5 ms·

This is great: SBC is widely supported and this seems like a natural extension of the existing standard. The issue I personally have is not about SBC vs LDAC or

This is great: SBC is widely supported and this seems like a natural extension of the existing standard. The issue I personally have is not about SBC vs LDAC or AAC, but that HFP is garbage. The moment the mic gets switched on, I’m transported back to the 90s. If someone wants to make bidirectional Bluetooth audio that doesn’t suck, I’d be thrilled.

baxuz 3y ago
I really don't understand why HFP is still the industry standard. Even devices within the same ecosystem, like MacBook / iPhone / AirPods seems to use it based on the audio quality. Or maybe it's AVRCP. Sounds horrible either way.
- jeroenhd 3y ago
  There are simply no common successors to HFP. There are a few handsets that use two A2DP streams, but that requires a lot of bandwidth and I don't think support is anywhere close to universal. Bluetooth 5.2 adds BLE Audio which offers more flexibility. The LC3 codec is supported by Windows 11, Android 13, and Linux, and it significantly improves audio quality compared to the older codecs. I'm not so sure about hardware support in headphones, though.
  - deleted 3y ago
    [deleted]
- vlovich123 3y ago
  AVRCP is the control protocol for BT media (e.g. when you volume up or play/pause from your headset). I’m assuming you meant A2DP which is the protocol for receiving audio. HFP is totally separate from A2DP in that it’s a bidirectional audio stream. That bidirectionality is the difficult part - you have in theory tight time bounds for transmitting the data for latency reasons + these cheapo headsets have 1 radio which means they’re nominally limited to tx or rx. Since the assumption for the design is voice calls, you severely clip the microphone audio into the frequency band for speech & transmit mono which is why the audio quality is so bad (+ you further lossy encode it but the frequency reduction is probably the biggest dip). All of this has to fit on top of the PHY packet transport that time-divides access to the channel + has to coex with other 2.4 GHZ radios like WiFi (at least historically). Now, could these designs be revisited? Probably. Maybe radios are small and cheap enough that we should have 2 and a protocol for bidirectional audio that allows independent streams over separate bands with software synchronizing and mixing audio. It’s also possible the audio encoders/decoders could be modernized with more modern compression techniques to improve audio quality without requiring changes to the bandwidth allocation. Bluetooth those is very ossified and the standards bodies move like molasses - most of the investment is in WiFi and radio vendors are more interested in milking what exists now (or coming up with proprietary solutions like aptx) than actually solving the problems.
  - jeroenhd 3y ago
    BLE Audio supports bidirectional audio up to ±1300kbps ("2Mbps" but with overhead subtracted) which is a LOT better than HFP, especially with LC3 as a replacement for the older codecs. I don't think many devices support it yet, but the spec has a perfectly acceptable bitrate for modern audio calls. We just need to wait for hardware vendors to pick up on BT5.1 features. Last I read about these I think the focus for BLE audio was on hearing aids and such, but there's no reason the spec couldn't be used for headphones. BLE audio also allows for things like connecting your headphones to multiple sources and broadcasting audio to multiple receivers. The standard has improved significantly, but without cheap, mass produced chips, these advancements will probably be stuck in expensive purpose-built devices for a while.
    - vlovich123 3y ago
      Yeah I was just reading that the latest standards have improved things so we’ll have to wait a few years for HW to filter out.
  - lloeki 3y ago
    > That bidirectionality is the difficult part Best hack I've come up with when I have to use Bluetooth headsets on calls is to use them unidirectionally by selecting my MacBook microphone as input (try option click on volume control in menu bar). (... but mostly I go wired most of the time).
    - carstenhag 3y ago
      Yep, this is also what u do. On top of that, the MacBook mics are way better than any earbud mic.
    - Pxtl 3y ago
      Just get a wireless headset that uses a USB dongle. It's archaic but it works. I can't stand to be tethered to my desk when I talk. It's annoying and silly how I have a BT headset and a USB-wireless headset on my desk at the same time and I switch depending on whether the call is coming over the phone or the PC, and theoretically I could get one device that does both with a switch (eg. my wife has a Logitech one that does that) but this approach works for me. I've literally gotten a compliment or two on how great the audio is when I'm doing remote presentations, but maybe that's because I often privately grouse about people who are using awful mic setups and so somebody was watching for that. I'm not using anything fancy, I just buy upper-mid-range gaming headsets (the $150US-ish ones that are good-enough that they don't cover them in neon plastic and LED lighting).
- lxgr 3y ago
  Newer HFP headphones at least have mSBC, which sounds slightly less horrible. Still, I’m also surprised that AirPods don’t use anything better within the Apple ecosystem, proprietary or otherwise.
HPsquared 3y ago
Isn't it just the need for low latency? "Media" (music, videos etc) has good sound quality but significant latency. It gets compensated by delaying the video by an equal amount, but it's too much latency for phone calls.
- eptcyka 3y ago
  It's Bluetooth not having enough latency.
  - eptcyka 3y ago
    I meant to say bandwidth.
- therein 3y ago
  > It gets compensated by delaying the video by an equal amount Is this actually done? Who would be doing it, the OS? It just sounds like the separation of concerns and the design of the interfaces would make it pretty unlikely.
  - explodingcamera 3y ago
    It is absolutely done, mostly by the media player/library used, e.g exoplayer on Android has automatic lag compensation for that purpose.
  - magicalhippo 3y ago
    Not always. Just got some wireless headphones at work, and now I can no longer enjoy YouTube videos (mostly KEXP) because of the 100ms audio delay. It's too disturbing even only in side view. So at least with a browser on Windows it's not done.
  - lxgr 3y ago
    I’ve definitely noticed it on macOS. Videos in the browser will stall for a fraction of a second after pressing play to give the audio time to catch up.
  - 3y ago
zwirbl 3y ago
It's slowly entering the market as LE Audio / Auracast. Might be a while till good os support is available though
- Namidairo 3y ago
  While Windows technically supports LE Audio and the profiles required, the encoding and such are left up to the vendor driver to implement.[0] I'm not even sure if Intel's newer products will actually properly do BAP etc. on Windows because of driver support, despite them listing very windows looking software version numbers in the certification on the Bluetooth SIG site. (AX210 and newer should be capable and advertise proper isochronous channel support in their drivers. AX200 and AX201 are not capable, and but kinda sorta advertise isochronous channel support anyway because of a bug I believe. BE200 obviously capable but they have a separate driver on Windows and I have no idea how stable it is in Linux.) [0] https://learn.microsoft.com/en-us/windows-hardware/drivers/bluetooth/bluetooth-low-energy-audio https://learn.microsoft.com/en-us/windows-hardware/drivers/b...
MonaroVXR 3y ago
I can vote for that as well.

baxuz 3y ago

I really don't understand why HFP is still the industry standard. Even devices within the same ecosystem, like MacBook / iPhone / AirPods seems to use it based on the audio quality. Or maybe it's AVRCP. Sounds horrible either way.

jeroenhd 3y ago
There are simply no common successors to HFP. There are a few handsets that use two A2DP streams, but that requires a lot of bandwidth and I don't think support is anywhere close to universal. Bluetooth 5.2 adds BLE Audio which offers more flexibility. The LC3 codec is supported by Windows 11, Android 13, and Linux, and it significantly improves audio quality compared to the older codecs. I'm not so sure about hardware support in headphones, though.
- deleted 3y ago
  [deleted]
vlovich123 3y ago
AVRCP is the control protocol for BT media (e.g. when you volume up or play/pause from your headset). I’m assuming you meant A2DP which is the protocol for receiving audio. HFP is totally separate from A2DP in that it’s a bidirectional audio stream. That bidirectionality is the difficult part - you have in theory tight time bounds for transmitting the data for latency reasons + these cheapo headsets have 1 radio which means they’re nominally limited to tx or rx. Since the assumption for the design is voice calls, you severely clip the microphone audio into the frequency band for speech & transmit mono which is why the audio quality is so bad (+ you further lossy encode it but the frequency reduction is probably the biggest dip). All of this has to fit on top of the PHY packet transport that time-divides access to the channel + has to coex with other 2.4 GHZ radios like WiFi (at least historically). Now, could these designs be revisited? Probably. Maybe radios are small and cheap enough that we should have 2 and a protocol for bidirectional audio that allows independent streams over separate bands with software synchronizing and mixing audio. It’s also possible the audio encoders/decoders could be modernized with more modern compression techniques to improve audio quality without requiring changes to the bandwidth allocation. Bluetooth those is very ossified and the standards bodies move like molasses - most of the investment is in WiFi and radio vendors are more interested in milking what exists now (or coming up with proprietary solutions like aptx) than actually solving the problems.
- jeroenhd 3y ago
  BLE Audio supports bidirectional audio up to ±1300kbps ("2Mbps" but with overhead subtracted) which is a LOT better than HFP, especially with LC3 as a replacement for the older codecs. I don't think many devices support it yet, but the spec has a perfectly acceptable bitrate for modern audio calls. We just need to wait for hardware vendors to pick up on BT5.1 features. Last I read about these I think the focus for BLE audio was on hearing aids and such, but there's no reason the spec couldn't be used for headphones. BLE audio also allows for things like connecting your headphones to multiple sources and broadcasting audio to multiple receivers. The standard has improved significantly, but without cheap, mass produced chips, these advancements will probably be stuck in expensive purpose-built devices for a while.
  - vlovich123 3y ago
    Yeah I was just reading that the latest standards have improved things so we’ll have to wait a few years for HW to filter out.
- lloeki 3y ago
  > That bidirectionality is the difficult part Best hack I've come up with when I have to use Bluetooth headsets on calls is to use them unidirectionally by selecting my MacBook microphone as input (try option click on volume control in menu bar). (... but mostly I go wired most of the time).
  - carstenhag 3y ago
    Yep, this is also what u do. On top of that, the MacBook mics are way better than any earbud mic.
  - Pxtl 3y ago
    Just get a wireless headset that uses a USB dongle. It's archaic but it works. I can't stand to be tethered to my desk when I talk. It's annoying and silly how I have a BT headset and a USB-wireless headset on my desk at the same time and I switch depending on whether the call is coming over the phone or the PC, and theoretically I could get one device that does both with a switch (eg. my wife has a Logitech one that does that) but this approach works for me. I've literally gotten a compliment or two on how great the audio is when I'm doing remote presentations, but maybe that's because I often privately grouse about people who are using awful mic setups and so somebody was watching for that. I'm not using anything fancy, I just buy upper-mid-range gaming headsets (the $150US-ish ones that are good-enough that they don't cover them in neon plastic and LED lighting).
lxgr 3y ago
Newer HFP headphones at least have mSBC, which sounds slightly less horrible. Still, I’m also surprised that AirPods don’t use anything better within the Apple ecosystem, proprietary or otherwise.

HPsquared 3y ago

Isn't it just the need for low latency? "Media" (music, videos etc) has good sound quality but significant latency. It gets compensated by delaying the video by an equal amount, but it's too much latency for phone calls.

eptcyka 3y ago
It's Bluetooth not having enough latency.
- eptcyka 3y ago
  I meant to say bandwidth.
therein 3y ago
> It gets compensated by delaying the video by an equal amount Is this actually done? Who would be doing it, the OS? It just sounds like the separation of concerns and the design of the interfaces would make it pretty unlikely.
- explodingcamera 3y ago
  It is absolutely done, mostly by the media player/library used, e.g exoplayer on Android has automatic lag compensation for that purpose.
- magicalhippo 3y ago
  Not always. Just got some wireless headphones at work, and now I can no longer enjoy YouTube videos (mostly KEXP) because of the 100ms audio delay. It's too disturbing even only in side view. So at least with a browser on Windows it's not done.
- lxgr 3y ago
  I’ve definitely noticed it on macOS. Videos in the browser will stall for a fraction of a second after pressing play to give the audio time to catch up.
- 3y ago

zwirbl 3y ago

It's slowly entering the market as LE Audio / Auracast. Might be a while till good os support is available though

Namidairo 3y ago
While Windows technically supports LE Audio and the profiles required, the encoding and such are left up to the vendor driver to implement.[0] I'm not even sure if Intel's newer products will actually properly do BAP etc. on Windows because of driver support, despite them listing very windows looking software version numbers in the certification on the Bluetooth SIG site. (AX210 and newer should be capable and advertise proper isochronous channel support in their drivers. AX200 and AX201 are not capable, and but kinda sorta advertise isochronous channel support anyway because of a bug I believe. BE200 obviously capable but they have a separate driver on Windows and I have no idea how stable it is in Linux.) [0] https://learn.microsoft.com/en-us/windows-hardware/drivers/bluetooth/bluetooth-low-energy-audio https://learn.microsoft.com/en-us/windows-hardware/drivers/b...

MonaroVXR 3y ago

I can vote for that as well.