WmAx said:
You find my generalizations to be "fairly good".
Okay. I just don't understand why it's a big deal if I generalize, when I carefully qualified the instances, to be certain that such statements were not made to imply fact.
Actually, I find them to be very good...I just didn't feel like givin ya any satisfaction..
...(well, ok...that second part was for my laugh..)
I specifically copied all your wall thickness/resonance stuff first, to clarify for you what I was referring to..you have executed "bose" based on assumptions, beliefs, tapping a surface, comparing to shoddy computer speakers, and providing a shoddy response graph..all in support of this "thin plastic no good" shpiel..
hence, the points:
A. without an actual measurement of the wall thickness
B. without a speaker to analyze
C. without the actual resonance frequency of the enclosure
D. without a real response graph from which to speak..what has been linked to is trash.
If one were to build a speaker using plastics, of course, many precautions have to be taken to assure the wall parameters don't affect the sound. If the wall can resonate in the power band, it can be stiffened to raise it's response above the band, by internal bracing, by thicker walls...which, of course, RAISE the frequency of the noise you get when you rap on the surface. A second possibility is to keep the walls thin, but use absorbtion to keep the power band from getting to the surface..easily done mid and highs, woofs, not so easy..
With plastics, the thickness and internal bracing are easily changed by changing the injection mold. Alternatively, the composition of the plastic can be changed, to increase the absorption and damping of the material..also, stiff plastic or metal inserts can be molded in...trivial to do, but I'm also pretty confident that it is not used by bose, as it would add a lot of labor cost to the parts.. But the molding changes are trivial, I'm confident bose didn't neglect that.
I've been looking into using that fake wood product in use for boats, the honeycomb aluminum core with thin laminated wood outer surface..it's really strong stuff, actually stiffer than the same thickness marine plywood for decking use.. A pair of subs (18 inch drivers gathering dust as we speak) folded horn, of the rog mogale kind made with this stuff would be really light, I could see mobile use with those..The only thing I gotta work out is the joints on the edges, and perhaps additional bracing as needed.. Don't know how to do that yet, but we have some techs here who are into boats big time..
(When I need bass, I NEED it..even the 128 4 inchers I have don't do what I want..)
WmAx said:
The only problems I have, is with the apparent lack of quality directed to sound quality for the relative price vs. other available products.
We concur. I build what I need.
Cheers, John
ps..hmmm.. a thread on honeycomb panels for building speakers in the near future?...that'd be fun.