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Articles & guides
Three content pillars: room acoustics, electroacoustic design, and audio engineering. Every article defines terms on first use and cites sources where relevant.
24 articles
- ElectroacousticsIntermediate
An introduction to loudspeaker crossover design
A crossover network does not just divide a frequency band — it determines how two drivers integrate acoustically at the listening position. Get it wrong and no amount of EQ will fix it. This article covers crossover frequency selection, filter order and alignment, passive versus active implementations, and a worked design example for a two-way system.
Read → - AcousticsIntermediate
Designing a Listening Room - Where to Start?
A listening room is not a neutral environment. Every room imposes its own acoustic signature — colouring frequency response, smearing transients, distorting stereo imaging. This article covers the sequence of decisions that define a successful design: from choosing room dimensions, to setting RT60 targets, to treatment strategy. Start here before you buy a single panel.
Read → - AcousticsIntermediate
Critical distance and its practical implications
The critical distance marks the point where direct and reverberant energy are equal. Understanding it determines optimal monitoring position, acceptable room volume, and the required RT60 for any critical listening application
Read → - AcousticsFundamentals
The decibel — what it is and why the world of acoustics uses it
Sound spans an enormous range of pressures — from the threshold of hearing to the threshold of pain, a factor of roughly one million in pressure amplitude. The decibel is the unit that makes this range workable. This article explains what a decibel actually is, how it relates to sound pressure, and why logarithmic units are the natural choice for acoustics.
Read → - ElectroacousticsFundamentals
Thiele-Small parameters explained
Fs, Qts, Vas, Xmax — the small-signal parameters that define a drive unit's behaviour. What they mean physically, how they interact, and how to use them to design enclosures.
Read → - AcousticsFundamentals
RT60 — what it is and why it matters
Reverberation time is the single most important descriptor of a room's acoustical character. This article explains the derivation, measurement per ISO 3382, and practical implications for studio and listening room design.
Read → - AcousticsFundamentals
Sound waves — pressure, particle velocity, and wave propagation
Sound is a mechanical disturbance that propagates through an elastic medium. Understanding what that disturbance actually consists of — pressure variations, particle motion, and the relationship between them — is the foundation for everything else in acoustics.
Read → - AcousticsFundamentals
Equal loudness contours — how hearing shapes what we measure
The ear is not equally sensitive at all frequencies. A 50 Hz tone must be considerably louder than a 1 kHz tone to sound equally loud. These variations — captured in the equal loudness contours — have direct implications for acoustic measurement, loudspeaker design, and mixing practice.
Read → - ElectroacousticsFundamentals
Baffle step — what it is and how to account for it
A driver mounted on a baffle does not radiate the same way at all frequencies. At low frequencies it radiates into full space; at high frequencies the baffle constrains radiation to a hemisphere. The 6 dB transition between these two conditions — the baffle step — must be accounted for in every loudspeaker system design.
Read → - ElectroacousticsIntermediate
The near field and far field: acoustic zones explained
Sound radiates from a source through distinct acoustic regions. Understanding the boundary between near and far field is essential for measurement, microphone placement, and loudspeaker design.
Read → - ElectroacousticsFundamentals
How a loudspeaker works — the electrodynamic transducer
The electrodynamic loudspeaker converts an electrical signal into acoustic pressure through a chain of physical mechanisms: electromagnetic force, mechanical motion, and acoustic radiation. Understanding each step — and where energy is lost or constrained — is the foundation for everything in loudspeaker design.
Read → - ElectroacousticsFundamentals
Directivity and the directivity index
A loudspeaker does not radiate equally in all directions. Its directional behaviour — how on-axis output relates to off-axis output, and how this changes with frequency — determines how the loudspeaker interacts with the room and what the listener actually hears. The directivity index is the key metric for characterising this behaviour.
Read → - AcousticsFundamentals
Frequency, wavelength, and the speed of sound
Three quantities — frequency, wavelength, and the speed of sound — are related by a single equation, and together they govern almost every aspect of practical acoustics: room modal behaviour, driver directivity, diffuser design, and barrier effectiveness. This article covers the relationship, how to apply it, and why it matters.
Read → - AcousticsFundamentals
The inverse square law — and when it doesn't apply
In a free field, sound level falls by 6 dB each time the distance from a source doubles. This is the inverse square law — one of the most cited relationships in acoustics, and one of the most frequently misapplied. This article explains where it comes from, where it holds, and where it breaks down.
Read → - AcousticsFundamentals
Sound absorption — what it means and how it's quantified
Acoustic treatment begins with absorption. But absorption is not a single material property — it is a frequency-dependent quantity that varies with material type, thickness, mounting, and measurement method. This article explains the absorption coefficient, how it is measured, and what it means in practice.
Read → - AcousticsFundamentals
Diffusion — what it does and what it doesn't do
Diffusion is widely used and widely misunderstood. It scatters sound energy across multiple angles rather than reflecting it coherently — but it does not absorb sound, reduce reverberation time, or treat low-frequency modal problems. This article explains what diffusion actually does, how diffusers are designed, and when to use diffusion rather than absorption.
Read → - ElectroacousticsFundamentals
Impedance in loudspeakers — what it is and why it varies
A loudspeaker's impedance is not a fixed value. It varies with frequency over a wide range, and this variation has consequences for amplifier matching, passive crossover design, and power delivery. Understanding the impedance curve — what causes each feature and what it means in practice — is essential for system design.
Read → - ElectroacousticsFundamentals
How to measure loudspeaker frequency response
A step-by-step guide to gate-windowed near-field and far-field measurements using swept-sine excitation. Covers hardware, software, and common measurement errors.
Read → - Audio engineeringFundamentals
Dynamic range and the noise floor
Dynamic range is the span between the quietest and loudest signals a system can handle. Understanding where noise enters the signal chain — and how bit depth, analogue design, and converter quality each contribute — is fundamental to getting clean recordings.
Read → - Audio engineeringFundamentals
Gain structure — setting levels through the signal chain
Gain structure is the practice of setting signal levels at each stage of the audio chain so that every device operates in its optimal range — loud enough to stay above the noise floor, quiet enough to avoid clipping. Getting it wrong compounds noise and distortion across every stage.
Read → - AcousticsFundamentals
Understanding room modes — a practical guide
Axial, tangential, and oblique modes arise from standing waves between parallel boundaries. This guide explains how to predict frequencies, identify which modes cause audible problems, and prioritise treatment.
Read → - ElectroacousticsFundamentals
Loudspeaker sensitivity and efficiency — what the specs actually mean
Sensitivity and efficiency are related but distinct quantities that appear on every loudspeaker datasheet. Confusing them leads to incorrect system calculations and misleading comparisons between drivers. This article defines both, explains the difference, and shows how to use them correctly.
Read → - ElectroacousticsFundamentals
Closed box vs ported enclosure — the fundamental trade-offs
The two most common loudspeaker enclosure types — closed box and ported (bass reflex) — represent fundamentally different acoustic loading strategies with different extension, rolloff behaviour, and tolerance to programme material. Neither is universally superior; the choice depends on the driver, the target application, and the constraints of the design.
Read → - Audio engineeringFundamentals
Signal levels — dBu, dBV, and dBFS explained
Professional and consumer audio equipment use different reference levels, and digital systems use a different scale altogether. Understanding dBu, dBV, and dBFS is essential for connecting equipment correctly and interpreting meters.
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