If more is better, then an IEM with no fewer than 21 drivers must be the best ever, right?
Ultimate Ears Pro are one of the biggest names in in‑ear monitoring, offering a wide range of custom‑moulded in‑ears based around balanced‑armature driver technology. The base model in their professional range is the UE 5 Pro, so called because each earpiece features five drivers. These work across high and low audio bands, with a single crossover. As you move up the range, the number of drivers increases, and the frequency spectrum is further divided by additional crossovers, until you reach the pinnacle of the UE Pro line: the new UE PREMIER, which packs in no fewer than 21 balanced‑armature drivers, working into five separate frequency bands.
The manufacturing process takes up to 14 working days from the point at which UE Pro receive your order and your ear impressions (see box). Various options are available, including two cable lengths and a number of faceplate colours. A $199 cost option is the Switch feature, which allows different faceplates to be swapped in and out, or for an extra $50 you can order the UE PREMIER with an Ambient feature instead. The Ambient feature (which is not compatible with the Switch feature) adds a small port in the faceplate with a plug that can be removed to reduce the level of isolation. The review IEMs came with neither feature, and I chose the clear faceplates so that I could better admire the intricate interior. With the 21 drivers arranged in blocks at different angles and connected by a tracery of fine, coloured wires, there’s a lot to see as well as hear.
As you’d expect with so many drivers to fit in, the UE PREMIERs are on the large side. The shape is of course highly irregular, but the most extended parts of each earpiece measure roughly 3cm on all three axes. The shell is made entirely from rigid plastic, with no ‘give’ to it anywhere. The user’s initials are printed on the inward‑facing part of the shell, with red and blue ink used to differentiate right and left. A robust and lightweight hardcase is supplied, and includes a cleaning tool with a stiff brush at one end and a wire loop at the other. The sound is delivered through two small holes in the tip of each earpiece, and I found I needed to use the wire loop to clear wax from these holes quite frequently.
The IEMs are inserted in the usual way by pushing the tips loosely into the ear and then rotating them backwards by about 90 degrees. The braided ‘SuperBax’ cable then emerges from the front, at the top, and can be looped back over the ear. UE Pro use something called an IPX connector to attach the cable to the earpiece, which allows completely free rotation whilst maintaining a very tight connection. At the other end, the cable terminates in a right‑angle quarter‑inch jack.
I often have trouble achieving a comfortable, secure fit with generic in‑ears, even when a wide range of tips is supplied. Not so with the UE PREMIER, which went into place easily, formed a tight seal and never threatened to move or fall out. For general music listening I didn’t even feel the need to loop the cable over my ears. Ultimate Ears Pro claim that the UE PREMIER provide up to 26dB isolation, which is reduced by 12dB if you open the port on the Ambient version. As ever, this is a bit of a simplification, since isolation is always greater at high frequencies than further down the spectrum, but my subjective impression was that the isolation is well up to the mark. In fact, I would probably be tempted to opt for the Ambient version if I were to order them again, as there may be times on stage when you want to trade separation for a feeling of involvement.
A comfortable, secure fit and a decent level of isolation are basic requirements for any custom‑moulded in‑ears, though, and UE Pro themselves offer much more affordable options that should do the same job in these respects. The considerable price premium for the UE PREMIER could only be justified by their audio performance. Is it?
On paper, increasing the number of drivers in a balanced‑armature system should improve performance in several ways. Each driver only has to work into a narrower part of the frequency spectrum, so they can be more precisely tuned and optimised for their individual roles; and with two, three or even four drivers per band, the dynamic range of the system is increased. The potential down side is that the presence of so many crossovers, and the need to align so many separate drivers, risks introducing artefacts.
Like practically all headphone and in‑ear manufacturers, Ultimate Ears Pro quote a very broad frequency range for their products — in this case, 5Hz to 40kHz — without giving any tolerances. A more concrete specification for the UE PREMIER model is sensitivity, which is given as 126dB for a 1mW input at 1kHz. In tandem with a specified impedance of 15Ω at 1kHz, that translates to the real world as “really, really loud”, to the point where carelessness with the volume control can have painful results. An optional buffer cable is available for those who find that things are just too hot with their chosen headphone amp.
The sound is remarkably well integrated given how many different elements go into making it.
UE Pro provide a comparison chart on their website which offers tasting notes for each of their different models, with ratings out of six for low, mid and high. Curiously, this chart appears in two different places on the site, and the UE PREMIER model gets different ratings for the mids in each case — but it’s clear that UE Pro see these as a versatile tool for music listening and studio applications as well as live use. (Some resellers even claim that they’re appropriate for mastering, which seems a bit of a reach.) And, I have to say, I was impressed. I’m not sure they sound quite as natural or smooth through the midrange as a top‑notch single‑driver system, such as a pair of high‑end headphones, but the sound is remarkably well integrated given how many different elements go into making it, with no obvious crossover artefacts or other weirdnesses. I can’t imagine needing more dynamic range than is on offer here: as I turned them up, my sense of self‑protection kicked in well before any distortion was audible, and I couldn’t detect any unwanted compression beyond what my own ears were doing in response to the high SPL.
And whether or not they really reproduce audio all the way up to 40kHz, there’s no doubt that the UE PREMIER are a genuinely full‑range monitoring option. The highs are crisp and clear, and there’s certainly no shortage of low end. In fact, their most obvious deviation from the completely flat is a fairly prominent hump around 150Hz or thereabouts. You’d need to ‘learn’ your way around this if you wanted to use the UE PREMIER to mix, but I think that would be possible, and in most of their intended applications I think this is preferable to their being bass‑light or anaemic. There is plenty of true bass below this hump, too, and though I had the sense that some overtones were also being generated when I fed low‑frequency sine waves into them, they will put across your 808s with plenty of weight.
If what you need is the most neutral monitoring system for mixing recorded audio on the go, then personally I’d still choose a pair of high‑end conventional headphones over any in‑ears. For this money, you can pretty much take your pick from the very best over‑ear phones around and still have some change. But if you want to invest in a really high‑quality IEM for live use that’s good enough to rely on in other contexts where you need to make sonic decisions with confidence, the UE PREMIER absolutely fit the bill.
Buying custom‑mould IEMs from any manufacturer necessitates having impressions of your ears taken. The standard technique for doing this is to have your ears plugged with cotton and then filled with goop, which sets to form a soft cast of your shell‑like. This cast can then be removed and used to prepare a mould, or scanned to generate a 3D model of your lughole. Ultimate Ears Professional are happy to work with 3D impression scans, and many of their official resellers offer this service, but at this year’s NAMM Show, they were showing off an alternative, goop‑free measurement technology, currently available only near their LA HQ. A trained operator inserts a scanning probe directly into your ear and moves it around to build up a 3D map. After a couple of false starts, this proved relatively fast, and although having things wiggled around in your ear isn’t exactly fun, it’s smooth, painless and doesn’t leave you feeling uncomfortably shut off from the world.
(Mind you, the NAMM Show floor is one place where I’d welcome being shut off from the world for a bit.)
These highly advanced IEMs deliver a rich, full‑range sound, with enough level and dynamic range on tap to satisfy anyone.