Sound quality for my calls on both sides improved dramatically! Since I've discovered this, I tell all my colleagues in our zoom meetings to switch microphones and it's immediately better for everyone on the call (not just the user that was using HFP).
This is because if you use the hands free profile, it'll use a codec that encodes your voice in a terribly bad bitrate, and even worse, the sound you hear in the headphones is also using a terribly low bitrate.
They should finally fix HFP (Hands Free Profile) spec as it's literally impacting call quality for billions of people.
Edit: apparently LE audio is a thing, but device support is still terrible.
Maybe not a problem with Macs, but call quality on most laptops using the built in mic is bad enough that people on the other side will have a bad impression of you.
I actually told him many salespeople get this completely wrong and sound like an absolute Muppet on their expensive headsets without even realizing it and explained to him that anything Bluetooth is basically never going to sound amazing. There’s a lot of snake oil in the market. I got some nice Sony earbuds recently. Tried it once and I was barely audible apparently. That’s supposedly a high-end option. It’s OK, I got them for music and podcasts and wasn’t expecting much for calls. But it managed to underwhelm me on that front. The weakness is Bluetooth and the standard codecs supported on Mac/Windows. You are basically screwed no matter what BT headset you use. For phones, it depends.
Apple fixes this with AirPods by doing a proprietary codec and probably quite a bit of non-trivial sound processing. None of that is part of the Bluetooth standard, and what little is supported in some newer codecs typically does not work in Windows/Mac. So it will still fall back to that low-bitrate codec that distorts your voice and makes you sound like a Muppet.
If you need to use a phone, getting a USB-C headset can be an alternative. Not that many wired headsets these days, sadly. Even Apple now uses USB-C. And both Android and iOS support most USB-based sound equipment.
I take most calls with my Mac. I configured an aggregate device with the MIDI tool so that my headset doesn’t hijack the microphone. Nice little hack if you have some decent BT headphones. On a Mac, the microphones in the laptop are likely way better than the vast majority of headsets. And that’s before you consider the latency and heavy compression Bluetooth adds to the mix.
Do you have any sources for that claim?
As far as I understand (and based on what I've seen in some Bluetooth debugging menus at least a few macOS versions back), for HFP they just use regular mSBC.
That's an optional codec for HFP (while SBC is mandated for A2DP), and a step above absolute potato quality G.711/PCM u-law, but still part of the regular Bluetooth HFP specs.