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Harbeth Xpression! DPM1 & MS1

Monitor System By Janet Harniman-Cook
Published May 1997

Janet Harniman‑Cook checks out the new kid on the monitoring block and discovers a history of serious loudspeaker design.

The Xpression! DPM1 two‑way passive monitor is the first studio monitor from Harbeth, a long‑established British company associated with loudspeaker manufacturing for broadcast and audiophile hi‑fi. Designed by MD Alan Shaw, the Xpression! DPM1, and the optional MS1 sub‑bass enclosure, are aimed primarily at the private studio and post‑pro market, though a Pro version is available, featuring auto‑sensing electronic speaker protection with LED peak power monitoring. Active versions are available to order, and the regular DPM1 may easily be converted for bi‑amping.

The quoted frequency response of the DPM1 used alone is 48Hz‑20kHz (±3dB), with a sensitivity of 87dB 1W/1M and a nominal impedance of 8Ω. The optional MS1 sub‑bass enclosure extends the system response down to 40Hz, and passive filtering inside the sub‑cabinet removes LF being fed to the DPM1s below around 140Hz. For this review, I used a Mass 500 which delivers 175W into 8Ω, though the recommended amplifier power is from 20‑200W with a complete system rating of 175W programme material.


Weighing around 10kg and measuring 420 x 255 x 285mm, the DPM1 cabinet is made from 15mm MDF with a textured grey finish. The 200mm woofer is made in‑house and features an alarmingly mauve injection‑moulded polymer cone and a high‑compliance, long‑throw rubber surround; it's driven by a 25mm aluminium voice coil. Handling the HF is a Morel ferro‑cooled 28mm soft‑dome tweeter, also driven by an aluminium voice coil; to minimise standing waves, the internal cabinet surfaces are covered with 16mm absorbent fibre blanket. The 15‑element critically damped crossover operates at 2.6kHz, and both the DPM1 and the MS1 are fed via Neutrik Speakon connectors.

Similar in size and weight to the DPM1, the Xpression! MS1 sub‑woofer is connected between the amplifier and the DPM1. It is built from 20mm MDF with a matching grey finish. Unusually, rather than the single central sub approach employed by some designers, each DPM1 has its own MS1 sub‑woofer, the idea being to minimise standing waves in the listening room. The MS1 driver uses the same transducer as the DPM1 and its cross‑over comprises both electronic and band‑pass acoustic chamber elements. There is no direct radiating element to the sub‑woofer — all the energy leaves the box via the circular port.

The DPM1s should be sited away from room corners, not too close to side or rear walls. I set them up around 1.3m apart, with the tweeters at ear level; after experimenting with the subs' positioning, I ended up placing them asymmetrically alongside the DPM1s.


My first test track was Richard Thompson's 'Sam Jones' from his album You? Me? Us?, and I was immediately impressed by the superb clarity and definition revealed by the system. The acoustic guitar came over with crisp and rich harmonic detail, while the vocals seemed natural and open. A deep string bass on this track held an even tone across the recorded range.

As a stand‑alone nearfield system, the DPM1s are outstanding performers.

Listening to a recording of the Beethoven String Trio in G Op 9/1, I was encouraged to hear the character of the instruments portrayed so accurately, with the string tone displaying a smooth yet refreshing natural brightness. The spoken word was also well balanced and free of coloration. Overall, the speakers worked well on all kinds of material, from pop and dance to large‑scale orchestral and choral recordings. The mid‑range definition in particular is outstanding for a speaker in this price range, and the low‑end response is impressive. The clean mid‑range translates into excellent stereo imaging, and even when you move off‑axis, the frequency response remains reasonably consistent.


Whereas hi‑fi speakers are often designed to flatter the programme material, the requirements of audio production call for an uncoloured reference that doesn't induce fatigue during periods of extended listening. The Xpression! DPM1/MS1 monitor system fulfils these needs impeccably — poor recordings exhibit their flaws, but well‑engineered material shines.

Harbeth Acoustics have made an impressive debut in the small‑studio market, with a sensibly priced and visually distinctive monitor capable of being used in serious monitoring situations. The creditable full‑range fidelity combines with particularly good mid‑range presence and stereo imaging to produce a compact reference monitor system that's effortless to listen to and inspiring to work with (and has been a joy to review).

Used without the MS1 sub‑bass units, the DPM1s are still very capable performers, and have a wealth of detail and presence that, in my opinion, places them well up the league within their price range. If you haven't heard these speakers yet, you should!

Second Opinion

With Harbeth being a new name in the private studio monitoring market, I was keen to hear how the DPM1s compared with other monitors I've tried. Initial impressions were good — the speakers seemed to be the result of serious engineering design rather than fashion, and they're just about the right physical size to use as main monitors in a private studio setup.

After connecting the system up to a Studiomaster 600B power amplifier, I wheeled out the usual suspects from my test CD collection. The first tests were done with the sub‑woofer connected, and this delivers plenty of bass extension though, to be quite honest, the mid‑range is difficult to evaluate properly when there's a lot of bass energy flying around. For dance‑music mixing, the sub‑bass units would be fine, but for regular work, I actually preferred the sound of the DPM1s on their own. They still deliver a realistic level of low bass, and the detail within the mix becomes much easier to hear.

Tonally, the speakers are creditably neutral and are especially natural on vocals and spoken‑word recordings. The high end is nicely detailed without being splashy and the bass end is pretty even and quite solid. If anything, the low‑end transient definition is a little way behind the very best monitors I've heard, but in this price range it would be churlish to nit‑pick. For close monitoring, both the level and bass extension are perfectly adequate and the stereo imaging is good.

On balance, I'd say these monitors are among the best I've heard in the mid‑price range, and I've witnessed far less impressive results from speakers costing well over twice the price. They make a good stab at telling it how it is, they aren't at all fatiguing to listen to, and they're sufficiently revealing of recording flaws to be relied on in serious monitoring applications. Best of all, they have no significant vices. I'd feel happy using these and I'd have no hesitation in recommending them, though I feel the sub‑bass unit is unnecessary for most private studio installations. Paul White


  • Accurate, neutral sound with good imaging.
  • Attractive price.
  • Magnetically screened.


  • Dual sub‑woofers may be awkward to site in small studios.


Given its price, the Xpression! DPM1/MS1 is a versatile studio‑monitoring system characterised by particularly good mid‑range detail. As a stand‑alone nearfield system, the DPM1s are outstanding performers, especially given their very modest cost. The subs provide significant bass extension for those mixing dance music or other material requiring the reproduction of very low frequencies.