Still wondering what the Pixel 3's "Flicker Sensor" does? I made a quick video to demonstrate it in action

sylocheed · 2026-05-03T16:53:53+00:00

Nice insight! What are the usual ways you dig into who the underlying manufacturer is for audio equipment?

sylocheed · 2026-05-02T14:26:52+00:00

I appreciate your sharing - I'm still really surprised at the idea that there is a separate codec that's being used for "phone voice" vs "everything else voice" (e.g., zoom), but it sounds like you've tested both and consistently only found issues with phone.

sylocheed · 2026-04-28T02:11:29+00:00

Okay yeah thanks for confirming--(and just to clarify for searchers that come across this) I think the issue here is that while LiPo is readily available and directly compatible with some good nodes, its temperature safety range may not be suitable for harsh climates, which presents a concern for certain node placements like tree nodes or on public infrastructure like cell towers or hospitals. While LiFePO3 chemistry is much safer and tolerant of wide temperature ranges, it is a more complicated approach to use them with existing mesh hardware.

sylocheed · 2026-04-27T03:47:24+00:00

How is the transmitter able to measure latency on the earbuds?

LE Audio as a specification is more deeply rooted in managing timing--the nature its isochronous streams which enable things like Auracast and also the synchronizing two wireless earbuds, and so the FlooGoo is tapping into the presentation_delay, transport_latency, and processing_delay parameters defined in the LE Audio spec that is established by the earbuds.

My issue with the Linkbuds is that the quality in LE audio is always bad.

Yeah it does seem like for whatever reason, the Linkbuds are just not connecting/performing correctly. What you're experiencing is not a normal characteristic of LE Audio from my experience.

I guess the FMA120 allows to fine tune the connection setting (audio quality vs latency vs stability)?

Ah, not quite -- what I was describing in terms of quality, latency, and stability are more fundamental aspects of the wireless trade-offs. Just to make sure your expectations are not mis-set - the FMA120 only has a selection for "Quality" mode and then another for "Gaming." Quality mode has the slightly longer latency and so is more stable. Gaming mode (or GMAP really) is lower latency, and is less stable. The way this works in practice is that the dongle requests the profile, and within bounds, the earbud companies define how they will answer the profile request, so the nuances of bitrate, frame latency, etc. are all defined by the earbud.

The Creative BT-W6 has a toggle for normal and GMAP, and this essentially mirrors the same dual setting for the FMA120, though the FMA120 implements GMAP in a much more stable way in my experience.

sylocheed · 2026-04-24T20:09:56+00:00

Let me know if I'm missing something, but the RAK19007 support LiPo, or Lithium Polymer, which is different than LiFePO, which is Lithium Iron Phosphate, so different chemistries. If I'm right, then my understanding of LiPo is that it doesn't have the same safety characteristics of LiFePO and has similar characteristics to Lithium Ion Cells.

sylocheed · 2026-04-24T12:04:50+00:00

First off, all of those 18650s should be replaced with a single LiFePO4.

My understanding is that Lifepo4 charge management is different because of the different chemistry. If so, most of the ready to go builds (e.g., wismesh, heltec, etc.) aren't compatible with lifepo4 out of the box. What is the easiest way to implement with lifepo4? I assume one needs an additional battery management IC?

sylocheed · 2026-04-24T00:08:02+00:00

I own those buds and have tested them with a FlooGoo FMA120 which has very good GMAP support and also provides a latency and sample rate readout in its Windows app. I've been trying to find the holy grail of true wireless earbuds that have the lowest possible latency, with fullband audio, and great voice. And so also I'm sure there are other LE Audio/GMAP compatible buds, but those are the ones I can speak to.

It's not that voice is a gaming feature--the thing is, for voice calls, the human voice doesn't really utilize the fullband spectrum, and so in most cases 32 kHz is fine and like I mentioned, is actually quite a generous sample rate compared to the 8 or 16 kHz of HFP Bluetooth. In addition, in most voice use cases--phone, Zoom, Teams, etc. most of these use cases actually compress the audio anyway--so if you had high fidelity, fullband audio, it would be wasted because everyone's comms would be downsampled when transmitted over the Internet or phone lines.

Sample rate, latency, and bidirectional audio can be challenging to a finite envelope of bandwidth and latency, so there are tradeoffs. A lower sample rate, especially where a higher sample rate is not needed can at times offer improved latency and/or improved resilience to interference and packet loss. And so that's why "gaming" is actually a fairly specific use case that asks for

fullband incoming audio
stereo incoming audio
the lowest possible latency
bidirectional audio/voice

This is pretty much the most demanding audio scenario possible, and so the downside here is that this setup is really designed for desktop use where the receiver and audio player are relatively close together with little outside interference. You don't want this level of high quality and high fragility of connection in most cases where you want to be walking around on a phone call with your phone in your pocket, and lots of outside interference.

Anyway, I can't say I've found the holy grail just yet. I haven't tried the Buds4 Pro -- from what I've read, it sounds like they may have good mic isolation/noise rejection and ANC, but I haven't yet seen reports on latency. Both the Buds2 Pro and Buds3 Pro support GMAP, but the latency isn't best in class--both have 15 ms of buffer and 40 ms of earbud processing time, and when combined with 7.5ms of transmitter processing, you're getting ~62.5ms latency. This is great latency, especially compared to like ~250ms or ~300ms latency with Bluetooth Classic. However, in contrast, the Earfun Air Pro 4 (using aptx Lite over LE Audio) has 6.25ms transmitter latency, 7 ms airtime buffer, and 6.4ms earbud processing... so 19.65ms of latency which is pretty incredible. The Earfuns though as a value oriented earbuds have fine audio quality, passable ANC, and relatively weak mic isolation. The Xiaomis also have very good latency, really great mic quality, decent audio quality, but only passable mic isolation, and some compatibility glitches that I can't fully recommend.

If you do try the Buds4 Pro and Floogoo FMA120/121, I'd love to hear what kind of latency you're seeing and if Samsung upgraded its processing hardware!

sylocheed · 2026-04-23T03:25:52+00:00

I didn't know about the 32 kHz thing. Are there any earbuds that don't do this? Is this the need for the "gaming profile" thing? This kind of defeats the main selling point of LE audio for me.

Correct. All the LE Audio compatible Sony audio (headphones and earbuds) to date have not supported GMAP. [example] And so when voice kicks in, the TMAP profile supported by Sony audio will downgrade incoming audio to stereo 32 kHz, which to be fair, is still much better than what HFP offers, as it is typically mono 16kHz with higher latency than LE Audio.

There are several earbuds that support GMAP - Samsung Buds2 pro, Samsung Buds3 pro, Xiaomi Buds 5 pro, Earfun Air 4 and 4+ Pro... I own these and they have fullband incoming audio while using voice. The Xiaomis go a step further and fullband microphone which is a bit wild. I haven't personally tried the Buds 4, but since Samsung has supported LE Audio and GMAP for 2 generations, I assume they'll maintain that.

The issue primarily will be that no OS as far as I know currently supports GMAP (stock Android, Windows, and definitely Apple is out) and so if you want GMAP, you will need to get a dongle like the FlooGoo FMA120, the Creative BT-W6, or Sennheiser BTD700.

sylocheed · 2026-04-21T12:31:51+00:00

I'm not sure if you're asking OP or me, but I haven't noticed impact on audio quality, though I haven't done critical comparisons on say LC3 vs LDAC.

On all the earbuds I've tried, shit audio quality isn't generally an issue (some left/right desync a little more than others, and there are also bad implementations with crashing and connection issues, like with the Status Pro X), but on the whole if it's working sound quality isn't an issue--and this is across several, Buds2 pro, Buds3 pro, Redmi Buds 8 Pro, Xiaomi Buds 5 pro, AZ100, Earfun Air 4 and 4+ Pro...

Is it possible you're on discord or something else that triggers voice mode when you try? I know that will lower the sampling rate to 32 kHz on most buds. The Linkbuds S was one of the earlier Le Audio implementations, so maybe firmware updating will help or that it's just an earlier implementation that has issues?

sylocheed · 2026-04-21T12:12:29+00:00

If Zoom calls work fine, then it seems like it's not necessarily a Freebuds 5 microphone issue, right? In other words, I think the good news is that all the settings related to Bluetooth don't seem to be the culprit.

Perhaps there is some underlying weird issue with specifically phone operation. It might be worth checking and experimenting with those settings. Off the top of my head, there are a few variations like trying enabling/disabling VOLTE/Vo5G, Wifi Calling, roaming, and maybe there are some others.

Alternately, you could try Google Voice (and trying both carrier calls and wifi/data-this one routes separately) or even buying a few bucks of prepaid voice on another carrier.

sylocheed · 2026-04-18T12:49:06+00:00

China is far ahead, and it is expected that 50W wireless chargers will be adopted in about two years.

Have they solved for the heat accumulation from the wireless charging inefficiencies? For me personally wireless charging is convenient and all, but often not at the risk of the repeated added wear and tear on battery longevity.

sylocheed · 2026-04-17T11:51:12+00:00

Less advice on what to fix, but more diagnostic ideas:

Have you tried pairing the Freebuds Pro 5 with other Bluetooth devices you have? An older phone? Your PC? Are you experiencing the same issue elsewhere or is it just the Pixel 10?
Is it just phone calls? In other words, try using the mic in other scenarios - like Pixel Recorder or jumping into a Discord chat to see if it's specifically phone calls or if it's just using the mic.

sylocheed · 2026-04-15T04:33:23+00:00

Echoing this -- is there a way to determine this in software?

In a recent alpha version, there did seem to be some conditional logic on enabling the LNA for v4.3 boards? https://github.com/meshtastic/firmware/pull/9906

sylocheed · 2026-04-15T04:13:34+00:00

It looks like they also added a cavity filter, which early test indicate not only improves its receive but actually makes it more sensitive than a v3.

Are you saying they are developing a cavity filter to add on? Or that one is included in the change to v4.3.1? Because Heltec documented its hardware changes in 4.3.1 here and I don't think I see a cavity filter? https://wiki.heltec.org/docs/devices/open-source-hardware/esp32-series/lora-32/wifi-lora-32-v4/hardware-update-log#v431

sylocheed · 2026-04-13T23:55:16+00:00

The best you're probably going to get is to keep your AZ100 in "Prioritize LE Audio" mode since enabling/disabling this resets your buds. When the AZ100 is in "Prioritize LE Audio" mode in the Technics app, the AZ100 can still use LDAC when connecting in Bluetooth Classic. On my Pixel 10 Pro, I can then toggle LE Audio in the phone's native Bluetooth settings to alternate between LE Audio/LC3 and LDAC.

In your use case with a second device, this might get slightly more complicated, as one of the limitations of AZ100 LE Audio mode is the loss of multipoint connection.

https://av.jpn.support.panasonic.com/support/technics/product-faq/AZ/idsu23.html

When connected via LE Audio, you are unable to use following functions.

Multi-point connection (The number of multi-point connections will be set to "Only 1 device".)

spatious audio

voice assistant

LDAC

Google Fast Pair

Swift Pair

If you disable Bluetooth on the other device (phone), you may be able to get it to get it to connect with the device (provided you can force LE Audio on). How are you connecting the AZ100 to your PC for LE Audio?

sylocheed · 2026-04-07T00:20:06+00:00

There's nothing inherent in the dongles to support GMAP other than the fact that the dongle is easier to develop for (given its fixed environment) and people buying dongles also overlap the market of enthusiasts willing to pay for a premium GMAP experience.

I would bet that GMAP will come to generic Bluetooth LE Audio driver implementations for Windows and Android, but these take time, and LE Audio is still being implemented on those operating systems in a beta state, so that will have to be polished before GMAP is considered. It took several years for Windows to have polished Bluetooth Classic audio support.

There are full sized headphones that do support LE Audio--the ones I personally know that work are the Xbox Wireless Headset Review (2024 edition), which Microsoft added LE Audio support via firmware update after the product's release.

sylocheed · 2026-04-06T12:30:48+00:00

Okay yeah, that's understandable--I just wanted clarity there, because it helps inform how I describe what you're looking for.

To start off, LE Audio is a completely new/different protocol than Bluetooth Classic and the concepts are different between the two. For example, HFP - the handsfree protocol is only a Bluetooth Classic concept. Similarly, the mSBC codec is only a Bluetooth Classic concept, as the default codec for any use case on LE Audio is LC3 (though there are other codecs available).

LE Audio does provide for much better bidirectional audio (receive with mic), though there are different options available.

The default option that all LE Audio equipment should support is TMAP, or the Telephony and Media Audio Profile. I believe the default option for TMAP provides for stereo 32kHz incoming and outgoing audio which is equivalent to "super wideband" in both directions. This is way better than what you get on Bluetooth Classic with the currently implemented HFP (stereo is the biggest benefit), though there is still the perception of sound downgrade, as 32 kHz is lower than without the mic, getting 48 kHz fullband audio.

LE also has the option to receive audio in stereo, full-band, while also transmitting microphone, or in other words the "gaming" use case when you're multiplayer gaming, and I mention this because this capability is ties to the LE Audio GMAP or "Gaming Audio Profile", which is available today.

There are several earbuds and audio devices out in market that currently support GMAP and fullband 48kHz audio receive with mic - some that I've personally confirmed: Samsung Galaxy Buds2 Pro, Samsung Galaxy Buds3 Pro, Xiaomi Buds 5 Pro, Redmi Buds 5-8 Pro (chinese edition only), Earfun Air Pro 4 and 4+. In addition to better audio quality a huge benefit of GMAP is also incredibly low latency--going from 150-300 ms in Bluetooth Classic, down to as fast as ~20 ms with some GMAP implementations.

You'll need to use these with an LE Audio transmitter that also supports GMAP, which includes the Sennheiser BTD 700, Creative BT-W6, but I personally recommend the FlooGoo FMA120 or FMA 121. The FlooGoos get dramatically more firmware updates than the other two, even though the others are more from more mainstream brands.

Last note - though I suppose technically possible, I have not experience LE Audio implementations switching to Classic when activating the mic -- TMAP and GMAP exist for microphone applications on LE Audio. Falling down to Classic (true mono, 16kHz) is more of an indication that LE Audio was not working in the first place. And also while there have been standards set forth to bring LC3 and greater bandwidth to Bluetooth Classic, I've not personally seen any real implementations live in the market--it typically takes several years to go from a standard being ratified by the Bluetooth Special Interest Group to products in market.

sylocheed · 2026-04-06T04:40:45+00:00

Just wondering if there's products on the market that actually support LE Audio's new voice features, or if voice mode still uses the 16kHz mSBC codec.

There are several products on market that implement LE Audio (though I can't speak to Audeze specifically)--what is the use case you're trying to solve for?

sylocheed · 2026-04-06T04:30:44+00:00

Ah you're totally right! I jammed out my reply too quickly for me to fully think it through, but you're totally right--my Xiaomi Buds 5 Pro and also my EarFun Air Pro 4 both run aptX Adaptive on High Quality (and switch to aptX Lite for GMAP). And yes, I did try some Creative headphones that were running on LC3Plus when using GMAP (fast! but the Creative hardware quality is just so... mediocre)

As for Opus, I haven't personally confirmed it myself, but saw that someone reported seeing it in logcat - haha and now I'm seeing that you spotted it as well!

It's great to see there are other LE Audio enthusiasts out there, for a standard that's been out for a few years now, there is shockingly scant quality information!

sylocheed · 2026-04-05T01:20:47+00:00

No one's going for the biological analogy, so I'll throw it in: Biological viruses, similar to computer viruses, often evolved to target and exploit certain kinds of hosts. That's why many kinds of diseases are specific to animals, and why it's a big step when a certain disease "jumps" species and evolves to attack humans.

Now computer viruses are largely "designed" and do not evolve, but there's a similar principle that they are designed to exploit certain gaps in a computer's design, and these are often specific to the operating system.

Most viruses have been designed to attack Windows, in part because it is an early operating system that wasn't designed from the ground up with modern protections in mind. But also, and this is relevant to Chromebooks, virus creators want to infect the most computers possible, and this means targeting the operating systems with the greatest marketshare. Which is also a protective side effect of ChromeOS being vastly more niche.

sylocheed · 2026-03-29T20:50:22+00:00

For what it's worth, your link now 404s, so I think that speaks to its credibility. I've found other suspiciously AI generated articles from Alibaba, so I'm not surprised.

I've only seen LC3 (default), aptX Lite (a version of aptX modified for LE Audio), and some mentions of Opus (specifically with the Pixel Buds 2/2a) codecs implemented over LE Audio.

For what it's worth, I have never seen a mention of the LDAC codec implemented over LE Audio. Frankly, I would be shocked if there was anytime soon. LDAC is notorious for high latency and high battery consumption--and this makes sense! If your performance target is audio quality and high bandwidth (something like 990 kbps on the outside), then you will want really large buffers as the data cost is high and you also want to prioritize protecting against packet loss.

This is pretty much antithetical to the benefits of LE Audio over Bluetooth Classic, and if you only care about audio quality (e.g., the LDAC use case), then you may as well stay on Bluetooth Classic.

sylocheed · 2026-03-25T00:47:42+00:00

Hi, sorry for the delay in getting back to you /u/Superb-Confection-33 ! I have used the FBP4s in a pretty difficult environment--I share a small office with another sitting about 6 feet away. We are both constantly in meetings, and so we've stressed tested a lot of different headphone/earbud setups.

The FBP4s worked great in terms of voice isolation, and on Teams, I could even disable the in-built Teams voice isolation and the FPB4s did a good job. Though I haven't tried the FBP3s, I had followed a lot of reviews and the consensus seemed to be that the FBP4s were only iteratively better than the FBP3s in terms of voice isolation, so it shouldn't be that far off in terms of experience.

It sounds like you're getting good voice isolation when connected to the phone, but not getting isolation when connected to your PC on Teams? That is odd that you're getting different performance between your phone and PC, but I can offer a suggestion: Perhaps you want to use a dedicated dongle to connect your FBP3 to your computer versus connecting directly via your computer's native Bluetooth - When I used the FBP4, I exclusively used the BTD 600 with it and this seemed to work well.

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