Archive-name: AudioFAQ/part2
Last-modified: 1995/12/7
Version: 2.01

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

	One of the simplest and easiest to make antennas is the folded 
	dipole, made from 300 ohm twin lead. It is approx. 58" long.
	This antenna is surprisingly good for receiving signals in a 
	moderately strong signal area. Folded dipoles come with many 
	tuners and receivers as a standard accessory. They are also 
	available for approximately $2 at audio and department stores.
	
	Whatever antenna you have, you can often get it to work better 
	for specific stations by moving it. In the case of the folded 
	dipole, sometimes it works better vertically, and other times it 
	works best horizontally. Sometimes, you can get that one 
	elusive station to come in perfectly if you bend the two ends of 
	it at funny angles. Don't be afraid to experiment. One 
	warning. As atmospheric conditions change, the best antenna 
	placement may also change.

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

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

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

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

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

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

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

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

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

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

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

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

COPYRIGHT NOTICE
The information contained here is collectively copyrighted by the 
authors. The right to reproduce this is hereby given, provided it is 
copied intact, with the text of sections 1 through 8, inclusive. 
However, the authors explicitly prohibit selling this document, any 
of its parts, or any document which contains parts of this document.
-- 
Bob Neidorff; Unitrode Corporation  |  Internet: neidorff@uicc.com
7 Continental Blvd.                 |  Voice   : (US) 603-429-8541
Merrimack, NH  03054-0399 USA       |  FAX     : (US) 603-429-8564