Revel Performa F30 loudspeaker Measurements part 3
In the vertical plane (fig.8), as expected from a design with fourth-order acoustic slopes, the balance doesn't change appreciably over quite a wide listening window. This is a good thing, considering that the Revel's tweeter is a quite high 40" from the floor.
Fig.8 Revel Performa F30, vertical response family at 50", from back to front: differences in response 10 degrees-5 degrees above tweeter axis, reference response, differences in response 5 degrees-10 degrees below tweeter axis.
Looking at the Performa F30 in the time domain, its step response (fig.9) indicates that all three drive-units are connected with the same positive acoustic polarity. The time delay, both from the high-order crossover and the different acoustic centers of the drivers, ensures that on this axis each unit's step hands over smoothly and linearly to the next lower in frequency. The Revel's cumulative spectral-decay plot on the tweeter axis is superbly clean and free from resonant behavior, other than the big ridge of delayed energy at the tweeter's ultrasonic resonance frequency. Just a little bit of hash can be seen at the top of the midrange unit's passband, but this is well-suppressed.
Fig.9 Revel Performa F30, step response on tweeter axis at 50" (5ms time window, 30kHz bandwidth).
Fig.10 Revel Performa F30, cumulative spectral-decay plot at 50" (0.15ms risetime).
The speaker's voicing means care will have to be taken with setup and room tuning. But that Revel's engineering team can achieve such superb measured performance at the F30's price point is a tribute to their abilities.—John Atkinson