Earlier I wrote about a measurement anomaly in the initial measurements of the baffle. Here is the response of the mid again, at 1m: Having just been trying to learn how to use the Edge simulator, I modeled an 80mm driver in a 300x900mm baffle, with the microphone at 1m distance. Look at this: So there’s the notch at 1700 Hz (more or less), in the open baffle simulator. It’s good that there is at least some match between theory and the actual measurement, although I still don’t understand why the notch is where it is, as I thought it should have been at aroundRead More →

With much help from Paul Spencer, I was able to do some gated measurements on the Francesca prototype. One thing we puzzled over was the frequency response of the midrange. Here is the 1m measurement (gate is about 8ms): Red is on-axis, blue is at (approx) 30 degrees. The frequency of the dip, around 1700 Hz, doesn’t correspond to any of the baffle dimensions! If it were the first dip in the dipole response, a 30cm wide baffle should exhibit this dip around 1150 Hz, not at 1700 Hz. And why does the depression continue up past 5 kHz? This was a puzzlement. In theRead More →

I’ve started a new dipole project, using the BG Neo3 PDR, Mark Audio CHR-70 (version I), and a pair of Exodus Audio DPL-10s (no longer in production, sadly). I’ve dubbed it “Francesca” for no particularly good reason. This project is an exercise for me to learn more about speaker measurement. Also, I want to see what can be done to make a dipole speaker for use in small rooms – or more specifically my study, which is 2.7m wide by 4.3m deep. I also wanted to experiment with getting dipole radiation from 30/40 Hz up to 20,0000 Hz. High output is not one of theRead More →