While monitoring using speakers remains the norm in most commercial studios, many people opt to use headphones to conduct the most intricate of recording, mixing and mastering tasks instead. In this section of our new monitoring series, we’ll explore the benefits and drawbacks of both approaches, take a look at some of the industry’s favoured cans for deep monitoring, the issues of maintaining aural neutrality and which approach actually presents the more accurate picture of your audio.

The story doesn’t end with setting up your speakers. Even in the most precision-calibrated, acoustically treated and impressively equipped studios, you’ll typically find at least one pair of high quality headphones laying around. And, there’s good reason for that. Though studio monitors present a clear depiction of your track being played within a real-world acoustic space, professional monitoring headphones offer a much more immersive window on your mix environment.

While there are some exemplary examples of well-designed, precision cans for such purposes, there are a series of fundamental differences to be mindful of when selecting a pair of monitoring headphones. Firstly, and perhaps most crucially, you’ll need to not be swayed by those which colour, disguise or enhance your music. Fundamentally, studio headphones are to be used to pick apart the flaws of a mix, not obfuscate them.

Some people, however have more broader issues with mixing via ‘phones. “Headphones can offer an unnaturally wide stereo image because the audio reaching the left ear is isolated from the right – and this is not how we hear things normally.” Explains PreSonus’s Director of Marketing, Wesley DeVore, “Compare this to a well-positioned mixing environment with speakers, where the two studio monitors are equidistant from each other and from the listener, as well as toed-in correctly. While the majority of the signal from the left side is directed at the left ear, there is a certain amount of bleed that reaches the right ear and vice versa. This makes it easier to create a more natural-sounding mix and properly position pans and levels.”

Another naysayer, KRK’s David Bower, points towards a fairly common drawback of long mixing sessions sporting headphones, “Typically, one can mix for a longer period of time using monitors. Headphones tend to cause ear fatigue to set in much earlier.”

Others however, point to some of the benefits of headphone mixing over monitoring, while DeVore’s stance on the unnaturally wide stereo image holds weight, using headphones can grant more clarity on those constituent mix elements and frequencies that may be conflicting in harder to discern ways. Adjusting the presence of a vocal, a guitar or a synth that occupies similar midrange frequency space can be done at a much subtler, incremental level than trying to scan the details using your studio monitors. KRK’s David Bower concedes that headphones have their place in this regard, “Headphones can and should be used to help hear and correct for minute details like distortions or interference of multiple instruments being played simultaneously in the same frequency band.” Bower explains.

PRECISION HEADPHONES

It’s typically advised then, that headphone mixing should be seen as more of a precision tool, and less as a holistic route to understanding how our mix – as a whole – is coming together. But, we’re making a lot of assumptions here. Firstly, it’s not always logistically or financially convenient to establish a peerless monitoring setup in your home or pro studio space. Monitors need to kick out some serious sound to really present an accurate take on our mix, something that headphones can do with minimal fuss – and minimal neighbour-irritating noise.

“The most critical part of mixing via speakers is, that you need a room which is acoustically treated.” Explains Beyerdynamic’s Senior Signal Processing Engineer, Dr. Simon Grimm, “Without proper acoustic treatment, you are not able to judge your audio material correctly and this can lead to bad mixing decisions. This is especially true for the low frequencies, where an acoustically bad room shows resonances/modes which alter your frequency response heavily.”

Grimm continues, “We think headphones can be indeed a very accurate monitoring tool. The amount of detail you get from hearing with headphones is unsurpassed. This allows you to perform editing tasks like listening for hum or hiss on audio files, check for pops and clicks, etc. And let’s not forget, that monitoring with headphones is independent of the acoustical properties of your room.”

So for those choosing to mix with headphones out of necessity, what are some of the biggest pitfalls to avoid? Well, a major drawback with even the most well-designed of reference-grade headphones is the lack of presence in those rumbly, sub bass frequencies. While monitors have dedicated woofers, to represent the low end with the most spine-shaking accuracy, headphones are often incapable of matching up. Even if your sub bass frequencies are intact in the mix, the lack of the true feeling of resonant low end can result in producers earnestly boosting those harder to perceive low frequencies, ultimately leading to bass overload once played back on a decent set of speakers. So watch out!

One such headphone maker who is keenly aware of the need for bass support is Audio Technica. Alex Lepges, Technical Director of Audio Technica, explains to us that his company have utilised proprietary 45mm drivers in many of their headphones, including the acclaimed M50x. These help to provide a balanced response, and extend low enough into the bass frequencies to give a useful sense of weight, that might be missing from other headphone designs.

Lepges continues to evangelise about headphone monitoring, “The biggest obvious drawback with monitoring speakers is that they’re not usable on the move!” Explains Alex, “These days if you’re creating mixes while actually travelling – on planes or public transport – as a lot of our users tell us they are, then headphones are the *only* option. And we strive to deliver as high quality, reliable an option as we possibly can. Next to this there is the transient response of a headphone which – when well designed – can be superior to a speaker setup. This allows you to really ‘zoom in’ on some sound artefacts that you might find in your final mix when several channels start to modulate with each other. The ATH-M70x is a good example of such a headphone which gives you a level of detail that helps the operator to really focus on the details.”

IF IT BLEEDS…

The levels of background bleed your headphones allow through is also a factor to consider when purchasing professional studio headphones. There are two main types of headphone, each has their own pros and respective cons when compared to the other. Open backed headphones allow air to ventilate through the ear pads from behind the speaker driver – this presents are more realistic depiction of how your mix is sounding. Letting external sounds interact with your mix is therefore much like listening to monitors in a live studio room. Open backed headphones are great for hearing a much more expansive, and airier sounding mix. Some excellent open-backed monitoring headphone solutions include Focal’s sublime Listen Professional, Audio Technica’s ATH-R70x and Beyerdynamic’s admired DT 900 Pro X.

Closed-back headphones, in contrast, are totally sealed, and therefore completely isolate your mix. This is useful if you’re trying to mix in an environment that isn’t tailored for deep listening, or requires more sharper-focused mix-correcting, for which external room bleed would muddy the waters. While both headphone types have their advantages, its recommended that you go with open-backed ‘phones for general purpose mixing, as it presents a vastly more accurate soundstage than a sharply focused tightness of closed-back cans. But, for those moments when you need to drill deeper and unpick your mix, Closed-backs are the way to go.

Among the most admired monitoring headphones in the industry, sit the aforementioned likes of Beyerdynamic’s DT 1990, Sennheiser’s HD 300 PRO and, more recently Austrian Audio’s Hi-X series. Specifically focused on creating affordable, yet remarkably accurate monitoring headphones, Austrian Audio’s wares include the likes of the Hi-X60 closed-back, over-ear headphones. With audio drivers delivering full spectrum audio between the frequency ranges of 5 Hz and 28 kHz – exceeding the human hearing range. Headphones like these also deliver distortion free sound reproduction, and emphasise comfort for prolonged mixing periods.

GETTING TO KNOW YOUR HEADPHONES

Certain headphones, such as the likes of the remarkable HEDDphone from HEDD Audio have been carefully modified to excel at their primary function – digging into a mix. “Some basics remain true” explains HEDD’s CEO, Dr Frederik Knop, tells us, “By blending out the room and potentially problematic acoustics, headphones will on a very basic level give you a more microscopic insight into the details of any mix, letting you discover tiny issues such as clicks, resonances, and/or editing mistakes. They also make it easier to precisely shape sub bass material, which is essential for a lot of contemporary musical styles. Monitors on the other hand are crucial to optimise the audio’s translation into all sorts of common listening environments. They add feel and body to the process of making music. That being said, with the rise of technically more sophisticated, especially open-back headphones and the fact, that more producers and engineers are interested in mobile production and mixing setups, there seems to be a new industry zeitgeist. The Air Motion Transformer based HEDDphone is designed to be much more than a simple problem detector –  it is a tool to professionally produce, mix, and master.”

So, if you’re thinking of sticking with headphones as your primary mixing tools, then heed the words of Beyerdynamic’s Dr Simon Grimm and Acoustic Engineer Sebastian Haberzettl, who stress the importance of getting to know your headphones as intimately as possible; “Get to know the sound signature of the headphone very well. If the headphones have a slight elevated treble or bass response you have to consider this when mixing with these pair of headphones. You may occasionally cross-check your intermediate mix with some reference tracks you know very well and, if possible, cross check your mix on a pair of studio monitors to better get to know the differences. Also check your mix using dedicated cross-feed plugins, which can help you make better mixing decisions on your headphones.”

“Get to know them. That’s absolutely the best advice I have” reiterates Alex Lepges of Audio Technica. “It would be the same advice for any monitoring speakers too. Listen to LOTS of music through them, mix with them, then see how your mixes translate elsewhere. Only by spending time with headphones can you really understand them and get an intuitive feel for how to mix with them. And maybe find one very detailed closed back headphone to drill into the details of the mix and then an open back headphone (like our R70x) for the extended mastering session where the focus is more on the overall soundscape.”

Read parts 1 and 3 here.