Revel Performa F30 loudspeaker Measurements part 2
Fig.4 Revel Performa F30, anechoic response on-axis at 50", averaged across 30 degrees horizontal window and corrected for microphone response, with the complex sum of the nearfield midrange, woofer, and port responses plotted below 300Hz.
In the upper frequencies, the trace is impressively flat, though again with a slight lack of presence-region energy apparent. From reading KR's comments on the speaker's treble balance, I suspect that his ear was latching on to the presence-region level as its reference and hearing the tweeter as being a little uptilted rather than, as can also happen, the ear taking the HF level as its reference and perceiving the presence region as being laid-back. The F30's level control provides quite accurate calibrated correction (fig.5) of the tweeter's output; still, in his room, Kal felt there to be too much top-octave energy.
Fig.5 Revel Performa F30, effect of tweeter-level control set to "±1dB," normalized to response on HF axis at 50" (5dB/vertical div.).
As KR implies, this perceived balance will also depend heavily on the speaker's dispersion. The big Performa's horizontal radiation pattern is shown in two different ways in figs. 6 and 7. Fig.6 shows the actual responses to the speaker's sides, fig.7 just the differences between those responses and the tweeter-axis response. Despite its relatively wide baffle, the F30 has a superbly well-controlled dispersion—note how evenly spaced the "contour lines" are in these graphs. While the tweeter's output in the top audio octave doesn't drop off quite as rapidly to the sides as I have seen with other 1" domes, it does get reasonably directional above 10kHz.
Fig.6 Revel Performa F30, lateral response family at 50", from back to front: responses 90 degrees-5 degrees off-axis, reference response on HF axis, responses 5 degrees-90 degrees off-axis.
Fig.7 Revel Performa F30, lateral response family at 50", normalized to response on tweeter axis, from back to front: differences in response 90 degrees-5 degrees off-axis, reference response, differences in response 5 degrees-90 degrees off-axis.