2018 Bluetooth Audio Codec Comparison Guide

gene

gene

Audioholics Master Chief
Administrator
Ratings
4,791 25 9
#1
One of the most important conclusions we took away from CES 2018, is that true wireless hi-fi has finally coming of age. Vendors have demonstrated new audio products using aptX HD and LDAC codecs, these are the high-resolution options we’ve been waiting for. Wireless audio over Bluetooth can be confusing, but it’s never sounded better than ever before. This article breaks down the different flavors of codecs and discusses how near CD quality audio is now possible over Bluetooth.

girl.png


Read: 2018 Bluetooth Audio Codec Comparison Guide
 
BoredSysAdmin

BoredSysAdmin

Audioholic Overlord
Ratings
5,878 22 38
#2
BT Transport =! Audio codec
Higher maximum BT transport throughput does not guarantee better quality.
I've heard plenty of AAC audio compressed at 128mbps, which should have been sufficiently low to use even basic SBC, but yet SBC always sounded like crap to me.
 
A

alvester

Audiophyte
#3
There are some prominent exceptions to "A common complaint about most Android phones is that the phone initiates the aptX handshake without notice to the user. Sure, it’s an automated convenience, but the drawback is that it’s often not possible to find any settings to prove that your phone is using aptX, leaving the listener with no method of switching between aptX and SBC."

On all of Google Pixel phones (and some older Nexus phones) the current codec used during active Bluetooth audio playback can be seen after enabling Developer options. To do this go to Settings - System - About Phone - Build Number. Tap on Build Number repeatedly until a notification comes up saying Developer Mode has been enabled. (I think 7 taps unlocks Developer Mode.) After this within Settings one can then see the newly enabled "Developer options" section. Enter this section, scroll down to the Networking section where the cutrently used Bluetooth codec will be displayed during playback.

By default when there's no Bluetooth audio connection it will display as SBC at least on my Pixel XL. Only when connected to devices using higher-than-SBC codecs will the setting then switch.

Within this section you can even adjust the LDAC options to favor connection reliability or highest level of potential sound qaulity by maxing out the Bitrate. When I connect to my various Sony LDAC speakers the codec displayed in this section switches to LDAC and when I connect to my various APT-X enabled headphones it displays the connection as being APT-X.
 
RichB

RichB

Audioholic Field Marshall
Ratings
502 6 1
#4
Excellent article.

I do wonder about double compression. I have found that sound in my car is better if I plug in the phone, than if I use Bluetooth. Also, it keeps the battery charged.

When working out, I use Bose QC20's (yes Bose :)) which are remarkable in their noise cancellation and sound pretty good. I considered wireless, but wanted longer battery life, the ability to keep them powered on a long trip, and the option to plug them into airplane audio.

Many of these products are missing a legacy direct plug-in option for travel and options to extend the battery life.

Are there headphones with built-in DACs designed for Apple devices, that would be interesting.

- Rich
 
B

BigH

Audiophyte
#5
My understanding is that aptX uses only 44.1kHz sampling rate, and it uses a fixed 4:1 compression ratio. 44.1k samples/sec x 16-bits/sample x 2 channels = 1.4112Mbps. Divide that by 4, and you get 352.8kbps, which is the fixed rate for aptX and aptX Low Latency. It also uses ADPCM techniques, which are rather old techniques developed in the 1980s. The quality is pretty good, but the overall efficiency of the codec is really not at all competitive with "modern" codecs. By "modern", though, I mean most higher-end music codecs from the last 20-30 years, most of which can achieve ratios of 6:1 up to 10:1 while still achieving the same quality as aptX. mp3, AAC, Vorbis, CELT, etc.
 
B

BigH

Audiophyte
#6
And note that SBC was contributed to Bluetooth as a reasonably good codec that all Bluetooth A2DP products could use and have available for interoperability. As most are probably aware, most companies that own codec intellectual property vigorously protect it, and so aren't generally keen on giving away such things to standards such as Bluetooth where any member-contributed IP required to implement the spec is available to all other members royalty-free under the Bluetooth licensing agreements. So, SBC was far from being top-notch codec even when it was contributed in the early 2000s, and it has fallen even farther behind over the last decade and a half. One big problem with SBC quality is that the quality is pretty much determined by the source device. Many sources will use "medium" quality settings producing a rate of around 200-250kbps. However, while the A2DP spec may call that "medium" quality, most people find it to be pretty bad. There is nothing the sink side (e.g., headphones, speakers, car stereo, etc.) can do about this. At around 330kbps, SBC sounds very good. Not stellar, but acceptable to the majority of listeners. aptX doesn't provide much improvement over this, and most likely a product that has aptX in the first place isn't going to fall back to a lower rate on SBC if the sink doesn't support aptX. And, what little aptX buys you over SBC @ 330kbps comes at the cost of even higher bandwidth usage.
 
B

BigH

Audiophyte
#7
Bandwidth usage may not be a big deal if you're just listening to music from your phone, and you're not using Bluetooth for much else. However, imagine the case where you've got a TV that's receiving video over 2.4GHz Wi-Fi (Bluetooth also uses 2.4GHz band),and is then streaming the audio over Bluetooth. Now imagine that TV also has a Bluetooth remote control, and a Bluetooth keyboard connected, plus Bluetooth 3D glasses. This is an extremely challenging scenario to juggle on a single Bluetooth radio. Increasing the Bluetooth A2DP codec bit-rate just pours gas on the fire.
 
B

BigH

Audiophyte
#8
And even if bandwidth usage is not an issue, most likely you still care about power consumption. Apple accessory design guidelines detail how to use AAC at 256kbps. Hopefully we'll see even lower rates in the future, e.g., 192kbps, 128kbps, or even 96kbps.
 
I

iMak

Audiophyte
#10
Can I use Aptx bluetooth headphones with my iPhone X? Or should I get headphones that support AAC codec?
 
Y

yakman

Audiophyte
#11
"If you’re using a pair of AAC-compatible headphones, you’re theoretically getting no loss in audio quality from your stored AAC files (the iTunes standard) or streaming from the Apple Music service. "

May not be the case here, seems iOS device would still decode, encode again in AAC bluetooth before sending to your headphone.
 
highfigh

highfigh

Audioholic Overlord
Ratings
3,291 9 15
#12
Until recently, I can't think of anyone who would use BT for any application where the signal needed to travel more than 10'-20' because, well, it usually didn't. One of my reps let me test a Mass Fidelity BT receiver that retailed for $299 at the time (~6 years ago) and the one I just saw online is priced at $249. I was using a Denon AVR at the time which worked with Airplay, so I streamed from my iPhone (I never use MP3) to the AVR and to the BT receiver. Not only did the BT receiver sound worse, the signal dropped when I was about 20' away, outside of my garage when the receiver was inside and separated by sheathing and vinyl siding. I. Was. Not. Impressed. I called the company to ask about increasing the range and they couldn't even tell me that SMA cables were easily available online. Meh.

Fast forward to September of this year, when I was in the process of upgrading the audio system at a school gym. I had originally recommended that a HEOS be used since it has more inputs/outputs than Sonos but since the school has a network administrator who didn't want to allow any settings to be changed to allow multicast and the sad fact that the people who would be using it weren't techy enough to load an app, sign in and remember to sign out when they weren't the one sending music to the device, we needed to find something easier to operate that would still communicate with the receiver over more than 100', through three concrete block walls and with a room filled with bags of water (people). The gym teacher overheard us and said that his little Ion Tailgater amplifier uses BT and he can send music over 100', which I didn't believe because almost nobody in the custom end uses or cares about things that don't use WiFi. Then, I saw it in action and I left to find out how this was possible.

Well, it seems that in the last few years, BT has undergone a big transformation and it now covers a much larger distance. I got back at 11AM, read about the changes, looked online for something that might work and ordered it around 11:30AM and it was at my door around 7:30 that evening (thanks, Amazon). I connected it to the stereo in my garage, started the music on my iPhone, started walking and expected it to cut out around 20', but it didn't. I kept walking and it continued to play. I reached the end of my 100' driveway and it was still playing, so I crossed the street. Still playing. I moved behind a tree- still playing. I walked West, which is at a right angle to the original path and it kept playing, so I reversed my direction and walked East. I walked until my house was between me and the BT receiver which, unknown to me, had fallen off of the box it had been placed on. Still played, never cut out and never had a single hiccup so I walked to the point where I had a straight path to the receiver and went back, counting my steps- I was 60 yards from the BT receiver!

I listened to the sound quality and decided that it was better than I had expected- the bass and treble were there, which is more than I could say for the other BT devices I have used and after I installed it the next morning, I walked in a zig-zag path through the gym, which has a full-size basketball court with about 15' of space around the perimeter- never dropped out. I went through the doorways at the far end and it never dropped out, so I contacted the facility manager and showed him how to pair to it and how it held onto the signal. I have had zero trouble calls and these are people who wouldn't hesitate to let me know if something wasn't working.

I bought another BT receiver to test for another customer who wants to put his turntable in a room that can't easily be wired to the basement rack where the other equipment lives, including a Denon AVR with BT. I tested it by connecting the Rec Out from my Sony ES integrated amp which I use for its phono section since I no longer have an actual preamp in my system, only a Yamaha MusicCast WXC-50, my Parasound A23, speakers and a few sources. I paired the BT piece to the Yamaha since it can transmit OR receive and started playing an LP. Sounded good, no objectionable lack of highs and the bass is a bit accentuated. I don't know if this is intentional, but it didn't hurt anything. I haven't tried it with headphones but, since I don't listen with them unless I'm troubleshooting a noise/distortion problem, I don't know that I really need to. I did reconnect the integrated amp to the MusicCast Aux In and found that the bass IS accentuated and the highs are a bit softer, but it still sounded better than any other BT device I have used on my system. I plan to use pink noise so I can measure the response with/without BT.

The piece I used is from a company called Miccus, based in Detroit. I had found that the first one had an unacceptable announcement for 'Paired' and 'Un-paired', so I contacted the company and they surprised me by responding to my e-mail within a half hour with instructions for the new feature of turning off the announcement.

It has stereo 3.5mm input and output jacks, as well as optical input and output. It can pair to two devices at one time, transmits OR receives and comes with a short SMA cable so the antenna can be mounted outside of a cabinet. If a longer cable is used, it can be located closer to the transmitting/receiving device.

The one I received on Tuesday cost $49.99.

https://en.wikipedia.org/wiki/Bluetooth
 
S

snakeeyes

Audioholic Samurai
Ratings
1,154 1 1
#13
@highfigh

Regarding the network admin not allowing multicast...

I can understand not allowing multicast between subnets if you have a choice. If you route it, you must take care to do it right to avoid multicast storm outages. These can be nasty because a multicast storm (a looping multicast) can consume all resources on the network devices (switches, routers, and firewalls). Most network admins will want to avoid multicast if given the choice or limit it to one subnet in one vlan. Also many network admins don’t work with multicast as much so they may have difficulty getting used to how it works.
 
Last edited:
O

Ordinary Geek

Audiophyte
#14
"Can I use Aptx bluetooth headphones with my iPhone X? Or should I get headphones that support AAC codec? "

This answer is late, but I'm only just joining this party now! Anyway, you should get headphones that support AAC. If you get APTX headphones, and try to use them with your iPhone, the iPhone (AND the headphones) will default back to the nearest codec they have in common: SBC. The Bose QC 35 II supports SBC & AAC (Just those two, surprisingly). The new Sony WH-1000XM3 supports SBC, AAC, APTX, APTX HD and LDAC). Many of the inexpensive Chinese ones support a variety of codecs as well (They're often quicker to the punch than even the "Big Boys"),though if you're on this site, you're probably not looking at those!
 
I

iMak

Audiophyte
#15
"Can I use Aptx bluetooth headphones with my iPhone X? Or should I get headphones that support AAC codec? "

This answer is late, but I'm only just joining this party now! Anyway, you should get headphones that support AAC. If you get APTX headphones, and try to use them with your iPhone, the iPhone (AND the headphones) will default back to the nearest codec they have in common: SBC. The Bose QC 35 II supports SBC & AAC (Just those two, surprisingly). The new Sony WH-1000XM3 supports SBC, AAC, APTX, APTX HD and LDAC). Many of the inexpensive Chinese ones support a variety of codecs as well (They're often quicker to the punch than even the "Big Boys"),though if you're on this site, you're probably not looking at those!
It’s never late as far as we breath ;)

I use Nuraphone headphones which they do support aptX HD and AAC, so if my understanding is correct I’m not loosing quality right?
 
O

Ordinary Geek

Audiophyte
#16
It’s never late as far as we breath ;)

I use Nuraphone headphones which they do support aptX HD and AAC, so if my understanding is correct I’m not loosing quality right?
I think it depends on the device and which service you're streaming from (assuming you're streaming at all). If you're using an iPhone streaming from Apple Music, yes you're fine. I believe Spotify streams using OGG Vorbis, so there would be some conversion going on there, I think. Don't know at all about Tidal. Which phone have you got, and which service are you streaming from?
 
I

iMak

Audiophyte
#17
I think it depends on the device and which service you're streaming from (assuming you're streaming at all). If you're using an iPhone streaming from Apple Music, yes you're fine. I believe Spotify streams using OGG Vorbis, so there would be some conversion going on there, I think. Don't know at all about Tidal. Which phone have you got, and which service are you streaming from?
My main phone is iPhone X and I also have Samsung Galaxy S7 Edge and Nvidia Shield TV. I stream from Spotify Premium and Tidal HiFi.
 
I

iMak

Audiophyte
#18
I also found out that my Samsung Galaxy S7 Edge default the codec to aptX when I connect my Nuraphones, and from the Developer Options, I can only switch to SBC and AAC. While on my Nvidia Shield Android TV, it defaults the codec to AAC and in Developer Options, the other codecs won’t activate, which concludes the SATV only supports AAC.
 
O

Ordinary Geek

Audiophyte
#19
Here's a great article, pertaining to this topic, precisely:

https:// darko.audio/2017/03/the-inconvenient-truth-about-bluetooth-audio/

Definitely worth a read.
 
O

Ordinary Geek

Audiophyte
#20
(You'll have to remove the space between "https://" and "darko", as the site didn't want to let me post a link)
 

newsletter
  • RBHsound.com
  • BlueJeansCable.com
  • SVS Sound Subwoofers
  • Experience the Martin Logan Montis