Walterw's bang on; the beaming doesn't really come from the center of the speaker. The physics are the physics. For anyone that's interested, there's a formula that will predict at what frequency dispersion will begin narrowing significantly, and on a 12" speaker that's gonna start happening around 1300Hz. The larger the speaker, the lower the frequency at which beaming begins. Beam blockers work, sort of. They've been everything from X's of duct tape to old CDs over the speakers to things like the Weber that you pay for to cabinets like this THD that have blockers built in: The issue is not whether they work, but whether there's a better solution. Turns out there ARE better solutions, and one was designed by an audio engineer (the rest of these beam blockers are just manufactured copies of the old "X" of duct tape, essentially). Beam blockers as we know them do strange and unwonderful things to the overall frequency response. The foam donuts work. Period. Without screwing with the sound overall. I will guarantee that anyone extolling the virtues of one of the various non-foam-donut beam blockers has never A/B'd the two. Though now I'm betting we'll get a few posters who will claim otherwise <G>. The real problem is that (far as I'm aware) you simply can't buy the foam donuts anywhere, while you can try the various beam blockers (both production and kludges) easily and inexpensively.