Soundman2020 wrote:The only thing is i don't know what i'm looking at
Me either! That's not what I expect from a diagram for dispersion angle.... Doesn't even say if that is vertical or horizontal!
What I was hoping for is a set of polar plots for different frequencies. That single graph is not much use at all...
And I certainly find it hard to believe that the total dispersion pattern at 20 kHz is practically the same on-axis as 15° off axis...
Still, being aware of the lousy documentation provided by Adam in general, this is not unexpected. In fact, it's rather surprising that they sent you anything at all!
I wonder why they are so darn closed to providing any useful technical details of their speakers. It almost makes you wonder what they are hiding....
- Stuart -
I would guess that they are hiding the transition from piston driver to AMT which has a drastically limited vertical dispersion compared to the cone driver. The "ART" is just their version of a traditional air motion transformer. Could be useful in a studio environment, but rest assured there is no graceful transition between the two. In order to smooth the vertical dispersion transition between the two they would need to have a fairly shallow slope in the crossover which has the potential of creating harmonic distortions, unless they move the crossover point down to the middle of the vocal range, which is
not desirable, especially since a shallow slope also creates phase distortions. There is no way to match the phase over a band of overlapping frequencies between a piston driver and AMT. They require a fairly steep crossover - third or fourth order - to avoid such problems, which brings us back to the problem with dispersion.
The AMT acts almost like a mini line array, which means it would need to be a bit shorter to widen the vertical response.
On another note, I'm actually not surprised by the consistency of the frequency response. A good AMT is quite consistent on the horizontal plane, and Adam make a pretty good AMT (or modify, more likely).
I must say that Adam speakers sound pretty fantastic - I owned a pair for awhile - and they likely don't want to scare off the potential customers who would raise a brow at the graphs. We are engineers, after all.
