
Ask HN: Why is Bluetooth audio always so bad? - pje
Pairing is famously a UX nightmare [0]. Even Apple&#x27;s AirPods cut out constantly, suffer from interference from other nearby devices [1], and apparently just don&#x27;t work in an open space [2].<p>To people with Bluetooth expertise: Why is the Bluetooth audio experience always so...bad? Are there some fundamental technical limitations in the spec? Are my expectations unreasonable? Or is it just always implemented poorly? Followup: are there competing technologies that Just Work™?<p>[0]: https:&#x2F;&#x2F;xkcd.com&#x2F;2055&#x2F;<p>[1]: https:&#x2F;&#x2F;support.apple.com&#x2F;en-is&#x2F;HT209369 (&quot;move away from places [with] a lot of Wi-Fi activity&quot;)<p>[2]: http:&#x2F;&#x2F;www.iphonehacks.com&#x2F;2018&#x2F;04&#x2F;heres-why-your-airpods-or-other-bluetooth-headphones-cut-out-while-crossing-a-street.html
======
conception
So, no one has touched on a technical limitation. Bluetooth sucks for going
through water. (If you like The Maths
[http://www1.lsbu.ac.uk/water/microwave_water.html](http://www1.lsbu.ac.uk/water/microwave_water.html)
)

Guess what people are mainly made of?

So, if you are standing between a BT transmitter and a BT receiver a lot of
magic needs to happen to get the data moving between the two.

People love Airpods. People often put their phones in their pockets. A lot of
water in the way.

If you notice BT being particularly terrible, look for how water might be
blocking the signal.

This, of course, isn't the cause of all BT problems, but knowing this
fundamental really helps troubleshoot when you run into a lot of them.

~~~
K2L8M11N2
WiFi also uses 2.4 GHz (or even higher in newer versions) and it seems to be
much more resilient. Is it really a matter of the underlying electromagnetic
link?

~~~
yuhc
Mostly bc WiFi has stronger signal, and the protocol is designed for higher
speed and better stability.

------
avian
> Are there some fundamental technical limitations in the spec?

It's the same issue as with practically everything else digital these days.
Hugely complicated thousand-page standards that few, if any, understand in
their entirety. Implementations that are rushed to market to "be fixed later
because it's just software" \- which never actually happens because the next
thing comes along and instead of fixing existing shit it's again a rush to the
deadline to push more of it out the door.

~~~
seph-reed
My dream is for society as a whole to decide we should just go back to the
beginning and fix things starting from there until we catch back up with the
present and blast right off into the future. For instance, agriculture. It
really seems like there shouldn't be any problems. But even a farmer who's
outstanding in their field will run into plenty of things that probably should
have been solved centuries ago.

~~~
greenpizza13
> outstanding in their field

I see what you did there.

------
Gibbon1
It's a low power legacy frequency hopper with a bloated USB like network stack
that isn't USB. That was the design from the very beginning.

It's unfixable.

My honest professional opinion is the people that wrote the spec had no idea
what they were doing.

~~~
jonny_eh
Would anyone at the time know what they were doing? Was there ever a similar
protocol in existence yet? If the answer is yes, why did we need BT to be
created?

~~~
Gibbon1
20 years ago I was working on firmware for cheap narrow band spread spectrum
cordless phone IC's.

It's easy to see the mistakes they made. If you look at the early to mid
1990's, there were cheap FM radio IC's that drew a couple of ma. At the same
time ISM band microwave IC's were expensive, made of GaAs and just an LNA
would cost you 50-100ma.

Wifi did exist back then. But the cost was around $150-200 for a chip set and
the power requirements precluded battery operation.

So 'of course' they went with a low power FM radio.

The problem was as you shrink CMOS transistor sizes they get faster. By the
late 1990's you could build a direct sequence transceiver IC out of CMOS. The
one my group rolled out in 1999 drew about 200mA in receive mode and cost
$4/1M

Zigbee came two three years later and the power requirements were down to
25-50mA.

Bluetooth designers completely failed to judge the progress being made in CMOS
RF IC design. That was completely obvious to anyone in the industry.

The second problem had to do with the baseband. The Bluetooth baseband has
several layers and essentially replicates the USB protocol/driver stack.
Notice how easy it was for Microsoft to roll out the USB stack? Yeah total
shitshow.

So you had a dumb simple frequency hopping radio married to a complicated
baseband.

The rub, out of about two dozen companies that tried to build Bluetooth
radios' circa 2000, all but three failed. Because they couldn't get the base
band power consumption low enough.

Usually when you design a spec like Bluetooth you get your potential
manufacturers on board working on silicon as you design the spec. They didn't.

Notable the Zigbee spec had the same problem with it's baseband and most
people solved that problem by ignoring it and just using the radio.

A third problem (which effected Zigbee as well) is the transmit power was too
low. Made worse with Bluetooth because the FM radio's sensitivity sucks. Back
then I knew from cordless phone stuff that you needed at least 5db of transmit
power to get reliable QOS. Bluetooth and first gen Zigbee radio's had less
than 0db.

All of the above a small brained primate like myself could have told you.

~~~
Gibbon1
> because the FM radio's sensitivity sucks.

It's worse then you think because Bluetooth is a frequency hopper which means
Streaming QOS is limited by the link margin on your worst channel.

------
jdietrich
The core Bluetooth spec is 2985 pages. Essentially no-one correctly implements
it; it's arguable that the spec is sufficiently complex, vague and self-
contradictory that it's impossible to correctly implement. Unless you're using
two devices by the same manufacturer (Earpods with an iPhone, a PS4 with the
PS4 controller) your odds of getting a consistent, reliable experience are
vanishingly slim.

~~~
rwz
I use airpods with an iphone and I constantly get connection issues, only one
pod playing, or sound cutting off.

~~~
pwinnski
Is it possible you have a defective pair of AirPods?

------
necovek
If I remember correctly, the bluetooth headset profile (if you require
microphone input) is pretty low bandwidth (think gsm quality), which would
explain low quality in that case.

Newer Bluetooth variants support higher quality audio without a microphone
(A2DP), and that's what you are likely using today unless you are in a call.

As far as interference in the 2.4GHz range, there is not much you can do about
it in areas you don't control.

~~~
skykooler
On that topic: why isn't there a way to connect headphones via A2DP and the
microphone with HSP? It's rather disappointing that I have headphones with a
built in mic, but I can't use the mic while using them as headphones.

~~~
dole
Limitation of the particular Bluetooth version (4 vs 5?), needs to use one or
the other. Believe it's addressed in a later version, either by a new profile
or maybe similar to the solution you suggest. Did a little research into this
after going nuts when headphone quality dropped when the mic turned on in a
mobile game.

------
unfocused
I'm still annoyed that I can't get FM radio to route over Bluetooth without
getting some bizarre up.

My old Moto G could play FM Radio, and you could select Bluetooth as the
output. Fast forward to today, and the Samsung A50 (in my hands right now),
has the ability to pick the app, and select the output to Bluetooth, but it
doesn't work for FM Radio. Why? Because Bluetooth is just not consistent in my
opinion.

EDIT: I am probably in the minority of people that insist on FM Radio on their
phone. Just putting that out there as most people will not run into my
problems.

~~~
yetihehe
Probably because FM is typically purely analog. You need to record signal,
then compress it realtime and send through BT. That uses up battery. When
using plain FM Radio, you just connect signal from fm chip to output
amplifier.

~~~
unfocused
That's a good point. The old Moto G did this out of the box. The newer ones,
cannot. You need some "bluetooth router app". Beware of super spammy links if
you google that. It's not an elegant solution and may or may not work
depending on when Android gets updated.

Right now the A50 has a really nice sounding tuner with either my Samsung
earbuds or Sony Headphones. NextRadio appears to be winding down it's
features, so you have to use the basic tuner, and manually seek to each
station, and add it to your favourites.

All this to say, there's not a lot of attention to FM Radio.

~~~
AstralStorm
We could be using more advanced variants of DAB+/DVB/DMB protocols instead. It
is still simple compared to WiFi but way more resilient than Bluetooth. But we
get regulation in the way...

------
neonscribe
Bluetooth audio quality, while still noticeably worse than wired connections,
is much better on iOS devices using the AAC codec than on earlier codecs.
Check device specs before buying. Many currently available Bluetooth devices,
even some very inexpensive ones, support AAC. Use aptX on Android, AAC on iOS.
If you care more about quality than convenience, use a wired connection. If
you are listening to contemporary popular music with extreme dynamic range
compression (not the same as data compression), you might not even be able to
tell the difference between a quality Bluetooth codec and a wired connection.

~~~
LeoPanthera
Recent versions of both iOS and Android include an improved SBC encoder that
have a perceived quality equal to aptX, so, as long as you're using a modern
device, the codec quality issue is largely moot.

------
marrone12
Bluetooth is much better on Android/Desktops with support for apt-x HD low
latency codecs.

~~~
sofaofthedamned
Also LDAC on the Sony headsets

~~~
lesny_ludek
Yeah, LDAC is mostly supported in new versions of Android. It's really
impressive on the Sony Wh-1000xm3 headsets.

[https://www.soundguys.com/ldac-ultimate-bluetooth-
guide-2002...](https://www.soundguys.com/ldac-ultimate-bluetooth-guide-20026/)

------
ReptileMan
Well Sony WH1000 MX2/3 perform really well, so do Bose QCII and the Harman
Kardon Esquire also provide high quality sound.

BT headphones can and do sound nice.

~~~
flyinghamster
My dad recently bought himself a WH-1000MX3, and after trying it myself, I
wound up also buying one. Pairing it with my LG Android phone was no problem,
and I'm quite impressed with both the audio quality (wired or Bluetooth) and
the noise cancellation. They blow away my old MDR-NC60 set in both categories.
Sony knocked it out of the park with this set.

It feels weird to shut them down and remove them in a room with modest
background noise and feel, for a few seconds, that the noise is quite loud.

The only nitpick I have is, after reading the legalese, I decided that there
was no way in hell I was going to use the Sony Connect app, but the phones
sound so good to begin with that it's unnecessary to install it in any case.

------
seph-reed
I do not know why it's so bad, but I do make a point to rant about it whenever
I can (around friends). I've had terrible luck with it, absolutely never works
for me. Another thing I've noticed about it which drives me crazy is that some
devices will try to make up for issues by stretching/shrinking audio. This
will either distort the tonality, or the rythm... but either way it messes up
the song. And it blows my mind. Aux cords are cheap and foolproof.

In terms of alternatives, I have heard "zigby" mentioned. Also, aux cords Just
Work. And I know this wouldn't work for everything, but I always wish I could
have infrared transmission wherever possible. Even if I can't actually hear
the transmissions, it still feels very loud to be blasting bluetooth out in
_every_ direction.

~~~
mdszy
Do you mean ZigBee?

[https://zigbee.org/](https://zigbee.org/)

~~~
seph-reed
That's got to be the one.
([https://en.wikipedia.org/wiki/Zigbee](https://en.wikipedia.org/wiki/Zigbee))

My friend who's an electrical engineer is quite fond of it. I really don't
know more than his opinion

~~~
mdszy
I haven't really heard of it being used for audio streaming, I think it's more
suited for creating mesh networks meant for IoT purposes.

------
bni
SBC codec, that is default and mandatory suck ass. It was chosen because they
didn't want to pay the patent licensing fees of something better.

SBC was made for voice and is acceptable for that. Better codecs like AptX and
AAC exists in many devices now, but because of incompabilites SBC is often
negotiated anyway.

~~~
KozmoNau7
SBC can be quite good, but only if your devices can agree on a high enough bit
rate. BlueZ on Linux can be prodded into negotiating a bit rate that's higher
than default, and then it sounds pretty good, certainly good enough for BT
speakers.

SBC is not a bad codec. It is a low complexity codec (sort of similar to MP2)
optimized for low power consumption and quick encoding/decoding, and I think
it's been unfairly maligned, due to devices that are way too stingy with bit
rates.

~~~
bni
ok, you are probably correct.

BT music from my iPhone to my car stereo sounds bad. There I cant verify what
codec or bitrate is used, but clearly is a difference when comparing to a
music file played from an SD card reader on the dashboard.

I also have a pair of Sony bluetooth headphones that I use with my MacBook,
here the sound is awful, until I use a BT utility to choose aptX instead, that
they also supports, but SBC is default selected anyway.

------
dirtyid
Wish there's easy way to broadcast to multiple devices to share media. Had to
use a bluetooth audio receiver with 3.5 jack + splitter + 2 cable headphones.

Also what is it about specific intersections that reliably causes connectivity
/ stutter issues? Is it something specific to the traffic signalling equipment
or spectrum pollution? It happens more in dense urban environments but there
are several extremely bland pedestrian crossings in my neighborhood where this
happens as well. And then only on certain headphones.

Also the fact that battery reporting is still not standard is annoying.

------
joncrane
I just bought a new car with BlueTooth integration, my first such car. I
listen to Pandora when I drive.

I notice that the connection is not reliable, even when the phone is in a
holder on the dash. I end up using the AUX input through the headphone jack.

I'm wondering if this is a common problem in cars, or if I should have my car
looked at.

~~~
pwinnski
Surveying audio support in cars over the last few years has taught me that car
manufacturers have some of the worst tech around. It's almost universally bad.

Toyota seems to be less bad than most. I'm sure some others are also less-
than-horrific. Maybe Tesla?

~~~
joncrane
Interesting, mine is a Toyota 86 (which I guess is really a Subaru BRZ so I
guess it's Subaru's Bluetooth stuff).

~~~
RotsiserMho
I drive a 2013 FRS (older US version of the 86) and I'll experience weird
dropouts all day like once every couple of months. Otherwise it works
flawlessly. Very strange. You might try using it now and again and see if the
problem "just goes away". Very frustrating though. I did not opt for the
touchscreen however. I think my head unit is made by Pioneer.

------
rl3
As far as the UX nightmare, I'd attribute that aspect to the same problem EFI
has: there are too many implementations, and most of them suck.

------
dingo_bat
I think you've used only bad devices so you've had a bad experience. Use a
good pair of Bluetooth headphones like Sony WH1000 or Bose Qc35 along with a
good phone like Galaxy S10. It's perfect. No cut outs, amazing quality, insane
range.

~~~
p1esk
FYI, you might be shadow banned.

~~~
dingo_bat
I know but I don't know what to do about it :(

~~~
p1esk
Email hn@ycombinator.com and find out why they banned you.

~~~
triplesec
it's really weird, because most of your (apparently perfectly ok) comments are
dead, but some not, like this one.

~~~
p1esk
It’s because I vouched for this one.

~~~
triplesec
ok, but then you can't reply to dead messages, so you must have some kind of
magic button!

~~~
p1esk
That magic button is called “vouch”.

------
moonbug
Go check the page count of the Bluetooth specs, and you'll have your answer.

------
mikestew
_Followup: are there competing technologies that Just Work™?_

The W1/H1 chips, here after referred to as "Makes BT Not Suck" chips or MBNS,
are the reason I put up with the otherwise unremarkable sound quality of Beats
Studios and AirPods. I was reminded why just recently as I took the Bluetooth
speaker out to the garage so the wife and I could do yoga. "Oh, yeaaaahhh. I
have to go find the last device it was connected to, and disconnect it. Then,
and only then, can I pair to her iPad."

If I had a HomePod or other AirPlay speaker in the garage, no matter what the
speaker was connected to previous, I could have just told the iPad to use the
speaker and be done with it.

~~~
steveeq1
How are airpod sound quality "unremarkable"? They sound good to me. . .

~~~
mikestew
Not bad, not great. I've heard worse, I've heard better. They get the job
done, but I otherwise have nothing of note to say about their sound quality.
That's the thing about being unremarkable: I by definition don't have much
else to say. :-)

