RBH Sound R-55E Floorstanding Speaker Measurements & Analysis
Measurements Conducted By: James Larson
The RBH R-55E Tower speakers were measured in free air elevated to a height of approximately 4 feet with the microphone at a 90” height to be level with the tweeter. Measurements were gated at 5 ms. At this windowed gate, some accuracy is lost below 400 Hz and is totally lost below 200 Hz. The microphone was placed 2 meters away from the speaker at a height level just below the tweeter. The below graphs use 1/12 octave smoothing.
RBH R-55E Horizontal Response +/- 100 degrees: 3D view
RBH R-55E Horizontal Response +/- 100 degrees: 2D view
The above graphs depict the R-55E’s direct-axis and horizontal dispersion out to a 100-degree angle in five degree increments. Here we can see the source of the upper-midrange brightness that Steve noted. It takes the form of a low Q rise of a few dB centered at 2 kHz. I would expect a response like that to be audible but not severe, as Steve mentioned. The rest of the range is relatively flat. Since this rise is a resonance that occurs at every angle, it can easily be addressed with equalization. The R-55Es show themselves to have admirably wide dispersion with good response correlation from direct axis to off-axis angles. This means that its reflected sound should have similar tonality to the direct sound, so a room heavy in acoustic treatments isn’t needed to make these speakers sound better. It also means these speakers do not have a small ‘sweet spot’; they ought to sound good anywhere in a broad angle in front of them. This characteristic has always been a strong point of RBH speakers.
RBH R-55E Polar Map of its Horizontal Response
The above graphs show the same information that the preceding graphs do but depict it in a way that offers new insight regarding these speakers’ behavior. Instead of using individual raised lines to illustrate amplitude, these polar maps use color to portray amplitude and this allows the use of a purely angle/frequency axis perspective. The advantage of these graphs is they can let us see broader trends of the speaker’s dispersion behavior more easily. Outside of the extra midrange energy at 2 kHz, we see a very consistent level of energy as we move off axis. The only frequency that tapers off at a higher rate off axis is the very high treble band, but that is true of nearly all speakers. The response out to 10 kHz is still strong even at a 50-degree angle. There won’t really be any bad seats in the house with this kind of dispersion unless the listener is seated at an extreme angle with respect to the speaker. Those who want a full sound projected over a wide area would do well to consider this kind of dispersion pattern.
RBH R-55E Direct Response: grille on and grille off
The above graph depicts the effects on the direct axis response of the utilization of the grille. While I always take this type of measurement, I don’t normally include this graph in reviews, since the differences don’t tend to be very significant. However, the use of the grille here is a bit more impactful on the response than normal. It wouldn’t make a major audible change on the sound character of this speaker, but it certainly does not improve the response. As usual, for the best sound, leave the grille off.
The above graph shows the RBH R-55E’s low-frequency responses that I captured using groundplane measurements (where the speaker and microphone are on the ground in a wide open area). At a glance, one might guess that the 80 Hz to 90 Hz region is the tuning point of this speaker, but that is not the case. The port tuning frequency of the R-55E is just below 40 Hz, as we can see below in our impedance measurement. We can see this in the low frequency response when we look a bit closer and see a 12/dB octave slope below the bump centered at 90 Hz and then a steeper roll-off below 30 Hz. This was done to use boundary gain to shore up the low frequencies, since tower speakers are normally placed near walls or corners. If the R-55E has a flat response down to 40 Hz, typical tower speaker placement would balloon the bass for a ‘boomy’ effect. The roll-off that we see in the R-55E lends itself to more natural sounding bass, at least when placed near walls or especially corners. If these speakers were placed in an open area that had no proximity to nearby walls, they would likely sound a bit thin for ostensibly full-range speakers. The specified frequency response window of 35Hz to 30kHz +/-3dB that RBH states for the R-55E should be taken to mean in-room response. Anechoically, this is not the case, but, in practical, real-world use, it would have that kind of window.
RBH R-55E Impedance and Phase Response
The above graphs show the electrical behavior of the RBH R-55E speakers. RBH specifies the R-55Es to be 6-ohm speakers, and this is a fairly conservative rating. Some manufacturers would call this kind of load 8 ohms, which might be pushing it, but it is certainly more benign than a 4-ohm load. The toughest part of this load occurs in the low frequencies where there are some steep phase angles at impedance minima, but those still occur above 5 ohms. Essentially any AVR or amplifier should be able to drive this speaker without worry. RBH specs the sensitivity of the R-55Es speakers at 88dB for 2.83v at 1m. Our measurements show 87dB (well, 86.963dB but we will call it 87), which is pretty good agreement. That is about what one would expect from a design like this- it’s not a low sensitivity nor is it especially high. Most mid-range AVRs will have enough power to drive these speakers to quite loud levels, but the R-55Es could safely handle a good deal more amplifier power than mid-range AVRs are capable of, if users wanted to add an outboard amplifier to really rock out.
I have used many of the same discs for many years to test loudspeakers, not simply because they’re well-recorded CDs, but because I know them so well that they are reliable test devices that I can compare from speaker to speaker and be confident of the differences I’m hearing. Minimizing the variables is the only way to ensure that one’s test results are truly valid.
CD: Steely Dan—Aja
A nicely-recorded pop CD, with Steely Dan’s trademark clarity, solid deep bass and crisply-etched vocals. Everyone knows this disc well. In its day, it set a new high-water mark for clarity, spaciousness and bass impact. Even today, only the best speakers can keep Steve Gadd’s explosive drum fills on the title track clear and well-defined under Wayne Shorter’s tenor sax solo. The5 R-55E’s did very well here, never losing their composure, even at near-uncomfortably high SPLs. They never got screechy or edgy and maintained a nice warmth and musicality at all times. Fagan’s voice was just a tad forward, but never objectionable.
CD: Jennifer Warnes—The Hunter
This is an over-played, over-used, totally synthetic-sounding and too-heavily processed pop recording. But the opening cut, Rock You Gently, is so chock full of quantifiable, repeatable audio tidbits that if one overlooks the questionable production merits of the song, its sonic traits do provide some valuable information. The recording has a very deep, strong bass line throughout and some sharp snare drum <cracks> that punctuate the background. But it’s at the 2:33 mark of the track that things get interesting. I’d used this cut for years to test how well a speaker can simultaneously deliver clean, low-distortion deep bass (long excursion), while keeping the female vocals clear and preserving detailed highs. It’s a tough test for most speakers. And if a speaker doesn’t have subterranean bass response on its own, it’s a good test to see how well the speaker will ignore the very deepest bass that it can’t reproduce anyway while still doing a good job with the rest of the spectrum. I’d gone years listening to this cut on all the speakers I’ve voiced without realizing that at 2:33 there is a sustained low-20s Hz tone (about three seconds long) that just rises up from the floor and absolutely dominates the room.
Very few full-range passive speakers will reproduce this tone, since most full-range speakers—even quite excellent, expensive ones—will only respond, honestly, down to 35-40 Hz or so. My reference speakers are sealed systems with dual 12” woofers (with the very shallow 12 dB/octave rolloff inherent in acoustic suspension systems), rated very realistically down to -3 dB @ 28 Hz. With a little room gain by virtue of being within a foot of the wall behind them, per the manufacturer’s recommendation, they are quite flat in my room down to the lower 20s. At the 2:33 mark of this cut, fed with 400 distortion-free watts, they make dogs cower and babies cry.
Unlike most other mid-priced/mid-sized floorstanding speakers I’ve reviewed, the RBH R-55E did not ignore the 22Hz tone at 2:33 as if it didn’t exist. It actually hinted that the tone was there. It wasn’t strong or prominent by any means, and if you didn’t know that there was a 3-second-long 22Hz tone on the recording, you really wouldn’t have any idea just from listening to the RBH’s by themselves. But I do know that tone is there and therefore I was impressed that the R-55E hinted at it.
The other thing I was impressed by was the R-55E’s poise in the presence of strong bass below its usable range. It didn’t overload, it didn’t distort, the presence of that tone didn’t cause havoc with the rest of the music. The R-55E simply hinted at it, while continuing to go about the rest of its business in a commendably relaxed, coherent manner, even at relatively high levels. Very impressive.
CD: Kurt Elling—Dedicated to You
This is a superb live recording of jazz vocalist Kurt Elling backed by a big band featuring Ernie Watts on tenor sax and Lawrence Hobgood on piano. The first track, All or Nothing at All, starts off with a string quartet intro, beautifully recorded. Played on top-flight equipment, it is almost believable that a string quartet is, in fact, right there. After that intro, there is a piano run ending in a single very high note, struck quite hard. It’s a great test of a tweeter’s power handling and ability to project a three-dimensional, organic sound into the room without being ‘spitty’ or ‘hissy.’ Although the string quartet’s overall tone was just a tick too bright to be totally believable as being there in my room, the R-55E’s were superb, and their extreme highs were as natural and well-reproduced as one could ask for.
Elling has a great voice, deep and resonant, with tremendous range, power and control. He is a master vocal stylist and his ability to go anywhere he wants and always return home is without equal among today’s singers. If you’ve ever seen him live, you know how he quickly captures the audience’s attention, gains their complete confidence that he’s in total musical command, and then takes them along for the ride. This recording is mixed with Elling in a very solid center image, and the R-55E’s convey that quite convincingly. Elling is front and center, and the band is behind him and wide to each side. There was never a time when the sound was thin or lacking in any way. Instantaneous A-B switches to my reference speakers revealed that deeper, more spacious sound was there to be had on the recording, but listening to the 55E’s alone never left you feeling as if something was missing.
CD: Ariel Ramirez/José Carreras—Misa Criolla
wonderful Phillips recording of classical/vocal music, the first two cuts
really test a speaker’s ability to resolve low-level detail and present a
three-dimensional sonic landscape. Carreras’ voice is pure and delicate, and is
accompanied by very subtle tympani strokes in the background. Properly
reproduced, these strokes convey a sense of the mallet head hitting the
drumhead and the resonant tail from the strike carries on long and quietly
fades off behind the vocal. The R-55E’s proved up to the task of speaking
quietly, but with precision and authority. Lesser speakers smear these details
together; the RBHs kept things clearly delineated and focused, but without
artificial hype or an exaggerated top end. This is a tough test disc, highly
CD: Smetana, The Moldau, Van Karajan
This is a 1983 recording of the famous Moldau by Bedrich Smetana. I chose to audition the R-55E’s on this disc for two reasons: 1) It’s a clean recording with a nicely-presented orchestral landscape and some very subtle triangle strikes in the background, and 2) It’s a 1983 recording, made when CDs were all “wrong”: this is the time period when CD sound was accused of being harsh and edgy, before recording engineers had supposedly mastered the subtleties of working within the then-new digital medium. If ever a classical recording was going to have that “steely, hard” string sound, this would be it. Since the R-55E’s had already shown themselves to have a bit of upper-mid emphasis, the combination of that trait and a harsh early-80’s CD might well produce a “perfect storm” of unbearable brightness.
To my great relief, the storm clouds never materialized. The R-55E’s were clean and precise, very detailed, very engaging. This is indeed a sharp recording but on the 55E’s that sharpness translated into detail and resolution, not edginess and glare. I shouldn’t have worried.
The RBH Impression Series Elite R-55E acquitted itself quite well during its stay. (They could shorten that product name a bit, though, don’t you think?) I’ve had some outstanding similar-sized and similar–priced speakers in my home in the past few years for review and extended evaluation: the $2,200/pr. B&W CM8, the $2,500/pr. Atlantic Technology AT-1, the $2700/pr. NHT Classic Four and the $3000/pr. Paradigm Prestige 75F. All are fine speakers, and easily among the best in their size/price category. The RBH R-55E (let’s just call it that, ok? I) is a solid contender among this group of excellent loudspeakers. Its bass extension and impact are clearly superior to the B&W and Paradigm and at least the equal of the NHT. From a midrange coloration standpoint, I rank them as follows, from the bottom up: B&W, AT, RBH, Paradigm, NHT.
I want to emphasize that the slight forward upper-mid empasis of the R-55E was by no means a show-stopper or game-changer. I simply noticed it in comparison to the others, using identical equipment in the same room, playing the same discs, compared to the same reference speakers. Lesser speakers have larger warts that prevent them from serious consideration. I could easily have the RBH’s as my main speakers and be quite satisfied. They’re not perfect—I haven’t heard a perfect speaker yet—but their deficiencies are not obnoxious to the point of disqualification. Not even close.
They look great. The finish is world-class and unexpected for $2000/pair. I think their other compromises—non-flush-mounted terminal cup and ports, non-flared ports, pin-and-receptacle grille attachment and few-time-only use wood screw foot attachment—are very minor issues, well-chosen compromises. Especially if those compromises are what enabled RBH to use beefy aluminum-cone woofer and midrange drivers and be able to offer such a nicely-done finish.
Overall, the RBH Impression Series Elite R-55E is an excellent product—outstanding sound, great looks, well-chosen compromises and above all, a truly outstanding value. This is a lot of speaker for two grand. I don’t think you can go wrong.
Note: RBH is currently running a 25% off promotion on ALL Impression series speakers.
RBH Impression Series Elite R-55E
MSRP: $1000 ea.
382 Marshall Way, Suite
Layton, Utah 84041
Tel: (800) 543-3300
About RBH Sound [from the company’s description on its web site]:
RBH Sound, founded in 1976, is a manufacturer of high performance audio products for residential and commercial applications. RBH Sound’s goal is to produce the finest products in each category we manufacture. Sonic and build quality are paramount at RBH Sound. We are constantly searching for new technologies and improvements that will keep us as a industry leader.
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