Bluetooth and digital/analogue conversion

Voyager2002

So my computer uses Bluetooth to send music to my headphones. Does the conversion from a digital signal to analogue take place in the headphones (so that a digital signal is being transmitted), or does this conversion happen on the computer first? Since the built-in soundcards on most computers are fairly low-spec, this would be an obvious way to start upgrading...

Neil_Jones

Voyager2002 said:

So my computer uses Bluetooth to send music to my headphones. Does the conversion from a digital signal to analogue take place in the headphones (so that a digital signal is being transmitted), or does this conversion happen on the computer first? Since the built-in soundcards on most computers are fairly low-spec, this would be an obvious way to start upgrading...

Bluetooth is a transmission technology.  On its own it doesn't do much more than that.

All its doing in this particular case is relaying the audio signal from the speakers to the Bluetooth device.  No different to if you plugged in a set of wired headphone.

Realistically you may not notice any difference in output quality between onboard sound and a separate card, especially if you're using poor speakers in the first place.  Like most of these things the end result is only as good as the weakest link.

Computers have semi-decent sound hardware these days and even a laptop should be able to output 5.1 or even 7.1 via HDMI, although USB is another solution.

Vitor

The conversion to analogue is done by the headphones. The computer's soundcard has no part to play. If you want to optimise the sound with Bluetooth, look for headphones that support Bluetooth protocols with less digital compression such as aptX HD or LDAC (and ensure the computer software also supports these). And obvioulsy start with uncompressed audio files such as FLAC rather than MP3

wongataa

Voyager2002 said:

So my computer uses Bluetooth to send music to my headphones. Does the conversion from a digital signal to analogue take place in the headphones (so that a digital signal is being transmitted), or does this conversion happen on the computer first? Since the built-in soundcards on most computers are fairly low-spec, this would be an obvious way to start upgrading...

The headphones do the digital to analogue conversion & amplification.  Bluetooth always transmits digital data.

A low spec sound card has a perfectly good digital analogue converter.  Digital analogue converter chips have been around for so long they are very cheap and more than good enough.

flaneurs_lobster

Neil_Jones said:

Voyager2002 said:

So my computer uses Bluetooth to send music to my headphones. Does the conversion from a digital signal to analogue take place in the headphones (so that a digital signal is being transmitted), or does this conversion happen on the computer first? Since the built-in soundcards on most computers are fairly low-spec, this would be an obvious way to start upgrading...

Bluetooth is a transmission technology.  On its own it doesn't do much more than that.

All its doing in this particular case is relaying the audio signal from the speakers to the Bluetooth device.  No different to if you plugged in a set of wired headphone.

Realistically you may not notice any difference in output quality between onboard sound and a separate card, especially if you're using poor speakers in the first place.  Like most of these things the end result is only as good as the weakest link.

Computers have semi-decent sound hardware these days and even a laptop should be able to output 5.1 or even 7.1 via HDMI, although USB is another solution.

Wrong, apart from the first sentence.

What's on the computer is a digital sound file. Your computer compresses the digital audio data (using a Bluetooth codec like SBC, aptX, AAC, etc.) and transmits it digitally over the air to your headphones.

The headphones decompress the file, and run it through Digital to Audio Analogue Converter (DAC) software/hardware on the headphones. That then gets amplified and drives the headphone speaker(s).

Wired headphones get an analog signal, the DAC is on the device that the headphones plug into. That's why audiophiles use a dedicated DAC box between their digital source (computer, phone, streamer, etc) rather than the cheapy job built-in behind a headphone socket. 

EDIT - Digital to Analogue not Audio

Heedtheadvice

Oh dear Neil, must be a bad day for you as your reply could hardly be more wrong in this instance.

A few good replies above save the day for MSE.....

DullGreyGuy

Voyager2002 said:

So my computer uses Bluetooth to send music to my headphones. Does the conversion from a digital signal to analogue take place in the headphones (so that a digital signal is being transmitted), or does this conversion happen on the computer first? Since the built-in soundcards on most computers are fairly low-spec, this would be an obvious way to start upgrading...

Bluetooth is a digital transmission technology so the DAC is in the headphones. Your sound card will play no part of the playback.

Vitor said:

The conversion to analogue is done by the headphones. The computer's soundcard has no part to play. If you want to optimise the sound with Bluetooth, look for headphones that support Bluetooth protocols with less digital compression such as aptX HD or LDAC (and ensure the computer software also supports these).

LDAC is the lowest compression, ideally paired with Bluetooth5. Ultimately however you are only as good as your weakest link and there are those out there that will tout that they are the latest and greatest because they can make easy claims like having BT5 but then they are using a sweetie wrapper for a cone and so sounds really bad despite having on paper the latest tech. Like the old megapixel trick on terrible cameras. 

jshm2

Depends. 

Some high end headphones do a lot of the upscaling - one reason they are more expensive. But most standard headphones don't do much processing, just straight convert as is. Obviously it depends on the quality of the cans, Bluetooth version used etc etc.  

You can improve the sound by jiggling the computer settings in some, but usually you would buy an amp - not a DAC for your PC. The other thing to check would be the sound quality. If you're playing MP3's then you would not get the same sound as you do with FLAC. 

It's one for the audiophiles for sure, as some go all out on hardware, some are more about improving the software, while others swear by various audio file standards. It's not a straight forward answer as it's between the three. i.e if you have crap headphones, then even the best amp and audio signal quality isn't going to do much. 

DullGreyGuy

jshm2 said:

You can improve the sound by jiggling the computer settings in some, but usually you would buy an amp - not a DAC for your PC. 

Buying an amp would make no difference if you are still using bluetooth headphones