        800-955-3000 or 804-973-1811
            or
        J&R Music World
        59-50 Queens-Midtown Expressway
        Maspeth NY 11378-9896 USA
        800-221-8180 or 718-417-3737

    This can be set to start a recorder at a particular time.  As
    the recorder will be started from a remote control rather than
    by the power line voltage, no timer switch is required. Radio
    Shack has a very similar product available for $99.95, may be
    less on sale.

    Damark also sells a learning remote with a built in on/off
    timer and sleep timer. It can learn 17 commands per device on a
    total of 5 devices and should be great for taping a few shows.
    They also sell a 8 device remote with timer.  As Damark sells
    close-outs, these items may not be available in the future.
        Damark
        7101 Winnetka Avenue North
        PO Box 29900
        Minneapolis MN  55429-0900 USA
        800-729-9000 or 612-531-0066

|    There is a similar learning remote available from MCM
|    Electronics.  They call it a Lonestar Learning Universal
|    Remote, item 80-450, $24.95 on sale.
|        MCM Electronics (Speakers, A/V Repair Parts, Etc) (+) (C)
|        650 Congress Park Dr
|        Centerville Ohio 45459-4072 USA
|        513-434-0031 or 800-543-4330

    Use a VCR for audio-only recording.  Hook the audio in to the
    output of a radio, tuner, or receiver.  You may also have to
    connect some video signal to the VCR so that the sync circuits
    work correctly.

14.16 Will CrO2 or Metal tapes damage a deck made for normal tape?
    No.  They will work fine.  They are no more abrasive than common
    tape and may actually be less abrasive than very cheap tapes.
    Recorders which are designed for CrO2 or Metal tape have
    different bias settings and equalization settings to take best
    advantage of the greater headroom and to give flat response with
    these different types of tape.  However, they use similar if not
    identical heads as less expensive tape recorders.  Almost all
    tapes are in some way lubricated, and these lubricants minimize
    wear and squeaking.

14.17 Why do my old tapes squeak in my car cassette deck?
    One problem that will cause this is "binder ooze".  The binder
    is the glue which holds the oxide particles to the backing.
    With time, this binder can ooze forward and actually get past
    the oxide particles, so that there is sticky stuff on the
    surface of the tape.  When this sticky stuff goes past the
    heads, it can cause a slight stick, which will sound like a
    squeak.  You won't feel it with your fingers, but it is there.
    If you have a prized tape with this problem, consider baking
    the tape in a home oven at a very low temperature, like 150F.
    This might cure the problem by drying out the binder.

14.18 Is VHS Hi-Fi sound perfect?  Is Beta Hi-Fi sound perfect?
    The HiFi recording format is subject to two different problems:
    Head-switching noise and compression errors.

    To get perfect reproduction, the FM subcarrier waveform being
    played back by one audio head must perfectly match the waveform
    from the other head at the point of head switching if a glitch
    is to be avoided.  If you record and then play the tape on the
    same VCR under exactly the same conditions, you have a
    reasonable chance of this working.  But if the tape stretches
    just a bit, or you play it on another VCR whose heads are not in
    exactly the same position, or the tracking is off, the waveforms
    will no longer match exactly, and you will get a glitch in the
    recovered waveform every time the heads switch.  This sounds
    like a 60 Hz buzz in the audio, which is often audible through
    headphones even if not through speakers.

    The same glitch will occur in the video waveform too, but since
    head switching always happens during vertical retrace, you won't
    see it.

    The wonderful signal to noise ratio of VHS HiFi is achieved
    through the use of compression before recording and expansion
    after playback.  The actual signal to noise ratio of the tape
    itself is about 35 dB and a 2.5:1 compressor is used to
    "squeeze" things to fit.  Like all companders, this produces
    audible errors at certain places on certain signals, such as
    noise "tails" immediately after the end of particularly loud
    passages.

    Worse, compressors often have problems simply getting levels
    right.  That is, if you record a series of tones, starting at
    -90 dB and working up in 1 dB increments to 0 dB, and then play
    them back, you will almost invariably have level errors.  The
    trend from soft to loud will be there but the steps won't be
    accurate.  Two or three of your tones might come out at
    essentially the same level, then the next one takes a big jump
    to catch up or even overshoot.

    For music, the result will be that the relative levels of some
    instruments, passages, etc. will not be accurate.

    This doesn't matter as much for movies, which tend to have
    steady volume level.  Also, movie enjoyment is rarely hurt by
    these level errors.  VHS and Beta HiFi is fine for reproduction
    of movie and tv soundtracks.  They are also perfectly fine for
    non-critical audio applications.  But VHS and Beta HiFi are not
    serious competitors to DAT, CD, open-reel analog tape, or even a
    high quality cassette deck.

14.19 How do HiFi VCRs compare to cassette recorders?  DAT recorders?
    VHS HiFi and Beta HiFi are analog recording formats which use
    modulation techniques to record a video signal and a stereo
    audio signal on a videocassette.  The audio capabilities
    typically surpass that of the "linear" audio tracks found on all
    video recorders, thus the "HiFi" designation.  "HiFi" is
    essential for getting good sound quality on your video
    recordings and out of pre-recorded videos.

    HiFi is also touted as an excellent audio recorder for
    audio-only (no picture) applications.  On paper, the
    specifications are typically superior to analog cassette but
    inferior to DAT.  In reality, the quality of HiFi video
    recorders is better than low quality cassette recorders but not
    as good as high quality cassette recorders when they are used
    with noise reduction systems.  In no case can a HiFi video
    recorder compare to DAT.  It suffers from generational loss and
    audible noise.

    Many people use VHS HiFi for recording radio broadcasts, since
    VCRs often have built-in timers and can record for up to 9
    hours.  If you use a HiFi video recorder to record from an
    audio-only source, beware that some decks will not function
    properly without a video signal for synchronization.  If you are
    interested in very good quality sound, use a deck with manual
    level control.

14.20 What is the difference between VHS HiFi and Beta HiFi?
    VHS HiFi uses "depth modulation"; Beta HiFi uses "frequency
    modulation".

14.21 Is there any good reason to buy a HiFi VCR for common TV shows?
    If you do not own a stereo TV, the purchase of a HiFi VCR will
    give you the capability to listen to stereo TV broadcasts to
    your system.

14.22 What is the best cassette tape?
    One simple answer to this question is that the best tape is the
    tape which was used to align your tape recorder.  A second
    simple answer is that more expensive tapes are frequently
    better in terms of quality of the backing, durability of the
    oxide, accuracy of the shell and guides, and life.

    Background: When you make a tape recorder, you build electronic
    circuits which have specific, non-flat frequency response.
    These circuits correct for the non-flat response of the tape
    heads, the recording process, and the tape.  These circuits can
    be adjusted after the recorder is made, but adjustment is
    tricky, and may or may not be successful with every tape made.
    The designer of the tape recorder picked one tape as their
    standard when they did the design, and built that recorder
    to work well with that particular tape.  It may work better
    with a different tape, but it won't necessarily sound the
    best with what one person calls the best sounding tape.

    From a review of frequently given answers to this question,
    it is obvious that almost every brand of tape has its advocates.
    Many brands also have their detractors.  Maxell and TDK tend to
    have a strong following, but that is in part because they own a
    large share of the US tape distribution market.

14.23 What is the best Reel-to-Reel tape?
    See 14.22.  Just as cassette tape recorders are set up
    specifically for one type of tape, reel-to-reel tape recorders
    are equalized and biased so that they are best with one specific
    brand and model of tape.  Just as more expensive cassette tapes
    will last longer and have less noise than cheaper ones, you can
    expect fewer dropouts, better quality control, and lower noise
    from more expensive reel-to-reel tapes.

    The major brands in reel-to-reel tape include Ampex, Scotch
    (3M), AGFA/BASF, and Maxell.

14.24 What is Type I, Type II, Type III, and Type IV cassette tape?

15.0 Mail Order
    Mail order is appealing.  The general hope is that by using mail
    order, you avoid pushy sales people, you pay fixed, discounted
    prices, and you have written catalog descriptions to help you
    select your purchase.  In practice, most mail order today is
    "phone order", in that the company completes the deal with a
    phone call.  Many of the "mail order" companies don't even have
    price lists or catalogs.  They are just retailers that are
    willing to sell over the phone and ship the merchandise to
    you.  In some cases, retail store sales are better deals than
    mail order.  Don't expect the lowest price from the first place
    you call.  Also, don't expect excellent service from everyone,
    and especially not from the company with the lowest price.

15.1 Who sells brand XXX equipment mail-order?
    Consult the frequent rec.audio mail-order survey published by
    [e-mail] (William R. Nau) or contact William Nau directly.
    This survey is also available via FTP in the pub/rec.audio
    directory of SSESCO.com.  If you have any mail order
    experiences to share, please send them directly to William Nau.

15.2 Is the stuff sold by DAK really awesome?  Damark?
    DAK buys in large quantities.  They buy what they think
    they can sell.  They buy close-outs as well as new first-line
    merchandise.  They honestly represent their merchandise with
    specifications.  They offer more information on their product,
    if possible, on the phone through their toll free number.
    I know of many people who have bought from DAK and been
    happy. I personally have bought from DAK and been happy.

    Regarding Damark, opinions of people on the net are similar.
    The products are as described, they deliver what they
    say they will, and will take back or replace unsatisfactory
    merchandise.  I have not heard any unsatisfied Damark customers.

    On the other side, the catalog writers at DAK use some very
    flowery language which is intended to lead you to believe
    that they are selling gold for copper prices. In this sense,
    the words in their catalog may be deceptive.

    The DAK people have a good sense of "what the market will bear".
    They price their products to sell, but not to give away money.
    Mail order prices tend to be 10% to 20% less than discount,
    which is 10% to 20% less than retail. DAK has to compete with
    other mail order dealers, such as Damark, but they send out SO
    MANY CATALOGS that they really don't have to cut prices too far
    to sell.

    DAK has recently gone through hard financial times.  This puts
    buyers in some slight risk, because if they go out of business,
    you may get easy warranty service on their products.  I say
    easy because most DAK products are covered by a manufacturer's
    warranty, and you can often get service from the manufacturer
    as well as from DAK.  I believe that DAK is over their slump,
    but I am not sure.  For more on warranties, see 19.1, below.

15.3 Is the stuff sold by Cambridge Sound Works really awesome?

15.4 What should I watch out for when buying mail order?
    Many of the cautions mentioned in warranties (19.1) apply.
    Look for a store which has been around a long time. Look for
    friends which have dealt with the store and been satisfied.
    Look for a store which does not lie or stretch the truth.

15.5 What is gray market?
    See warranties (19.1), below.

15.6 Are there any good mail-order sources for recordings?
    Noteworthy has a good reputation among net readers as a supplier
    of CDs.  They have a range of discs available centered firmly on
    the mainstream, and are reasonable in price.  Shipping is $3.75
    for 1-5 CDs.  They offer over 14,000 different CD titles.  Their
    offerings are all from US labels.  They give a free catalog and
    also have modem software and catalog on floppy discs for $9.95.
        Noteworthy Music, Inc
        17 Airport Road
        Nashua NH  03063 USA
        800-648-7972 Voice
        603-881-5729 Voice
        603-883-9220 FAX

    BMG and Columbia also sell CDs mail-order, but have a smaller
    list of offerings and higher prices. However, BMG and Columbia
    have interesting deals to entice new customers.  Read the fine
    print before you sign to be sure that they are right for you.
    BMG and Columbia both have promotional offerings to "members"
    which allow you to buy two or three discs for the price
    of one.  These can be very good deals, if you want what they
    have.  Look at their advertisements in common magazines and
    Sunday newspapers for a better idea of what they carry.  They
    list much of their line in their ad.  Don't expect much more.

    Bose Express also sells CDs.  Their reputation so far is very
    knowledgeable people, a large collection, and high prices.
    Their catalog costs $6.00.
        Bose Express Music
        The Mountain
        Framingham MA  01701 USA
        800-451-2673 or 508-879-1916 Ext. 2008

    Tower Records has a mail order department which also sells CDs.
    Their classical catalog costs $13.45.  Their other catalog costs
    $10.45.  Tower is a large retail chain.  Many have bought from
    their retail outlets happily, but no one has expressed any
    comments on their mail order service yet.  Contact:
        Tower Records Mail Order Department
        692 Broadway
        New York City, NY 10012  USA
        800-648-4844 or 800-522-5445

    Another source is Music New Hampshire; 800-234-8458.  They sell
    many $3.79 post-paid sampler CDs and also many independent label
    single-artist discs.  Most single artist discs are $15.00 each.
    Shipping is $3 for 1-3 discs and $5 for 4-up.  Their stuff is
    mostly obscure artists.  They have Rock, Jazz, Classical, Folk,
    Country, and Children's offerings.  Affiliated with CD Review.
        Music New Hampshire - Wayne Green Inc
        70 Route 202N
        Peterborough NH  03458-1107 USA

    If you like the idea of buying CDs by Modem, consider
        The Compact Disc Connection
        1016 East El Camino #322
        Sunnyvale CA  94087 USA
        Voice 408-733-0801
        Modem 212-532-4045 New York City NY
            312-477-3518 Chicago IL
            408-730-9015 Sunnyvale CA
    They have a collection of over 58,000 CD titles.  People have
    said that their service is excellent.  Prices are fairly good.
    Shipping is $3.50 for orders under $100.00 and free for larger
    orders.  They do not stock anything, but deliver from the
    warehouses of their suppliers.  This means that some items may
    be back ordered or completely discontinued while remaining in
    their on-line data base.  They advertise 94.2% of orders in
    1992 shipped, though not necessarily immediately.  If you have
    a modem and enjoy browsing a data base, their data base is a
    a very enjoyable experience.  However, the phone bill can be
    quite prohibitive to those calling from out-of-town.

    There have been a couple of music (cd/lp) mail-order lists
    compiled on the net - one older list can be found via anonymous
    ftp to ftp.uwp.edu in the file: /pub/music/misc.mailorder.rmm
    Someone is revising this file and it should be updated or found
    in a new file name there in the future.

    Another list contains vendors that specialize in progressive
    rock, electronic and experimental music, is maintained by
    Malcolm Humes and posted sporadically to alt.music.progressive,
    rec.music.misc, & rec.music.info.  This also can be ftp'd from
    ft.uwp.edu, in the file: /pub/music/misc/mailorder.progressive

    Federal Music and Video markets "Discount Coupon Books"
    featuring two-for-one CDs and Tape deals.  They require payment
    with the order, which many consider risky.  One company that
    distributes these coupon books for Federal Music is Reed Music.
    The price from Federal or Reed Music with the two-for-one deal
    is comparable to the price from Noteworthy.  So far, no net
    user has yet related any positive or negative experience with
    Reed Music or Federal Music and Video.  Federal Music and Video
    has been in business since 1985, so is probably legit. However,
    in that they require payment in advance it is probably safer to
    avoid them completely and use a discounter like Noteworthy.

    When considering mail purchases of CDs, consider shipping costs.
    It is common for people to charge between $1 and $3 per disk for
    "shipping and handling".  This makes mail order less attractive,
    but may be equally balanced by a lack of sales tax.