- Sonarworks Reference 3
- Sonarworks Reference 3 Headphone Plugin
- Sonarworks Reference 3 System Requirements
The third version of Sonarworks’ calibration software promises to help you get the most out of your monitoring setup. Bruce Aisher puts it to the test.
It’s all too easy to get lured into buying the next great synth, plugin or other piece of tech kit in the vain hope that it’s the missing link to production nirvana. We’ve all fallen prey to this, but sadly it’s often the less immediately glamorous items that can make the most difference. Acoustic treatment and studio monitoring, for many, fall into this latter category. It is true that upgrading the sound in your studio may not appear to deliver immediate dividends in terms of pure creativity, but it can be a game changer for the quality of your mixes – which will, eventually, feed back into the writing process.
All deliverable items from Sonarworks store are shipped by DHL Express within 2-3 working days in the EU and 3-5 working days in the rest of the world. If we are out of stock, purchases are usually delivered within 2-3 weeks. But don't worry, it happens very rarely. All digital products are delivered immediately via email provided upon purchase. Measured at Sonarworks lab with proprietary compensation curve. Not to be compared directly to AFR measurement from other sources. After we meticulously measured every dip and peak found in the M50x, our engineer generated a calibration profile. These profiles are available for every Sonarworks Reference 3 plug-in user. Sonarworks SoundID Reference. So far, monitor and headphone calibration systems have targeted music makers exclusively. Sonarworks’ SoundID aims to solve the problem of mix translation from the consumer end too. An accurate monitoring system is a crucial part of any music production system. It’s also something that can be difficult to achieve.
The ‘sound’ of your monitoring is, in reality, a combination of both the acoustics of a given space and the speakers you place in that acoustic environment. More specifically, audio accuracy is the degree to which the audio generated in your DAW (or mixing desk) remains unaltered before arriving at your ears. There are many ways in which the perceived sound level at any given frequency can be changed, and even moving your listening position slightly can have an effect – so there is lot that can go wrong.
Frequency response analysis of the reviewer’s monitoring environment before calibration with Reference 3
Theoretically, one way in which things can be improved is with the use of corrective processing in the audio monitoring chain – and this is where Sonarworks‘ Reference 3 comes in. Reference 3 is a two-part software system available for Mac or Windows. The first piece of software is the analysis element, with the second a plugin hosted in your DAW to apply any necessary processing. The analysis software is used with a measurement microphone, and only requires running once (or if any changes occur to your monitoring setup or environment).
The full system comes bundled with a measurement mic and the relevant software registration code. The mic itself is a somewhat generic-looking silver unit (not dissimilar to a number of low-cost measurement mics out there), though each has its serial number printed clearly on the case. This is a clue to one important aspect of the Sonarworks system: microphone calibration. Although modern manufacturing techniques mean that there are only relatively small differences in frequency response between microphones built on the same production line, Sonarworks provide an individual calibration file for each mic they provide. In essence this allows for more accurate results by negating any frequency response anomalies in the microphone. In reality, it is surprising how similar many measurement mics are in their handling of low and mid frequencies, which makes basic demoing of the system cost-free if you have one lying around. However, Sonarworks currently offer a 21-day trial kit that includes a microphone for €49. You get to keep the mic even if the software isn’t for you, and it can be pressed into service as a pretty reasonable instrument microphone if required.
Once you have the mic plugged into a (phantom powered) mic pre-amp, the calibration process itself is fairly straightforward. Sonarworks have put plenty of effort into making this as painless as possible, with clear on-screen instructions and graphics to show where the microphone should be placed at every step. The program emits swept pitch tones, from each speaker in turn, for the tests. To begin with, these establish the working sound pressure level and the distance between each speaker. This is followed by a further series of sweeps from each speaker, analysed from around the chosen listening position. While the software offers some additional options for different listening situations, a conventional single seat near-field monitoring scenario takes no longer than about 15 minutes to capture once you get the hang of things.
Once complete, you are provided with an overview of the results. The software calculates the workable correction frequency range, generates a correction curve and shows the before and after results. Remember that, like any other similar system, Reference does not magically improve your whole room – so if you have a ‘producer’s chair’ and a ‘sofa listening area’, then you’ll need to run through this process for each.
Having saved each analysed position as a separate SW project file (in my compact studio there was only one), you can then proceed to testing the results using the Reference plugin. The plugin (provided in all the main OS X and Windows formats) is loaded across your monitor path and requires you to open the relevant calibration project file from earlier.
It’s important to realise that the processing is intended to be applied only to what comes out of your speakers, and not what is exported during the final mix. Each DAW handles this in a different way, so this may necessitate turning off the plugin on the final bounce. The aim is to improve what you hear in the room, in order to make better mixing decisions – not to change the actual audio mix itself.
While it is possible to load a calibration file and pretty much leave the plugin alone, it is worth at least exploring some of the other features it offers. The central area of the window provides an overview of the various relevant frequency response curves, the most important perhaps being those for the corrective processing and ‘after’ result. There are also options for choosing alternative reference curves (i.e. non-flat) and simulating various models of speaker. Some may find this useful, but for me it somehow distracts from the main aim of the whole thing. The Avoid Clipping switch is a quick and easy way for the plugin to manage any overheating of the gain due to frequency boosts during the correction process.
The Calibrate section, showing choices of reference curve
Of more interest is the Advanced page, where it is possible to define the filter type used in the correction engine. Sadly, there is no way to apply EQ in the real world without some unwanted side-effects, and here you can at least experiment with the trade-off between CPU load, latency and phase response changes. The default Mixed Phase setting is suggested as the best for most situations.
The plugin’s Advanced page, showing the frequency response after processing using the Mixed Phase setting
For those who regularly make music on the move, don’t want to annoy their neighbours or just don’t trust their monitors, Sonarworks have another solution: headphone calibration. This works somewhat differently to the speaker-based system. Clearly, headphones have minimal acoustic interaction with the room in which you are listening. This means that the overall accuracy of their frequency response is determined almost solely by their inherent physical design. With this in mind, it is reasonable to assume that the same make and model of headphones will sound broadly similar when fed the same audio stream. If one could measure the particular frequency response curve for a few examples of the same model then it would be pretty straightforward to create an averaged corrective EQ that would make them (theoretically) flatter. This is exactly what Sonarworks have done. Assuming your model of headphones has been analysed by Sonarworks, then €69 will buy you the Reference 3 Headphone plugin and the averaged calibration file you require for your headphones. If you want a more exact calibration file for your personal headphones, then Sonarworks will (for an €88 fee) create you a custom-made calibration profile. You send them your headphones and a few days later they are posted back with their own specially measured profile.
Sonarworks also sell ready-calibrated headphones, and I managed to check this out with a pair of AKG K271 ‘phones (currently €246, including the plugin). Without calibration, they are a little boxy and lacking in low end, but switching on correction turned them into something much more pleasant to listen to. Most importantly, the mid-range issues were significantly improved, but the lower frequencies also came up in the mix. Overall, the result was huge, and massively for the better. As with the Reference speaker plugin, frequency response is not the sole factor in determining quality of sound, so it didn’t turn these mid-range headphones into high-end studio monitors, but it did make a significant improvement. Switching to the averaged calibration profile for the same headphones resulted in a similarly big sonic change, with subtle, but audible, differences from the custom profile.
Having been a long time user of IK Multimedia’s ARC System – which works in a broadly similar way – I was keen to make a comparison with the newer Sonarworks system. I configured both using their respective microphones from the same listening position and through the same monitors (with and without a sub). They did deliver different correction curves, and audibly different results. The IK capture process is arguably a little less exacting than that from Sonarworks (and happens to use the mic vertically rather than horizontally). It appears that Reference works on a wider frequency range as far as correction is concerned, and – at least in my case – utilised less corrective gain alteration in places. In particular, this seemed to make for better results than the ARC when the monitors were used without the sub. Reference 3 also offers much more in the way of tweaking and visual feedback.
Overall, the results were very positive. I believe that used correctly, Sonarworks Reference 3 will help improve your monitoring environment, and allow you to deliver mixes that play back well on a wider range of systems. This, of course, goes with the very important caveat that this approach is not a replacement for embracing good monitor placement and appropriate acoustic treatment – there is clearly more to the room sound than frequency response. However, for smaller studios, where effective low-end treatment in particular can be both expensive and less than compact, this is a very useful tool.
The Verdict
The Final Word
Reference 3 will help improve your monitoring environment, and allow you to deliver mixes that play back well on a wider range of systems
This review will mostly focus on M50x’s qualities from a studio professional point of view – what to expect when using these headphones as a monitoring device for mixing and do they really cut it for mastering work.
After all, you should make your decisions based on what’s in the material, otherwise you might end up with mixes that translate well on your gear and not much else. Know the limitations of your equipment and you will be able to work around them. This text will attempt to illuminate, what to keep in mind when using the M50x for critical studio work.
The original ATH M50 has been one of the most recommended closed headphones at the $150 price point. Most of its fame comes from the consumer segment. One of its largest communities – The Head-fi forum – has generated dozens of reviews praising its qualities and excellent price/performance ratio. Currently there is a distinct lack of dedicated pro-audio headphone reviewers, therefore most of M50’s pro-fame has largely spilled over from the consumer audio segment. At the same time both M50 and M50x have an abundance of qualities useful for both music listeners as well as producers.
Uncalibrated sonic performance
Perceived Acoustic Power Frequency Response (PAPFR) graph. Measured at Sonarworks lab with proprietary compensation curve. Not to be compared directly to AFR measurement from other sources.
These headphones perform just like they measure – a fun, bright sound. This is mostly due to M50x’s U-shaped FR and extremely low THD. Looks like ATH has really put in some serious R&D work in M50x’s driver, because THD this low at sub bass frequencies has usually been reserved only to planar headphones. Kudos to ATH for bringing clean bass to the masses!
These headphones perform just like they measure – a fun, bright sound. This is mostly due to M50x’s U-shaped FR and extremely low THD.
Now onto the sonic issues to keep in mind if one wants to use these headphones successfully for music production. All of the M50x headphones we measured exhibited level differences between channels. At 200Hz-600Hz there is a wide dip which drops to around -5dB, whilst not too annoying to consumers, it can cause trouble to LCR mixing advocates. With the M50x, some string instruments like guitars for example will change tonality, depending on how they’re panned. The effect will be subtle, but must be taken into account to prevent chasing ghosts in the mix.
On the top end of the U curve we have a peak at 5.5kHz-10kHz which goes up to +7dB at 10kHz which can cause a number of issues. First of all, too much de-essing will be applied to the vocals, as the peak resides right at the sibilant range. Secondly, your sweeps won’t be as accurate because the FR peak will give you a false sense of rising. In general, this peaking can cause your mixes to be dull – one of the inherent cons of all “exciting” headphones, if used in studio.
Total Harmonic Distortion (THD) measurements done at 83dB.
The low-end response on these headphones is positively thunderous – there is no sub-bass roll-off until 20Hz and THD stays extremely low. The channel imbalance which starts at about 350Hz is still present, but on lower frequencies it shouldn’t be much of a nuisance. Most of the signal at these frequencies is mono anyway and humans don’t really excel at positioning low frequency sound.
If it’s not evident from the sonic impressions, we really liked what ATH has done. Just revise the build quality and you might have a winner here. As it is, the headphone is very suitable for mixing stuff which hasn’t got too much going on under 50Hz. Just keep in mind to compensate for that extra sparkle up high.
Calibrated sonic performance
Perceived Acoustic Power Frequency Response (PAPFR) graph. Measured at Sonarworks lab with proprietary compensation curve. Not to be compared directly to AFR measurement from other sources.
After we meticulously measured every dip and peak found in the M50x, our engineer generated a calibration profile. These profiles are available for every Sonarworks Reference 3 plug-in user. They turned these headphones into a serious instrument even fit for mastering. This paragraph will explain what can be gained by applying digital calibration to these already great headphones.
We can bet that when you turn on the Sonarworks Reference 3 plug-in, you’ll wonder who flicked the fun switch off! Resist the urge to take the headphones off and listen to some well- mastered tracks. Your ears will need some time to readjust to the reference sound signature and your first impression will surely be dull for lack of a better word. At the same time, it will allow your mixes to translate well to speakers and just about any headphone out there.
All in all, these headphones are a great candidate for calibration due to the low inherent THD and little change in tonality depending on how they’re placed on one’s ears. Obviously Sonarworks calibration gets rid of the U curve and makes these headphones a perfect candidate for mixing and mastering just about any kind of music. One thing to keep in mind is that the average calibration curve won’t be able to combat the channel imbalance properly, because only individual calibration profiles do stereo calibration.
As always there will be some loss of output when applying calibration. In this case it should be about 8dB, which isn’t too bad due to the fact that these headphones are very sensitive. Most audio interfaces will be able to drive these headphones at ear-splitting levels even with calibration enabled. For some higher gain devices, the loss of sensitivity might turn out to be a blessing in disguise, as it will give more usable volume pot range.
If it’s not evident from the sonic impressions, we really liked what ATH has done. Just revise the build quality and you might have a winner here. As it is, the headphone is very suitable for mixing stuff which hasn’t got too much going on under 50Hz. Just keep in mind to compensate for that extra sparkle up high.
Ergonomics
Just like its predecessor, the M50x has a great fit that doesn’t get in the way of everyday use. Unlike most on-ear headphones, this one doesn’t rely on a strong clamp to achieve a good seal, therefore it is fairly comfy even in longer sessions. One thing to note, however, is that all pleather pads are prone to becoming sweaty in hotter environments.
Sonarworks Reference 3
Construction wise the M50x is decent, but isn’t the tank that is the venerable HD25-II is. Like almost every other headphone out there, most of the outer construction is plastic, however it feels like it’s the kind of plastic that breaks rather than bends on stress. Both earcups are on hinges which allow them to be folded up for a more compact package. At the same time, every moving part does present more points for wear, tear, and ultimately – failure.
This time Audio Technica has given the M50x a swappable cable and generously included three additional cords. The standard package includes a coiled 1.2 – 3m cable, 3m straight cable and 1.2m portable cable. All three of them feature 1/8’’ TRS jacks and the two longer ones have a thread for 1/4’’ jacks. On the headphone end, M50x have a 2.5mm TRS connector which seems to be proprietary due to a locking groove. All in all, kudos to Audio Technica for choosing to go this route because with most headphones, cables seem to be the first to prematurely fail.
Most studios tend to stick with their headphones until they disintegrate due to natural or unnatural causes and very few give attention to earpad wear. We recommend swapping out pads as soon as they start changing their initial geometry. Old pads seal worse and let the drivers sit closer to one’s ears, thus changing the initial FR. Fortunately the pads on the M50x are swappable as well, so the user is able to maintain their headphones at peak performance for a longer time.
In terms of noise sealing, the M50x works well, but again is overshadowed by Sennheiser’s HD25-II and many in-ear monitors. The seal should be good enough for mixing in moderately noisy environments and will guard musician’s ears from excessive SPL’s, but most of the time noise will obstruct the finer details. The seal will also keep the user from disturbing others working in close vicinity, good for mixing on the road.
Conclusion
Has ATH hit a homerun again? Could be so – at least for consumers! At the studio professional end, things are a tad more complicated. No doubt, it’s a great headphone with relatively little shortcomings, but the tuning might be too “fun” to be considered reference grade. At the same time M50x’s competition doesn’t fare any better, most of the other closed studio headphones at this price range are starting to show their age. Sennheiser HD25-II scores some hits in the ergonomics department, but its drivers are a bit long in the tooth. Same goes for Sony MDR-7506. Now, Beyerdynamic DT770 is a worthy competitor to M50x sound wise, but the Japanese headphone is able to land some hits with its three detachable cables and superior portability. Everyone at the lab agreed that these headphones calibrate very well and after calibration pose a serious threat to newer higher end closed studio phones like Focal Spirit Pro and maybe even ATH M70x.
Sonarworks Reference 3 Headphone Plugin
In the end, this is a modern headphone meant for modern music. Engineers who work with a lot of bass heavy material will be in for a treat as the M50x offers excellent performance in this regard. They might not mind its other shortcomings, but should keep them in mind. Or they can use calibrated headphones and focus entirely on their work. Sonarworks calibration turns the M50x into one of the best closed headphones at any price.
About
Sonarworks Reference 3 System Requirements
Sonarworks is an acoustic calibration software development startup. For years, the company has been working with custom studio and headphone calibrations for awarded sound engineers. The technology behind measurement and calibration is a result of more than 3 years work and 1M USD investment in R&D. The headphone reviews are based on numerous measurements in our lab and feedback from our professional clients. More about our headphone calibration: htts://sonarworks.com/headphones/overview/