USB audio vs Optical audio?

[_Grid21]

I recently plugged my optical cable for my Astro A50 headset into my base station and then into my motherboard, and while the USB audio was fine, I was curious what the difference is between Optical audio and USB audio if any difference at all? 

[Pixel5]

since both are digital signals there is no difference at all.

[Alex Atkin UK]

There shouldn't really be any, as optical should bypass the sound cards DSP in both cases.

[Taf the Ghost]

25 minutes ago, _Grid21 said:

I recently plugged my optical cable for my Astro A50 headset into my base station and then into my motherboard, and while the USB audio was fine, I was curious what the difference is between Optical audio and USB audio if any difference at all? 

Hello again.

 

Optical is going to act as a passthrough from another soundcard. The USB connection has its own soundcard, in the base station, that it should use.

[_Grid21]

26 minutes ago, Alex Atkin UK said:

There shouldn't really be any, as optical should bypass the sound cards DSP in both cases.

 

5 minutes ago, Taf the Ghost said:

Hello again.

 

Optical is going to act as a passthrough from another soundcard. The USB connection has its own soundcard, in the base station, that it should use.

 

27 minutes ago, Pixel5 said:

since both are digital signals there is no difference at all.

Well what I did noticed, and it may solve, is 1. the volume wheel seems to work better outputting sound as the default audio "Game" driver seemed quieter, and 2. I know that the base station's USB port can actually drop on random. So I figured using audio from the Optical from the motherboard maybe more reliable. Also, what is DSP?

[Taf the Ghost]

2 minutes ago, _Grid21 said:

 

 

Well what I did noticed, and it may solve, is 1. the volume wheel seems to work better outputting sound as the default audio "Game" driver seemed quieter, and 2. I know that the base station's USB port can actually drop on random. So I figured using audio from the Optical from the motherboard maybe more reliable. Also, what is DSP?

Digital Signal Processor. 

[Taf the Ghost]

https://en.wikipedia.org/wiki/Digital_signal_processing

[TechyBen]

Sometimes interference (bad shielding on some motherboards may give whine on certain audio devices... but that's mainly on board or power issues).

Optical may have different lag/latency too.

 

I've little experience between them all though, so it may take some trial and error to get the setup you want.

 

For example IIRC sometimes optical cable solutions don't send volume over to the speaker/amp device. So you need a seperate remote/dial for volume. Again, it tends to be specific to each device.

[Taf the Ghost]

4 minutes ago, _Grid21 said:

 

 

Well what I did noticed, and it may solve, is 1. the volume wheel seems to work better outputting sound as the default audio "Game" driver seemed quieter, and 2. I know that the base station's USB port can actually drop on random. So I figured using audio from the Optical from the motherboard maybe more reliable. Also, what is DSP?

The Optical is using the soundcard that's on your motherboard. The USB connection's actual sound card is in the base station, and you use drivers/software to connect to it over the USB connection.

 

For your purposes, the sound quality should be roughly the same, but it could have a different sound signature (by a little bit).

[_Grid21]

1 minute ago, Taf the Ghost said:

The Optical is using the soundcard that's on your motherboard. The USB connection's actual sound card is in the base station, and you use drivers/software to connect to it over the USB connection.

 

For your purposes, the sound quality should be roughly the same, but it could have a different sound signature (by a little bit).

Oh ok. I did notice, although I don't use it much, that the Dolby surrounds in the Astro actually seemed to sound better and the EQ switched also seemed better than the sound card inside the USB base station itself. 

[Taf the Ghost]

1 minute ago, TechyBen said:

Sometimes interference (bad shielding on some motherboards may give whine on certain audio devices... but that's mainly on board or power issues).

Optical may have different lag/latency too.

 

I've little experience between them all though, so it may take some trial and error to get the setup you want.

You cut out a lot of the on-board audio issues by using Optical Out. A little trick that most HDMI-based HTPC actually leverage.

 

In this case, USB-powered sound card isn't going to have much different interference issues as an on-board solution. USB-based power is pretty bad. Bad enough that Schiit sells a "USB de-crapifier" and it actually works. They're not quite sure why, but it does.

 

http://www.schiit.com/products/wyrd

 

Fun stuff!

[Taf the Ghost]

4 minutes ago, _Grid21 said:

Oh ok. I did notice, although I don't use it much, that the Dolby surrounds in the Astro actually seemed to sound better and the EQ switched also seemed better than the sound card inside the USB base station itself. 

I actually had to go check the product page, as the question seemed strange unless it's a hybrid solution.

[Pixel5]

23 minutes ago, Taf the Ghost said:

The Optical is using the soundcard that's on your motherboard. The USB connection's actual sound card is in the base station, and you use drivers/software to connect to it over the USB connection.

 

For your purposes, the sound quality should be roughly the same, but it could have a different sound signature (by a little bit).

the optical signal is digital and does not use the soundcard on the motherboard as well, the soundcards sole purpose is to transform the digital signals into analog that can be send to a speaker or headphone which is not the case here as everything is digital in both cases the soundcard of the headset will do this work.

 

this headset is wireless so the soundcard is also not in the base station it must be in the headset itself to convert the digital signal to an analog one.

[Pixel5]

22 minutes ago, _Grid21 said:

Oh ok. I did notice, although I don't use it much, that the Dolby surrounds in the Astro actually seemed to sound better and the EQ switched also seemed better than the sound card inside the USB base station itself. 

there is no soundscar in the base station, it is a wireless headset and everything is completely digital all the way to the headset itself where the DAC then converts the digital signal to analog to send to the speakers inside the headset.

 

There should be not difference at all unless they artificially limit the USB bandwidth for some reason but even then its digital and that means either there is a signal or there is none there is no in between.

[_Grid21]

3 minutes ago, Pixel5 said:

the optical signal is digital and does not use the soundcard on the motherboard as well, the soundcards sole purpose is to transform the digital signals into analog that can be send to a speaker or headphone which is not the case here as everything is digital in both cases the soundcard of the headset will do this work.

 

this headset is wireless so the soundcard is also not in the base station it must be in the headset itself to convert the digital signal to an analog one.

Well for it being a digital optical to analog speaker converter, it sounds pretty good. What's cooler is that the AUX port allowed me to run an analog cable from my Yamaha MG20XU mixer headphone/monitor out to my Astor Wireless base station. So it serves 2 purposes. As weird as it sounds though, somehow the Optical audio seemed to sound more detailed than the USB port did and that's what doesn't make sense, same digital data, 2 different ways of converting it. 

[Taf the Ghost]

8 minutes ago, _Grid21 said:

Well for it being a digital optical to analog speaker converter, it sounds pretty good. What's cooler is that the AUX port allowed me to run an analog cable from my Yamaha MG20XU mixer headphone/monitor out to my Astor Wireless base station. So it serves 2 purposes. As weird as it sounds though, somehow the Optical audio seemed to sound more detailed than the USB port did and that's what doesn't make sense, same digital data, 2 different ways of converting it. 

USB uses a different sound card. The one built into the base station. The Optical is a pass through, so it's using your computer's motherboard audio. At least, that's what the website is pointing to as how it works.

[Alex Atkin UK]

Its my understand that with optical out it effectively is bypassing the sound card entirely, that's kinda the point.

 

However if you are using EQ or other effects (eg encoding to surround sound), it may have some impact, although its probably more likely all that is happening in software and its merely the difference between the on-board sound card drivers and the USB ones.

 

Plus its all limited by the Windows mixer (which HAS to mix the many different sounds playing at any given time into two-channel stereo to output over optical) which is far from optimal, some sound cards I believe bypass this with their own implementation which again can improve sound quality.  It used to be common for this to be done by the sound card hardware itself, but once CPUs got fast enough it all moved to software to save manufacturing costs and number of sounds being able to be played concurrently limitations.

 

On the other hand for movies you can usually just passthrough the original codec and let the device at the other end of the optical link do all the decoding.  Music can have even less interference if you use passthrough, which would disable your PC being able to play any other sounds at the same time but will then send the PCM stream of your music down optical without any modification from the original at all.   The principle there being that the DSP at the other end of the optical link is usually better than the on in your PC or sound card, so any EQ should be done there.

So as you can see, there are various different stages that can change the audio depending on what you are using or doing.

[an actual squirrel]

For audiophile purposes, usb can have lower jitter, but optical guarantees electrical isolation. People tend to value jitter more and use usb now.

 

However, your case is different, since you are using an astro headset that wants surround sound input. On console, you would use optical, and configure the console to output dolby digital. On pc, with the newer models of the astros, it is easier to get surround sound from usb afaik (just set windows to 7.1).

[Alex Atkin UK]

How does USB have lower jitter?  Just the fact you can buy a better sound card than the in-built cheapo?

 

I'm certainly aware optical can have its issues as I had to switch to HDMI from one of my machines as on optical my receiver kept dropping out on HD audio.  Plus the fact the converting from digital, to light, to digital again adds a little latency.

[_Grid21]

This has been a really interesting topic for sure. I didn't know optical and USB had slightly small differences, but I think in my case, I prefer the optical as I know USB is subject to dropouts and glitches.

[an actual squirrel]

2 hours ago, Alex Atkin UK said:

How does USB have lower jitter?  Just the fact you can buy a better sound card than the in-built cheapo?

 

I'm certainly aware optical can have its issues as I had to switch to HDMI from one of my machines as on optical my receiver kept dropping out on HD audio.  Plus the fact the converting from digital, to light, to digital again adds a little latency.

With spdif, the clock is embedded in the signal. And with optical, since the cables have limited bandwidth, the signals will be distorted. So the dac has it's work cut out in recovering all the information. With usb, the dac can control the flow of information, so the dac can use its own clock for timing information. With high end gear, both can be done equally well, but optical is harder.

 

59 minutes ago, _Grid21 said:

This has been a really interesting topic for sure. I didn't know optical and USB had slightly small differences, but I think in my case, I prefer the optical as I know USB is subject to dropouts and glitches.

If you want to use dolby headphone on the astro and have good results, you need to give the astro a surround sound signal. With the optical connection, you have to use a proprietary type of audio compression called "dolby digital" for surround sound. This is easy to do on consoles, because they come with dolby digital encoders. On pc, the process is more involved, and you probably have to find and install unlocked drivers with "dolby digital live" (the dolby digital encoder), and set that up.

 

With usb, I think you can just send a surround sound signal over it when you install the astro drivers, with no compression needed. So things become much simpler.

[Alex Atkin UK]

3 hours ago, an actual squirrel said:

With spdif, the clock is embedded in the signal. And with optical, since the cables have limited bandwidth, the signals will be distorted. So the dac has it's work cut out in recovering all the information. With usb, the dac can control the flow of information, so the dac can use its own clock for timing information. With high end gear, both can be done equally well, but optical is harder.

Thanks, that explains a lot.  I had never really considered it that way.

 

I presume HDMI has similar problems thus why I get drop-outs from some sources?  I never quite understood why my Bluray player bragged so much about having a HDMI port dedicated to audio, this rather explains it as presumably embedding the video in the same signal increases the chance of jitter even with a higher bandwidth link?

 

It would also go so far as to explain why HDCP adds to the chance of synchronization problems even more, as now you have two-way communication over a jittery link?

[_Grid21]

6 hours ago, an actual squirrel said:

With spdif, the clock is embedded in the signal. And with optical, since the cables have limited bandwidth, the signals will be distorted. So the dac has it's work cut out in recovering all the information. With usb, the dac can control the flow of information, so the dac can use its own clock for timing information. With high end gear, both can be done equally well, but optical is harder.

 

If you want to use dolby headphone on the astro and have good results, you need to give the astro a surround sound signal. With the optical connection, you have to use a proprietary type of audio compression called "dolby digital" for surround sound. This is easy to do on consoles, because they come with dolby digital encoders. On pc, the process is more involved, and you probably have to find and install unlocked drivers with "dolby digital live" (the dolby digital encoder), and set that up.

 

With usb, I think you can just send a surround sound signal over it when you install the astro drivers, with no compression needed. So things become much simpler.

So should I keep using my optical port for the sake of knowing I am not relying on my USB port which can and has dropped out? Or should I use USB instead?