AUDIO 101

Speaker Terminology

A loudspeaker is a device which converts an electrical audio signal into a corresponding sound. When an alternating current electrical audio signal is applied to its voice coil, a coil of wire suspended in a circular gap between the poles of a permanent magnet, the coil is forced to move rapidly back and forth due to Faraday's law of induction, which causes a diaphragm (usually conically shaped) attached to the coil to move back and forth, pushing on the air to create sound waves.

Audio frequency - the acoustic spectrum of human hearing, generally regarded to be between 20 Hz and 20 kHz.
Highs (or High end, Top end, Treble, or Air) – The section of the frequency spectrum above 8kHz.
Lows (or Low end, Bass, or Sub-bass) – The section of the frequency spectrum between 60Hz-200Hz.
Mids – The section of the frequency spectrum between 600Hz-3kHz.

Cone - the conical diaphragm of a speaker attached to the voice coil which produces pulsation's of air that the ear detects as sound.
Crossover Network (Filter) - an electric circuit or network that splits the audio frequencies into different bands for application to individual speakers.
Diaphragm - the part of a dynamic loudspeaker attached to the voice coil that moves and produces the sound. It usually has the shape of a cone or dome.
Driver - a loudspeaker unit, consisting of the electromagnetic components of a speaker, typically a magnet and voice coil.

Dome Tweeter - a high frequency speaker driver with a dome-shaped diaphragm usually made of metal or silk.
Spider - the flexible material that supports the former, voice coil, and inside portion of the cone within the speaker frame.
Surround (suspension) - the outer suspension of a speaker cone; holds the diaphragm in place but allows it to move when activated. Usually made of foam or rubber.
Voice coil - the wire wound around the speaker former. The former is mechanically connected to the speaker cone and causes the cone to vibrate in response to the audio current in the voice coil.

Dispersion - the spreading of sound waves as it leaves a speaker.
Efficiency: Another very important characteristic, it is the ratio between the output power and power consumed.
Efficiency rating - the loudspeaker parameter that shows the level of sound output when measured at a prescribed distance with a standard level of electrical energy fed into the speaker. However, a driver with a high efficiency rating needs a larger box to play a lower frequency than a driver with a lower efficiency rating.

Electronic Crossover - uses active circuitry in addition to passive to filter unwanted signals for each driver. Usually active filters are employed as LPF(Low Pass Filters) for subwoofers or for the sub out of a preamp / receiver.
Enclosure - a box that contains the driver(s).
Full-range - a speaker designed to reproduce all or most of the sound spectrum within human hearing (20Hz - 20KHz)

Treble (highs) - the upper end of the audio spectrum reproduced by tweeters, usually 3 - 4 kHz and up.
Tweeter - a speaker designed to reproduce the high or treble range of the sound spectrum.
Subwoofer - a loudspeaker designed to reproduce bass frequencies.
Woofer - a loudspeaker transducer designed to reproduce low-frequency sounds.

SPEAKER DESIGNS:

Two-way - a type of speaker system composed of two ranges of speakers, usually a woofer and tweeter.
Three-way - a type of speaker system composed of three ranges of speakers, specifically a woofer, midrange, and tweeter.

Monitors – This refers to speakers that are used for mixing.
Standing wave - a buildup of sound level at a particular frequency that is dependent upon the dimensions of a resonant room, car interior, or enclosure. It occurs when the rate of energy loss equals the rate of energy input into the system. This is what you hear when you listen into a sea shell.

Horn - a speaker design using its own funnel shaped conduit to amplify, disperse, or modify the sounds generated by the internal diaphragm of the speaker.
Imaging - it is the speakers ability to localize different instruments playing simultaneously
Timbre - The quality of a sound related to its harmonic structure. Timbre is what gives a voice or instrument its sonic signature -- why a trumpet and a saxophone sound different when they play the same note.

Sound Stage - the sound systems ability recreate an imaginary stage. A good speaker will faithfully make the stage seem close to the actual height, width and depth of the actual performance stage where recorded. Imaging is similar, but the speaker must be able to place each instrument or voice in the correct location on the soundstage. The reproduction of the way the music would sound if you were actually watching the musicians play in front of you. The stage should always appear to be in front of you, with a proper "image" of where each musician is playing on the imaginary soundstage.

Ambience – Background noise added to a musical recording to give the impression that it was recorded live. Often done using short room reverbs.

Bandwidth – The amount of space on the frequency spectrum that the sounds of an instrument are being produced at. For example, an average electric guitar has a bandwidth of 80Hz-5kHz, as the instrument cannot produce sounds above or below those frequencies.

Decibel (or dB) – the main unit of volume measurement. A dB is relative, as there are several different “scales” of dB’s that are used in audio (dB-FS being the most common, along with dB-VU, dB-RMS, and dB-LUFS). Each dB scale has a certain function in audio.

Dynamics (or dynamic range) – The loud and soft points of a sound over time. The higher the range, the more difference there is between the loudest point and the softest point.

Decay – How fast a sound fades from a certain loudness.

Distortion – The result of a sound source overloading an amplifier or sound processor. Basically, new frequencies are added where there were none before. This can be pleasing or very harsh. The nature of the distortion depends on the equipment that is being distorted.

Feedback – When a signal is sent through an amplifier and into a microphone, which picks up the sound and sends it back through the amplifier, and so on. The loop of sound creates high pitched whines. Also refers to the parameter on a delay that adds more repetitions of the sound.

Listener fatigue – The natural degradation of the accuracy of the human ear over several hours of listening. The ear is like a muscle – when it is used a lot, it gets tired. When a mixer reaches the point of listener fatigue, he or she needs to rest their ears, or they will start to make poor mixing choices as their ears are no longer accurate.

Phase – The nature of the location of two similar waveforms in relation to each other. If two similar waveforms are “in-phase,” then the peaks and troughs of the waves are lined up with each other. If the waveforms are “out-of-phase,” then the peaks are in line with the troughs. This causes low and low-mid frequencies to get lost. Ultimately, out-of-phase waveforms sound bad.

Types of Amplifiers

An integrated amplifier simply combines a power amplifier and pre-amplifier in a single box. This is the 'beating heart' of your hifi system, linking your sources (turntable, cd player, streamer etc.) and driving your speakers.

An integrated amplifier typically takes up far less space, simplifies your system and can save you some serious money.

Amplifier (or Amp) – an electrical circuit designed to increase the current or voltage of an applied signal.
Transistor Amplifiers: A well known type of amplifier, especially to engineering students, a transistor amplifier is a multi configuration high output amplifier that uses transistors as the working base.

Solid State Amplifiers: Warm up quickly and require little to no maintenance. They are Energy efficient and available in in half or full-size chassis. They tend to deliver faster bass than tube amplifiers and more of it as well. There is a wide variance in the voicing or tonal characteristic of Solid state amps so speaker matching, musical taste and room conditions are important factor when selecting the right model.

Valve or Tube Amplifiers: Require about 30 minutes to reach ther optimal performance & are less eneg efficient than other options. Checking the bias (matching the left and right tube output) periodically will improve performance and tube life. (Not a big thing but they do require some maintenance). They tend to deliver a warmer, more relaxed sound than solid- state amps. Tweaking the sound can be easily done by changing tube brands. Brighter speakers and hard-surfaced rooms can often benefit froma tube amplifier. Power output tends to be lowerso some speaker matching is required.

Hybrid Amplifiers (tube/Solid State): Tube, solid-state amplifiers offer the best of both worlds & tend to be cost-effective for their performance. They are dynamic but remain smooth due to the tube preamplifiersection. Because the solid state section typically does the heavy lifting, these amps warm up quickly & are energy efficient. There is no maintenance on hybrid models but the sound can be tweaked by changing preamp tubes. This type of tube is long-lasting & there is little need for ever changing them from use.

One Good Ear Brands

Class A Power Amplifier

This class of amplifiers offers low signal distortion levels. It has its fair share of disadvantages though, and is generally not used in high power applications. Some of its characteristics are:

Low signal distortion levels
Simple design
The device is always conducting due to amplifying element bias
No turn on time or charge storage problems
Quite stable
Highest linearity
Low efficiency due to being on all the time, around the vicinity of 25-50%
High heat output during operation

Class B Power Amplifier

Class B Power Amplifiers, unlike Class A, work for only half of each nput cycle, which means they have a conducting angle of 180 degrees. In simple words, these amplifiers amplify only half of the input cycle. On paper that probably sounds unusable, but in reality, it’s quite different. Class B amplifiers consist of a positive and negative transistor, which run alternatively, amplifying the positive and negative cycle respectively, which in the end is combined to form a full output cycle. It’s a more efficient design, and has its own set of advantages and disadvantages compared to the Class A power amplifier. It’s characterized by:

Uses 2 complementary transistors, one each for the positive and negative cycle
Much higher efficiency, around 75-78.5%
Lesser heat output
Stable and reliable
Requires at least 0.7 V to start conducting, which means anything under it doesn’t register, so cannot be used for precise applications

Class AB Power Amplifiers

A Class AB Power Amplifier is, as the name suggests, a mix of Class A and Class B power amplifiers. Like the Class B amplifier, it also uses 2 conducting elements (transistors), but they both run at the same time. This eliminates the ‘dead zone’ from -0.7 V to + 0.7 V seen in the Class B power amplifier. But in this case, while each transistor conducts for more than a half cycle, they conduct less than a full cycle completely. So the conduction angle is somewhere around 180 degrees and 360 degrees, commonly shown as 270 degrees in some cases. Here are it’s characteristics:

Uses 2 transistors that work together
Each transistor is active for slightly less than a full cycle but more than a half cycle
Combines Class A and Class B characteristics
No crossover distortion
Fairly efficient, at around 50-60%
Most common audio amplifier design

Class D Power Amplifier

Class D Power Amplifiers, which sometimes aren’t considered among the 3 mentioned above. It’s a non-linear switching amplifier in which the two transistors function as switches instead of linear gain devices.

Class-D amplifiers theoretically can reach 100% efficiency, as there is no period during a cycle were the voltage and current waveforms overlap as current is drawn only through the transistor that is on.

It converts the analog signal into digital via pulse width modulation, pulse density modulation or something similar before being amplified. The end result is a cycled output with high efficiency and gain, without too much distortion. Contrary to popular belief, the ‘D’ in the name doesn’t stand for digital, because the converted signal is pulse width modulated analog, and not pulse width modulated digital. It is characterized by:

High efficiency, can theoretically be 100%
Low power dissipation
Low power consumption
More complex than other types of power amplifiers
Precise and accurate output

there are other classes:

Class F, G (Arcam for instance), I, S and T Amplifiers but these are not as common.

Tube Amplifiers

Valve (or) Vacuum Tube Amplifiers: An amplifier that uses vacuum tubes to provide an increased power or voltage output is known as a valve (or) vacuum tube amplifier. In high power applications, they’re still in use because of their cost effectiveness and output quality.

Amplifiers: Characteritics

Bandwidth: The frequency range at which the amplifier can operate.
Gain: Perhaps the most important, the ratio between the magnitudes of input and output signals.
Linearity: The degree of proportionality between input and output signals.
Noise: The amount of unwanted extra information included in the output.
Stability: The ability to provide constant and reliable output.
Output Dynamic Range: Ratio between the largest and smallest useful output levels.

Capacitor - a charge storage device made up of two metallic plates separated by a dielectric, with equal but opposite charges. The AC impedance of a Capacitor is (1 / jWL) and acts as an open circuit in DC applications.
Circuit - a complete path that allows electrical current from one terminal of a voltage source to the other terminal.

What's a Watt?

The watt (abbreviated W) is the International System of Units' (SI) standard unit of power (energy per unit time), the equivalent of one joule per second. The watt is used to specify the rate at which electrical energy is dissipated, or the rate at which electromagnetic energy is radiated, absorbed, or dissipated.
Hertz (Hz) - a measurement of the frequency of sound vibration. One hertz is equal to one cycle per second. The hertz is named for H.R. Hertz, a German physicist.
Kilohertz (or kHz) – 1000x the unit of measurement for frequencies. 1 kHz = 1,000 Hz.
Volt - a unit of measurement used to measure how much "pressure" is used to force electricity through a circuit.

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DAC's

DAC - digital-to-analogue converter, turning on/off pulses into analogue sound. CD players have DACs built in. Separate DACs can upgrade a CDplayer or other digital player/ recorder, or can be used with dedicated CD transports.

Cables: What are audio connectors?

Audio encompasses a large number of interfaces including digital and analog. These are used in a number of applications from home theater and portable use to the pro audio mixing boards that DJ's and other audio professionals use.

Audio cables are often referred to as accessories. However, an audio system cannot make sound without cables installed which implies that they are essential components.

Much like the other components in the system, cables must be chosen with the same research that one would perform in choosing an amplifier, a speaker or a turntable.

Characteristics such as colouration, distortion and other anomalies must be minimized in order for the system to perform at its optimum.

Too often, audiophiles and music lovers treat these essential components as after thoughts and end up compromising the performance of their carefully chosen audio gear.

RCA connectors

The RCA connector is used in several audio applications. Stereo RCA Cables connect two analog audio components together. They are found on most types of A/V gear.

S/PDIF (Sony®/Philips Digital Interface) is the "red book" standard for digital audio signal transfer. A S/PDIF coaxial cable can carry linear PCM or multi-channel Dolby® AC-3/DTS® digital content.

For dual channel stereo audio, two RCA connectors deliver the analog composite audio signal to the left and right channels of audio. In home theater, RCA can be used as a powered sub-woofer connection.

LFE (Low Frequency Effects)

Home theater receivers use a single RCA output for the sub-woofer connection - that's the ".1" in a 5.1 system. This output is often labeled LFE. It sends bass information to a powered sub-woofer.

Headphone connections (1/4" and 1/8")

Stereo headphone connections come in two sizes: full-size (1/4") and mini (1/8").

Home A/V components like CD players, receivers, and headphone amplifiers use the 1/4" connection.

Smartphones, tablets, and computers use the smaller 1/8" jack.

Headphones with 1/4" plugs can be stepped down to 1/8" to plug into a mobile device.

Headphones that use a 1/8" plug can be stepped up to 1/4" to fit equipment that uses a full-sized connection.

Speaker Wire:

Speaker Wire connects a non-powered speaker to an amplifier or receiver. Speaker wire has two leads: one for the positive signal, and one for the negative. Usually speaker wire is marked (+) and (-) to help distinguish between the two.

Wire thickness is identified by its American Wire Gauge (AWG) number. The lower the gauge number, the thicker the wire. Thicker wire presents less resistance to current flow.

Thick wire (12 or 14 gauge) is recommended for long wire runs, high power applications, and low-impedance speakers (4 or 6 ohms).

What gauge do you need?

For relatively short runs (less than 50 feet) to 8 ohm speakers, 16 gauge wire will usually do just fine. It’s cost-effective and easy to work with.

Speaker Wire Connectors:

Add speaker wire connectors to bare wire for additional connection options.

Banana Plugs:

If you have binding post terminals on your speakers and/or receiver, banana plugs are a great choice. The flexible metal collar of a banana plug is slightly wider than the center hole of a binding post. It compresses to fit when you plug it in, resulting in a very solid connection.

Spade Connectors:

Spade connectors feature a forked piece of metal that hugs the collar of a 5-way binding post terminal. The spade is then secured by tightening the binding post's cap. Spade connectors give you very secure contact.

Pin connectors:

Pin connectors may either be straight or angled. They work with spring clip speaker terminals, as well as with binding posts.

Power cables (C7 and IEC)

Many home A/V components feature a detachable power cord. There are two common plug types: a 3-pole IEC connector, and a 2-pole C7 connector. Replacing the stock power cord can improve audio and video performance.

Longer cord lengths also provide flexible placement options.

Audience

XLR – primarily found on professional audio equipment. XLR Cables pass an analog signal between compatible audio components. They're commonly used with high-performance two-channel systems, as well as with microphones.

An XLR connector has three pins - a positive conductor, a negative conductor, and a ground. The presence of the ground wire makes XLR cables known as "balanced" cables. It helps reduce electronic noise throughout the cable.

A clasp built into the round XLR plug locks it tightly into the receiving socket, ensuring a secure connection.

Digital Cables:

USB (Universal Serial Bus)

USB is a digital interface that connects compatible devices together. It's used to transfer audio, video, and other digital information. Originally designed for computers, USB cables are now used for data transfer and charging in a wide range of components. USB inputs can be found on computers, TVs, home theater receivers and car stereos.

The standard USB connection is considered Type A - that's the one that plugs into your computer. Type B USB plugs are commonly used with printers.

Micro USB plugs are found on smartphones and other portable devices.

HDMI (High Definition Multimedia Interface) - This digital video interface allows high definition video and audio to be transmitted over a single cable.

Cables can be made of copper (limited to ~30 feet without electronic signal boost and equalization) or fiber optic, with the latter able to reach almost unlimited distances.

An HDMI cable is today's go-to connection for high-definition audio and video transmission. It's used with TVs, gaming systems, home theater receivers, computers, and HD monitors.

The standard HDMI cable has an identical plug on each end. Inside there are 19 individual wires. They carry audio and video data along with control signals, low-voltage power, Ethernet, and copy protection.

Standard-size HDMI cables are called Type A. Compact devices like smartphones, cameras, and camcorders use mini HDMI (Type C), or micro HDMI (type D) because of their small form factor.

TOSLINK is the name of an optical interface for digital audio signals. The interface was developed by Toshiba, and TOSLINK is their registered trademark. The TOSLINK (also known as EIAJ optical) connector is a small, round optical conductor housed in a squarish connector body. Originally intended for use solely with Toshiba CD players, it has been adopted by many other manufacturers and is standard equipment on many A/V sources, receivers and surround sound equipment. Even though TOSLINK uses fiber optic cable, it is limited to a maximum cable length of about 5 meters, due to the low power of the LEDs used in transceivers.

Coaxial digital cable

A coaxial digital cable transmits a digital audio signal between two devices. It's commonly used with home theater receivers, music streaming devices, and disc players. Coaxial digital cables look virtually identical to single analog RCA cables. But they are specially designed to handle the wide frequency bandwidth of digital signals.

A single cable is used to transmit the entire digital signal. Coaxial digital connection ports are typically orange.

In Memoriam: Teachers who Are No Longer With Us...

Daniel Fragman

My dad was the person who got me "hooked" onto this industry...

He passed away on July 5th, 1998

We worked together at numerous audio/video stores: Atlantique Image et Son, Laval Audio, Le Marché de L’électronique, Aventure and La Boutique Electronique.

Robert Fragman

Paul Masson (Cambridge Audio International Sales Manager)

Paul Masson passed away in August 2012

“Some people pass by in life’s businesses, others make something of a useful comment that you learn from, just a few make a massive impact. Paul was one of those...”

Paul was an amazing person who sadly passed away much too soon.

George Tordai

May 29, 1946 - May 28, 2020

George's store; Audio Oasis was located in Toronto. The last time I saw him he was more than happy to share how much he was enjoying a well deserved retirement.

Art Dudley

A true gentleman...

Art was a writer at Stereophile magazine.

"Art was quiet, funny, and self-effacing, but in his own way he was—that word again—fierce in everything he did. He was my partner and my friend." -Michael Fremer

Analog Planet article Apr. 14, 2020

Ron Simek: Altronics Stereo 2000 November 22, 2021

Ron was the most knowledgeable person I have ever met! He owned Altronics Stereo 2000 on Bloor street and had built quite the reputation in the industry as someone who was both a “straight shooter“ and a no nonsense individual. Very opinonated but also willing to back up his conviction with facts and figures!

He received the Lifetime Achievement Award at the 2020 TorontoAudioFest…

Peter Lau (March 2021)

Peter worked in a few audio stores in the GTA: I had the pleasure of dealing with him at Kromer Radio and Update TV.

Andy Lenton from G&G Electronics & JVC January 2021

Andy was a staple at G&G Electronic… he was a friendly person who was always ready to assist clients. An integral part of the G&G team/family for over 20 years.

Jay O’Brien

Jay was an exceptional sales representative and a wonderful human being… I first met him in Toronto when I managed a store from 1999 to 2001: Mt. Pleasant Stereo. At the time, Jay was the sales rep for Boston Acoustics; he would come up to Canada a few times a year from his home base in Massachusetts and I would often tell him that I was always impressed by his knowledge and work ethics. In fact, I saw him more often than some reps who lived minutes away from the store!

As luck would have it, we ended up working together for the North American distributor of Monitor Audio loudspeakers; Kevro International. It was truly a pleasure working with him…

Terry Richardson (1942-2023)

I had the pleasure of working with Terry for 10 years for the Canadian distributor of such prestigious brands as Focal, Naim, Rega, Cambridge Audio, Martin Logan & many more; Plurison (now Focal-Naim North America).

Terry was kind hearted, armed with a sharp sense of humour (very British!), and a terrific wealth of knowledge. He was “the Man in Black”…”Naim’s brand ambassador”

Terry received the Lifetime Achievement Award at the TorontoAudioFest in 2018

Gérard Rejskind

Gerard Rejskind passed away on December 7, 2023 after a brief illness. As editor-in-chief since 1984 of Ultra High Fidelity (UHF) magazine, then called Hi-Fi Sound Magazine, Gerard played an important role in the growth of the audiophile hobby in Canada. For his contributions to the audio industry, he received the Lifetime Achievement Award by the Montréal Audiofest in 2011. A lifelong audiophile, Gerard continued to be an integral part of the audiophile community until the very end. He will be missed, but he will also be remembered for his kindness and unwavering dedication to sharing his passion for audio and music with others.

AUDIO 101

Speaker Terminology