We review the Audirect Beam 4, which is a compact portable DAC and headphone amplifier capable of up to DSD512 and 230mW of balanced output power. It is priced at $239.99.
Disclaimer: This was sent to us as a sample for our honest opinion. Headfonics is an independent website with no affiliate links or services. We thank the team at Shenzhen Audio and Hilidac for giving us this opportunity.
To read more about Audirect products previously featured on Headfonics please click here.
Note, that this article follows our latest scoring guidelines which you can read in more detail here.
The Audirect Beam 4 is riding the return of the classic battery-powered portable amplifier and DAC which has recently gained significant traction in the audiophile community with the likes of the Shanling H5 and H7 as well as the FiiO Q7 and their soon-to-be-released Q15.
Currently, and despite the rising popularity, portable amplifiers such as these are still few and far between. I’ve not reviewed one like this since the last decade with the Ray Samuels and ALO Audio portable amps.
I will always prefer the stacked DAP or phone and portable amp experience. It defines my favorite and most exciting times in audiophilia, as I am sure it does for many others as well. I wonder how many of us still have our silicone or rubber straps from our portable brick totes?
Tech Highlights
Power
The Audirect Beam 4 is a compact portable amplifier and DAC that offers both a 3.5mm unbalanced and a 4.4mm balanced output. Sadly, the 4.4mm balanced higher gain is rated at just 230mW 32Ω, which is about 5 times less powerful than something like the larger xDuoo XD05 BAL 2 amplifier.
Is that a big deal? Not really. You shouldn’t be using a tiny amplifier for excessively needy headphones anyway. But back in the day, talking about 10 years ago or more, there were a few smaller amps out there that had more than double this output and they weren’t even balanced.
I am not sure why the output power, even in balanced mode, is that low. Unbalanced 3.5mm output is roughly half of this. The battery, for being so small, the battery is quite good at 1200 mAh.
DAC
The ESS9281 AC PRO is a chip that I’ve never tested before. I believe that it is the same chip in the FiiO KA1, which I’ve not heard before. But, Louis, another writer here at Headfonics, reviewed that one some time ago.
Despite sharing the same chipset, the Beam 4 seems to have a better USB stage allowing it to handle a maximum of DSD512 natively as well as PCM up to 32Bit/768kHz as well as Apple Lossless.
I/O
The sides of the unit offer a standard power and gain button that you have to hold to activate. Thank God it isn’t a one-touch experience. You need to hold it down for a few seconds before high gain activates or disables itself. Great design feature.
On the opposite side, a Play, Pause, FF/RW, and volume + and – can be used in DAC mode.
The balanced and unbalanced ports can be seen at the top of the unit, while the USB-C port is at the opposite end. This is not the right way to design a portable amplifier anymore and it never was. You do not want two long cable leads sticking out of both ends when you can have them on just one side.
The USB-C DAC port should be right next to the headphone ports, on the same side. This makes it more pocket-friendly and better when you want to strap it to your DAP or your cell phone.
Having a unit this small and then ruining the point of it being so small by making sure long cable leads extend out to add another 50%+ of the size.
Design
Despite the negative thoughts I have about the port design, the unit itself is slick and gorgeous. I think it is one of the best portable DAC and amp designs I’ve seen in a long time with a very futuristic and modern art-looking aesthetic.
The Beam 4 weighs 62g and it is visually quite compact in terms of its form factor. This is a solid piece of metal the size of a cigarette pack.
The build quality is excellent and I’ve never seen one better for this type of device. No joke, I’ve never seen anything in a portable DAC or amplifier that feels like this. This is the most solid, thick, weighted, quality piece of pure metal that I’ve ever seen.
This is how it should be; I want it dense like this. I don’t want it cheap feeling. I mean, damn. This is easily the best build in a portable amp that I have ever reviewed, puts everything else right to shame.
Packaging & Accessories
The box is super tiny and cute, nothing much in there except the USB-C cable and the foam cutout. The supplied USB-C to USB-C cable is the nicest short cable I’ve ever tested. Bar none.
Best build? Yep. Best included short style USB-C to USB-C? Check. I will be using that for a long time, years into the future.
The leads on this USB-C interconnect are heavy-duty, and like little lead weights. The fabric casing is also quality. What a great little accessory. I have tons of these, but nothing even close to this level of quality has ever been included in anything I’ve ever reviewed.
Sound Impressions
Bass
With no EQ active, my Sony Xperia 1iii phone 3.5mm puts out much more bass, but far less treble. The fidelity between them is about the same for bass quality. Simply put, the Beam 4 is bass-light and treble-prominent.
The bass also cannot be boosted much without it going overbearing and warping a bit. Once we hit +5dB, things get not-so-nice. I’d rate this moderately good at responsiveness unless you are basshead, this is perfect, and the quality is great overall. Bassheads though, this isn’t for you.
The bass is also fast and snappy, this is not a mellow or relaxing sound. It is fast-paced from top to bottom, meaning it sounds quick and the decay is very light on its feet.
The tonality overall is on the border of clinical and natural. It isn’t supremely clinical and 100% reference, but it also isn’t quite in the middle, it’s looming between the realms there. It is far from musical or warm in sound striation.
Midrange
The midrange location is very forward and highly engaging. A direct swap to my Xperia 1iii showcases that the Beam 4 is significantly more forward feeling and “in your face” in terms of feel and tactility.
The clarity is, once more, pretty much the same as my phone here and roughly on par with something like the now older Ultrasone Panther, which I reviewed a few years ago.
Both of these models are roughly the same price now, the used Panther going for the same price as the new Beam 4, but the Ultrasone blasts out 950mW where the Beam 4 maxed out 3x less than that in the same ohmage load.
The upper mids are bright and vivid, crisp, and highly aired out. Energetic upper mids are usually a problem, getting it right is hard. It can be nasal, or too hostile.
In this case, I enjoy it. The quantity is just right, plentiful but not lacking, engaging, but not wince-worthy or overly bright and icy.
Treble
The top side is bright. Again, just like the mids, it’s hard to get right without it sounding painful but, in this case, the experience is just a bit fatiguing over time.
It doesn’t extend too far into that territory but it is a hard sell for me coming off something like that xDuoo XD05 BAL 2, or even my XRK Uber, which remains the best overall low-output portable amplifier I’ve ever heard.
Bright is fine, and I applaud the tuning here that makes it a highly refreshing and very open feeling. However, the physical impact of some harsher, or clinical tone headphones, can end up feeling a bit too potent at times.
Mellow headphones don’t showcase this problem, for example, using the Beam 4 as a DAC for my warmer-than-usual and somewhat bassy Stax 007, HIFIMAN HE-R9, or Drop + Ultrasone Signature X, these headphones are warm enough to not be bothered by it.
However, my Starry Night v2 and Drop + Sennheiser HD 8XX are not the headphones I would want to use the Beam 4 with as the DAC that would then fuel a more powerful amplifier. The treble would become too hostile, too quickly.
Staging & Dynamics
Due to the excellent upper mids and airy treble, the imaging experience is very nice.
Swapping from the Ultrasone Panther, the experience is pretty much dead even, almost like these two amps are clones of each other. The XRK sounds smaller, however, also more focused and refined in the XRK than the Beam 4.
The dynamic kick is plentiful, as mentioned. That ‘kick-and-wallop’ can hit pretty nicely if your headphones are not reserved and chill in that regard.
Probably a good idea to avoid hostile and harsh treble IEMs with this Beam 4. I think the top-side bright slam effect would be too much unless you drastically downplay the treble with some EQ and DSP usage.
Is it a sound stage titan? Nah. But it is still very good, all things considered. It makes a good DAC for on-the-go usage, without a doubt. I wish it had a bass switch to offset that sometimes excessive treble bite.
Synergy
The Beam 4 doesn’t mesh with warm amps or musical headphones that lean toward bassy and slow. This amp/DAC plays better with reference tier and clinical tone but be careful with icy and plentiful treble in amps and headphones that are paired with it.
Beyond that, it doesn’t offer that physical treble or bass option, so it doesn’t mesh with a wider range of products.
Also as mentioned, the responsiveness to the alteration of sound, via EQ, is less than stellar and just fine overall. It won’t get you nice bass experiences in quantity terms and it won’t offer a warmer than neutral experience for warmer rig pairing.
Overall, though, it is just fine and a good option if that sort of thing is something you don’t care about. It is a great dac and amp combo in a tiny unit, so don’t let that stop you if you don’t care about tone matching.
Select Comparisons
Ultrasone Panther
The Audirect Beam 4 is pretty much the same as the Panther, it sounds like they are related and sometimes I failed blind testing to hear which is when I had someone else plug my sources and headphones into them.
I prefer the Panther because it offers significantly more power than the Beam 4. Tone though, is dead even between them. Same sort of middle border of natural and clinical, with a bright treble.
XRK Uber
The Uber is pristinely musical, noticeably more dense feeling, and refined. It is also like a glistening sparkling beautiful thing in the night, whereas the Beam 4 is more of a harsh spotlight in tone.
The XRK is even less powerful than the Beam 4, so it’s only suited to IEMs and very easy to drive larger headphones. The tone of the XRK is magic. It’s stunning, even 6+ years later, it is untouchable in terms of musical flare.
However, it is also just a bit too thick and muted, veiled feeling, compared to the Beam 4 which feels more raw and pure.
Earmen TR-Amp
The Earmen TR-Amp is flat-out stark neutral and does not bias toward warm or cold, whereas the Beam 4 is closer to a reference clinical cold tone than anything else.
Yes, the TR is much larger, but it is also noticeably more bassy and has a flatter feeling in placement, the Beam 4 is very forward and engaging, more slamming, and physically tactile. The Earmen TR is also much more powerful in terms of output but has no balanced output.
Our Verdict
The Audirect Beam 4 is an excellent amp and dac. It has excellent build quality, perhaps one of the best in any portable amp I have ever seen. However, some of the marketing slang they used just doesn’t make any sense and I feel like the experience with it has far exceeded what they said about it, (in a good way).
The Beam 4 is a solid little source but the I/O needs a revision to make the USB port and the headphone ports on the same side. Beyond that, the experience is set up for those who want a brighter-than-neutral sound signature, or a more clinical tone overall.
Audirect Beam 4 Technical Specifications
- Output: 3.5mm SE+4.4mm Bal.
- Frequency Response; 20Hz-40kHz.
- Output Power: Up to 230mW(Bal), Up to 141mW(SE).
- SNR: -119dB.
- THD+N: 0.0003%.
- Battery Capacity: 1200mAh.
