Exploring Common DIY Terminology - SINAD

SINAD (Signal to Noise and Distortion ratio)

While not directly applicable to loudspeaker design, SINAD is a term in common use and is a valuable tool when comparing electronic equipment to match with your speakers. It can also be used when deciding what equipment you'd like to use for your measurement setup. SINAD stands for "Signal-to-Noise and Distortion ratio." It is a metric used to quantify the audio quality of electronic devices, particularly audio equipment like amplifiers...

Fs (Thiele/Small Parameter)

The Thiele/Small parameter "Fs" refers to the resonant frequency of the loudspeaker driver. Fs stands for "Free-air resonance" or "System resonance." It is a crucial parameter that characterizes the natural frequency at which a driver's diaphragm vibrates with maximum efficiency when operating in free air, without any enclosure or load. This resonant frequency is determined by the combined effects of the mass of the driver's...

Qts (Thiele/Small Parameter)

Qts (Total Q-factor) is a significant parameter in loudspeaker design that characterizes the overall damping of the loudspeaker driver. It is derived from the combination of two other Thiele/Small parameters: Qes (Electrical Q-factor) and Qms (Mechanical Q-factor). Qts provides important insights into the loudspeaker's frequency response, impedance behavior, and overall system performance. Total Q has several implications on loudspeaker design:

1. Frequency

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Damping Factor

The damping factor is a measure of the amplifier's ability to control the movement of a loudspeaker's voice coil and bring it to a stop after the audio signal has stopped. It quantifies an amplifier's ability to provide an electrical damping effect on the speaker. Mathematically, the damping factor is defined as the ratio of the loudspeaker's nominal impedance (typically 4 or 8 ohms) to the output impedance of the amplifier. It is usually expressed as a number, such as...

Gap Height

Gap height refers to the vertical dimension of the air gap between the magnetic pole piece and the voice coil. It is a critical parameter that affects the performance and characteristics of the loudspeaker driver. The gap height has a direct impact on several aspects of the loudspeaker driver's operation:

• Voice Coil Clearance: The gap height determines the clearance or distance between the voice coil and the pole piece. Sufficient clearance is essential to prevent any physical

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Underhung Voice Coil

An underhung driver is a type of design where the voice coil's winding height is shorter than the height of the magnetic gap in which it operates. In other words, the coil does not extend fully through the magnetic gap, and it remains "underhung" within the magnetic structure. In a standard loudspeaker driver, the voice coil is wound on a cylindrical former and moves within the magnetic gap, which is a cylindrical space between the pole piece and the magnetic...

Compression Driver

A compression driver is a type of loudspeaker driver used primarily in high-frequency reproduction. It is commonly found in professional audio applications, such as PA (Public Address) systems, studio monitors, and high-end home audio speakers. The compression driver is designed to handle the high frequencies efficiently and deliver them with clarity and power. A compression driver consists of several key components:

• Diaphragm: The diaphragm in a compression driver

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Soundstage

Soundstage refers to the perceived spatial placement and localization of sound sources in a recording. It describes the three-dimensional presentation of audio, making it seem as if the sound is originating from specific locations within the listening environment, rather than coming directly from the loudspeakers. When a recording and playback system is capable of creating a convincing soundstage, listeners can experience a more immersive and realistic audio experience. The...