I started a new project that uses passive radiators. I have no idea what i am going to do with this speaker. I just got really curious about passives and wanted to experiment. Parts Express had the 8" passive as Deal of the Day for $10 each so i picked up 4 of them along with two 10" Dayton DVC drivers. It will probably turn into some kind of three way speaker when all is said in done.

I found a link on the Madisound message board about some white papers produced by By Dr. Floyd E. Toole who is the Vice President Acoustical Engineering at Harman International Industries, Inc.

There are three papers that are a great read:
Part One:How many loudspeakers? What kind? Where?

Part Two:Making a good loudspeaker - imaging, space and great sound in rooms.

Part Three: Getting the bass right

I am starting a new speaker project and just put an order in for 10 woofers and 7 tweeters.

It is going to be for a home theater setup. Front and centers are going to be MTM's and the surrounds will be Two Ways.

I should have the drivers in the next few days so stay tuned for more information on T/S parameters, box sizes and if they will be ported or sealed.

I got a tip from the SE email list to check out the book 'High Performance Loudspeakers' by Martin Colloms. It took me a while to find a used copy (the book is not cheap). I highly recommend this book. It is a really good read.

ISBN Information for 5th edition Paperback and Hardcover:

High Performance Loudspeakers
Paperback - Show all editions
Martin Colloms, June, 1997 John Wiley and Sons
List Price: $79.95
ISBN: 0471970891

High Performance Loudspeakers
Hardcover - Show all editions
Martin Colloms, 27 June, 1997 John Wiley and Sons
List Price: $170.00
ISBN: 0471970913

I am using a BEHRINGER ECM8000 mic from Parts Express
A Mackie mixing board that has pre-amp (phantom power) for the mic
M-audio Delta 410 Sound Card

You also need to build the test probes detailed in Chapter 16. I made a new wiring diagram for RCA based cables. The third diagram down is the simplest illustration of the wiring for RCA cables.
http://chadgray.info/speakers/RCAbasedtestcables2.jpg

I made a super simple jig to help make measurements easier. It is just a 4 position switch that turns on a 10ohm resistor (for T/S measurements), a 20uF (two 10uF caps in parallel from Radio Shack) Non Polar capacitor to protect tweeters on SPL measurements and a straight pass through. I can't remember why I put a 470 Ohm resistor in there. Plus there are banana jacks positioned before and after the switch so you can move the probes around.
http://chadgray.info/projectdetail.cfm?ProjectID=25

Make sure the sound card you buy is on the compatible list if you want to do DE (Digital Equalizer) and DF (Digital Filter) in the future.
http://www.interdomain.net.au/~bodzio/

Also make sure your computer has enough CPU power. My Athalon 650 is fine for T/S and SPL measurements, but I doubt will cut it for DE and DF.

From what I understand, you can use the Wallins Jig, but I have no idea how you would wire it up.

Read John Kreskovsky's design guide found on the Bodzio web site. This will give you a jump start using SE. Also I found reading 'Loudspeaker Recipes' by Vance Dickason is a great way to understand what each measurement is really doing and how to build a proper crossover.