I've tried to keep it simple! It's not easy because there are so many terms and so many products.
In this section, I would like to put on my "teacher's hat" (or Lab Coat!) and give BASIC definitions of terms often used when discussing Audio products...
I promise there won't be any tests at the end of this!
This is simply meant to answer the basic question: “What in the world do all of these words mean?”
If you have any questions or comments:
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.
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.
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.
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.
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.
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:
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:
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:
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:
there are other classes:
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.
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.
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 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.
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 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 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.
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.
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.
My dad who 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'Electronique, Aventure and La Boutique Electronique.
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.
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