First Listen: Ultimate Ears’ New Flagship Personal Reference Monitors (PRM)

Earphones and in-ear monitors
Logitech/Ultimate Ears PRM
First Listen: Ultimate Ears’ New Flagship Personal Reference Monitors (PRM)

Custom Fit, Custom Sound, Custom Everything

Now that the press embargo has been lifted, I can finally tell AVguide/Playback readers about an impressive new Ultimate Ears custom-fit in-ear monitor called the Personal Reference Monitor (or PRM for short), which I had a chance to sample last week at UE’s headquarters in Irvine, CA. As of today, the PRM ($1999.99) will take its place at the very top of the Ultimate Ears product line up.

What exactly is the PRM? Well, in simple terms it is an ultra high performance in ear monitor that not only offers the expected custom-fit earpieces and exotic array of drivers, but that also—and please let the full importance of this one sink in for a moment—offers completely customizable voicing to suit the needs, preferences, or sonic tastes of the owner.

Think about it: in every audio product review you’ve ever read, and probably in every personal listening experience you’ve ever had, you’ve likely seen (or offered) comments where some product seemed better than others, but where all product fell short, even if only in small ways, of your own personal sense of the sonic (platonic?) ideal. Now imagine that a manufacturer turned to you with an in-ear monitor design that offered tons of core performance and upside potential, but then told you, “This monitor is completely tunable; feel free to make it sound however you want it to sound, or think that it should sound.” The freedom to shape the sound exactly as you see fit, my friends, is what Ultimate Ears’ new PRM is all about.

The Basics

The PRM is a custom-fit in-ear monitor that leverages Ultimate Ear’s extensive experience in building great-fitting acrylic custom-fit earpieces—something that, please trust us on this one, seems like it would be simple and straightforward, but that in practice is part art, part science, and part practical know-how. Unlike UE’s reigning accuracy champ, the three-driver In-Ear Reference Monitor, the new PRM is based on a platform that uses five balanced armature-type drivers. But the driver count, per se, is not what makes the PRM special. What does is the fact that virtually everything about the crossover networks used within the PRM is adjustable and tunable, giving owners the freedom to have monitors built with response curves custom shaped to fit their exact needs or desires.

Naturally, everything about the PRM purchase and ownership experience has been planned out by Ultimate Ears to give owners a luxurious, first-class experience from day one. For example, when customers approach UE about the PRM, they are assigned a customer service representative who will walk them through every step in the process. The process will include several steps, including:

•Having ear mold impressions taken by UE-certified audiologists who must meet exacting UE procedural requirements,
•Sitting down at a special UE-designed, high-transparency “define your sound” listening station (UE calls it the "Personal Reference Tuning Station") with a set of purpose built PRM test-version monitors to explore and then choose from among an almost infinite range of voicing possibilities (you’re encouraged to bring your own music materials and, if you wish, your own audio source components for this phase of the process),
•Choosing a custom exotic wood finish for the outer “ID” panels of your PRMs (choices include walnut burl, Carpathian elm burl, cherry, and purple heart woods),
•Placing your order,
•Communicating with the UE team while waiting for your pair of PRMs to be built (the process takes about a week, though UE can do one-day rush orders at extra cost),
•Communicating with UE after your PRMs are shipped, and typically,
•Communicating with UE once again after you PRMs arrive and you’ve had a chance to audition them.

UE has paid fanatical attention to even the smallest aspect of the PRM, including the fit, finish, and build quality of the monitors themselves; the sonic quality and durability of the signal cables provided, the packaging and (sumptuous) road case in which the monitors will arrive, and—of course—the documentation and accessories that come with the PRMs. As a very cool touch (one that will leave many wondering, “Why has no one thought of this before?”), the case for the PRM will come marked with a special so-called RewardTag that advises anyone who might find your PRM’s that by returning the monitors to UE they will qualify to receive (on a “no questions asked” basis) a significant reward from UE (I believe this will take the form of a UE gift certificate). Interesting idea, no? But for obvious reasons, the single most interesting (and crucial) part of the process involves the time users will spend at the Personal Reference Tuning Station. Let me tell you more about how that works.

With Great Freedom Comes Great Responsibility

When first you sit down at the PRM “define your sound” station, here’s what you’ll see. First, you’ll a UE-labeled, gently wedge-shaped mini-console where you’ll see separate left and right hand banks of three control knobs each, plus connectors for the PRM test monitors and for source components. Most Beta listeners have used an iPod as their source component of choice, although I used an iPod (loaded with lossless and/or WAV files, of course) connected via a very high-quality line out dock (LOD) cable to an extremely high-quality Ray Samuels Audio fully-balanced SR-71B Blackbird portable headphone amp during my listening tests.

The test PRM monitors are built using the normal PRM driver array, but differ from production PRMs in two key respects:

•First, the test PRM is fitted with an extra long sound outlet tube that is shaped to allow used of a wide variety of universal fit-style ear tips (UE keeps an extensive array of ear tips on hand at the PRM station), and
•Second, the test PRM does not use an onboard crossover network as the production PRM does, but rather is wired to use the adjustable crossover components that are built in to the Personal Reference Tuning Station.

UE concedes that this arrangement isn’t precisely like listening to your personal pair of PRMs, in that the production PRMs made for you will offer superior fit and noise isolation and will, of course, be much more comfortable to wear (because they will be shaped to fit you and only you). Nevertheless, the Tuning Station does give you a chance to hear the PRM driver array in action with your music and source components, and with precisely the crossover settings that will be used in your finished pair of PRMs.

Once seated at the station, a UE attendant explains how the control knobs work. The left bank of three knobs controls the left monitor earpiece, while the right bank controls the right earpiece. The upper knob in each bank controls high frequency balance, the middle knob controls midrange balance, and the lower knob controls bass balance. It is helpful to know, though, that these knobs are more than just “level controls,” although they do in part affect perceived level across their respective frequency bands. Indeed, the phrase that UE representatives used was to say that the control knobs affect “the ratio of highs/mids/bass relative to adjacent frequency bands.” In practice, this meant the controls seemed to me to be interactive to some degree, so the adjusting one knob sometimes led to further adjustments for other knobs as well.

As a reference point for the listener, the control knobs are precisely calibrated with built-in numerical readouts where the available range of adjustment runs from 0-100 (where “0” = maximum output/emphasis for the frequency band, and “100” = minimum output or emphasis for the band). When all three knobs are set to “50”, the PRM is delivering what measures as the flattest, most neutral frequency balance possible. However, UE advises that different listeners perceive frequent balance in very different ways, so that it is best to ignore the markings on the knobs and to simply adjust them for what the listener perceives as the most natural, most accurate, or simply the most desirable response characteristics possible.

The good news, here, is that the listener is in charge of the response curve (which is where the freedom part comes in), but the potentially bad news for those of us who lean toward “audio nervosa” is that each PRM buyer must personally take responsibility for creating a response curve that he or she will find satisfying over the long term (gulp!).

UE’s initial plans call for Personal Reference Tuning Stations to be set up at four US locations: New York, NY; Nashville, TN; Los Angeles, CA; and at UE headquarters in Irvine, CA. More US stations may be set up later on, UE also expects to set up PRM stations at strategic locations in Europe and in the Pacific rim.

Recognizing that thePersonal Reference Tuning process will be liberating for many buyers, but potentially a bit stressful for others, UE offers several suggestions (plus one very handy listening tool) to help make the process flow more smoothly, as noted below:

•UE provides detailed marking on each control knob and explains that the “50/50/50” settings make a good starting point. In principal, those who just hate tinkering with an already good thing could simply order their PRMs with a “50/50/50” high-neutrality curve and call it a day.
•UE strenuously advises listening to a minimum of five different recordings, preferably of different genres, before finalizing one’s choices for response curve settings. UE invites PRM buyers to take their time and listen for as long as they like before making a final selection. Some listeners take only about 20 minutes, while others take much longer (I listened for nearly two hours before coming up with settings for my personal pair of PRMs).
•UE argues that there are no “right” settings for the PRM and therefore recommends adjusting the control knobs with one’s eyes closed, so as not to be overly influenced by the marking on the knobs. The objective, UE explains, is simply to pay close attention to what your own ear/brain interface is telling you and then to choose settings that, for you, simply sound right on most recordings, most of the time.
•UE points out that many, many listeners have slight differences in left/right hearing and that it is fully possible (and often desirable to have different voicing settings for the left and right earpieces). To this end, UE keeps on hand an iPod, which contains narrow band test tones that span a wide range of frequencies, and which also provides monaural tones that can be handy for make left/right earpiece adjustments.
•Finally, knowing that some listeners may find it difficult to relax and simply trust their own ears, the UE test station provides left/right “Bypass” buttons that temporarily return the crossover networks to the baseline “50/50/50” settings so that buyers can verify that their personal settings really do, for them, represent a worthwhile sonic improvement.

Once you’re done at the Tuning Station, a UE representative carefully notes the crossover settings you’ve chosen, records your choice of exotic wood to be used for you PRM earpiece ID plates, and that’s all there is to it.

Listening Impressions (from the Personal Reference Tuning Station)

I’ve not yet received my production PRMs, though UE’s Director of Sales & Marketing, Chuck Reynolds, called me yesterday to advise that my PRMs had been built and would be shipping later in the day. Am I excited to receive and hear them? You bet I am. In the interim, though, I thought I’d offer some first impressions based on the listening I did at the PRM test station.

How does the PRM sound? Well, with baseline “50/50/50” crossover settings the PRM sounds a fair amount like a set of UE’s In-Ear Reference Monitors, but on steroids. By this I mean that the PRM has a smooth, open, and more-or-less neutral sound (as does the IERM), but with several important differences. First, I’d say the PRM offers notably higher resolution with less apparent sonic “grain,” so that it offers significantly more of that effortless, transparent, “see-through” sonic quality that I and many other audiophiles crave. Second, it offers slightly more free-flowing and expressive dynamics—especially in terms of capturing subtle vocal inflections or variations in playing techniques. On paper, these might seem like tiny changes (and in an absolute sense they probably are), but in terms of musical satisfaction and involvement they actually make a quite significant difference. But third, the PRM offers its own signature “special sauce” in the form of customizable voicing that can be tuned in minor (or, if you wish, major) ways to bring the sound of the PRM as close as possible to your personal idea of sonic perfection. And that, let me tell you, is truly cool.

Because I found the baseline “50/50/50” sound of the PRM to be very, very good, I was initially reluctant to move away from the baseline settings. However, UE’s Vincent Liu, who is both the product manager for and the designer of the PRM, encouraged me to be more adventurous in my adjustments (at least at first)—if only to learn what the full scope of tuning possibilities for the PRM were like. What I discovered is that UE has allowed for a remarkably wide range of possibilities ranging from changes so subtle that they are (to me) only just barely audible on up to much more obvious high impact changes (with plenty of adjustment range in between).

What I wound up doing was to tune my PRMs so that they achieved a sound reminiscent to that of the in-room sound of the most accurate and expressive high-end loudspeaker that I’ve yet had in my home; namely, the YG Acoustics Carmels. The neat part, though, is that the PRMs cost $1999.99, whereas (last time I checked) the Carmels sold for a cool $18,000/pair (which, sadly, is more than my household budget can handle). If a $2k/pair in-ear monitor seems a bit, well, crazy, then just consider this: it’s roughly 10X cheaper than some of the killer loudspeakers whose sound it can many ways emulate.

UE’s promise is that your PRM settings will be kept strictly confidential, so that they are known only to you, God, and to the UE technicians who do final testing and assembly on your PRMs. No one else needs to know what your response curves look like, or why you chose them. The only thing that matters is that you wind up with monitors that sound, for you, true to the music.

I’m looking forward to reviewing the PRMs in Playback, but until then I hope this blog gives a sense for why this product is so significant.

Happy Listening.

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