Fit and Comfort

Seen above is the Focal Bathys placed on a mannequin head to help show how these headphones would look on the human head. Note that the head is slightly under average sized, so account for the discrepancies accordingly. As with all headphones, getting a good fit and seal is crucial, so make sure to properly use the various pivot points, and the height adjustability of the headband and ear cups. This section is mostly a summary of the points expanded upon in more detail on the previous page, but I will point out that the Bathys weighs 350 g—more than the typical set of Bluetooth headphones and this is a result of the larger form factor as well as the dedicated DAC w/associated hardware no doubt. It also explains the use of aluminium, magnesium, and plastic for the exterior that helps keep the mass down without compromising on build quality, while also being premium looking and feeling. We previously noted how there are multiple sizing options here courtesy vertical, horizontal, and ear cup swivel movement built in. I had zero issues getting these over my ears comfortably, and I have an average-sized head at that. In fact, there were still some vertical sizing steps left to where I dare say the vast majority of users would be fine with this set when it comes to fit and comfort. I do wish the headband was more plush though, and I can see customers potentially adding in a wrap-around headband cover or even something such as the Dekoni Nuggets if they can fit. The initial clamping force felt slightly tight for a few seconds but then the softer pads kick in to absorb it well, to where I had no issues on the ears themselves. Indeed, the larger ear pads compared to your average wireless headphones make the Bathys automatically more comfortable in that these are legitimately over-ear sets that also don't have the ears touching the inside of the cups. The passive noise cancellation is also plenty adequate with a good seal courtesy the closed-back nature of the Bathys. But be aware that the Bathys does not claim any dust/spill resistance so it's probably not a good idea to use this for workouts, assuming anyone was going to at all.

Audio Performance

Audio and Tech Hardware

Focal does not go into much detail on the Bathys drivers online except to say it still uses a dynamic driver with a 40 mm aluminium-magnesium alloy dome. This is a slightly updated version of the same speaker-style M-shaped dome Focal uses in many of its headphones, except with a smaller surround and magnet to fit the rest of the electronics in the ear cups. I will also recommend watching this video from The Headphone Show that includes a tour of the Focal facilities and a closer look at the drivers that helped me capture the two other photos above, and there is a comparison to the equivalent driver from Focal Clear that has a larger overall foot print. Focal also talks about the assembly process done in-house in France, including gluing precisely the dome to the surround and voice coil as well as testing the completed drivers, before shipping them to China for final assembly with the rest of the headphone components. There's also active digital signal processing employed for the hybrid ANC feature in addition to having the USB DAC for further refinement. There is fully passive mode here thus and so the Bathys effectively relies on its internal battery to power the drivers and ANC. This is also why battery life goes from 30 hours on Bluetooth to 42 hours on USB DAC mode with the latter only turning off the Bluetooth SoC and allowing trickle charging. It's not the best scenario for someone who wants to charge the headphones while listening, but admittedly the battery life has not been a concern for me—especially given the shorter charging time coupled with fast charging support. Focal also recommends using the Bathys in Off mode to get the most juice for someone simply wanting to use the set in ANC mode without anything playing.


Indeed, the vast majority of users here will be purchasing the Bathys to use wirelessly, even if the DAC mode will be superior from an audio perspective. The Bluetooth 5.1 connectivity works flawlessly here although the lack of LDAC support suggests it could be something other than a Qualcomm SoC. I mentioned before how codec support can be lackluster for those on certain Android devices and LDAC connectivity would have helped, based on the audible difference I've noticed with good Bluetooth headphones on LDAC vs. aptX vs. SBC. The Bathys also has a total of eight microphones—four per side—with two dedicated for communication and the rest for the ANC modes. I was pleasantly surprised by how natural and clear the microphones sounded on phone calls and online meetings, to where this can be a legitimate headset too. ANC, on the other hand, could be better. I thought the Bathys canceled noise well enough without inducing the associated pressure drop in the ears from worse such implementations, and some of this could also be because it doesn't actually cancel out as well as the current mainstream ANC flagships from Sony and Bose, with Apple still taking the win on transparency mode based on my limited testing of a friend's unit. But make no mistake—the ANC modes on the Bathys are not just a gimmick to tick off a feature set.

Another point of contention is the physical controls aren't the easiest to identify and use—especially the multifunction button that does quite a few things as seen above and ends up stuck between the volume controls rather than getting a dedicated button as with the voice assistant function. Then there's the part where most changes made take 1-2 seconds to activate, during which the Bathys does not play anything nor transfer your voice if on a call. This can be annoying if you are in a rush to switch to transparency mode to hear a notice when waiting for your plane or train, for example, or even pick up incoming calls. But these all pale to the bigger issue I've noticed wherein the volume controls on the Bathys lead to relatively big changes in volume on your phone compared even to the finer controls most phones provide natively. This means it can be hard to get the listening volume spot on to your preferences and the Bathys can go from quiet to overly loud instantly. Once again I hope this is fixable via a firmware update, especially seeing as how it works fine on Windows, but so far Focal has been lacking on the technological front. Bluetooth 5.2 and support for LC3 codec would have been nice to see, although right now there are clearly bigger issues.

Frequency Response Measurement and Listening

I will mention that I have a general preference for a warm-neutral signature emphasizing a slightly elevated bass and smooth treble range with detailed mids and good tonal separation. I also generally prefer instrumental music over vocals, with favored genres including jazz and classical music.


Our current headphones test setup uses a set of two custom in-ear microphones for the two channels. These microphones closely adhere to the IEC711 class, but have been tweaked to be more reliable in the >10 kHz frequency range that was the issue with my previous setup, which is still very good and will continue to be used for IEMs and earphones. Two soft silicone pinnae are installed on the sides, separated by a distance matching my head, and multiple "height" adapters have been 3D-printed for further customization based on fit and head size and shape. Each set of microphones has an XLR output I separately adapted to 3.5 mm. These Bluetooth headphones were first connected wirelessly to my laptop using aptX and Bluetooth followed by using the Bathys in USB DAC mode via Type-C connectivity as well as the jack mode connected to a portable transparent source, the FiiO Q7, to complete the set. Listening was also done so with my mobile phones on aptX and SBC codecs.

This artificial head simulator feeds the microphone lines into a reference USB sound card, which in turn goes to the same laptop that has ARTA and REW running. I begin with an impulse measurement to test for signal fidelity, calibrate the sound card and channel output, account for floor noise, and finally test the frequency response of each channel separately. Octave smoothing is at the 1/12th setting, which nets a good balance of detail and noise not being identified as useful data. Also, the default tuning was used for testing, and no external EQ settings were used unless specifically mentioned. Each sample of interest is tested at least thrice with separate mounts to account for any fit issues, and an average is taken of the three individual measurements for statistical accuracy. The raw data is then compensated based on a custom curve created after having worked with Crinacle from In-Ear Fidelity to get measurements with this setup on par with a GRAS 043AG industry-standard measurement rig, especially by accounting for the slightly different pinna gain here compared to the KEMAR anthropometric pinna there.


I noticed right away that the Bathys was one of the hardest headphones to accurately measure the frequency response for. The first measurement I took did not really correspond to what I had heard before going about measuring the Bathys, and this is where people need to be careful in purely relying on measurements from those who just take a single recording without accounting for multiple mounts in addition to confirming what you measure matches what you are listening to. In this case, it's a combination of the softer pads and the directed drivers angled towards the ear canal, coupled with the active DSP ongoing that usually compensates for bass drop during ANC. The Bathys always have ANC on, except in transparency mode, and Focal made sure that the tonality is the exact same irrespective of the ANC mode or even the connectivity type. Seen above is a set of representative frequency responses for the Bathys averaged across both channels as a function of manually applied clamping force as measured relatively using a pressure gauge. The overall trend is quite significant on the upper mids, which in turn changes the balance of the sound signature for the Bathys ranging from being punchy with recessed vocals all the way to a shouty and fatiguing response. There's some compensation ongoing for the ANC here based on the bass response being quite similar across the board until the seal starts to break, whereby you also notice the slightly elevated 50 Hz peak further indicating as much. Bass drop-off only happens with a fully broken seal here and even so it remains fairly intact through the mid-bass. Basically, I am letting you know that the Focal Bathys may sound different from person to person more so than usual for a closed-back passive set that also has a similar effect with clamping force, but not as much as seen here with the pads and DSP adding to the complexity. Your experience will be somewhere between the extreme scenarios plotted above and I highly encourage trying out the Bathys for yourself to see whether it works out well for you or not.


Given the limitations here and also the softer pads on the Bathys perhaps not working as well with my specific measurement rig, I could not get a measurement that exactly showcased the intended response. This is why I showed you the range of responses measured, which is also a valid result, but also now want to talk about the ideal scenario should you not have any fit/clamping issue. The measurements above are taken from Headphones.com again courtesy Resolve/Andrew Park, and I recommend going through his initial impressions too. He uses the same combined Harman target I do so you can also get a better idea of how the Bathys works out for my tuning preferences.

My standards for Bluetooth headphones and earphones are generally low so I was pleasantly surprised to see the Bathys have a deliberate and mostly balanced sound signature. Focal mentioned the goal here was to give you a hi-fi experience akin to its other closed-back sets except with slightly more bass and treble based on the target customer needs. This feels like marketing talk for giving the Bathys a more V-shaped tuning for mainstream appeal, and indeed I'd certainly call the Bathys to be a pretty punchy set. Bass hits quite hard and deep—especially on USB DAC mode—to where you can certainly groove in your own little world listening to the Bathys playing electronic music. I did feel like the mid-bass is slightly bloomy and bloats the lower mids to an extent though, and I had to take the bass down ~2 dB on the first two EQ filters via the app. Vocals are forward facing and arguably the best part of this set to where classic rock and country music feel at home. Bass guitars with EQ also are extremely well represented, with drums benefiting from a pretty natural timbre owing to the dynamic drivers despite all the ongoing DSP.

Indeed, the technical performance here is what really differentiates the Bathys from pretty much any other wireless set I have ever listened to, including the more expensive HIFIMAN Ananda BT open-back set. The Bathys is quite resolving and does well with layering to where you can appreciate leading and trailing ends of tones even in complex tracks with lots of different tunes playing simultaneously. It's not a particularly fast set but one with plenty of dynamism to the sound output. Instrument separation is excellent even with a slight haze to imaging around the ears. The central channel images almost perfectly though, and perhaps some of this comes from the relatively cramped soundstage. Indeed, I never felt that Focal headphones had an expansive sense of space even for open-back sets so don't expect a concert hall in your Bathys. Then we get to that 900 Hz dip which I would actually suggest leaving as is and not EQ'ing up. It does make for a punchier bass that you can handle separately, but also helps make female vocals sound more natural to me. Your mileage may vary here though, as outlined above, so there is a possibility of the upper mids coming off slightly shrill instead. I will also mention here that some people have claimed this dip to be a result of deliberate channel cross-feed and I can de-bunk this. Stereo channel measurements showed no change in the phase response across the frequency range, and I also did a separate test wherein I played a sine sweep in the right channel and measured the response in the left one only to get just noise to confirm no cross-feed going on here.

The treble response is elevated slightly, particularly in the mid-treble, and this is also where you will notice the biggest compression in detail retrieval with the various operating modes. Bluetooth on SBC was not a fun experience for me listening to piano keys and orchestral music in general, so perhaps if you are the type to listen to classical music on your wireless headphones and own a Samsung phone then maybe reconsider buying the Bathys. AptX helps slightly, but really it is the USB DAC mode that kicks things up a notch. I don't anticipate most people using the Bathys wired but if you are a fan of acoustic jazz and classical music then you may want to consider just that. I can pick out harps from cymbal clashes much easier now, and it also gives more tactility to the bass too. I even bumped up the mid-treble slightly via the app because that's how much more I liked the Bathys now! It would be fair to classify the Bathys as an audiophile headphone primarily, and a wireless ANC set second.

Comparisons

I was hoping to get some of the direct competitors to the Bathys in for testing and review, including the likes of the Bowers & Wilkins Px8, the Sony WH-1000XM5, and even the Mark Levinson 5909. Unfortunately none of them materialized so I can only suggest looking at other reviews to see how the Bathys fares against these if you are in the market for a premium wireless set of headphones. On my end I can tell you that the overall experience with the Focal Bathys exceeds what I got from the already-impressive Edifier STAX SPIRIT S3, which is a planar magnetic set that comes with a design more amenable for travel and two sets of pads, but loses out purely on the driver technical performance and lack of ANC for those who care. The Bathys is also more comfortable in use and doesn't creak at times owing to the better build quality to where I can certainly see this worthy of the price hike compared to the Edifier set. There's also the final UX3000 which costs significantly less and also has ANC support but no customization/controls and is in a completely different market where sound quality isn't as critical. Purely from a value for money basis I would recommend the UX3000 though as it's a set that doesn't stand out in any way being a jack of all trades which you can easily use daily. I also had the Bang & Olufsen Beoplay H95 here for a few weeks but it's another set that's quite hard to really talk about objectively, given the mostly on-ear experience you get. Those will smaller ears can appreciate the H95 being a fashion piece that does ANC quite well if others who tried this unit were to be believed, however I did not get a good enough seal here to where I can't recommend it over the Bathys at all—especially given it also costs more. Then there's the Apple AirPods Max which is fairly crippled on Android to where doing a fair assessment would not be possible. The Bathys still out-performs the AirPods Max almost every which way except for Transparency mode, but note the AirPods also cost much less than the Bathys.