APS Germano Aeon 2

For their newest speaker model, Polish monitor makers APS teamed up with experienced studio designer Troy Germano.

We've covered a couple of monitors from the Polish APS company over the last few years, and they've acquitted themselves well, delivering a good level of professional nearfield monitoring performance at a pretty reasonably price. This latest APS monitor, the Germano Aeon 2, appears to be a relatively conventional, ported, two-way active speaker sporting a 180mm paper‑cone bass/mid driver and a 19mm soft‑dome tweeter. However, like the recently reviewed Avantone Pro CLA 10, an extra level of intrigue is added by the design involvement and endorsement of a pro-audio personality. In the case of the CLA 10 it was Chris Lord-Alge, and for the APS Aeon 2, it's Troy Germano.

The Germano family is probably as close to royalty as things get in the recording studio business. Troy Germano's father Ed founded the Hit Factory studio in New York and, in the mid-'80s, expanded that enterprise, in cooperation with Sony, to open a studio in London of the same name. The two Hit Factories were hugely successful and influential, and a further expansion took place in 1993 with the purchase of Criterion Studios in Miami. Around the time Ed's son Troy took over the reins, the traditional studio business had begun to contract, but he proceeded to create a successful Germano studio design and build operation, and by 2002, 16 recording/mixing rooms, six mastering suites and six writing rooms had been built under his supervision. In both 2003 and 2008 Troy was awarded the TEC Award for Studio Design, and later in 2008 he opened a new Germano Studios facility in New York's NoHo district. The new Germano studio complex has since played host to some of the biggest names in music, on both sides of the studio glass, and also plays host to a few pairs of APS nearfield monitors — hence the collaboration that produced the Aeon 2.

Of course, with or without a big-name endorsement, a monitor still faces all the same electro-acoustic issues to be resolved and price-versus-performance equations to be balanced. Looking at the design and ingredients of the Aeon 2, I think its fair to say the APS/Germano approach is one of thoughtful development and careful component choice rather than any radical rethink of nearfield monitor technology or format. I'll begin my description by looking at the most obvious expression of component choice: the drivers..

On Paper

I mentioned in the opening paragraph that the Aeon 2 bass/mid driver sports a paper cone, but there are probably as many different kinds of 'paper' used for speaker diaphragms as there are alternative cone materials. The paper in this case appears to be of a relatively stiff variety, and pressed into a classically curved diaphragm profile. The central dust cap appears to made from the same material as the cone. Somewhat unusually for such paper components, neither the cone nor dust cap carry any kind of coating of the type often used to damp the potentially high-Q break-up resonances of paper. The lack of a damping layer can result in a usefully lighter diaphragm, but it demands careful optimisation of paper characteristics, diaphragm profile and surround behaviour if the driver is not to demonstrate some significant cone resonances. The Aeon 2 bass/mid driver comes from SEAS, a specialist Norwegian company with many decades of experience in driver design and manufacture, and the kind of careful optimisation required to make a successful non-coated paper-cone driver is very much within the SEAS skill set.

The Aeon 2 tweeter also comes from SEAS. It's a relatively conventional 19mm soft-dome, ferrofluid‑cooled unit, but has a larger than usual surround around the dome. The small‑dome/large‑surround arrangement is claimed to combine the wider high‑frequency dispersion of a 19mm dome with the lower fundamental resonance of a 25mm dome. There's probably a grain of truth within that claim, but it's a not one for which I'd hold the front page for very long, as the difference in dispersion between 19mm and 25mm domes is not typically all that significant. There's little doubt, however, that, as with the bass/mid driver, the inherent quality and performance of SEAS drivers is a good thing where the Aeon 2 is concerned.

Staying on the front panel of the Aeon 2, below the bass/mid driver is a letterbox‑style reflex port that's created from an internal shelf in the cabinet. The port is flared at its exit, but the flare radius is limited by the 18mm thickness of the cabinet panels so it's not particularly generous. The port area is generous though: at around 54 square centimetres, it's equivalent to approximately an 8cm‑diameter circle. That's a big port. The corollary of such a generous port area is that the port length needs to be extended in order for the resonance to hit the desired tuning frequency (around 40Hz in the case of the Aeon 2). And extended it is. At around 26cm, the port extends almost all the way to the inside rear face of the cabinet, leaving a relatively narrow slot for the airflow to negotiate. Another quirk of the Aeon 2 port is that I'm not sure just how much low-frequency output it will contribute. The reason I question this is because it was apparent on removing a bass/mid driver that the Aeon 2's cabinet is very well filled with wadding, and doing such a thing on a reflex‑loaded speaker is likely result in a pretty low port resonance Q. One of the battles of ported speaker design is attenuating unwanted internal box resonances without simultaneously damping the port resonance. The traditional technique for achieving this is to line the internal walls of the cabinet with foam, but leave the central volume unfilled. That's not how the Aeon 2 is configured.

On the subject of the cabinet, it is of satisfyingly solid‑feeling MDF construction, with softened front edges intended to reduce high‑frequency diffraction. Not only does the Aeon 2 cabinet feel solid; there's a precision‑engineered, well-built feel to the entire monitor. The review pair of Aeon 2s was finished in black paint, although white is also available as standard and, APS say, almost any colour can be specified.

Power Play

It probably won't come as a great surprise to learn that, on the rear face of the cabinet, there's a panel that contains controls, connections and the amplifier heatsink. The Aeon 2 uses conventional Class‑A/B amps rated at 200 Watts for the bass/mid driver and 100 Watts for the tweeter. The difference in power ratings reflects simply that the tweeter is more efficient than the bass/mid driver, so requires less power. The amplifiers have a conventional linear power supply.

Connections on the rear panel comprise just a mains inlet and a balanced XLR/TRS analogue input socket (with a daisy-chain output socket and an earth lift option). The Aeon 2 may not be blessed with multiple inputs, but it does offer a good selection of EQ options. There's a high‑frequency shelf switch offering ±1.5dB and 0dB options; an 80Hz bass level control offering settings of 0dB, -1.5dB and -3dB; and bass extension options labelled Active, Passive and Roll-off. The Active option adds low‑frequency extension, the Passive option offers the natural roll-off of the cabinet and bass/mid driver, and the Roll-off option introduces early low‑frequency bandwidth curtailment intended to reflect the character of smaller monitors.

Diagram 1: The Aeon 2's frequency response, with various HF EQ options engaged.Diagrams 1, 2 and 3 comprise some FuzzMeasure acoustic measurements that illustrate the effect of the various EQ settings. Along with illustrating the HF equalisation, Diagram 1 shows that the Aeon 2 has a very well behaved axial frequency response, with no evidence of significant bass/mid driver diaphragm misbehaviour towards the top end of its range. The 2.7kHz crossover between bass/mid and tweeter also appears well implemented, with no sign of any great discontinuity. I performed some off-axis measurements along with the axial curve and found the results to be similarly competent. The pair matching of the two monitors was also very good.

Diagram 2: The various 80Hz EQ options.Diagram 3: The Aeon 2's response in Active (yellow), Passive (red) and Roll-off (green) modes.Diagrams 2 and 3 respectively illustrate the Aeon 2's 80Hz LF attenuation and low‑frequency extension options, and at first glance what they reveal is as expected: the 1.5dB and 3dB 80Hz attenuation is clearly apparent, and the extension options seem pretty sensible (the Roll-off option endows the Aeon 2 with LF bandwidth in NS10 territory: -3dB at around 90Hz). The diagrams also reveal something a little more intriguing, though, as the Aeon 2 displays a slightly odd characteristic — the bump and suck-out around 275Hz. I'll move on to investigating that in a moment, but first I'm going to write a little about what I found when I first listened to the Aeon 2, which, as always in monitor reviews, I did before I undertook any measurements.

In Use

As usual, I installed the Aeon 2s on the uber-sturdy wall shelves either side of my DAW in a classic nearfield arrangement. Listening, again as ever, to some well‑loved reference CDs and high-res download material, along with my own Pro Tools sessions, the good news is that on a fundamental level the Aeon 2 is clearly a very competent monitor. It is well balanced tonally (although I preferred the -1.5dB HF setting), and its level of mid‑range clarity and explicit accuracy sounds competitive. The SEAS bass/mid driver is clearly a good one. Imaging was well focused too, with good portrayal of depth and ambient effects. At the low frequencies I found the Aeon 2 initially a little over‑enthusiastic in my room, but its EQ options helped, and once I'd made some adjustments, I was reasonably happy with the bass, despite a slight port‑loaded sluggishness. Putting that mild negative to one side, however, even in Passive mode, the Aeon 2 has good bass extension for its size, which it combines with an ability to play loud without sounding stressed or changing significantly in terms of tonal balance. But I definitely preferred the Passive bass EQ option to the extended Active one. In Active mode I felt the Aeon 2 was trying too hard to get low‑frequency bandwidth from a relatively small box and driver, and the bass quality in terms of punch and definition suffered as a result. In the context of monitors at around the same size and price of the Aeon 2, however, I think its bass character and performance is easily competitive. At the top end, the quality of the SEAS tweeter was fully apparent, with no vices and a good level of fine detail in cymbals and reverb tails, for example. A good test for me of a tweeter in a mix context is to question if I'd be confident de-essing vocals. The answer is a definite yes with the Aeon 2 tweeter.

So, in many respects the Aeon 2 is very capable nearfield monitor. But as I listened to more material, including male vocals, I began to become aware of specific coloration, and once I'd noticed it, I kept hearing it. If I was writing in a 1980s hi-fi magazine I'd wheel out the term 'boxy' and, to begin with, I thought I was hearing an Aeon 2 cabinet panel resonance, but the cabinet construction seemed too solid for that and the coloration too specific. In a nearfield mix context, the effect was to subtly reduce intelligibility of voices and low-mid instruments. I think I've used this analogy before, but it was as if the voices weren't recorded with quite the right microphone. If you were tracking and heard the effect you'd try a different mic.

Organ Grinding

So, here's where we get back to the oddity revealed by Diagrams 2 and 3. The bump and suck-out around 275Hz is unusual, because there ought not be any mechanism within the speaker to cause it. At 275Hz the bass/mid driver diaphragm will be well within the band where it operates as a pure piston, and similarly, the diaphragm surround won't reach its potentially resonant region for another octave and a half. So what's causing it?

Diagram 4: A measurement of the port output.Back with FuzzMeasure, following the measurements aimed at wide‑band and LF frequency response analysis, I investigated the Aeon 2 port, looking for organ-pipe resonance, and the mystery was solved. Diagram 4 shows the close‑measured frequency response of the port, from 20Hz to 1000Hz. The hump around 40Hz shows, as expected, the intended (but unusually low-Q) port resonance, but up at 275Hz there's an organ‑pipe resonance that's so strong it peaks all of 5dB above the desired port output. Its second harmonic around 550Hz is also apparent. It's almost certainly this resonance that was audible on male voices.To confirm the resonance, I created a FuzzMeasure waterfall display illustrated in Diagram 5. The 275Hz phenomenon is obvious, as is the second harmonic.

Diagram 5: A waterfall plot of the Aeon 2, showing the time-domain response between 20Hz and 1kHz. The organ‑pipe resonance around 275Hz is pronounced.So the coloration I was hearing on male voices is a port organ-pipe resonance, but that means it's not a show stopper, because ports can be blocked — it's at this point that I should probably apologise to APS for messing with their monitor, but needs must! So I reinstalled the Aeon 2s on the wall brackets and listened again, this time with the ports closed off with foam. The male voice coloration was eradicated, the stereo imaging tightened still further, and the overall quality of the Aeon 2's performance for me jumped a couple of notches into the 'extremely good monitor' category. Partly that was thanks to the extra mid‑range clarity and accuracy, but partly it was also because I preferred the closed‑port bass performance. There was less low‑frequency bandwidth, of course, but the quality of bass in the context of appreciating the low‑frequency elements of a mix was, to my ears, improved.

Diagram 6: The Aeon 2's low‑frequency response, in the default Passive mode with port open (orange) and closed (pink), and again with the port closed but with the Active mode engaged (blue).I've illustrated the effect of closing the port on the low‑frequency extension, and on the 275Hz resonance (you'll see how much flatter the response around 275Hz is with the port blocked) in Diagram 6, but there's also a third curve in that diagram. It shows the response with the port closed and the Aeon 2's Active low‑frequency extension option engaged. Engaging Active mode restores all the low‑frequency extension lost by closing the port. Before we celebrate a free lunch, however, the health warning attached to this strategy is that the Aeon 2's maximum volume levels, in terms of both bass/mid driver and amplifier limits, will be compromised. You have been warned.

Conclusion

There's two ways to sum up the Aeon 2. The glass‑half‑empty view is that, due to its port organ‑pipe resonance and its slightly slow bass character, it's a fundamentally flawed monitor. There's a glass‑half‑full view — and the one that I subscribe to — that the Aeon 2 can offer the best of both worlds. With its port open it plays loud and has genuinely extended bass, but it's a little coloured. And with its port closed it won't play as loud, but the coloration disappears to reveal a really classy mid‑range performance, and the bass tightens up to become more informative. So APS, a pair of foam port inserts supplied as accessories would be just the job. How about it?