Headphone correction gets physical with IK’s neat desktop DAC.

The benefits of using EQ to flatten the response of a monitoring system are now widely accepted, and competition is hotting up. In 2024, IK Multimedia introduced ARC Studio, a hardware device that can load room correction profiles created in their ARC software. In 2025, Audient countered with the ORIA Mini, the first dedicated, standalone solution for hosting profiles created in Sonarworks’ widely used SoundID.

ARC and SoundID will both improve the in‑room response of a speaker system. SoundID is also designed to correct the frequency response of headphones, but the ORIA Mini can’t host these headphone curves. There are a handful of audio interfaces that can do so, but there’s never been a dedicated hardware counterpart to the ARC Studio or ORIA Mini targeted at headphone listening. If you sensed that you were just about to read the words “until now”, you’d be spot on, because that’s exactly what IK Multimedia’s ARC On‑Ear is.

Into The ARC

ARC On‑Ear ships in a cute and compact cubic cardboard container, and comes with a handy semi‑rigid carry case. The form factor of the unit itself recalls that of the old Focusrite VRM Box from many years ago, being a square‑ish unit about three inches across designed to sit on a desktop. It’s surprisingly heavy for its size, partly because its shell is made of metal and partly because it has a built‑in lithium‑ion battery. Audio I/O comprises a full‑sized headphone jack on the front, plus a mini‑jack labelled Analog In on the rear, where it’s joined by an on/off switch and a USB Type‑C socket. The top panel features three buttons with logos that illuminate when active, and a large volume control. This is an old‑school potentiometer rather than an encoder, and the one on the review ARC On‑Ear felt a bit wobbly.

The package includes a short USB cable and an equally short balanced audio cable with mini‑jacks at either end, one of which has a full‑sized jack adaptor screwed on. This enables two separate modes of operation. You can use the ARC On‑Ear as a USB DAC for your computer. In this scenario, your DAW software and operating system address the ARC On‑Ear directly as an output device, and there is bidirectional communication between the hardware and IK’s ARC On‑Ear software, of which more presently. Connecting the USB cable to a computer or to a suitable power source will also charge its internal battery.

This battery enables the other mode of operation, whereby the ARC On‑Ear is used as a fully standalone device. Audio is piped in through the Analog In mini‑jack socket, which is a fixed‑gain, line‑level input that can accept a maximum level of +10dBu, and the unit is controlled from the three top‑panel buttons. This might benefit any diehards still mixing in the analogue domain, and also makes it easier to integrate the ARC On‑Ear with a larger audio interface.

Both the controls and the analogue input are always operational, so as long as you have a spare USB socket, you can still have the benefits of bus powering, hardware control and software integration while supplying audio from a line out on another interface. IK say that the ARC On‑Ear will deliver around four hours’ continuous listening on a single charge, depending on various factors such as playback level. On the output side, the ARC On‑Ear uses a ‘zero impedance’ headphone amp that will deliver 100mW per channel and a maximum output level of 19dBu. I found it plenty loud enough with all the headphones I tried.

ARC Curves

Once you’ve registered the hardware and installed IK’s Product Manager, you’ll in turn be able to install the ARC Studio software. This is a friendly, mostly single‑window affair, and I found that almost everything about it was sufficiently intuitive that I didn’t need to look anything up in the PDF manual. Which is lucky, because the PDF manual doesn’t go into great depth about anything.

The ARC On‑Ear hardware can store five Presets. A Preset is configured in the ARC On‑Ear software, and is made up of several elements. First and most importantly, there’s the choice of headphone model. As this is the first headphone correction product IK have made, I was expecting to find only a handful of headphones supported. Not so. Even at launch, ARC On‑Ear includes well over 200 correction curves, for models from more than 60 manufacturers. It was enough to make me wonder whether IK had simply licensed these from another company, but I’m told that all of them have been measured in‑house using a proprietary testing system. Moreover, the list is impressively current, with many brand‑new models represented. At present, however, IK don’t offer the option to send in your own headphones for custom measurement.

The correction curve for each set of headphones maps its measured frequency response onto a custom target, which is adapted from the widely used Harman curve. But that’s not all. IK have also measured the phase response of each pair of headphones, and ARC On‑Ear also offers the option to flatten this, at the cost of increased latency. Finally, each headphone curve also includes a Safe Headroom option that is engaged by default. This reduces the overall gain to compensate for the maximum degree of boost that is applied in the correction curve, to avoid clipping.

On The Lines

Within the ARC On‑Ear software, a familiar EQ‑type display shows the target response as a flat white line. Deviations from that target in the measured response of the headphones are illustrated on a blue curve, whilst an orange curve shows any deviations in the response of the corrected headphones. If you simply engage the correction and leave all the other settings in their default position, this too is a flat line. However, a rotary Tone setting can be used to apply a very gentle ‘flat tilt’ EQ centred at about 650Hz, providing a simple way to push the results towards a warmer or brighter tonality. This setting is reflected in the orange line, as is the effect of a three‑band, user‑configurable parametric equaliser. It might have been interesting to visualise the phase response, too, but this currently isn’t possible.

ARC On‑Ear doesn’t stop at correcting the response of the headphones. It can also apply a ‘studio simulation’, either with or without the emulated response of different loudspeaker types. This comes with a Width setting that ranges from 10 percent to 200 percent, and a simple switch that toggles added ambience on and off.

The currently selected Preset is highlighted in orange on the lower right of the ARC On‑Ear window, and by one of five LEDs along the side of the hardware unit. Any changes you make are automatically written to the active Preset, and there’s no undo function. In practice, this is actually a positive, as it saves time, and the whole system is simple enough that there’s no possibility of getting lost in a maze of edits. Presets can also be named in the ARC On‑Ear software; I would welcome the option to have the selected headphone model automatically chosen as the Preset name.

ARC Tangents

Of the three buttons on the ARC On‑Ear unit itself, two have fixed functions and one is assignable. The function you give it is retained across all Presets. The Cal button engages and bypasses the headphone correction for the active Preset, whilst the Studio button does the same for the virtualisation. It’s possible to assign the FN button to turn the speaker emulation on and off; if not, it follows the setting stored in the Preset. The virtualisation can be active regardless of the headphone correction, but you can’t have the speaker emulation without the virtualisation, which seems logical.

Other possibilities for the FN button include mute, dim (by an amount configurable in the software settings), mono, phase correction on/off, LEDs on/off and to trigger and pause playback. Since only one of these can be chosen at a time, this does mean that there will always be settings that can’t be accessed in standalone mode within a Preset. However, on the assumption that you don’t need to store Presets for five different pairs of headphones, you could set up multiple Presets using the same headphone curve and access them that way. Preset switching from the ARC On‑Ear itself requires pressing the Cal button whilst holding down FN; what the manual doesn’t tell you is that once in Preset selection mode, you then need to let go of FN and hold it again, whereupon Cal will cycle through the Presets.

Story ARC

In my experience, the correction curves produced by different room calibration packages tend to be pretty similar, assuming the same room and the correct measurement procedures. For example, IK’s ARC Studio, Sonarworks’ SoundID and Genelec’s GLM all deliver much the same end result in my test space. This is very much not the case with headphone correction tools. Each of the major developers here has their own test procedure and their own target curve.

Consequently, there can be surprising differences between the calibration curves that different products apply. The Shure SRH1840 open‑backed headphones provide a particularly extreme example. SoundID applies very little correction between 50Hz and 8kHz, whereas dSoniq’s RealPhones recommends a broad cut from 1kHz to 5kHz and a pretty obvious boost above this. ARC On‑Ear’s curve is different again; it too thinks the midrange is overblown, but the high frequencies even more so. Consequently, whereas SoundID does nothing much at 11kHz, RealPhones boosts by around 5dB and ARC On‑Ear cuts by around 5dB! If you’re thinking they can’t all be right, that’s obviously true, and in this case RealPhones is the outlier to my ears, making the ‘corrected’ SRH1840 sound significantly worse, whereas I quite liked what ARC On‑Ear did.

The contrast is much less stark with some of the other headphone models I compared. For example, all three products suggest that the Neumann NDH 30s have a noticeable bump somewhere in the 2kHz region, although they disagree about exactly where it lies and how much correction is needed. If the examples I compared are representative, I’d say that RealPhones tends to apply the most correction and ARC On‑Ear the least. However, RealPhones allows the degree of correction to be varied — I usually keep it around 75 percent — whereas ARC On‑Ear does not have any sort of Amount control or wet/dry balance.

It’s also clear that the target curves of the three products vary significantly at the top end, as do their approaches to calibration. RealPhones’ idea of a calibrated monitoring system is significantly brighter than IK’s or Sonarworks’. However, whereas SoundID profiles often include detailed notches and peaks in the treble region, ARC On‑Ear tends to offer smoother curves.

Which of these curves sounds best will depend on many factors: personal taste, the specific model of headphones you’re testing, how closely your own pair of headphones matches the generic curve derived from different samples, and so on. I tried ARC On‑Ear with several different pairs. As always, it makes the most difference with headphones that are audibly not flat to start with, but in every case the calibration seemed to me an improvement, and in most cases a substantial one. I struggled to detect much benefit from the phase correction, but it certainly didn’t make things worse, and the additional latency is not enough to be a problem at mixdown.

Subtle Space

If the ARC On‑Ear calibration is relatively conservative, the virtualisation is even more so. You certainly don’t feel as though you’ve been plunged into a different acoustic environment, and I never had that uncanny sensation of being fooled into thinking I was listening on speakers. In that respect, it’s the polar opposite of something like Sony’s 360VME. But in terms of utility, I found the studio simulation surprisingly useful. Whereas engaging bypass on 360VME can be quite disorientating, toggling the Studio button on the ARC On‑Ear make just enough difference to offer a valuable alternative perspective. For this reason, I preferred using it with one of the high‑end monitor emulations rather than a virtual pair of NS10s or similar.

All the other dedicated headphone correction tools I know of are software‑only, so unless you’re using one of the relatively few audio interfaces that can apply sophisticated EQ to its headphone outputs, the ARC On‑Ear is the only hardware option in its field.

Finally, these product comparisons ignore the ARC On‑Ear’s uniqueness. All the other dedicated headphone correction tools I know of are software‑only, so unless you’re using one of the relatively few audio interfaces that can apply sophisticated EQ to its headphone outputs, the ARC On‑Ear is the only hardware option in its field. You can buy bus‑powered digital‑to‑analogue converters that have DSP, but most of them don’t have headphone outputs, and they certainly won’t come with a library of 200+ calibration curves for different headphone models.

The flip side of this is that IK’s headphone correction tech is presently not available outside of the ARC On‑Ear box. There’s no systemwide software with virtual drivers, or headphone equivalent of the ARC plug‑in. How much does that matter? For mixing and editing on the go, not at all. But in other scenarios, it ties you into using the ARC On‑Ear alongside your main audio interface, which could be a nuisance. The analogue input offers an alternative to messing about with aggregating interfaces, but I can’t help feeling that a digital input would have been a better option here. The analogue input is intended primarily for connection to the headphone output on another device. That might be the best way of hooking ARC On‑Ear up to a mixer, but with an audio interface, it means passing the signal through two headphone amps and two stages of conversion. Most of us have a spare S/PDIF output somewhere on the back of our audio interface, and that would seem a better option to me.

However, that’s really the only serious criticism of the ARC On‑Ear system I can muster. In every other respect, I like this product a lot. The headphone calibration is effective, the virtualisation is useful, the companion software is intuitive and easy to use, and the huge catalogue of headphone profiles is impressive. In a world where you can pay a lot more for a supposedly audiophile USB DAC that lacks any of the same functionality, the ARC On‑Ear also looks very good value for money.