
Identify equipment for loudspeaker measurements, including frequency response options, Dayton impedance meter, phantom-powered Dayton mic or USB UMIK-1, Focusrite Scarlett 2i2 interface, and microphone and speaker stands for Thiele/Small parameters.
Learn to use Room EQ Wizard for loudspeaker measurements, compare free and paid software, and apply an Excel workflow to export and re-import frequency response data with calibrated microphones.
Explore the theory of loudspeaker measurements, using free-field and near-field techniques to adapt to different speaker configurations. Indoors, apply gating to isolate direct sound from reflections and approach anechoic data.
Place the microphone close to the center of the mid-bass for a near-field measurement during playback, ensuring it does not touch the speaker, and reveal the 51 Hz bass-reflex resonance.
Learn to perform consistent far-field and near-field loudspeaker measurements by standardizing levels across amplifier, audio interface, and Room EQ Wizard, with a practical correction for mismatched tweeter levels.
Combine the near-field port and speaker responses by scaling the port with the area ratio, then use a plus b to sum the curves into the port plus speaker response.
Process loudspeaker measurements by smoothing, applying far-field and near-field windows, and splicing bass, mid-range, and tweeter data with baffle diffraction to prepare frd files for crossover design.
Measure electrical components with the Dayton Audio test system, including capacitors, inductors, and resistors. Compare actual values to rated values to assess tolerance and ensure accurate component ratings.
Learn how to measure frequency response
The first thing you will learn from this course is to measure the frequency response of a certain speaker driver, loudspeaker or sound system. The difficult part is to get an anechoic response without an anechoic chamber. Using different measuring techniques and with the help of intuitive software, you will learn how to measure the full frequency bandwidth anechoically in your own living room. This will help you set up your audio system using measured data, or it can be used to design crossovers for your particular DIY loudspeaker.
A little bit of electrical engineering
A sound system is a combination of both acoustical and electrical parts. You will also learn how to measure impedance and create impedance plots. Measure different electrical components like capacitors, inductors and resistors. Also, if you have an unknown speaker driver you will learn how to measure the Thiele / Small parameters without much fuss.
Dip your feet into crossover design
While this course will not teach you how to design a crossover, it will show you how to create FRD and ZMA files. These are frequency response and impedance files which are used in crossover design apps. At the end of the course I will show you how to load these files into such program, and tryout different circuits and see how adding crossover components behave. A comprehensive course about crossovers will be released in the near future.
Do I need certain equipment?
Yes, you will need 2 core pieces of gear :
A measurement microphone (like miniDSP UMIK-1).
A device for measuring impedance (like Dayton Audio DATS v2 (recently released v3 as of 2020).
These are roughly 100$ each, but you will get a more comprehensive list of the equipment needed inside the course. With alternatives that you can buy, or more cheaper options. Also, some accessories that will make your life easier are included in the list.
Software option
For the different acoustical measurements we are going to use Room EQ Wizard (or REW). This is a free to use software. Usually, acoustics software are quite expensive and difficult to follow. However, REW is free and quite intuitive to use. Pretty much a complete package. It only misses one function, which I consider important. Don't worry, we're are not going to step up to those complicated application. I devised an Excel spreadsheet which handles this shortcoming. You will find the spreadsheet inside the course.
Nov 2018 Update - Added English subtitles.
June 2019 Update - Corrected a measurement error for the 3-way speaker and added more info to that section
Jan 2020 Update - Update the equipment list