Hifiman Ananda-BT: Audiophile Bluetooth Headphones Review

The hunt for better...

Sitting beside me is a complicated stack of portable geekery.  An Astell & Kern XB10 Bluetooth puck sits atop a miniDSP HA-DSP, which in turn feeds into a Fiio A5.  With the signal received and decompressed, properly arm-wrestled into a neutral response curve, then sufficiently amplified, it is finally worthy of feeding into my treasured set of Dan Clark’s Aeon Flow Open headphones.

For headphone audiophiles, this sort of complicated cluster of swaggy electronics is a part of life.  Some of us relish the twisting of knobs and designing of FIR filters to achieve our optimum recipe for aural enlightenment.  Others roll tubes and try to choose an amp with a flavor to match their headphones’ desired response.  I find as I get older, I’d rather my gadgets just work.  Effort is for those who have not yet paid their dues.

And so, one must choose.  Which do you value more: transcendental audio reproduction, or mobility?  Unfortunately, there are few audiophile-grade Bluetooth headphones on the market – at least not in the same class as the Sennheiser 800 S, the ZMF Aeolus, the Focal Clear, and other $1000+ offerings.  In your home, headphones of that grade are practically as stationary as a pair of Salk SongTowers with a Hsu sub: set them up, then they never leave the room. 

Unless you’re in a recording studio, headphones that stay in the same spot are a bit of a paradox, aren’t they?  Even with my mobile stack of electronics, I almost never travel with my Aeon Flows.  On the go, one may achieve a neutral response from the likes of the Sennheiser Momentum 3, the Sony WH-1000XM4, and the Bose QC35 II.  Well-tuned as these headphones may be, they will never come close to the sort of sound stage offered by open-back headphones; never offer the extreme detail of headphones with more refined transducers.  Ultimately, mainstream Bluetooth headphones fall far short of transcendent.  With the Ananda-BT, Hifiman is working to fill that gap.

Transcendental audio reproduction

These headphones are outstanding for everything from Franz Biebl to Justin Bieber.  Speaking of, in “Stuck With U” by Ariana Grande and Justin Bieber, did you realize the studio added a subtle spinning vinyl snap-crackle-pop track?  Neither did I until the first time I wore these headphones.

The Ananda-BT headphones are detailed, revealing, and airy.  As is typical for planar magnetic headphones, the midbass can be a bit overcooked, while sub bass could use a little more authority.  Honestly, though, this is all very trivial, and I would be content to listen to these headphones without EQ.  Every other register is spot on.  Mids are well represented without being nasal.  Treble is well-controlled, neither shouty nor veiled.  Overtones are airy without being sibilant.

Having said that, you only live once.  I do have a slight correction applied using Neutralizer, an Android 10-band EQ app.  These headphones lend themselves very well to EQ.  I applied a slight boost to the 32 and 63 Hz bands while taming the 125 and 250 Hz bands a bit.  These filters pivoted the cymbal range down a couple dB, which I accepted with indifference.  The result leaves me grinning like an idiot.

Listening to VOCES8 sing “Sleep” by Eric Whitacre, I can close my eyes and almost smell the incense and wood oil smells of an enormous church sanctuary.  No other headphones have ever tugged at my emotions this way.  The experience is ethereal.  After having listened to a dozen songs since, each time I pause to answer an email or accept a phone call, the buildup beginning at 2:43 repeats in my head.  This is an earworm done right.

2 minutes, 53 seconds into “Groovin’ Hard” by Groove For Thought is the cure for my earworm.  Whenever you have a group of vocalists in a tight Count Basie sax section arrangement, such vocals are often difficult for headphones to reproduce as distinct individuals.  One often gets a mush of chord, chord, chord, maybe some clipping.  The Ananda-BTs do an admirable job of separation so you can say, “Oh, Amanda’s singing a sharp 9 against Kelly’s major 3rd.  Nice!”

“Spain” by Bobby McFerrin & Chick Corea is all the more impressive when you consider every performance of this tune is an improvisation with a heavy dose of experimentation.  On this track on the 1992 album “Play”, I hear not only the full range of both the piano and Bobby at the sort of volume and timbre one would expect in live performance from pianissimo to fortissimo; but also the buzz of power surges in the recording equipment during quieter phrases.  These headphones reproduce everything, warts and all.  In any case, it really is a shame that “Don’t Worry, Be Happy”, the least of his songs, is the only Bobby McFerrin song most people know.

I promise I did not buy these headphones merely to pick out flaws in familiar recordings.  But I thought I might switch gears and go for some old school Chicago.  “Call On Me” is my lifelong favorite Chicago track.  I’ve listened to it more times than I can remember.  First time listening with the Ananda-BT, as I was admiring the rather excellent airy, brassy overtones of the horns and the punchy quality of the kick drum, I heard it.  30 seconds in.  The accidental minor 3rd, the wrong note from the rhythm guitar in my right ear.  That’s the first time I’ve ever heard that.  It’s still the coolest tune in Chicago’s discography though, and that much cooler for the quirk I found.

A friend of mine recently introduced me to Martin Miller as a worthy subject to put my new headphones through their paces.  I arrived for the great tunes the band covered.  I stayed for the virtuoso instrumental performances.  Martin Miller and Tom Quayle’s cover of Stevie Wonder’s “Isn’t She Lovely” is a fine example.  I find this recording noteworthy not only in the performers’ technical proficiency, but also in how much horizontal and vertical space is represented by the Ananda-BT from only two guitars.  Going back and re-listening to this track on a pair of exceptionally tuned but closed-back Parrot Zik 2.0 is like I’ve suddenly lost all aural depth perception, the sonic equivalent of covering one eye.

Hifiman Ananda-BT Headphones Measurements & Conclusion

The Ananda-BT headphones can get signal either via USB-C or via Bluetooth.  Both require the headphones to be powered on and for signal to flow through the onboard DSP.  Because I intend to use these headphones exclusively as Bluetooth headphones, I performed measurements over Bluetooth.

According to the graphed response I would expect to be missing some detail around the 2kHz range.  Honestly, I don’t.  This is a good argument for spending some time becoming familiar with your equipment before letting a graph tell you what you should expect to hear.  It’s a bit of a Catch-22 for one who shops for equipment based on response graphs, right?  How does one choose what to buy without some expectation of what he will hear?  All I can say is, graphs are the beginning of wisdom, not the end.

The subtle rise from 600 Hz down to 60 Hz explains the slightly overcooked midbass I mentioned earlier; but as I said, it’s not enough to make the sound displeasing.

Because this was measured over Bluetooth also using itself as a timing reference, I’m not certain how reliable it is.  Measurements in the time domain have diminished meaning with such a latent transmission method.  Regardless, there is no range on these headphones where I hear any ringing.  The waterfall plot seems to support this.

Comfort

The headband expansion mechanism is tight.  Pulling the ear cups down takes some effort.  Unfortunately, this feat of brute strength is required right next to a delicate wire feeding up into the headband.  Hopefully over time this tension will relax.

Once the headphones have been properly sized, they are supremely comfortable.  They are deceptively lightweight.  The clamping force is barely noticeable while still sufficient to support their insubstantial heft, and the open backs allow my ears to breathe.  Comfort is not affected by wearing glasses, nor can I perceive any audible difference with glasses versus without.  The polyester face of the ear pads may get sweaty after an hour or two of listening.

Bluetooth controls

The buttons on the left ear cup are minimalist.  Power button controls power and pairing.  Charging button starts charging, preventing the Ananda-BT from vampiring the battery charge from a mobile phone or laptop.  That’s it.

Kudos to Hifiman for not copying the Bluetooth features and human interfaces from other manufacturers, and for sticking to their guns despite criticism.  The Ananda-BT don't have ANR, no head tracking, no app-controlled tone settings, no touch or swipe gestures, none of the frivolities that make mainstream Bluetooth headphones less headphone and more head-mounted appliance.  For Hifiman’s headphones for grown-ups, Bluetooth is merely the wireless wire, nothing more than a means of transmitting signal.  Those who claim the Ananda-BT's Bluetooth controls are lacking need to stop associating the Ananda-BT with mainstream Bluetooth headphones.  They are in a class of their own, and should absolutely behave like it.

Comparisons

Sony WH-1000XM4
The Sony headphones have less sound leakage, active noise canceling, more robust controls, and a cheaper price tag.  However, their superiority does not extend to sound quality.  Although tuned for a neutral response, the Sony headphones sound unrefined and 2-dimensional compared to the Ananda-BT.  The difference is not even close.  The Ananda-BT headphones have a significantly expanded soundstage and better detail, and are genuinely more exciting to listen to.  They are simply the best sounding Bluetooth headphones on the market that I've heard.

Aeon Flow Open Back v1
Dan Clark makes some nice headphones, make no mistake.  However, the typical midbass hump characteristic of planar magnetic headphones is more pronounced on the Aeon Flows, limiting their suitability to fewer genres of music without significant EQ.  The Ananda-BT headphones sound more open, presenting a wider, taller, and deeper soundstage than the Aeon Flows.  Both offer similar levels of detail and supreme comfort.

Hifiman HE-560 and HE6SE v2
A friend of mine recently acquired a pair of HE6SE to replace a pair of failing HE-560.  He says the Ananda-BT remind him of his 560s.  However, I recall A-B testing his (then working) 560s against my Aeon Flows with my preferred EQ curve, and thinking the Aeon Flows clearly won that matchup.  The sound of the Ananda-BT reminds me more of his HE6SE headphones, but he would never admit that my headphones might be better than his.  The HE6SE may have a slightly deeper soundstage and a marginally more neutral natural response curve, but the infinitesimal gains would probably not be noticed without a side-by-side demo, especially with EQ applied to the Ananda-BT.  The HE6SE headphones have more in common with the Ananda-BT than do the HE-560.

The state of the market

In the past, enjoying the convenience of wireless headphones has meant compromising on sound quality.  Almost all wireless headphones are closed back, employing entry-grade dynamic drivers.

Grado Labs was the first to enter the market with an open back offering, the Grado GW100.  Unfortunately, its native response curve is somewhat V-shaped, with bloated bass and mid-bass, veiled mids, and a top end approaching sibilant.  With the response hammered into shape with EQ, you've still got an on-ear headphone with transducers among the lowest grade that Grado offers.  When asked whether they would be open to converting one of their more premium offerings, the GS1000e, into Bluetooth, the terse response from Grado Labs indicated a hard no.

Drop.com seeks to address the other side of the niche by incorporating higher quality planar magnetic drivers and upgraded amplification into the Drop + Panda.  These headphones approach audiophile-level resolution, but are sadly still closed-back, and thus limit the soundstage.

Hifiman seems to be experimenting as they enter into the Bluetooth fray.  They began with a pair of truly wireless ear buds, the TWS600.  The Ananda-BT came second around the middle of 2019, and as of this review are the last to offer an integrated Bluetooth DSP.  The more budget-minded Deva came next featuring a pluggable Bluemini module, allowing its owner to choose passive wired or active wireless.  The Deva may not match the bass response or overall presentation of the Ananda-BT, but it does come at a much lower price.  Hifiman also offers a Bluemini option for its higher end wooden closed back headphone, the HE-R10 Dynamic.

I contacted Hifiman's customer service staff to ask about the future of Bluetooth development.  Will the Ananda-BT be their last model to offer an integrated Bluetooth DSP?
They responded:

"The new Bluemini is still under [development]. We will adjust our goal[s] in accordance with the trend[s] and technic[al] development, ultimately, to achieve the best sound quality and balance."

I take that to mean that, for the immediate future, they will continue developing their Bluemini independently of their headphones, making it an available option where impedance and sensitivity permit being driven by a 230mW power source.  Beyond that, who knows?

In any case, more options are becoming available for those who want the freedom of wireless without having to sacrifice sound quality.  For now, the Hifiman Ananda-BT headphones are the unqualified best sounding Bluetooth headphones on the market.

The Score Card

The scoring below is based on each piece of equipment doing the duty it is designed for. The numbers are weighed heavily with respect to the individual cost of each unit, thus giving a rating roughly equal to:

Performance × Price Factor/Value = Rating

Audioholics.com note: The ratings indicated below are based on subjective listening and objective testing of the product in question. The rating scale is based on performance/value ratio. If you notice better performing products in future reviews that have lower numbers in certain areas, be aware that the value factor is most likely the culprit. Other Audioholics reviewers may rate products solely based on performance, and each reviewer has his/her own system for ratings.

Audioholics Rating Scale

• — Excellent
• — Very Good
• — Good
• — Fair
• — Poor

Metric	Rating
Build Quality
Appearance
Treble Extension
Treble Smoothness
Midrange Accuracy
Bass Extension
Bass Accuracy
Imaging
Soundstage
Dynamic Range
Fit and Finish
Performance
Value