Coaxially mounted speakers may seem a bit old‑school, but there's nothing wrong with the theory — and a touch of DSP can make them very modern indeed!
Equator Audio Research may not be a familiar name in the UK, but the man behind this company has plenty of experience: Ted Keffalo started out as a studio owner, before working at Alesis for many years and then going on to co‑found and run Event Electronics. In setting up Equator, Ted sought to create the best midfield speaker he could, combining the latest in power‑amp and DSP (digital signal processing) technology with some concepts that had impressed him in the 1970s, including the sound of the Urei 813 monitor, with its infamous, blue, foam‑lined, coaxial horn arrangement. To this end, he gathered a team of highly experienced and talented speaker and DSP designers: the result is the 'Q' series of 'self‑correcting' bi‑amplified reference monitors.
The idea of a coaxial monitor system is to deliver true coincident source monitoring by circumventing the time and phase anomalies inherent in more traditional two‑way systems. This approach potentially results in better imaging across a wider sweet spot and (arguably) a more natural sound character. There's nothing revolutionary about that (in fact, several manufacturers offer time‑aligned co‑axial systems), but the cream on top in the Equator design is a built in DSP facility, which not only fine‑tunes some aspects of the speaker design and performance, but can also be used to analyse the acoustic environment in which the speaker is placed, helping to address a range of problems, including standing waves and the comb filtering caused by early reflections.
The 'Q' series comprises five models, starting with the baby Q8 reviewed here ('baby' is a relative term: think baby elephant in this case!). There are three larger models, the Q10, Q12 and Q15, and the number describes the size of the LF driver in inches. There's also a subwoofer, the Q18, which can be used with any of the main monitors. All are active designs and share the same technology and design philosophies.
The Q8 is the smallest and most affordable of the range, but is a surprisingly heavy thing. The 13‑inch cuboid cabinet, with shiny, dark-grey, 'micro‑metallic' finish, is built from a heavily braced, three‑quarter‑inch‑thick, 13‑ply Baltic Birch timber, to maximise stiffness, and is intended for relatively small rooms and project studios. Omnimount‑compatible mounting holes are provided on the rear. The one‑inch-thick, high‑density fibreboard front baffle is dominated by an eight‑inch, fibreglass‑impregnated, paper‑pulp woofer with two large, round ports in the bottom corners, but most of the woofer is obscured from view by the centrally mounted, coaxial horn, driven by a one‑inch, titanium compression driver. Equator call this coaxial driver arrangement 'Zero Point Reference' and, thanks to a pair of integrated 200W amplifiers, the combination can generate serious sound pressure levels, of over 110dB SPL at one metre. The woofer's chassis is made of aluminium to aid with cooling, and the motor assembly is magnetically compensated to minimise external fields.
An LED display fills the area between the two ports, and provides information about volume, network communications and protection: the system soft-limits at extreme levels and protects itself from thermal, short-circuit and under-voltage conditions. (Thankfully, the level bar‑graph metering can be switched off from the front panel.) Inside the cabinet, sophisticated DSP is used to match precisely the performance of each drive unit to the ideal frequency response (based on data derived from individual drive‑unit testing before installation in the cabinet), as well as to produce the required crossover filtering to couple the two drive units over the full working range of the system — which is given as 38Hz to 22kHz (at the ‑3dB points) in the case of the Q8 system. The interesting 'no slope' crossover design is shrouded in some mystery, but it appears that the nominal 2kHz crossover frequency might be tailored dynamically by the digital crossover in some way, to help minimise mid‑range distortion.
The DSP can do more than simply fine‑tune the on‑axis response of the speaker system: it has the capacity to provide a degree of room‑correction processing as well. Included with the Q‑series speakers is some software that enables the user to input data to help correct basic room acoustic anomalies, such as response errors caused by placement near room boundaries (nearby walls or corners), and to apply an overall equalisation curve. But the really impressive functions are realised when the optional Equator Room Analyser Calibration Kit is employed (discussed in the 'Automatic Room Compensation' box). Both systems support a wide variety of speaker configurations, from plain stereo through 2.1 and 5.1, and on up to 8.2 rigs (eight main speakers with two subwoofers).
The rear panel includes an IEC mains inlet and power switch, and audio connections presented on XLR and quarter‑inch TRS sockets (wired in parallel). There's no volume control on the speakers, but the configuration software can provide a digital attenuator function. When setting the speakers up, a Mac or PC is hooked up to the USB port, and the monitors are linked via the pair of RS485 sockets, using Cat 5 cables. An eight‑way DIP switch on the rear panel allows the role of each monitor to be programmed (front left, front centre, and so on), along with the speaker group to which it belongs. Up to four groups are possible, allowing for separate calibration and operation of multiple arrays in the same room: perhaps a stereo pair and a separate surround system. The last switch allows programmed room‑compensation processing to be bypassed without connecting to a computer, which is a thoughtful provision.
The standard Equator control software is apparently supplied on CD‑ROM, but the review system included the optional room analysis software, which comes on a USB memory stick. Installation was trivially simple on my PC laptop, although Mac users have to go through an additional manual step of installing a USB driver prior to loading the main program. With the software installed and everything hooked up, the monitors can be powered up and the software run to configure the system. The control screen shows the appropriate number of speakers set up in a virtual mix room, with options to select the different control groups as well as to solo, mute and select each speaker within the group, or to mute the entire group, bypass all the processing, and to compare different processing configurations.
The control functions are distributed over nine tabbed panels at the bottom of the screen, with very comprehensive options including, amongst other things, the ability to adjust the speaker LED display brightness (a good thing, because the default setting is pretty bright!). The manual room-correction tab allows all three room dimensions (in feet or metres) to be entered, along with a rough indication of the position of each speaker (free standing, or near a wall or corner), and this data is then used to calculate an approximate room equalisation for each speaker. However, the calculated filter parameters can be manually adjusted, if required, either via a window tab showing the frequency‑response chart and filter‑setting boxes for a selected speaker, or from a window tab that shows the filter parameters for all speakers within the selected group as a spreadsheet. The Compare button mentioned earlier allows the existing (default or previously programmed) speaker equalisation to be compared with the newly configured equalisation, which is handy when fine‑tuning a system. A Tone Contour tab provides the facility to introduce a 'personal preference' EQ curve (for example, a little more bass, or a little less high end), and the final control‑screen tab allows the new settings to be stored on the computer and loaded into the speakers' DSP systems. Five quick‑access presets here also allow alternative pre‑defined settings to be quickly recalled — and this is intended to be used to reset optimised auditioning conditions at the producer's desk, say, or for the comfy sofa at the back of the room, or even to a flat reference condition. The automated room response and secondary reflections tabs are apparently greyed out unless the optional room analysis software is installed.
I set up the Equator speakers in my listening room alongside my reference PMC IB1s, well away from all walls and about eight feet from the listening position. I initially configured them for a flat response, to get an impression of their basic sound character.
The first thing to strike me was that these relatively modestly sized speakers have a greater bass extension than you'd expect from an eight‑inch driver (no doubt thanks to the DSP driver equalisation). However, the bass certainly isn't overblown or hyped, and some casual listeners might initially feel it isn't as powerful as that obtainable from some other ported speakers. Personally, I find ported cabinets generally portray an unnatural quality with bass instruments, which is something that becomes clear when compared with sealed-cabinet designs (or, indeed, PMC's ATL approach). However, the Q8's bass response seemed closer to a sealed‑box character in some ways than the conventional ported design it appears to be — which is perhaps thanks to corrective DSP phase control — and the bass end goes low without obvious ported resonance peaks.
These speakers are also capable of going extraordinarily loud without getting too nasty. The two internal 200W amps have massive transient capability, and even when you push them close to their continuous limits, the in‑built compression/limiting circuitry makes sure they still play nice, rather than rip your head clean off!
I'm not normally a fan of compression drivers and horns (I've spent far too many years listening to genteel silk domes) but the Q8 drivers work remarkably well, delivering a pretty clean and smooth sound, free of the harshness that I associate with many horn systems, at least until silly levels are reached (when a hint of the mid-range beast lurking behind the DSP facade appears). It's also worth saying that the last time I heard a horn driver that sounded like a dome was in the huge Meyer Sound X10 studio monitor, which costs a great deal more than a Q8.
The stereo imaging is very sharp and stable, with rock-solid phantom images and an impressively broad sweet zone, which is thanks, in large part, to the coaxial nature of the drivers. However, when selecting different listening material I noticed something a little less impressive: the Q8s generate quite a lot of self‑noise (the background hiss from the DSP and amplifiers). Even with the might of a Bryston 4B amp behind them, my IB1s are completely silent at the listening position, and it's hard to hear any background noise, even when standing right in front of them. But the Q8's constant background noise was audible at my listening position, some eight feet away — and since they're intended for use in smaller rooms with closer listening positions than mine, I fear this might be an issue for users with very quiet mix rooms.
Overall, then, I'd say that the 'raw' Q8 delivered an accomplished sound with a wide bandwidth, natural dynamics and transients, supported by plenty of clean power, and a detailed, revealing (but I wouldn't say fatiguing) character. If I were being picky, I'd suggest that the mid-range didn't seem quite as smooth and 'natural' as on my reference PMCs (out of the box it was slightly 'forward', in a typical American‑voicing way) — but then there are many users who find that this characteristic actually aids their mixing precision, and the software contour equalisation also allows personal tweaking of the sound character to a limited degree. I'd also say that the extreme high‑frequency end didn't feel quite as open and airy as my favoured soft domes, but that is a subtle difference.
After my initial listening, I placed the test mic at my preferred listening position, fired up the automated room‑analysis software, and left the room for the system to get on with it. A couple of minutes later, I came back to find out what it thought should be done. Aside from tackling a low bass mode at 30Hz and its harmonics (which I'm well aware of), it didn't feel the need to do too much in the way of room equalisation, but it did detect and correct for a number of early reflections. Comparing the raw system with the reflection‑compensated settings revealed a small but definitely worthwhile improvement in the stability and precision of the stereo imaging, which I thought was already pretty good anyway. I have to say though, that I found I actually preferred the overall sound with the room and delay compensation turned off. The sound stage seemed to deliver a greater sense of depth to me, but perhaps it's simply that I'm too used to the sound of reflections in my own room, and miss them when they're processed out! In my case, the area between the speakers wasn't cluttered with a console or computer screens, and I think the reflection compensation would prove its worth far better in that kind of situation. Likewise, my listening room is large and the acoustics aren't too shabby, but in a smaller, more troublesome room the automatic correction facilities will inevitably work harder and deliver subjectively far more beneficial results.
I suspect that the Equator E8s won't win awards for their aesthetics — unless you happen to be into the industrial and heavy‑duty look. But if you can get past this unique styling, the sound of the Q8s is genuinely impressive and well worth an audition.
At this price level, there are a lot of very competent monitors, but not many with DSP‑based equalisation. Roughly equivalent DSP‑based monitors would include the Digidesign RM2, Dynaudio Air 15, Genelec 8250A and Tannoy Ellipse 8.
The Automatic Room Analysis software may be sophisticated, but room calibration is fairly painless. The measurement mic is set up at the measuring position (any number of positions can be analysed and stored), and connected to your audio interface. You select the relevant input and output, and the signal level can be adjusted on the DAW according to a bar‑graph display on screen. With routing and levels set, you select the Automatic room‑compensation tab in the control software, and enter the longest room dimension to determine the run time of the analysis.
The test begins with a loud noise burst and frequency sweep through the speakers, but thankfully a delay can be set to allow time for people to escape the room! The test calculates and generates the speaker‑equalisation curves, which can be viewed and edited in the same way as in the manual version of the software. The Secondary Reflections tab displays the measured room reflections (up to 5ms) and the appropriate compensation. Individual reflections can't be edited, but the correction sensitivity can be adjusted from the default ‑24dB: a lower value will result in fewer reflections being compensated.
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