There has been a lot of talk on the BassList lately about how a 6 inch long ribbon has limited vertical dispersion, and has very wide horizontal dispersion. I get real tired of people arguing incessantly about something they know very little about, so I set up my Raven R-2s on my deck this morning and ran a series of frequency response measurements. Now you can actually have some facts to argue about.

I used my Mitey Mike microphone set 48 inches from the center of the tweeter. I did horizontal measurements by rotating the speaker(see Big Baffle, below) on a quasi turntable made from a piece of particle board and a nail. I took measurements at 0, 15, 30, 45 and 60 degrees.

Next I did the vertical measurements. I can't lay this speaker on its side, so I calculated how high the microphone had to be in order to get the desired angle. Then I carefully measured the distance from the microphone to the tweeter to try to match the measurement conditions used in the horizontal measurements. I was only able to get up to 20 degrees in 5 degree increments, but this is plenty to demonstrate what is happening

Then just to give some basis for the differences between a 1 inch dome and a ribbon, I made similar measurements on a Scan Speak D2905/9300 tweeter. You may notice that the plot legend says 9500, but that is an error.

Well, that's what I did on my Sunday morning, what did you do on yours?