Any way to control the Volume of Dolby Digital through Toslink?

[Informant X]

Greetings,

Having an issue here with Media Center in Win 7 Ultimate 64 bit. I can control the volume of all my movies/shows in it except movies that are Dolby Digital Plus. Same thing happens outside of media player. Is there anyway to fix this?

I'm using a Toslilnk cable into my audio reciever. And the only way to control the volume for those movies currently is on my reciever, which means a second remote.

 

[zerogear]

I tried to figure that one out myself but eventually gave up and went with HDMI.

 

[mmntech]

Toslink is just sending the raw data, so no you can't control volume. That's controlled by the amplifier. You could always find a universal remote that handles both.

 

[mfenn]

Toslink is just sending the raw data, so no you can't control volume. That's controlled by the amplifier. You could always find a universal remote that handles both.

Its a little more complicated than that actually. Toslink is just a physical-layer connection. Many different types of data can be sent over it.

If your just bitstreaming the Dolby Digital as-is, then you are correct, you cannot change the volume. However, if you are decoding the DD stream on the CPU, and then sending PCM to the receiver, then your volume control should work.

 

[Informant X]

Yea I mean I can control the volume with everything else fine over Toslink, just not Dolby Digital Movies. :/

Hate having to have two remotes half the time.

 

[mfenn]

Yea I mean I can control the volume with everything else fine over Toslink, just not Dolby Digital Movies. :/

Hate having to have two remotes half the time.

If you go into your sound properties for the digital output, you should see a bunch of checkboxes where you can select which sound formats your receiver supports. Uncheck the Dolby Digital one and that should force software decoding of the Dolby Digital stream. This should allow you to control the volume. I'm on Linux at work atm, so I can't give you the exact steps, but it's not too hard to find.

 

[Informant X]

You cool homie. Will this degrade the sound quality tho? Will it still be 5.1?

 

[mfenn]

You cool homie. Will this degrade the sound quality tho? Will it still be 5.1?

The sound quality should be the same, since its just doing in software what the receiver would be doing anyway.

However, I'm not sure if you can pass 5.1 channels of PCM over Toslink. There may not be enough throughput available on the cable for that.

 

[Swivelguy2]

The sound quality should be the same, since its just doing in software what the receiver would be doing anyway.

However, I'm not sure if you can pass 5.1 channels of PCM over Toslink. There may not be enough throughput available on the cable for that.

You can't. SPDIF (both optical and coaxial) will only pass 2 channels of PCM.

Also, adjusting the volume on your computer instead of on the receiver won't allow you to take advantage of Audyssey Dynamic EQ, if your receiver supports it.

 

[Informant X]

Wait so neither Optical or Coaxial is 5.1? I should've just stuck with RCA connection then. I thought optical/coax was an upgrade over that.

 

[mfenn]

Wait so neither Optical or Coaxial is 5.1? I should've just stuck with RCA connection then. I thought optical/coax was an upgrade over that.

It is an upgrade in that you can pass 5.1 digital audio. DD and DTS are compressed formats because, as Swivelguy2 confirmed, there just isn't enough bandwidth available to pass 5.1 channels of PCM (PCM is uncompressed audio). RCA will work, but you will need to run 6 cables!