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Active speaker design workshop (Bathurst) ?

So, I'm thinking maybe of putting together an active speaker design workshop. It will be a proper class, probably two 3-hour sessions. Slides, practical sessions, etc. Prerequisite is that you can use REW.

What do you think?



    How much REW do I need to know?

  • Just the basics. If you can run a sweep that's it. You should be fine - ?

  • I've a Random Echo Widget somewhere...

    Problem is that it's a four and half year old model. Will that matter?

  • So John, do I bring my own laptop with REW, sound card, mic, cable, stand etc...? :-??

  • Not sure yet. I expect it will be better but optional.

  • edited June 2014


    This workshop introduces participants to the foundations of active digital loudspeaker design. It focusses on the electronic and processing aspects and assumes that box/enclosure design is already taken care of. At the conclusion of the workshop, participants will have successfully developed a crossover for an active digital loudspeaker. We will be using the miniDSP PWR-ICE digital plate amplifier for the workshop, but the knowledge gained will be applicable to DSP active speakers in general.

    Prerequisites and participation

    Participants need to have a basic working knowledge of Room EQ Wizard (REW). This can easily be obtained online and by asking questions on the REW forum.

    One or two participants will need to bring their own laptop, soundcard, and (calibrated) microphone. These laptops must have REW installed and working, as well as additional software that I will provide. They must also have an Ethernet port for connection to the DSP plate amp. There will be two loudspeakers and two mic stands available, so we will divide into two groups for the practical sessions. The group leads (those bringing their own laptop/mic) will learn more because they will get more hands-on time.

    Casual onlookers are welcome but please don't interrupt the class or the flow of activity, as there's a lot of ground to cover.


    There are two, three-hour sessions, followed by a 90-minute "wrap-up" session. The three-hour sessions are divided into a theory section (45-60 minutes) and a practical section (the rest of the time).

    Theory 1

    • Basic flowchart of an active speaker and how it's connected together
    • Fundamentals of EQ
    • Fundamentals of crossovers
    • How we measure a loudspeaker (instead of a room)

    Prac 1

    Each group will measure both drivers of their test speaker, EQ them, and implement a basic crossover.

    Theory 2

    • Loudspeaker dispersion and off-axis measurements
    • Gated measurements
    • Distortion
    • That pesky little thing called phase
    • Introduction to ACD (active crossover designer)

    Prac 2

    Each group will perform additional off-axis measurements of their speaker, and use ACD (*) to refine their crossover. They will then perform additional measurements on the completed design to present to the class in the wrapup session.

    Wrapup session

    Each group will present their "finished" loudspeaker. We will load both crossovers into both speakers, and do some listening tests. Then we'll have a celebratory drink (see below).


    A bottle of plonk, a box of fresh cinnamon donuts, or a bunch of flowers (for Lindy's room).

    (*) I'm not sure about ACD yet as I haven't used it much. Fingers crossed.

  • That (above) is the first draft. Any comments welcome. BTW yes, I've had a lot of practice at running classes and seminars ;)

    If anyone happens to have a portable projector that they could bring along, that would be very helpful.

  • One or two participants will need to bring their own laptop, soundcard, and (calibrated) microphone.

    I can do this

    A bottle of plonk, a box of fresh cinnamon donuts, or a bunch of flowers (for Lindy's room)

    I can also do this

    Looking forward to it John

  • For months I thought this site was down. Not sure why I couldn't access it. fukn computers.

    This looks like a good opportunity to learn, so if it goes ahead and if I make it I'd like to join in and drive.

    Thanks John, nice idea.

  • Cool Phil.

  • edited September 2014

    Hey, time is running out but if I am able to get this together then I think I'll basically follow the approach here:


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