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From: Bob Neidorff <neidorff@uicc.com>
Subject: FAQ: rec.audio (part 3 of 4)
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Summary: Answers to common questions about audio equipment, selecting,
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Archive-name: AudioFAQ/part3
Last-modified: 1994/2/15
Version: 1.13

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
	"The Uneasy Truce Between Music and the Room" 
		F. Alton Everest
		Audio, February 1993, Pgs. 36-42
	"Coloration of Room Sound by Reflections"
		F. Alton Everest
		Audio, March 1993, pgs. 30-37

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
	nau@SSESCO.com (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
			617-639-0238 Boston MA
	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.
