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Genelec 8340A & 8350A SAM

Active Monitors
Published October 2017
By Phil Ward

Genelec 8340A & 8350A SAM

Genelec have never shied away from technological innovation, as these classy, DSP-equipped monitors demonstrate!

It’s occurred to me more than once that the monitor design business is unlike almost any other. I’m inclined to think this is due to the enormous range of technological ambition among manufacturers fighting for the same customers. Monitor companies manufacturing products that, in conceptual terms, are really not all that different to those of, say, four decades ago, fight it out with companies manufacturing monitors that are genuinely on the bow wave of technology. Does such a phenomenon happen in any other technology sectors? Very few I suspect (sports cars, maybe; Porsche and Morgan fighting over the same customers?), and I think there are two reasons for it. Firstly, there will always be a subjective element in our response to the sound of a pair of monitors, so however strong is the technical justification for a particular set of performance characteristics, at the end of the day, it’s ears that will decide. Secondly, at a basic level, monitor design and manufacture is far from rocket science and, as the Yamaha NS10 showed, if you get the recipe right, even partly by accident, you can go an awful long way on a particular combination of relatively low-tech components.

Did I say there are two reasons? I was wrong, there are three. The last reason is that we still don’t really know enough about the psychology of auditory perception to be able to say, without doubt, what performance characteristics a ‘perfect’ monitor should have. We’re not short of opinions, but we are still missing quite a few unambiguous facts.

Now, I’ve kicked off with a paragraph on context because the twin subjects of this review, Genelec’s SAM 8340A and 8350A are, in some technological respects, not far off as advanced as two-way monitors get. From the perspective of that much-loved (or loathed) white-coned monitor, the Genelec SAM monitors may as well have been parachuted in from the future. And as I write that, I realise from the NS10’s perspective, that’s pretty much what’s happened.

Genelec have a long tradition for remaining apparently unswayed by engineering trends or marketing fashions, and the result is a range of characteristically unmistakeable products. You can’t really mistake Genelec monitors for anything else, to the extent that they hardly need a logo on the front. Genelec’s co-founder and engineering figurehead Ilpo Martikainen, who sadly passed away shortly before I took delivery of the review samples, I suspect would have argued that the shape, appearance and technological content of Genelec monitors is driven entirely by research and electroacoustic requirements. Martikainen was, by all accounts, an engineer who stuck steadfastly to his beliefs and principles. And he backed them with an unswerving dedication to rational and logical design and engineering. Without there being unquestionable objective evidence for the significance of a particular technology or performance characteristic, I suspect it wouldn’t even so much as blip on Martikainen’s radar.

So, to the 8340A and 8350A. The two monitors apparently differ only in terms of scale and, consequently, in their low-frequency bandwidth and maximum level capabilities, and their retail prices. The 8340A drivers comprise a 6.5-inch bass/mid-range unit and a 3/4-inch metal-dome tweeter, and the system is capable of 110dB SPL (100Hz upwards at 1m), with low-frequency bandwidth extension down to 38Hz (-6dB). The 8340A internal amplification comprises Class-D electronics rated at 150 Watts for both LF/MF and HF channels. The 8350A drivers comprise an eight-inch bass/mid-range unit and a one-inch metal-dome tweeter, and the system is capable of 112dB SPL with low-frequency bandwidth extension down to 33Hz (-6dB). The 8350A amplification is rated at 200 and 150 Watts respectively for the LF and HF. The design of the 8340A and 8350A bass/mid drivers in terms of their diaphragm material is difficult to establish due to their perforated metal grilles.

Reflex Reaction

Both monitors are constructed in the same style of two-part aluminium die-cast enclosure with generously flared reflex ports exiting on the back of the rear section. Genelec describe the reflex ports as, “designed to minimise noise, compression and distortion”, but of course if the monitors had been designed from the outset as closed boxes, there’d be no port noise, compression and distortion to minimise in the first place (although of course such a decision would then ask rather more of the bass/mid driver and amplifier).

So the 8340A and 8350A leave me wondering (once again) why so many monitor manufacturers persevere with reflex-loaded active monitors? Back in the days of conventional Class-A/B power amplification, where power was limited by heat-sink and transformer size, reflex loading was all but unavoidable if low-frequency bandwidth extension was required from a compact enclosure, but now, with Class-D amplification making power so much less expensive, and DSP making complex equalisation a breeze, why stick with port tubes and their inherent issues? Perhaps it’s a fact of commercial electroacoustic life that a hole and tube, even one that’s carefully designed, is still a more cost-effective route to low-frequency bandwidth extension than a more expensively engineered bass driver and more amplifier power.

Die-casting a speaker enclosure brings two huge advantages over construction from wooden panels. Firstly, the possibility of panel resonance can be removed substantially from the equation, and secondly, the die-casting process provides the opportunity to create a soft-edged shape that minimises the acoustic diffraction effects that are all but unavoidable with rectilinear forms. These characteristics will help clean up both the time- and frequency-domain performance of a monitor. The die-cast freedom of form also provides the opportunity for tweeter dispersion to be controlled by a wave guide incorporated into the shape of the monitors’ front panels. Die-casting comes with a down-side, however, in the shape of eye-wateringly expensive tooling. Also not an inexpensive item in terms of tooling is the rubber de-coupling and angle-adjusting foot fitted to the underside of each monitor. Each of these expensively tooled items just reinforces how seriously Genelec take designing and engineering their monitors. There are clearly very few corners cut.

Diagram 1. The group-delay curves for the monitors taken from their user manual.Diagram 1. The group-delay curves for the monitors taken from their user manual.Moving on from engineering to acoustics, the low-frequency bandwidth numbers for both monitors are impressive considering their compact dimensions, and are achieved through a combination of electronic equalisation and reflex loading. There’s never a free lunch with speakers, however, and the downside of the extended low-frequency bandwidth reveals itself in the monitor’s time-domain characteristics. Reflex loading generally results not only in increased low-frequency latency (known technically as ‘group delay’) but also in extended low-frequency ‘overhang’ following transients. In the absence of a very large and silent measuring environment it’s difficult to put a number on the low-frequency overhang exhibited by the 8030A and 8040A. However, Genelec are very unusual (and should be applauded) for publishing group-delay specifications for their monitors, and at 50Hz the 8340A and 8350A delay the signal by 17ms and 14ms respectively. Diagram 1 illustrates the group-delay curves for the monitors taken from their user manual and shows also what a great job Genelec do in respect of publishing specs and data.

Now, those of you familiar with my ramblings on speaker design and monitoring will perhaps be aware that I’m of the opinion that the low-frequency overhang and group delay inherent to reflex loading can be audible and, in a mix context, can add an element of uncertainty to voicing and balancing low-frequency elements (kick drum and bass guitar being the obvious examples). I’m far from alone in my opinion (see ‘Group Delay’ box), and there’s a significant body of opinion with the same mind, so in that context, one thing I’d really like to have seen on the Genelec SAM monitors is some of its DSP horsepower deployed towards group delay compensation. I’d be surprised if such a feature were not viable and while it would obviously result in around 15ms latency across the entire bandwidth, it would perhaps satisfy those of us who feel uneasy knowing that the fundamentals of the bass player’s E-string are effectively located up to five metres behind the rest of the band.

The rear panel houses the analogue and digital audio inputs, as well as a bank of DIP switches that engage various DSP functions, including room and placement compensation filters.The rear panel houses the analogue and digital audio inputs, as well as a bank of DIP switches that engage various DSP functions, including room and placement compensation filters.Moving on, however, having finished that last paragraph describing a feature that’s not present on the Genelec monitors, I suspect I should redeem myself now by describe those features that are present. So, the 8340A and 8350A rear panels, along with incorporating the expected power socket and balanced analogue input, are home to a seriously comprehensive set of sockets and switches. Take a deep breath, ‘cause it’s a long list. Firstly, since the monitors are digital in terms of their internal signal processing, it would be missing a trick for them not to offer a digital input — and there are AES3 digital input and ‘thru’ sockets fitted alongside the analogue input XLR. The digital thru socket enables a pair of monitors to be daisy-chained, with each one specified as left or right via one of the rear-panel DIP switches.

And speaking of those DIP switches, a bank of 14 enables EQ configuration along with a number of other setup functions such as LED brightness and automatic standby mode. The EQ options available comprise LF roll-off and tilt, HF tilt and a ‘desktop’ profile that introduces a 4dB suck-out at 160Hz. Diagram 2, again borrowed from the monitors’ user manual, illustrates the effect of the various EQ options.

SAM I Am

Diagram 2. The effect of the various EQ options.Diagram 2. The effect of the various EQ options.I wrote in a previous paragraph that the Genelec monitors incorporate some significant DSP horsepower. The DSP is present primarily to enable the most significant technical element of the monitors, and the one that lends them their ‘SAM’ model identifier. SAM stands for Smart Active Monitor and, in combination with the optional GLM (Genelec Loudspeaker Manager) OS X or Windows acoustic optimisation app, a measuring microphone and a small USB interface box (both supplied as an accessory), SAM technology enables the 8340A and 8350A monitor’s response in the frequency domain to be optimised at the listening position. The monitors can be used conventionally without their SAM technology, but as we’ll see, and without entirely giving the game away, I think you’d be pretty crazy not to use it.

Once you get past what I found to be the somewhat clunky user interface of the GLM software, the process for implementing SAM is relatively straightforward. With the USB interface box connected to the computer on which the GLM app is running, the monitors connected to the box via the supplied Ethernet cables, and the Genelec measuring mic plugged into the box, the app first requires that the monitor setup be specified. This is done by dragging and dropping icons representing the monitors ‘found’ on the GLM network into a visual matrix that also includes an image of the measuring mic position. The app names this arrangement of monitors a ‘group’. As each monitor icon is dropped into the group, the corresponding speaker will output an identifying chirp. Screen 1 illustrates the GLM app group layout screen.

Screen 1: The Genelec Loudspeaker Management software.Screen 1: The Genelec Loudspeaker Management software.With just a stereo pair of monitors in the GLM group the process is easy, but with more complex systems (and GLM can handle groups of up to 30 monitors and subwoofers, and multiple microphone positions) it will undoubtedly become a relatively complex task. However, with the stereo group specified and the measuring mic at the listening position it’s simply just a case of initiating the analysis and calibration process, sitting back and waiting. The process involves each monitor in the group reproducing a swept sine-wave signal that’s recorded by the measuring mic and routed to the GLM software for analysis. Once the analysis is complete, which takes a couple of minutes, an equalisation curve is created that flattens the monitor amplitude response at the listening position. The EQ curves can be uploaded to each monitor in the group so that the system can be used without the GLM software running or its USB interface connected. One of the rear-panel DIP switches on the monitors enables the uploaded SAM EQ curve to be either engaged or disengaged.

Listening Tests

I began listening, starting with the 8340A in conventional mode without SAM EQ engaged. As usual the monitors were located on the rigid wall-shelves either side of my DAW — a pretty typical contemporary nearfield application. As usual also, I listened to a variety of familiar material from CD and my own Pro Tools sessions. First impressions were, it has to be said, slightly mixed. There was much to admire, in particular the extended low-frequency bandwidth and general sense of low coloration and tonal accuracy that comes from well-designed drivers and an inert, low-diffraction enclosure. But there was also a slight sense of less than ‘hear-through’ clarity and less than sharply focussed stereo imaging in the mid-range. Adjusting the monitor EQ using its rear-panel DIP switches helped (the ‘desktop’ LF curve in particular was useful), but I never felt entirely comfortable that the tonal character of the monitors quite dovetailed with my listening environment.

The low-frequency extension also, it seems to me, does come with a price — a slight sense, for example, that the transient slap of kick drums and their low-frequency body are disconnected. Having said that, however, there’s no argument that it can be incredibly useful to be able to hear things going on right down near 30Hz on a genuinely compact pair of monitors. Extraneous low-frequency pumps and rumbles that would be verging on inaudible with, say, a pair of NS10s, are revealed and become fixable if necessary.

Moving on to the 8350A, perhaps the most remarkable thing for me was just how much it and the 8340A sound part of a family. Leaving aside simple tonal balance similarities, their overall character is clearly closely related. To my mind this speaks volumes for the integrity with which Genelec design and engineer their monitors — two different monitors don’t sound so similar by accident. It happens because the engineering values and principles that gave rise to them are the same. There are differences though, between the 8340A and 8350A. As you’d expect from their specifications the 8350A goes significantly deeper and, potentially, louder. It sounds like a bigger speaker with more explicit dynamics and a greater sense of scale. I still wasn’t entirely convinced by its imaging and ultimate ability to reveal everything I felt I needed to hear in a mix, but then I started using it in SAM mode, and suddenly things began to snap into focus...

Correctional Facilities

The effect of SAM on both the 8340A and 8350A was similar. The misgivings I had over mid-range clarity and stereo image focus were much reduced and the performance of both monitors jumped up a level. The slightly veiled and unfocussed effect I heard was much reduced, and replaced instead with the kind of explicit clarity that makes mix decisions so much easier and begins somehow to remove the monitors from the equation. To my way of thinking, the signature of a really good monitor is that you all but forget about it, and both Genelecs, in SAM mode, began to approach that level of performance. But of course SAM does nothing to fix the low-frequency group delay and overhang, and on both monitors this remains a question for me. Perhaps, however, the bottom line is this: for every music mix environment where the Genelec’s low-frequency character might be an issue, there’s a broadcast or perhaps mastering studio where simply being aware of extraneous low-frequency noise is vital. If your work and needs fit with the particular set of qualities that the 8340A and 8350A deliver, then you certainly won’t ever regret choosing them.

Alternatives

Without the optional extra GLM package of software, measuring microphone and USB interface, monitors such as the Dynaudio Lyd 48, Focal Solo 6, Neumann KH301, PSI A17M and Unity Audio Rock MkII all fall in or around the same price bracket as the 8340A and 8350A and would be worth considering. Adding the GLM package moves the Genelec price up a little, but then ‘after-market’ software-based room optimisation apps such as Sonarworks Reference 3 are priced similarly to GLM, and could play a similar role with conventional monitors.

Group Delay

The audibility, or otherwise, of low-frequency overhang and group delay has long been a subject of debate among speaker designers and electro-acoustic geeks. Numerous Audio Engineering Society technical papers have discussed and analysed the issue over the decades, and in doing some memory refreshing research while using the Genelecs I re-read papers on the subject by Laurie Fincham, Malcolm Hawksford and Günter Krauss. The best technical discussion and analysis of the subject I know of, however, is in Philip Newell and Keith Holland’s book, Loudspeakers For Music Recording And Production. Chapter 11 in particular, ‘Low Frequency and transient response dilemmas’, is the section to read, although the entire book constitutes a superb general overview of its subject and is one I can’t recommend more highly.

Published October 2017