I am curious about comparing the masses of the different waveguide compositions. For instance, I have a pair of plastic SEOS-12s and they weigh about 1lb 5.8oz each. The frequency response and polars (when used with the DNA-360) are already posted on the main ordering page. I am wondering about the others and am interested in seeing how changes in mass correspond to changes in performance. Are there any posted polar or frequency response measurements for any two comparable waveguides (plastic 12 vs fiberglass 12; fiberglass 15 vs concrete resin 15)? There are also no weights listed for any of the waveguides though I would assume someone knows these things. Best to everyone. Thanks.
FYI, I covered the back of my plastic SEOS 12 WG's with Alphadamp and didn't see any differences in FR or distortion. http://www.diyma.com/sound-deadening/alphadamp.html
I applied 14oz duct seal in an even distribution along the backside of one of my plastic SEOS-12s. It is audibly less resonant and acoustically excitable than the other (without the duct seal) but I don't have it wired up nor have I the ability to measure it. I used both the knock-test and the most advanced scientific speaker trial ever, the mouth-as-compression-driver "doo-di-doo" test. Patent pending.
The horn gets much more rigid when it is mounted to a baffle, seems quite dead then. I've measured responses of both fiberglass and concrete SEOS10 , no noticeable difference. Same with plastic vs. fiberglass SEOS12, no change in the measurement. Don't have plots to post, sorry. The most dead, on a "knock" test, is the concrete construction ones. I doubt you could tell a knock test difference when the guides are mounted.
Thanks Bill. So if I'm following you, you're basically saying a crossover design for a SEOS12 would not be any different if the SEOS12 were of a plastic, fiberglass, or concrete resin composition?
