Loudspeaker-building

I'm not sponsored by any company or individual here, but this is some of the gear and literature I have used for making loudspeakers. The materials shown here will set you back some 2,000 US $ minimum to get started. Besides this you need a milliohm meter to measure driver Re accurately. These don't come cheap, usually around 400 US $. Click links or images to go to websites.

There used to be a long story on my CLIO equipment dating back more than ten years. It hasn't always been easy but I guess if you start from scratch these days, life should easier. That is, if you can find a laptop with a firewire port or a laptop allowing an express card with firewire connection. Check out all this carefully before ordering the CLIO system! I find it problematic that Audiomatica display the image above as though you just plug your CLIO FW into a laptop. Some customer service in terms of suitable laptops the CLIO FW would be nice. And they might have told you most likely will need a 12 V DC adaptor to run the CLIO box. If your laptop doesn't have a firewire port, then what PC Cards are suitable, etc., because PC Cards comes in a wide range of variants and you have to learn about IEEE 1394a and IEEE 1394b, etc. For the non-computer nerds, this takes quite some time and this is an ever changing world where things may change rapidly and what you think is safe for the foreseeable future may be extinct tomorrow. If you want to be on the safe side, I suggest the CLIO PCI card - but then we're no longer talking a portable CLIO - and that was one of my main reasons for buying the FW-version (05-05-2011: It appears Audiomatica has discontinued the PCI solution and there is no longer a Lite version). At the end of the day the - when working - CLIO-FW is an excellent tool. I enjoy the new applications and all the things that have been developed since version 6.52, and I find very few things I wish they would have kept from the old software.

Above from Audiomatica website and it all looks so easy, doesn't it. That is if encircled connection is in place. Make sure you have the firewire option before starting. The problem is the CLIO works real-time and you have to shut down all other programs and services to make sure there won't be interruptions during mesurements. Getting the CLIO10FW/Win7 working properly appears more complicated than first anticipated. I strongly suggest reading the technical notes founds here at Audiomatica website: http://www.audiomatica.com/wp/?page_id=983. Last but not least - and thanks to Lennart/Sweden for pointing this out - check if your laptop is suitable for high-speed applications by running this software: Download DPC Latency Checker What seems to work on both my laptops is turning off the network adaptor. Read here: http://www.thesycon.com/dpclat/dpclat.pdf. This application seems to seriously interrupt real-time applications. The general advice by Audiomatica is to have a computer dedicated to CLIO FW and nothing else. I have my Lenovo on-line via a wireless hookup - but never during CLIO work. Update 2014: Finally CLIO has put together a comprehensive paper on trouble shooting: http://www.audiomatica.com/wp/wp-content/uploads/technote_001.pdf Read it before investing. All that said, the CLIO is a wonderful tool! ~2 kEUR is not cheap, but the best toy I've ever bought.

Audiomatica has recently introduced a USB based system for 500 EUR including microphone! CLIO Pocket. Based on available info, this looks like all we need for making the basic measurements needed for crossover simulation. And it's available for MACs as well.
Complete kit can be seen here: http://www.audiomatica.com/wp/wp-content/uploads/CLIO-Pocket-Package.jpg

Click image to go to Audiomatica website

Finally!!! CLIO has come up with an USB based measuring system, the CLIO12.
I bought it.

Latest addition is a Earthworks M50 measuring microphone doing 50 kHz.
I wanted to see what tweeters do in the 20-50 kHz range. Just to know.
This mic plugs directly into the CLIO system with a balanced cable - and it doesn't change polarity.
After calibration - plug'n play.

Here measuring some ScanSpeak 15M/8631G00 midrange drivers.

To the left the CLIO + power supply and a Thinkpad 530. To the right a gain-clone amplifier to run speakers.

Left: Milliohm meter for measuring inductors and low-ohm resistors. Right: LCR meter and general multimeter.

Great articles here from John Atkinson @ Stereophile: Click image to download article, 35 pages, pdf.
Directly from Stereophile here: http://www.stereophile.com/features/99/

Publisher notes:
In this book, Geoff Hill demonstrates modern software and hardware being applied to the processes behind loudspeaker design and modelling. Modern computing power has progressed to the point that such analyses are now practical for any interested individual or small company. Loudspeaker Modelling and Design: A Practical Introduction examines the process from initial concept through specifications and theoretical simulations and onto detailed design. It demonstrates the processes of design and specification, by using detailed simulations of a loudspeaker driver; sufficient to give re-assurance that a design is practical and will perform as expected. This book brings together many different strands of modelling from electro-magnetic through to mechanical and acoustic, without getting bogged down in theoretical discussions and arguments. This practice-based book shows the techniques used in designing modern loudspeakers and transducers.

Geoff Hill is a passionate engineer, active member of the Audio Engineering Society, and a consultant working with a wide range of companies in the UK, Europe, and Asia. His latest venture, Hill Acoustics, marks in many ways a return to his roots, combining his 40+ years of experience with a determination to make a difference and do things better.
Geoff can be contacted at www.geoff-hill.com or through his business www.hillacoustics.com.

If you want to dig deeper into the science of speaker drivers, take a look this book written by Geoff Hill. This is not a book where you will find practical applications of current commercial loudspeaker transducers, but if you want to understand the fundamental science and physics behind modern drivers, here you'll find a comprehensive introduction to what goes behind the moving coil loudspeaker. A device that has kept some of us occupied for decades in the pursuit of the perfect loudspeaker.
Reading through the various chapters I couldn't help thinking "Loudspeakers" by Gilbert A. Briggs. My copy is 5th edition, bought in 1971 when I was still in high school. Now, the chapters in Loudspeaker Modelling may not be garnished with poetic quotes like G.A. Briggs did, but in many ways this is an update on what has happened over the last 50 years. There are similar chapters on voice coils, suspensions, cone materials, etc., etc., but thanks to computers we have come a long way in designing better speaker drivers and predict their performance.