« Last post by Paul2 on November 17, 2021, 02:14:14 AM »
yeah. over 2 years ago, around mid 2019, probably on around may 2019, my middle brother introduced me to his blue tooth headphones and when i first used it, i was hooked. its better than wired headphone that i don't get wire touching my body where it was connected to my smartphone in my pocket.
with bluetooth wireless headphones, there are no wires going through from where my ears are to my pant's pocket. so anyway, if i remember correctly, not long afterward, i checked out about bluetooth specs online, either that or i did read a little bit about blue tooth technology years prior where is said blue tooth data rate is like 300 kbps to around 400 kbps. maybe its 400ish kbps and so that means it can't playback uncompressed cd audio quality sound since uncompressed cd audio quality bitrate is 1.4112 mbps or 1,411.2 kbps. it needs like 4 times that bitrate to playback uncompressed cd quality audio.
so that means if you playback uncompressed cd quality which is again 1.4112 mbps via bluetooth, it will compressed it down probably lower than 400 kbps in lossy quality before the transfer. maybe 256 kbps is my guess. if that is the case, then about 5.5 times of data has been compressed out in lossy quality. 5.5 times of lossy compression is still consider mild compression. that means most listeners might not notice much of a difference compare to uncompressed or lossless compression for that matters since the compression is quite mild.
not long after that, maybe a year later or so (it could be months later for all i remember), i happened to read that newer bluetooth chipsets can support up to 1.536 mbps but the range has been cut down 4 folds. older bluetooth versions can transfer data up to 10 meters away in distance between two blue tooth devices which is 33 ft apart. while newer blue tooth supports transfer speed of 1.5 mbps or 1,536 kbps which is about 4 times more than older version but the range has been cut down to about 4 times which is like 2.5 meters or about 8 feet apart. i could be wrong though since i don't really remember that well of what i read about the newer blue tooth chipsets versions.
so anyway, 1.536 mbps should be enough to transfer 1.4112 mbps of data via bluetooth and even better, lossless codec like flac should on average compressed it down to about 1 mbps for audio and decode it back to 100% uncompressed audio.
a few days ago after i happened to read your reply to this post, i got curious and googled bluetooth and went to wikipedia link and read somewhat more about it and it said newer bluetooth can supports up to 2 mbps for the low power consumption or something like that which is cool, a bit better than 1.536 mbps. i also skimped through the part where it said the difference between blue tooth and wi-fi and i got confused of what its talking about if i remember correctly so i jus skimped through it but i guess blue tooth consumes less energy hence why the data rate is low while wi-fi can send data much higher than blue tooth but consumes more power i think.
i also read that blue tooth can send data higher than 2 mbps but it also consumes more power i think. just how much higher i don't remember but i don't feel like looking it up. kind of lazy and tired now. recently, when i forgot my blue tooth headphones in my middle brother's car, i just used a wired headphone to listen to musics on my smartphone when i went outside for a walk, i can kind of hear that the sound quality via uncompressed connection on my wired headphone sounds a bit crisper than my blue tooth headphones. all three of my wired, wireless headphones, and my smartphone are cheap though so the dac on my smartphone for the wired headphone is about as good as the dac done in the wireless bluetooth headphone. except the big difference is the sound is being process in uncompressed quality via analog wired headphone plug.
sorry for this long story. i am bored and just wanted to share of what i know even though my knowledge is not that much.
oh yeah, one last thing, since blue tooth consumes less power that means blue tooth headphones batteries should last a long time before it runs out. no wonder my blue tooth headphones can last as much as 30 hours of playback like it claimed before it needs a recharge.