POSITIVE FEEDBACK ONLINE - ISSUE 39
as reviewed by John Acton
In spite of the considerable advances made in the past several decades, loudspeakers continue to represent the most colored component in a high-end audio system. With no speaker being perfect, successful models reflect a careful blend of science and art, of attributes and compromises, as often as not dictated by the sonic predilections of their designers. Jeff Joseph, of Joseph Audio, makes no secret of the design goals for his speakers. Every Joseph Audio loudspeaker, from the stand-mount RM7XL, all the way to the top-of-the-line Pearl floorstander, is designed for tonal accuracy, wide dispersion, wide dynamic range and an easy-to-drive impedance curve for compatibility with a wide range of tube and solid-state amplifiers.
The RM25XL Special Edition sits almost squarely in the middle of Joseph Audio's speaker lineup and, from an evolutionary perspective, represents the third incarnation of the RM25 model (the previous version, the RM25si Signature MkII was reviewed here at Positive Feedback Online by Chip Stern). A tall, slender floorstander containing three drivers, the RM25XL is externally identical to its predecessor Signature MkII model, measuring 46" high by 8.5" wide by 11.5" deep and weighing 60 pounds. The RM25XL includes a plinth that attaches to the bottom of the speaker via wood screws, and four small cones that attach to the plinth for floor decoupling. A detachable, decorative black-knit cloth grille is also included.
The changes to the Joseph Audio RM25XL are all internal and comprise updated drivers and crossovers. While the driver complement remains the same, the actual drivers themselves are all new. The tweeter, built to Joseph Audio's specifications by SEAS, is a 1" Sonatex dual-section dome, a design attribute that heretofore had only appeared in Joseph Audio's top three loudspeakers. With this improved tweeter, Joseph cites improvements in dispersion, which he claims translate into increased airiness and improved image focus. The 7" woofer and 7" mid-woofer that flank the tweeter are still both aluminum and built by SEAS to Joseph Audio's specifications, but differ from earlier versions in possessing 50% larger magnets and 50% larger voice coils, which Jeff Joseph says imbue them with outstanding dynamic capabilities. Indeed, Joseph refers to them as "super-duty" drive units. The crossover, which continues to leverage Richard Modafferi's patented Infinite Slope technology, albeit in an asymmetrical implementation, employs a very steep cutoff for the mid-woofer (approximately 120dB / octave at 2 kHz), and a slower cutoff for the tweeter. This revised asymmetric Infinite Slope crossover is said to confer a more seamless transition between drivers. Additional crossover filtering is employed to roll the top woofer off at 200 Hz, effectively making the RM25XL a two-and-˝-way design. The one thing that hasn't changed is the quality of parts—from Cardas wire and polypropylene capacitors in the crossover to extensive internal bracing in the cabinet, only the finest parts are utilized in the RM25XL's manufacture. The RM25XL is bi-wire capable via two pairs of sturdy five-way binding posts, and is reflex-loaded via a slot-loaded port located on the bottom rear of the cabinet.
The RM25XL has a stated frequency response of 32Hz - 20kHz (+/- 2dB). The nominal impedance is 8 ohms, with a minimum rating of 6 ohms. Sensitivity is 88dB, and recommended power is 11 watts to 250 watts. Joseph Audio provides a five-year warranty on all its products.
The Joseph Audio RM25XL is offered in a choice of five real-wood veneers—black, cherry, maple, oak, and for a $200 premium, rosewood. My RM25XLs came in the premium rosewood veneer and were absolutely beautiful. It's your money, but for me, the rosewood finish more than justifies its cost. The RM25XLs were well packed in Styrofoam-reinforced cardboard boxes. The manual is thorough, and covers such topics as design and placement.
For optimum tonal balance and imaging at the listening position, Joseph Audio recommends positioning the RM25XL Special Edition loudspeakers parallel to the wall behind them, with a minimum of toe-in. After some experimentation, I concurred with their recommendations. Starting with the RM25XLs parallel to the wall behind them, I finally settled on a few degrees of toe-in, which brought the imaging and soundstaging into optimum focus. In my small-to-medium-sized room, the RM25XLs performed best when sited well away from the walls, each other and the listener. I finally settled on the speakers placed about 4.5 feet into the room, about 7.5 feet apart and 8.5 feet from the listener, all measurements taken from the tweeters.
During the course of this review, my system was comprised of a Simaudio MOON SuperNova CD player paired with Ayre AX-7e, conrad-johnson CA200 and Pass Labs INT-150 integrated amplifiers. All components were supported on a Solidsteel 6.2 audio rack. Cabling was by Audience and Ecosse, with power cords by Custom Power Cord Co and Ecosse. Room treatment was provided courtesy of multiple ASC Tube Trap and Studio Trap products.
The first thing that struck me upon listening to the Joseph Audio RM25XL Special Edition loudspeaker was its overwhelming neutrality and sense of balance. There was very little in the sonic signature of the RM25XL that drew my attention to it as a producer of sound, and certainly no gross colorations to distract from the musical message. Listening to an old favorite like Donald Fagen's The Nightfly (Warner Bros. 9 23696-2), I was impressed with the lifelike way the RM25XL portrayed Fagen's vocals on "Green Flower Street," imbuing his voice with the requisite amount of understated menace and bite. Another example of the supreme way the Joseph Audio speaker handled vocals was "If You Were Here" from Poe's sophomore release, Haunted (FEI / Atlantic Records 83362-2), with Poe's vocal evincing outstanding natural warmth and realism.
The RM25XL's bass performance sublimely juxtaposed extension and control. There was absolutely no overhang, bloat or unnatural emphasis in the upper or mid-bass regions, but when called upon to do so, the Joseph Audio speaker could shock with its ability to plumb the deeps. Listening to "Ants in Me Room" from Radio Massacre International's Solid States CD (Northern Echo Recordings NE012), the subterranean bass synthesizer pulses at the beginning of the track literally shook my room, with no dynamic compression evident, regardless of how loudly I listened. And the RM25XL consummately reproduced Chris Squire's frenetic bass guitar runs in "Tempus Fugit" from Yes' remastered Drama CD (Elektra/Rhino R2 73795).
The new tweeter in the Joseph Audio RM25XL was responsible for some of the airiest and most transparent highs I've heard from any speaker in my listening room. I was astounded by the verisimilitude of the cymbal work present in well-recorded albums like the eponymous bill frisell with dave holland and elvin jones (nonesuch 79624-3) and Pink Floyd's Dark Side of the Moon (Capitol Records 7777-46001-2). This superb performance was very much dependent upon proper placement, however. The RM25XL is designed for little to no toe-in, and indeed, I found that, toed in to the listening position, there was simply too much energy in the top octaves.
I found the RM25XL to be a remarkably coherent speaker, with no indication whatsoever as to which drive unit was producing which sounds. This coherency translated into a spacious soundstage and well-focused imaging that was not localized to the speaker itself. Listening to "Leisure Suite" from Feist's Let It Die CD (Cherrytree/Interscope Records B000442-02), Feist's vocal hung convincingly between and above the speaker cabinets, with the instrumentation arrayed behind in fully-dimensional layers. Despite the lack of toe-in, the RM25XL carved out some of the most solid center images I've experienced, with the serendipitous advantage of producing an extraordinarily wide soundstage.
What about dynamics? To be honest, in my smallish room, and at the levels I listen, I'm sure I never came close to exposing the Joseph Audio RM25XL's dynamic ceiling. However, I never discerned any compression or distortion-related colorations, even when playing source material that literally had the woofer cones visibly flapping with its infrasonic bass content. What I did quickly make note of, however, was the RM25XL's rhythmic prowess. The RM25XL excelled at grabbing and letting go of notes, literally propelling the music into the room when the source material called for it. I sat mystified listening to King Crimson power through "FraKctured" from their ConstruKction of Light CD (Virgin Records 7243 8 49261 2 0), with the arpeggiated electric guitar runs and full-out power-chord assaults alternately undulating and exploding out into the room.
From a negatives perspective, I could find few nits to pick with the RM25XL's sonics. While the RM25XL goes remarkably low on its own, fans of the absolute lowest bass may still opt for a subwoofer to augment frequencies below 30Hz. And the RM25XL's wide dispersion mandates that greater attention be paid to placement and acoustic treatment with respect to side walls. Functionally, I would like to see upgraded cones for coupling the speaker to the floor. In its current configuration, the RM25XL did not adequately allow me to level the speaker to account for my uneven floor.
In comparing the Joseph Audio RM25XL Special Edition to its predecessor, the RM25si Signature MkII, it was easy to hear the improvements that have gone into the current model. The RM25XL not only had greater extension at both frequency extremes, but resolution in the all-important midrange was subtly improved. Perhaps owing to its expanded dynamic envelope, the RM25XL was more effortless sounding at all volume levels. Lastly, I noticed a greater coherency, with the drive units more effectively speaking as an indistinguishable point-source.
It's all too easy for reviewers to compartmentalize the relative merits of a speaker's performance. And while this play-by-play breakdown of a speaker's technical aspects is important, it's just as necessary to understand how these pieces and parts coalesce into a cohesive whole. In the case of the Joseph Audio EM25XL Special Edition, there was an unquantifiable and almost ineffable level of musical involvement and immediacy that transcended the speaker's already outstanding technical performance. This gestalt musicality consistently drew me into recording after recording, immersing me utterly and completely in the performance. At its price, the RM25XL represents an outstanding loudspeaker and an unqualified bargain. Recommended without reservation. John Acton
RM25XL Special Edition loudspeakers