Acoustic correction of your room brings back stereo image: the ARC 2.5 system

Acoustic room correction is a process that only million-dollar studios can afford, at least that’s what many of us think. And yet, with a growing number of movies and videos playing on devices that have wildly differing sound characteristics, sound accuracy at the source is increasingly important. So, is there a system that costs less but is up to the job, nevertheless?

How can you make sure your audio will sound exactly as users expect when they increase or decrease bass or treble if you don’t have an acoustically corrected studio? And is there such a system that doesn’t break the bank and has a nice bonus when you listen to music with an audiophile player app?

While loudness is incredibly important, so is making sure others have a ‘pure’ or ‘zero’ starting point when listening to your movie. Sound accuracy is one of the hardest parts of any sort of audio or video project because it involves so many parameters. The factors to consider include the equipment used to monitor the audio, how well you hear and the room where the audio is played back. All of those should allow you to hear what you’ve recorded exactly as it was recorded, without colouration of any kind — speaking in more technical terms, your studio should allow for a flat tone curve.

Acoustic correction, then, is one factor to ensure that curve is flat. It’s an important element and it works by ruling out the differences between one room and another. IK Multimedia’s ARC 2.5 system is an inexpensive system (around €300) that helps with this. It includes a special, calibrated measurement microphone and a combination of a measuring stand-alone app and multi-platform adjustment plug-in. The latter can be integrated with any Digital Audio Workstation (DAW) or with a plug-in capable NLE and is capable of correcting the distortion caused by room acoustics.

Once you’ve measured your room, the correction applies only to that exact room configuration, i.e. if you had the shades down halfway you will need a new measurement with the shades up, for example. That’s not a problem as measuring a room’s sound characteristics is very easy with ARC 2.5. All you need to do is follow the on-screen instructions, click the Next button and duck out of the mic’s position once a measurement is being taken. The system forces you to take a minimum of seven measurements, but it’s recommended to take more – up to 16.

Once the room’s sound “fingerprint” has been calculated, the ARC System 2 automatically detects the bass roll-off point of each speaker to ensure that no correction is applied below that point, as it may potentially overload your speakers.

To apply the corrections, you load the plug-in in your DAW or NLE. This allows you to use the corrections as they are and gives you a flat rendition of your recorded sound with the room’s corrections applied. It will sound a bit weird at first, but given that the other components of your setup are calibrated, it’s the way any calibrated flat sound system will render the audio.

Since the flat curve represents a listener who has set their audio equipment to a flat equaliser curve, which few of us do, you can adjust your sound in ARC 2.5 afterwards to change the EQ curve to your liking, or more appropriately, to the loss of frequencies you can still hear at your age. If you have a sonogram, it’s easy to dial back in those frequencies you’re not hearing correctly.

With the ARC 2.5 settings plugged in, you’re now hearing exactly what someone else in a standard room would also hear. If your viewer/listener now wants to hear more low or high tones, they can turn up the bass or treble level on their equipment.

Can you play through the ARC 2.5 system?

Well, here’s the bonus. If you have a player app on your Mac that supports Apple’s AU plug-ins, you can actually listen to your music routed through the ARC 2.5 plug-in.

I have a copy of Audirvana Plus on my system. It has been reviewed here before and if you happened to read that review, you’ll know that the latest versions come with the ability to load plug-ins that alter the way your music sounds.

The ARC 2.5 plug-in loads as well and by clicking the “Configure” button in Audirvana’s Preferences > AudioUnits screen, you can launch the plug-in interface and select the room corrections you want, the “after-corrections” to the tone curve, etc.

I’ve tried it and the result was stunning. As my studio monitors are very close to me and there’s some obstruction in the sound path, I usually lack a clear stereo image. After activating ARC 2.5, no more. It’s as if I’m listening to my full-scale stereo installation of a few years back when I still had time to listen without doing something else simultaneously — like writing this article.

It’s no imagination, either, because when I turn it back off, there’s a very clear difference.

So, if you are an audio producer of whatever kind, the ARC 2.5 system is definitely worth considering, especially if your budget isn’t the six-figure kind. If you’re a listener, you will benefit from ARC as well. Thank you, IK Multimedia!