• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

UK Radio Stream 48khz/32bit - do I therefore need a 32bit capable DAC?

rotel5675

Member
Joined
Aug 12, 2020
Messages
9
Likes
1
I've just noticed that some good quality 320kps Radio streams are reported as 48kHZ/32bit within VLC player.


I'm decision making on buying an external DAC and Headphone Amp. I was including some well respected older DACs often limited to 96/24 (and sometimes 48/24), which I thought would be fine, as long as they are well designed & made.

However, this new discovery that the streams are 48/32, is it correct? Are they really 32bit?

With my onboard ALC1220, direct into some HD595s the streams sound nice, as good as some ripped 44.1/16 CDs.
But, I cant genuinely hear a difference when I change between 48/16 48/24 & 48/32, but it's nice to be able to do that and test.

With a higher quality DAC and Headphone Amp will it become possible to distinguish between 16bit and 32 bit?

And so, as I am buying my first DAC, would it be wise to pick one that does 32bit?
 

paddycrow

Senior Member
Forum Donor
Joined
Oct 28, 2019
Messages
342
Likes
572
Location
Grand Haven, MI
If you want to play 32 bit content, you will need a DAC that is capable. Will you be able to hear the difference with 24 or 16 bit content? I doubt it.
 

Jimbob54

Grand Contributor
Forum Donor
Joined
Oct 25, 2019
Messages
11,066
Likes
14,700
I've just noticed that some good quality 320kps Radio streams are reported as 48kHZ/32bit within VLC player.


I'm decision making on buying an external DAC and Headphone Amp. I was including some well respected older DACs often limited to 96/24 (and sometimes 48/24), which I thought would be fine, as long as they are well designed & made.

However, this new discovery that the streams are 48/32, is it correct? Are they really 32bit?

With my onboard ALC1220, direct into some HD595s the streams sound nice, as good as some ripped 44.1/16 CDs.
But, I cant genuinely hear a difference when I change between 48/16 48/24 & 48/32, but it's nice to be able to do that and test.

With a higher quality DAC and Headphone Amp will it become possible to distinguish between 16bit and 32 bit?

And so, as I am buying my first DAC, would it be wise to pick one that does 32bit?

How will you be playing them? Windows PC to new DAC? you set the sample rate and bit depth to convert to in sound settings. Or software you use in player app will convert.

I wouldnt sweat it- suspect it will work out of the box anyway.

changing the bit depth of such content will have zero audible impact unless downsampling introduces massive errors and glitches.
 

Soniclife

Major Contributor
Forum Donor
Joined
Apr 13, 2017
Messages
4,500
Likes
5,417
Location
UK
Do you have an example stream?

The streams I use show as 48/24 in roon.
 

twsecrest

Addicted to Fun and Learning
Joined
Nov 27, 2018
Messages
894
Likes
291
Location
California
I've just noticed that some good quality 320kps Radio streams are reported as 48kHZ/32bit within VLC player.
I'm decision making on buying an external DAC and Headphone Amp. I was including some well respected older DACs often limited to 96/24 (and sometimes 48/24), which I thought would be fine, as long as they are well designed & made.
However, this new discovery that the streams are 48/32, is it correct? Are they really 32bit?
With my onboard ALC1220, direct into some HD595s the streams sound nice, as good as some ripped 44.1/16 CDs.
But, I cant genuinely hear a difference when I change between 48/16 48/24 & 48/32, but it's nice to be able to do that and test.
With a higher quality DAC and Headphone Amp will it become possible to distinguish between 16bit and 32 bit?
And so, as I am buying my first DAC, would it be wise to pick one that does 32bit?
CD-Audio is 16-bit/44.1K, so no reason (benefit) for streaming at 24-bit or 32-bit or 48K (but I'm not the expert).
What is your budget for a DAC (DAC/amp)?
Schiit Fulla 3 ($100) DAC/amp is a good bargain.
 
OP
R

rotel5675

Member
Joined
Aug 12, 2020
Messages
9
Likes
1
The audio links are from this site http://www.radiofeeds.co.uk/hifi.asp

And the download links are for a file which opens my the stream in VLC player, screenshots of codec info attached. Annotation 2020-08-18 225046.pngAnnotation 2020-08-18 225046-2.png
 

twsecrest

Addicted to Fun and Learning
Joined
Nov 27, 2018
Messages
894
Likes
291
Location
California

Beershaun

Major Contributor
Forum Donor
Joined
Oct 3, 2019
Messages
1,864
Likes
1,910
? I didn't see anything in that link that indicated 32 bit sample rate files. They were all lossy compressed formats as mp3, aac, or ogg vorbis with their bitrates between 32kbps and 230kpbs or so. Any dac that supports decoding those file formats will work. Which is basically all of them since those are formats that are all commonly used for the last 10-20 years by all the major streaming services.
 

paddycrow

Senior Member
Forum Donor
Joined
Oct 28, 2019
Messages
342
Likes
572
Location
Grand Haven, MI
32 bits is a ridiculous amount of resolution. Even 24 bits is over the top. However, both are easily feasible with modern computing equipment. So what's a mother to do?

I'm personally not going to worry about formats > 96kHz / 24bit.
 

AnalogSteph

Major Contributor
Joined
Nov 6, 2018
Messages
3,338
Likes
3,278
Location
.de
The dynamic range provided by a measly 16 bits is greater than you might think. Depending on how loud you listen and how dynamic your music is, it is not unlikely that you have never even heard the noise floor of 16-bit, 44.1 kHz CD audio.

As a rule of thumb, completely undithered 16 bit provides an effective dynamic range of about 72 dB (12 bits). On very dynamic music, the very quiet bits will sound a bit rough if you crank them up unrealistically. So if you're after closer to the full 96 (or 98) dB, it makes sense to decode lossy formats to >16 bit in order to avoid rounding errors.

Dynamic range in the analog world is quite commonly exceeding the capabilities of 16 bits. If you want a headphone amplifier that'll output up to 6 Vrms but have a noise floor no higher than 2 µV, that's a dynamic range of 129.5 dB right there. Mind you, as a user will never require both at the same time (but rather a 100-110 dB max slice anywhere in between), but if you're a soundcard manufacturer who doesn't like PGAs but would prefer to run your DAC directly into a headphone driver, that's the challenge you are faced with. (That's the approach popularized by Asus Xonar cards.) A 24 bit output format setting is definitely a must under these conditions.

Applying the same rule of thumb as above to 24 bits, the very minimum dynamic range provided would be 120 dB. I doubt there even is any music recording with a noise level as low as -120 dBFS, so chances are what's being played played back will contain plenty enough noise to dither a 24-bit DAC adequately. Actually you wouldn't even need this much, -130..-140 dBFS would still be fine.

So who needs 32 bits? Digital signal generator manufacturers. For converter manufacturers, a 32 bit data format is easily implemented and good PR.
 

Blumlein 88

Grand Contributor
Forum Donor
Joined
Feb 23, 2016
Messages
20,524
Likes
37,057
Is this supposed to be 32 bit fixed or 32 bit floating point?

Floating point I suppose might have its uses. It gives something like 25 bit resolution which is more than enough generally.
 

mansr

Major Contributor
Joined
Oct 5, 2018
Messages
4,685
Likes
10,700
Location
Hampshire
Is this supposed to be 32 bit fixed or 32 bit floating point?
Software decoders generally work in floating-point since it is easier to write and runs faster on modern desktop processors.

Floating point I suppose might have its uses. It gives something like 25 bit resolution which is more than enough generally.
In IEEE 32-bit floating-point, the smallest step down from 1.0 is equivalent to 25-bit fixed-point precision. The same relative precision is maintained down to very small values. For each halving, a fixed-point format would need an additional bit to keep up. This can be useful during processing since you don't have to be (as) careful about normalising the range after each step in order to avoid losing precision. Of course, you always have to convert to an integer format eventually since that's what DACs accept.
 
OP
R

rotel5675

Member
Joined
Aug 12, 2020
Messages
9
Likes
1
So irrespective of whether or not 32 bits is overkill and the difference is impossible to tell apart from 24 or 16 bits, do you think the stream is broadcast as 32 bits as stated in the codec information in the screenshot I provided?
 

mansr

Major Contributor
Joined
Oct 5, 2018
Messages
4,685
Likes
10,700
Location
Hampshire
So irrespective of whether or not 32 bits is overkill and the difference is impossible to tell apart from 24 or 16 bits, do you think the stream is broadcast as 32 bits as stated in the codec information in the screenshot I provided?
The streams are MP3 or AAC. They don't have a defined bit depth. The 32-bit figure you've seen refers to the output of whatever decoder was being used.
 
OP
R

rotel5675

Member
Joined
Aug 12, 2020
Messages
9
Likes
1
ahh I see now, demonstrating my ignorance.

So the stream was never 32bit my VLC player just outputs the stream at 32bit and that is what I see in the codec information.
 

dkinric

Addicted to Fun and Learning
Joined
Nov 21, 2018
Messages
667
Likes
1,446
Location
Virginia, USA
Uncompressed 16/44 is a good standard for a reason. 24/96 makes me feel good when I see it playing, but any benefit is usually due to remastering rather than bit depth/rate.
 
OP
R

rotel5675

Member
Joined
Aug 12, 2020
Messages
9
Likes
1
Yes, I was always happy with 16/44 and now I understand a little more I will re-include any older DACs limited to 24/96 in my shortlist.

I suppose leave the 24/192 and 36bit rates for the producers/sound engineers to use in their workflow and once they have the finished product we can have the expertly downsampled 16/44 or sometimes 24/96. A bit like working in Camera RAW for all the editing/retouching while retaining all the original info from the sensor, then when its finished output as an 8bit or 16bit TIFF for the end-user to enjoy.
 

Jimbob54

Grand Contributor
Forum Donor
Joined
Oct 25, 2019
Messages
11,066
Likes
14,700
Yes, I was always happy with 16/44 and now I understand a little more I will re-include any older DACs limited to 24/96 in my shortlist.

I suppose leave the 24/192 and 36bit rates for the producers/sound engineers to use in their workflow and once they have the finished product we can have the expertly downsampled 16/44 or sometimes 24/96. A bit like working in Camera RAW for all the editing/retouching while retaining all the original info from the sensor, then when its finished output as an 8bit or 16bit TIFF for the end-user to enjoy.

Leaving aside bit depth, what are your requirements for a dac?
 
OP
R

rotel5675

Member
Joined
Aug 12, 2020
Messages
9
Likes
1
Requirements less than £100:
Separate power supply
USB digital in
RCA Out
Transparent - but the most revealing it's going to be paired with is something like an Atom Amp and HD595 headphones
16/48, 24/48 and 24/96
Desk Top form factor

Nice to have in order or importance:

On/Off Switch
Optical/Coax Out
Optical/Coax In
Good aesthetic design
Fancy lights/display showing bit rate
Higher bitrate/sample support



I think new its going to be D10s or D30, probably a D30.
 
Top Bottom