Improving Your Studio With Room Correction Software

When it comes to improving your listening environment, be it a home studio or more professional space, there are key steps you can take such as monitor placement and acoustic treatments, which we've detailed in previous guides. If after those steps you still need to make improvements, then you might want to look into the world of room correction solutions.

Coming in a variety of forms, room correction solutions tweak the output of your speakers, applying EQ and phase shifts to ‘correct’ the imbalances that come from the specific layout of your room. The goal being that when you listen to your music with those tweaks in place the result is more balanced and accurate because it’s not being affected by the layout, shape, or surfaces of your room.

The process of analysing your room often involves setting up a reference microphone and playing noise through your speakers so the correction software can build a picture of the frequencies that are being abnormally boosted or dipped by your room. It then analyses that information and creates an EQ curve and/or phase shifts to help smooth out the inconsistencies. The results of these calibrations can vary from subtle to dramatic and many software-based room correction solutions will have an option to choose how much correction is applied to the output, allowing you to tune for your preference.

The benefits of room correction are obvious, starting with ensuring that your space doesn't get in the way of your music making or engineering work. The challenge however is that room correction often improves the sound in the so-called ‘sweet spot’, where you sit at the detriment to other listening positions in the room, which might impact how collaborators or even clients hear the same music in the same room.

You may also not necessarily want an even room when you work primarily in the composition, writing, or production stages of music making, because you may often want to feel the music rather than hear it 'correctly'. Equally, you might work with artists or musicians who want to enjoy a little more volume and energy whilst they create and a balanced room can sometimes feel as flat as its frequency response. As such, room correction software should be of primary interest to engineers and to anyone who also wants to have the option to adjust their listening environment after the music is made. 

Like many things in the audio world, room calibration isn’t an exact science but there are today multiple options available, each with their own processes and price points. Below we take a look at some of the options available today from entry level room correction solutions to more advanced, and expensive, ones.

Speaker tuning options

Before considering room correction, you should check your speakers. Many monitors today come with Digital Signal Processors (DSP) which lets you alter the tone of their outputs, helping them suit your taste and work better in your room. Low and high frequency boost or cut are common options and some models may also offer ways to improve phase alignment or compensate for the reflections from your workstation. HEDD's MK2 line of monitors offers not only DSP-powered options, such as the Lineariser, which allows users to control the linear phase response, and a desk filter for reflections, it's also the only monitor range in the market to offer speakers that can be transformed between closed and ported, giving you more freedom to work as you want. 

The TYPE07 MK2 backplate in production, featuring some of the DSP-enabled controls available on the MK2 range.

Analog options

Before room correction software was invented most studios would have a hardware EQ unit dedicated to tuning the output from the main speakers. These were often graphic EQs which could boost or cut at predetermined frequencies across the audible spectrum and might also have built-in Hi- and Lo-pass filters to help manage the extremes of the range. Over recent years, some speaker setups have been designed with digital EQ units that can be tuned to address specific frequencies.

There are several advantages to using a hardware unit in your monitoring chain, mainly being able to set-and-forget once you’re happy with how the output is corrected for your room. The software won’t get updated and become incompatible with your laptop, the subscription won’t run out, etc. In commercial studios this is still standard practice and is part of the ‘sound of the room’ that you pay for.

Digital options

If you don't work with hardware or can't easily afford to acoustically treat your room, then digital room correction solutions can help by doing some of the same work that acoustic treatment would. 

There are various room correction systems available on the market today, and below we’ve chosen three of the best known solutions.

ARC from IK Multimedia

IK Multimedia’s Advanced Room Correction System (ARC) has rapidly become an affordable solution for engineers and producers working in small rooms. The affordable price point helps keen engineers and hobbyists invested in improving the sound of their room even if they’re not making a living from music. The system is simple: you can buy the software license along with a reference microphone, or use your own, and then the software will analyse your room by playing frequency sweeps out of the speakers and listening to what the reference microphone hears. You can run sweeps with the microphone in 7 or 21 locations in the room, which can help build a bigger picture and is ideal if you have other people in there regularly and need a bigger ‘sweet spot’ to accommodate more than one listener.

ARC sits as a plugin on your the master bus of your Digital Audio Workstation so all audio you playback will go through the corrected EQ and phase settings, using your computer’s processors, so make sure to remember to bypass the plugin when you're ready to export your final mix or master. You can also purchase the ARC Studio solution which is a physical unit that sits in the chain between your sound card and monitors and can store your ARC presets and use its onboard DSP.

SoundID from Sonarworks

As the price point for room correction systems has come down, Sonarwork’s SoundID has come to the forefront for many active professionals in the field. Based in Riga, Latvia, the company has become synonymous with room correction and has created solutions that can be used with headphones, stereo monitors, and immersive audio systems.

The principles of recording sweeps into a reference mic still applies, but SoundID can have a big impact for people that are adding immersive audio capabilities into their studio setup. If you’re building a room from scratch and you know you want to have an immersive system then you can design it with the best ratios so the sound isn't too adversely impacted by reflections from walls or ceiling. But if you’re adding immersive to an existing room that wasn’t built with it in mind you can encounter issues that you didn't notice when working in stereo.

As Biggie once said (kind of), “mo’ speakers, mo’ problems,” and SoundID can help time align your speakers to create smooth transitions in the three dimensional space of an immersive setup, so that your audio glides from speaker to speaker instead of jumping.

SoundID can run as a standalone app, as a plugin in your DAW or be exported to, and run from, a small selection of 3rd party hardware units. The majority of users will still need to use their studio computer DSP to process the corrected output signals though.

Nova and Dmon from Trinnov Audio

If you can expand your price range - from the hundreds to the thousands - then Trinnov Audio’s correction solutions are an obvious choice, trusted by professional studios around the world. Featuring dedicated hardware units that handle DSP and routing, their Nova and Dmon solutions offer room correction and monitor controlling in the same box, reducing the number of units in your monitoring chain.

Trinnov systems also require a microphone to help analyse your room but theirs is very different from those used by IK Multimedia and Sonar Works, and features 4 capsules to pick up sound both horizontally and vertically. This means that the setup time is greatly reduced and you can have a reading of your room sound in less than a minute, compared to the 10-20 minutes that other systems can take.

The Atmos-ready studio at the Mastering Academy, Hamburg, featuring Trinnov room calibration.

Insider Knowledge

Matt Ward is the Technical Manager at Level Acoustic Design, one of the world’s leading studio design companies and he answered our questions about what to look out for when calibrating your speakers.

HEDD: When you’re making tweaks to the speaker output are you aiming to make them completely flat?

Matt Ward: When making room corrections it is important to understand first why the measurement is deviating from flat, and what impact any proposed correction will have. Furthermore, when assessing a “target” response, it is important to consider the purpose of the room, the decay time of the room, and how that varies with frequency, associated industry standards, and the attitudes and taste of those using the room. Furthermore, where, how and how many measurements are made can significantly influence the measured response.

When we’re tweaking a room, we’re trying to evaluate all the above and balance the requirements appropriately so that decisions made in the room translate better. Whilst we might not be looking for exactly flat, we are looking for smooth, and we’re also looking for a smooth phase response (the phase response can also inform our tweaking and whether we’re correcting something that should be corrected or not). There may be a small tilt from slightly more bass to slightly less treble depending on room treatment; the other way round is almost never appropriate.

HEDD: What’s a typical or acceptable level of db variance across the audible range?

MW: That depends on measurement as well. We would be looking for all measurements to be well within +/- 3dB from whatever target curve we might be working to, based on 1/3 octave smoothing/banding (depending on the measurements being made). “Well within” here means that we would expect the majority of the response to be within +/- 1dB of the target curve.

We would also be looking for the summed response of a stereo pair to sit within the same tolerances and the Left and Right channel individually to track each other within a dB at worst (and preferably much less).

HEDD: Do you use a dedicated hardware EQ in the monitoring chain? Or room correction software?

MW: These days we use whatever the client has in their monitoring path, or try and have a conversation around monitoring to work out what we can do and will need early in the project. In the case of soffit mounted speakers they will always need correcting for the mounting condition and the manufacturer’s built in functionality may or may not be suitable. We don't tend to use analogue hardware EQs, but that doesn’t mean we never use them and that they can’t be useful.

If it’s a Dolby Atmos or other immersive room then we will insist that there is something for time aligning and EQing every speaker as per the Dolby recommendations. We’ve seen that this requirement appears to have driven the market so more and more audio interfaces now have monitoring correction available.

With regard to automated room correction, we will use it if it’s available, although we will usually run the automated system, re-measure with our own tools and tweak from there. We like most of the tools where it’s easy to see and adjust the automated correction directly. However, we would generally prefer comprehensive parametric EQ with an option of uploading FIR filters for rooms where the latency introduced isn’t an issue.

HEDD: How much do you trust your ears over your eyes when it comes to finding balance in room correction?

MW: It’s much less measurements versus ears than correlating the two. If your ears are saying something different to the measurements then we work out why – which will then dictate what/if we would apply a correction.

Conclusion

Whether it’s the first or last thing you try in your room, room correction might be the missing piece of the puzzle that gives you the sound you want. If you have some major bumps and standing waves or you’re consistently struggling with a frequency range when you mix then employing a calibration solution can be a game changer. But it’s worth remembering that  flat isn’t always right, and sometimes a room needs some life to help with creating.