Acoustics 101 : Speaker design basics and enclosure design
4.5 (878 ratings)
Course Ratings are calculated from individual students’ ratings and a variety of other signals, like age of rating and reliability, to ensure that they reflect course quality fairly and accurately.
2,525 students enrolled

Acoustics 101 : Speaker design basics and enclosure design

How to design your own sealed or bass reflex enclosure. Loud speaker building techniques for a great DIY audio system.
4.5 (878 ratings)
Course Ratings are calculated from individual students’ ratings and a variety of other signals, like age of rating and reliability, to ensure that they reflect course quality fairly and accurately.
2,525 students enrolled
Created by Marius Tanasescu
Last updated 7/2020
Current price: $69.99 Original price: $99.99 Discount: 30% off
5 hours left at this price!
30-Day Money-Back Guarantee
This course includes
  • 3.5 hours on-demand video
  • 2 downloadable resources
  • Full lifetime access
  • Access on mobile and TV
  • Certificate of Completion
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What you'll learn
  • Design sealed speaker enclosures.
  • Design bass reflex speaker enclosures.
  • Understand how sound waves work and their characteristics.
  • Know how a speaker is producing sound and what are the speaker components.
  • Interpret the data on a speaker specification sheet.
  • Understand the pro's and con's of different enclosure types.
  • Build loudspeaker boxes which produce linear sound with minimal distortion.
  • Design a basic 2-way crossover network
  • You should be passionate about audio and sound quality.
  • You need to have an understanding of mathematics at an intermediate level.
  • You should own and be able to use a PC at a basic level.
  • You need Microsoft Excel installed or other application that can open *.xlsx files.

Design an enclosure to match your preferences

The main purpose of this course is to teach you how to properly design an enclosure for your speaker. There is no such thing as "This enclosure is the best choice for this particular speaker". You have to take into consideration your application and your personal preferences. Do you want it to sound loud? Do you want it to sound deep and don't care about loudness? You want it to be as smooth and linear as possible? These are all just a few examples of questions that needs answering before you get to work. The final result will always be a compromise between the acoustical qualities of an enclosure. Only you can decide which sound qualities are more important to you and you should be the one who "moves the sliders".

Acoustics basics

This course assumes that you have minimal knowledge about acoustics, and therefore starts slowly with some basic information about sound waves, how they are created and what are their characteristics. Then moves on to how the speaker is designed and some other relevant information about acoustics. This is obviously needed for a beginner, but it's also good for an intermediate student, as I'm sure he will also find new information to make matters even more clear.

Enclosure types

Most of the common enclosure types are listed, explaining their working principle, pro's and cons for each one. But, we will focus our attention for the sealed and bass reflex enclosures. These are covered with extensive details regarding their characteristics and how to design them according to the standard alignments, or to complete custom response curves.

Modeling software

To model the response curve of the enclosure and to calculate the dimensions of the box, two methods will be used. You will receive an excel spreadsheet, that has all that you need to model a sealed or a bass reflex enclosure with minimal difficulty. It even has a chart to show you the modeled frequency response. It's basically a complete package for a beginner. The other method is by using a paid application. There are a lot of speaker design software solutions out there but I chose : "Subwoofer design toolbox". The main reasons are : it's cheap, simple, easy to understand and it has all the basic functions. If you are a beginner it's very important to start slow, otherwise you will get overwhelmed by complicated applications with extra features that will only confuse you.

Nov 2017 Update - 2-way speaker build example and basic 2-way crossover design.

Jan 2018 Update - Added English subtitles.

Jul 2020 Update - Added more animation to some lessons.

Who this course is for:
  • Audiophiles who want to learn more about sound and speaker systems.
  • DIY-ers who want to build their own speaker enclosure.
  • People who built enclosures by following some speaker plans, but want to understand the design process.
  • People interested in acoustics and electro-acoustics
Course content
Expand all 41 lectures 03:30:41
+ Introduction
1 lecture 03:25

How the course is structured and a quick briefing about each section.

Preview 03:25
+ Sound waves
5 lectures 26:06

A visual perspective on how sound waves work.

Visualization of sound waves

How sound is created with emphasis on a speaker.

How sound waves are created

Explanation of the first three (out of 4) sound wave characteristics.

Sound wave characteristics : Amplitude, frequency, wavelength

The last sound wave characteristic : Phase.

Sound wave characteristics : Phase

With the help of a signal generator and an oscilloscope, we will see in real time how amplitude and frequency change, and how it affects the sound.

Real time sound wave analysis
+ Speaker design
1 lecture 07:09

Overview on how the speaker each designed. Complete description on each component of the speaker and how they function.

Speaker design
+ Frequency response
3 lectures 16:23

How to interpret a frequency response chart. What to look for, and explanation of few common response curves.

Frequency response charts

The F points on a frequency response chart : F0 , F3 and F10.

F points

What is an octave and few examples. Explanation on why the response curve is rolling off and how to interpret the steepness of the roll-off slope.

Octaves and roll-off slopes
+ Thiele / Small parameters
6 lectures 16:29

Brief description of the Thiele Small parameters. The resonant frequency (Fs).

Introduction to T/S parameters, Fs

The quality factor : Q.

Qms, Qes and Qts

Compliance (Cms) and Equivalent compliance as a volume (Vas).

Cms and Vas

DC resistance (Re) and Nominal Impedance.

Re and Impedance

Maximum linear excursion (Xmax), Maximum mechanical excursion (Xmech), Effective cone area (Sd).

Xmax, Xmech and Sd

Speaker moving mass (Mmd) and Total moving mass (Mms).

Mmd and Mms
+ Decibel scale
1 lecture 07:40

How sound is measured and how to compare different sound levels. Efficiency of speakers and how to interpret the numbers in the specification sheet.

Decibel scale
+ Enclosure types
7 lectures 11:18

What is the purpose of an enclosure, and what do they have in common, regardless of their type.


The Infinite baffle enclosure.

Infinite baffle

The Sealed / Closer / Acoustic suspension / Air suspension enclosure.


The Bass reflex / Ported / Vented enclosure.

Bass reflex

The Bandpass enclosure.


The Transmission line or Acoustical labyrinth enclosure.

Transmission line

How an enclosure is actually a compromise between 3 qualities.

Hoffman's Iron Law
+ Sealed enclosure
4 lectures 28:50

Complete explanation on how the sealed enclosure works.


Learn how to design a sealed enclosure using the included Excel spreadsheet.

Preview 06:36

Learn how to design a sealed enclosure using the designated paid application.

Design using the paid application

What are the effects of filling the box with sound dampening material.

+ Bass reflex enclosure
5 lectures 33:57

Detailed explanation on how the bass reflex enclosure works.


What are box losses (QL), and how they affects the frequency response.

Box losses

Predefined alignments which you can chose when tuning the box.

Bass reflex alignments

Learn how to design a bass reflex enclosure using the included Excel spreadsheet.

Design using the Excel spreadsheet

Learn how to design a bass reflex enclosure using the designated pain application.

Design using the paid application
+ Box builds examples
3 lectures 32:37

Tips and tricks on how to build a great enclosure.

Construction tips

Full detailed example and how to design a sealed box, and how to calculate the box components using the Excel spreadsheet.

Sealed enclosure design from start to finish

Full detailed example on how to design a bass reflex box, and how to calculate the box components using the designated paid application.

Bass reflex enclosure design from start to finish