Review: Pioneer DJ RM-07
Stephen Bennett finds out whether these new speakers from the DJ gear specialist are a match for some of the well-established names in professional monitoring.
The wonderful thing about speakers is that speakers are wonderful things. Their cones are made out of – well, most anything really. Since the first primordial stirrings of the electromagnetic speaker, they have appeared in many varieties.
One question that is always asked by the audio engineering novice is the difference between studio monitors and their brethren destined for a domestic setting. Although we seasoned engineers may mumble something about ‘ruggedness’ and ‘flat frequency response’ the truth is, especially when we are talking about near-field monitors, that there is very little difference between these speaker types. More than often it all boils down to the cosmetic – speakers destined for the home tend to be veneered in woods or other materials that are acceptable in a domestic environment, while studio-bound speakers are usually more functional in physical design.
Pioneer DJ may not be the first company that springs to mind when considering professional studio monitors. The company has a long and excellent reputation regarding the production of audio gear of course – in fact, my first turntable was the company’s PL112d and its headphones and cassette decks have graced my home over the years. However, its DJ series of equipment is well respected among those who spin the real or virtual decks. The S-DJs are perfectly conventional monitors – biamped and ported, with a separate tweeter and mid-range drivers of various sizes to suit different applications. Pioneer DJ, however, has thrown something of a curve ball with its latest speakers.
The RM series of professional studio monitors eschew the traditional multi-driver approach for a design that found its most memorable and mature development under the auspices one of the most famous speaker manufacture in the world: Tannoy. All speaker designs have positive and negative attributes and I’ve always thought that choosing a pair is like a relationship – select the ones who annoy you the least and learn to live with the problems. I’ve had a sort of Tinder-like relationship with speakers, never being entirely happy with any of my choices. Early in my career, I came to the conclusion that I mostly preferred certain speaker designs such as sealed box and transmission lines, so I’ve spent a large proportion of my professional life – and my income – on trying to find that always-elusive ‘perfect’ monitor.
One of my other favourite designs is the one employed by both Tannoy and the speakers under review – the dual concentric or point-source speaker. In an ideal world, you’d be able to reproduce the whole of the useful frequency range with a single driver and, while this would solve many of the problems that beset speaker design, it is, of course, impossible. Having two or more speakers in a cabinet introduces quite a few problems into the complex speaker equation – the crossover itself, the effect of the cabinet on the drivers mounted in different, separate, locations and the phase differences between those drivers – something to which those of us who record drums become extremely sensitive.
A compromise employed by the point-source speaker is to place the tweeter – the high frequency driver – within the second (low or mid-frequency) driver, usually, though not always, smack bang in the centre. This addresses several of the problems mentioned above, but unless the combined driver is extremely well engineered, the point-source design can introduce other sonic issues. Currently there are two monitors in this new series, the RM-07 and RM-05. The RM-07 is the larger of the two, sporting a 6.5in aramid fibre ‘woofer’ mid/bass unit, while the RM-05 has the smaller 5in unit. Consequently the former is some 40mm taller (337mm) and 3kg heftier (12.3kg) than the latter.
The speakers specify a similar frequency range – 40Hz to 50kHz for the RM-07 and 45Hz to 50kHz for the RM-05 – but the Class A/B amplifiers in the speakers differ more greatly, with a 100W into 4 Ohm amp driving the low frequency unit and a 50W unit driving the tweeter in the RM-07, and a 50W unit driving the low frequency driver in the RM-05. As you would expect, the crossover frequencies also vary, as does the maximum SPL: 109dB in the RM-07 and 104dB in the RM-05 – both measured at one metre.
Apart from these few areas the two monitors are otherwise identical. The 1.5in hard dome aluminium tweeter is the same for both units and mounted centrally in the low frequency driver. This HSDOM (Harmonised Synthetic Diaphragm Optimised Method) tweeter was developed using technology from Pioneer subsidiary TAD Labs, which drew on the company’s expertise in the AV sector and is what gives the monitor its ultra-high frequency response. The cabinet is made of an extremely stiff die-cast aluminium with an integrated heat sink on the rear panel to channel away the heat generated by the two internal amplifiers. The speakers are forward-ported and the front is a smooth surface that flows back from the effectively single driver in a way that multi-driver designs cannot match. The grooved port employs the Japanese manufacturer’s Acoustic Filter Assisted System Tuning (AFAST), an acoustic tube that is designed to reduce the effect of internal standing waves and improve the port’s output. There’s an LED on the front panel that displays any overload and if the speaker has gone into a power saving standby mode – this can be disabled using the rear panel Auto standby switch.
The rear panel itself sports screw mountings for wall fitting, unbalanced RCA input and a balanced XLR inputs alongside the expected IEC mains socket, power switch and fuse holder. A comprehensive EQ section is also available, with low mid and high rotary dials alongside an overall level control (-40dB to +6dB). The hi-fi geek in me balks at a speaker with tone controls, but I have found that even a small tweak of the bass output of an active speaker in challenging conditions can bring you closer to that mythical ‘flat frequency response’ – but how effective that is does depend on the quality of the tonal control design.
The low and high controls are shelving filters that offer attenuation or boost from -4dB to +2dB at 50Hz and 10kHz respectively, while the mid control is a dipping notch filter set at 140Hz, with a variable Q that gets narrower at extreme settings. The supplied rubber legs and soft cushions offer various table and stand mounting options – although, as I’m a believer in using rigid stands, I opted not to use these in testing.
In Use
So far, so good, but as we know, specifications are not everything in the audio world. I was kindly supplied with a pair of RM-07s for review, so I set these alongside my current near-field monitor of choice: the active ATC SCM16. The ATC retails at over four times the cost of the RM’s, so I also set up a pair of Focal Alpha 80 active monitors and an ancient pair of Tannoy Little Red concentric dual speakers powered by a Quad 45 amplifier for a fairer comparison. I’m always surprised by how different speakers of similar size and design can sound so the difference between this rag-bag of speaker technology was quite marked.
I auditioned the RM-07’s via a Metric Halo UL-N 2 in a reasonably well-treated studio. The first impressions were positive. They appeared a little brighter than the ATC’s but a judicious tweak of the high frequency knob brought them under control with little apparent loss of detail. Buoyed up by this, I moved the RM-07’s to a part of the studio where I knew there were bass issues and had a play with the low frequency control. Again, this helped enormously with flattening out the bass response. I’d still prefer to place the speakers optimally in a room, but if I were restricted in this aim, I’d be glad of the tonal correction offered by the Pioneers.
Back on the stands, they offered a reasonably detailed high frequency and midrange, with none of the ‘smearing’ that can occur with inexpensive two-way designs. I could hear subtle changes in a mix I’d recently undertaken and the speakers were not obviously fatiguing over extended periods.
The amount of bass delivered by both the Alpha 80 and RM-07’s was impressive for their size – but when I switched back to the sealed-box ATC’s it became obvious that the low frequencies were slightly over-hyped and ‘one note’. This is common with ported designs, but the RM-07’s give enough real low frequency information to make sensible mix decisions and, if I was mixing dance music for clubs, I’d probably appreciate the extra heft and weight. I’ve often noticed that some ported speakers appear to add bass to everything, but the RM-07’s seemed reasonably well-balanced overall.
Stereo imaging was excellent and they did not exhibit any obvious frequency changes when I moved my head around. Comparing them to the Tannoys, I detected something of the benefits of concentric speaker design: accurate positioning of instruments in a mix and mid range clarity with no obvious phase issues, alongside a little of the restriction of treble dispersion that the Little Reds are also prone to.
These new studio monitors are up against some well-established competitors in this price range and it remains to be seen if the company can make waves beyond its DJ and home-audio reputation and into the professional studio market. The manufacturer has used the benefit of its experience to create a speaker that employs a relatively rare design that might just make them stand out from the crowd. If you are looking for a robust, flexible, decent sounding near-field monitor, the list of those you need to audition just got slightly longer.
Key Features
- HD-Coaxial driver unit for ‘accurate point-source monitoring’
- 40Hz-50kHz frequency range
- AFAST acoustic tube to reduce standing waves
- Front-loaded bass reflex system with grooves
- Low/Mid/High EQ settings
RRP: €729 (RM-07), €549 (RM-05)
Stephen Bennett has been involved in music production for over 30 years. Based in Norwich he splits his time between writing books and articles on music technology, recording and touring, and lecturing at the University of East Anglia.
