# Realtek ALC1150 optical: no DD option, but plays DD anyway



## TomONeill (Mar 31, 2016)

I know the title is a bit odd when you read it, but I want to discuss this issue in detail with you guys.

Using Realtek ALC1150 with SPDIF, I don't have a 6 channel option even though I hear sound from every speaker when playing test tone at the "Supported formats" tab. I've tried many different drivers, but none seem to work. I also tried replacing the RltkAPO64.dll file with regedit DisableProtectedAudioDG to 1: I do have the option then but when test toning it, I hear only two tones (L and R) with a somewhat longer pause in between. Owning the Logitech Z906 cinema set which allows you to change the levels of each speaker, which allows me only to change two levels (sub and the rest). When I'm playing the test tone, it does allow me to change them all. Here's the strangest part of all: When I'm using Media Player Classic -HC it does play 5.1... How to fix this?
*
Side information:
Little history, you can skip this:*
I had owned a Gigabyte motherboard which has an onboard Realtek ALC892 chip. After upgrading to Windows 10 I had some issues with 5.1 sound, but it turned out this was a bug (which got fixed... one full year later). 5.1 was in the Advanced tab and it all worked out (so this setup had been working before).

*Drivers that I tried:*
R270 (don't know exact version)
R271 (don't know exact version)
R275 (don't know exact version)
6.0.1.6409
6.0.1.7727
6.0.1.7779


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## TomONeill (May 5, 2016)

Update:
I just found out replacing RltkAPO64.dll and changing DisableProtectedAudioDG to 1 in the register DOES work!
The test-tone is not fully played, but my receiver is actually telling me 5.1 audio is coming in anyhow.


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## Mussels (Feb 9, 2022)

You're mistaking the passthrough function, where pre-encoded 5.1 audio goes direct with real time encoding (for non-dolby surround sound, like games and general PC audio)


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