Thiel CS6 Loudspeaker Measurements part 3
Fig.8 Thiel CS6, excess phase response on tweeter axis at 50" (top); B&W Silver Signature, excess phase response on tweeter axis at 50" (bottom). (90 degrees/vertical div.)
The CS6's cumulative spectral-decay plot on the tweeter axis (fig.9) confirms the existence of the interference-related suckout on this axis, but is otherwise very clean through the low and mid-treble. There appears to be some hash present in the high treble, but this might actually be due to early reflections of the tweeter's output from the edges of the midrange cone. I noticed no HF graininess or grittiness during my auditioning.
Fig.9 Thiel CS6, cumulative spectral-decay plot on HF axis at 50" (0.15ms risetime).
Finally, I commented earlier that the CS6's cabinet seemed rigidly constructed. This was confirmed by looking at the output of a simple plastic-tape accelerometer attached to the various surfaces. The only modes present are at high frequencies —535Hz and 750Hz—considering the size of the panels involved, and although I could hear them with a stethoscope, their subjective effect was minimal. Interestingly, the concrete baffle produced quite a large impulse response with this test, but its frequency content was balanced, with no resonant modes apparent except at very low levels.—John Atkinson