Here are the measurements for the Klipsch speakers (click on each chart to view it in a larger window).
Frequency response (main section)
On-axis: ±2.4 dB from 37 Hz to 20 kHz (±1.3 dB to 10 kHz)
Average ±30° horiz: ±2.3 dB from 37 Hz to 20 kHz
Average ±15° vert/horiz: ±2.7 dB from 37 Hz to 20 kHz
Main section: min. 3.1 ohms/137 Hz/-10°, nominal 8 ohms
Atmos section: min. 4.6 ohms/147 Hz/-12°, nominal 8 ohms
Sensitivity (2.83 volts/1 meter, anechoic)
Main section: 92.5 dB
Atmos section: 87.5 dB
The first chart shows the frequency response of the RP-280FA, the second shows the impedance. For frequency response, three measurements are shown: at 0° on-axis (blue trace); an average of responses at 0°, ±10°, ±20° and ±30° off-axis horizontal (green trace); and an average of responses at 0°, ±15° horizontally and ±15° vertically (red trace). I consider the 0° on-axis and horizontal 0°-30° curves the most important. Ideally, the former should be more-or-less flat and the latter should look the same but should tilt down slightly (by perhaps -6 dB at 20 kHz) as the frequency increases.
In the first chart, you can see that the RP-280FA delivers an impressively flat response on- and off-axis, but it has a slightly rising treble response, with about +1 to +2 dB of added output from 5 to 10 kHz. As a result, the off-axis averaged response is almost perfectly flat. Whether you perceive this as slightly bright or airy and detailed will depend on your taste in sound, the music you listen to, and how sonically absorptive your room furnishings are. Although the specs claim 32-Hz bass response, the best I was able to achieve was 37 Hz at ±3 dB, using a ground-plane measurement.
The second chart shows the impedance magnitude and phase of the main section of the RP-280FA. No problems here, and considering the speaker's high sensitivity, you should be able to drive it to satisfying volume with practically any amplifier.
The third chart shows the responses of the center and surround speakers, both measured on-axis. (The surround was measured on-axis with the left-side drivers.) The center shows a dip of about -5 dB at 1.5 kHz, followed by a +2 dB peak at 2 kHz; this corresponds with the coloration I noted in my listening tests. The surround's response is elevated by +2 to +3 dB above 1.8 kHz, but that's as it should be, because this speaker's drivers will not face you directly; without that elevated treble, the surround might sound a little dull.
The fourth chart compares the on-axis and 30° off-axis responses of the RF-280FA's top-mounted Atmos section and the RP-140SA add-on Atmos speaker. Both show the slight boost at 7 kHz and the fairly large dip at 12 kHz that are built into the crossover of Atmos-enabled up-firing speakers. What's interesting is that their midranges are quite a bit different, with the RF-280FA's Atmos section showing a broad dip between 1 and 3 kHz (which I assume is a result of the speaker being recessed into the top of another speaker) and the RP-140SA showing a boost over the same area. I wonder if the RF-280FA's reduced midrange highlights the HRTF effects of its Atmos crossover and results in the enhanced effect I heard? Also, the RP-140SA proved to be about -3 dB less sensitive than the Atmos section in the RF-280FA.
Here's how I did the measurements. I measured frequency responses using an Audiomatica Clio FW 10 audio analyzer with the MIC-01 measurement microphone, and the speaker driven with an Outlaw Model 2200 amplifier. I used quasi-anechoic technique to remove the acoustical effects of surrounding objects. The RF-280SA was placed atop a 28-inch (67-cm) stand. The mic was placed at a distance of two meters at tweeter height, and a pile of denim insulation was placed on the ground between the speaker and the mic to help absorb ground reflections and improve accuracy of the measurement at low frequencies. (I also did a measurement at one meter, which I spliced in between 200 Hz and 1 kHz to improve the accuracy in this band.) Bass response was measured using ground-plane technique, with the microphone on the ground two meters in front of the speaker; I got better results with this method than I did when I closed-miked and summed the responses of the two woofers and the port. For the center and surround speakers, I placed the speakers atop a two-meter-high stand and did the measurements at two meters. For the Atmos speakers, I suspended the microphone on-axis with the Atmos speaker, then moved the speaker over to a position where the drivers would be 30 degrees off-axis from the microphone. (This produced a slightly longer measurement distance and thus the slightly lower level of the off-axis measurements for the Atmos speakers.) Quasi-anechoic results were smoothed to 1/12th octave, ground plane results to 1/6th octave. Post-processing was done using LinearX LMS analyzer software.
I don't have much to complain about with the RP-280FA, other than that the subtle brightness can be a bit much with certain snippets of certain recordings.
Going back to the jazz album Old Folks, on "True Blue," upright bassist David Friesen slaps his strings against the fingerboard to get a percussive effect. This should produce a fairly subtle "click" with each note. With the RP-280FA, it sounds like each note is accompanied by a drumstick being whacked against the side of his bass.
Here's another example: In "Sentenza del Cuore: Allegro" from The Coryells, a Chesky Records recording of jazz guitarist Larry Coryell and his sons all playing acoustic, the castanets in the background sounded like they were made of plastic instead of wood; the speaker's elevated treble buried the subtleties in the instrument's tone.
These are obviously isolated instances. Jarring as this effect could be, it was also rare.
The only issue I really had with this system was with the RP-450C center speaker, which exhibited what sounded to me like a dip/peak in the two-kHz region (an effect I know well because the Genelec HT205 recording monitors I use have a similar dip/peak at 1.5 kHz). As noted above, it had the effect of enhancing voice clarity, but it also made voices sound unnatural at times. For example, when James Taylor introduces the backup singers after "Shower the People" from the Live at the Beacon Theatre DVD, I could tell there was a big peak in the lower treble; it had the effect of making his voice sound thinner and harsher.
Comparison and Competition
Just to get an idea of the RP-280FA's accuracy, I compared it with my Revel Performa3 F206 tower speakers, using the Van Alstine ABX box to match the levels and provide quick, remote-controlled switching. There's no doubt that the F206 sounded more neutral, especially with voices; dialogue and singing always sounded smooth and natural. However, the F206's treble sounded a little soft, especially after hearing the Klipsch system. I expect that, if I (and most other listeners) did a blind test with no idea what speakers I was hearing, I would prefer the Klipsch's bigger, more lively sound. Which one you would like I can't say for sure, but I can say they're both in the same ballpark when it comes to performance. And of course, the RP-280FA's dual eight-inch woofers easily outpunch the F206's dual 6.5-inch woofers.
The RP-280FA has little real competition because there aren't many Atmos tower speakers out there yet. One major competitor is the Andrew Jones-designed Pioneer Elite SP-EFS73, which costs $699 each, or $500 less per speaker than the RP-280FA. Both are well-designed, good-sounding speakers. However, the SP-EFS73 has three 5.25-inch woofers against the RP-280FA's dual eight-inch woofers. That gives the RP-280FA a 55-percent advantage in woofer surface area, and its drivers have a larger box to work in, plus probably more excursion. So the RP-280FA will have much greater bass capability and more dynamic capability; it could easily form the core of a large, high-powered home theater system, whereas the SP-EFS73 might be overtaxed in such a situation.
Of course, you can also put an Atmos add-on module atop a tower speaker; for example, Definitive Technology offers the $499-per-pair A60 Atmos module that fits atop the $999-each BP-8060ST tower speaker. That makes the combo $1,250 per side, about the same price as the RP-280FA. Yet the Definitive Technology towers each incorporate a powered subwoofer with a 300-watt Class D amp, a 10-inch driver and two 10-inch passive radiators--probably a match (and maybe then some) for the RP-280FA's dual eight-inch woofers.
I thoroughly enjoyed my time with the Klipsch Reference Premiere system, and the RP-280FA towers specifically. I think a lot of audiophiles will dig the way the RP-280FA's subtly, slightly elevated treble brings out the details in movie soundtracks and music without messing up the experience, and I know home theater fanatics will appreciate the way these speakers can crank really loud off practically any amp...and sound great doing it. The Atmos modules built into the tops of the towers are just icing on the cake.
• Check out our Floorstanding Speakers category page to read similar reviews.
• Klipsch Debuts Reference Premiere Dolby Atmos-Enabled HT Speakers at HomeTheaterReview.com.
• Dolby Atmos at Home: The Known Knowns and the Known Unknowns at HomeTheaterReview.com.