ag TWS04K True Wireless Earphones

True wireless earphones are earphones in which the left and right earbuds aren’t tethered via a cable – they pass the signal from one side to the other wirelessly. Over the past few years they have become the dominant devices for wireless connectivity to your phone. So, can a new brand, the unusually-named “ag” compete in the space?

Well, with some support from the great high-fidelity headphone and earphone brand, Final Audio, it turns out that it can, as demonstrated by its new ag TWS04K true wireless earphones.


  • ag TWS04K true wireless earphones with charge case
  • Supports SBC, aptX and AAC codecs
  • 6 hours battery life in buds when using aptX codec, 9 hours when using SBC or iOS-friendly AAC
  • Astonishing capacity in charge case: twenty recharges of buds! Up to 180 hours – 7.5 days – freedom from power points
  • Bluetooth 5.0 connectivity
  • Qualcomm QCC3030 chipset
  • 20-20,000 hertz frequency response
  • IPX7 water resistance, which means they can withstand immersion in up to one metre of water for up to half an hour. Drop them in the swimming pool, and they should be fine if you retrieve them without undue delay
  • Charge case can charge other devices
  • Five sizes of silicone ear tips included
  • Available in black or white
  • Weight: 4.8 grams for left bud, 4.7 grams for right, 91.2 grams for case, 100.6 grams total
  • Case size: 76mm by 45mm by 33mm.
  • Excellent tonal balance, with a bass performance that would not seem out of place in $2K earphones. Incredible value for money.
  • Available from fine high fidelity equipment retailers, and direct from here.
  • Price: $235
ag TWS04K true wireless earphones

    More on the ag TWS04K true wireless earphones

    The ag TWS04K earbuds themselves are compact and fit neatly into ears without excessive protrusion. My ear canals tend to be quite large, usually demanding the largest ear tip size available for a good seal. Of the five sizes provided with these ones, the second-largest proved to be the best fit for me.

    The top of the charge case is spring loaded and easily opened. The shaped cavity for each earbud is magnetised, drawing each bud in for a secure fit. There are four gold-plated contacts per bud to ensure a reliable recharge (and avoid accidental shorts).

    The case is charged via USB Type-C. A short cable is provided, but, as is the norm, its up to you to provide the standard USB charger. Charge time is two hours for the buds and four hours for the case. ag doesn’t mention any fast-charge capabilities – any five-minutes-of-charging-gives-you-an-hour-of-playback kind of thing.

    ag TWS04K true wireless earphones


    On receipt, I opened the box, placed the earbuds in their left and right receptacles and plugged them in to make sure everything was entirely charged. Clearly there was already some charge in the case and in the earbuds, but after two or three hours, case and buds were full. A LED on the front of the case made this clear.

    Pairing went uneventfully. Both earphones make themselves known to the Bluetooth device to which you propose to connect them, but they primarily talk to each other. My 2019-model Huawei P30 Pro phone connected uneventfully.

    (May I pause, briefly, here to note that as I’m writing about the practicalities of these earphones, “I See the Light” by Billy Paul is playing, and the bass guitar and kick drum are being delivered with distracting authority. That’s so unusual.)

    The Huawei phone supports all the high-end codecs, and it reported its connection to these earphones as using aptX:

    Phone connection information

    The buttons on the left and right earphones are a touch heavily-sprung for my taste. Only slightly. That makes it harder to do double taps, which are required to increase the volume (left bud) or reduce it (right bud). A single press on either left or right plays or pauses playback. Holding down the right skips to the next track. According to the instructions, holding down the left skips to the previous track, but I could not get that to work. If I held it to the first beep noise, nothing happened. If I held it a little longer, I risked accidentally shutting down to the earphone.

    Playing with this for a while, I managed to hopelessly confuse the earphones, my phone or both. In the end I had to perform a factory reset on the earphones and restart my phone to get them connected again.

    You can also use the buttons to answer phone calls and invoke Siri/Google Assistant.

    ag TWS04K true wireless earphones

    And while I mostly used these earphones with my Android phone, I also paired it with an iPad. It worked well with that and sounded good. Apple devices won’t tell you which codec they’re using, but the earphone specifications say they offer AAC, so I assume that’s what they did use.

    I charged up the case and, within it, the earphones, only once. I confess, I was expecting that the extreme battery lifespan of the charge case may have been exaggerated. If so, it wasn’t apparent to me. I’m pretty sure I used these earphones for close to a hundred hours without recharging. This lifespan is, frankly, astonishing. With virtually all true wireless headphones, their charge cases are good for only two, three, or perhaps four recharges. Not twenty.

    Yet the case isn’t really much heavier or larger than most.

    On top of this, you can actually use the charge case as a battery bank.  If you plug a USB Type-C cable into it first, it switches to power supply mode. So you can then plug it into some other device and it will supply power to that other device. It’s modest – 5 volts at 1 amp – but useful in emergencies to add a little more charge to your phone. Since the full charge capacity of the case is 2600mAh, it can fill a substantial proportion of the capacity of a smart phone. And, yes, it works.

    In terms of connection reliability, these earphones were remarkably solid. When I went to the food court of the local mall, where Bluetooth connectivity space is at a premium, I found that I could just leave my phone in the pocket of my trousers. With the Sennheiser earphones, I find that in the same location I have to put the phone in a pocket closer to the earphones, and sometimes carry it in my hand close to the earphones.

    Listening with the ag TWS04K earphones

    As is my wont, I ran these earphones in for a few hours – quite a few hours – with podcasts before trying out some real music. Even with podcasts you can tell a lot about headphones and earphones. In particular, they had a natural, clean midrange. They were perhaps a touch brighter than the Sennheiser Momentum 2 True Wireless earphones I normally use, but that added a bit of clarity to the spoken word, allowing me to keep the volume down a little.

    But it was when I switched to music, after perhaps sixty hours of use, that the true nature of these earphones was revealed.

    Actually, I’m sitting here a little stunned. “Bad Guy” by Billie Eilish is streaming from TIDAL via my phone, and the bass is exceptional. I don’t think I’ve ever heard bass as full and extended from true wireless as these are producing. They sound huge. The extended deep bass notes are reproduced solidly by the earphones, which no loss of energy as time progresses. The tonal descents at the end some of the bass notes are reproduced full, in detail. Eilish’s voice is produced cleanly, and with a close-miked intimacy (in those parts where it isn’t being heavily processed). Everything sounds close. There’s little of the sense of distance that truly fine in-ear earphones can deliver, but that doesn’t detract from an exciting, and highly enjoyable, delivery of music. In any case, it would be ridiculous to expect those kinds of high-end characteristics from a set of $200 earphones.

    ag TWS04K true wireless earphones

    Billie Eilish’s bass is synthetic, so how about something that involves actual instruments? Billy Paul’s 1973 track “I See the Light” from the album War of the Gods is just that. Everything in the music – including the bass – was in superb balance.

    I went through a period, perhaps five years ago, of despairing of the possibility of reasonable tonal balance in true wireless earphones. So many of them came with horribly ear-piercing treble and no sense of musicality. In recent years an increasing number of enjoyable, if not entirely accurate, true wireless earphones have appeared. They achieve this low bar – enjoyability, listenability – simply by not being painful. And that means a moderately accurate tonal balance.

    The ag TWS04K earphones provide that, plus that something extra: a deep, powerful bass that “completes” music.

    I flipped around a few genres, just to make sure I wasn’t being misled. Schubert’s String Quintet in C isn’t chock-a-block with bass, despite the use of two cellos, but it is very revealing of any screechiness in earphones. And there was none. Instead, there was just a solid, listenable delivery of the music.

    Now, let me be clear about this. While the ag TWS04K earphones have been tuned by Final Audio, they aren’t going to challenge that company’s higher-end IEMs. Final Audio’s own IEMs typically deliver an exuberant, open, loudspeaker-like performance. But ag and Final Audio have between them produced a tonal balance that works extremely well for just about any music.

    Once I’d settled on size 4 out of 5 of the included silicone ear tips, I found that these units gave excellent isolation from excellent isolation from outside noise, and a first-class seal to allow the delivery of the aforementioned bass.


    The ag TWS04K earphones are … well, ridiculous. They deliver a balanced performance, with an almost unbelievable bass. They do not include active noise cancellation, but compared to the Sennheiser Momentum 2 earphones, which do include this, the difference in protecting me from noise was, at best, minimal.

    These earphones are astonishing value for money.

    AgTrue wireless earphones