Vero 4K+ with Pioneer VSX-920 amp, no centre through S/PDIF I/P

Hi there,

As per title, I don’t seem to get a centre speaker working and will only work if I use 4.1 audio configuration on the Vero and below.

I have read around and it seems that I have a slightly different problem to this person: No 5.1 center channel

The Vero drives a projector directly as I don’t have a UHD receiver (Pioneer CSX-920) and the audio is fed back to the amp via the S/PDIF input.

No matter the configuration I try to set on Vero I don’t seem to be able to get the centre to work.

This is happening with files I know work on my Rpi 3 using OSMC.

Any help would be appreciated.


Have you seen this?

Hi there thanks for your reply, yes I did,

had a read of this:

Recommended audio settings when connecting your OSMC device to your AVR/soundbar’s S/PDIF input

Go to Settings/System/Audio… Select the following settings:

  • Audio device:
    • Vero 2, 4K/4K +: PCM or HDMI
    • Vero 1: S/PDIF
    • Raspberry Pi: your S/PDIF soundcard
  • Number of channels: 2.0 (S/PDIF only supports 2-channel LPCM)
  • Output configuration: Best match
  • Passthrough: enabled (on Raspberry Pi select Passthrough device: your S/PDIF soundcard)
  • DTS/AC3 passthrough: enabled
  • DTS-HD passthrough: disabled (only present on Vero 1 and Vero 4K/4K +)
  • TrueHD passthrough: disabled (only present on Vero 1 and Vero 4K/4K +)
  • E-AC3 passthrough: disabled
  • AC3 transcoding: enabled (enable this if you don’t want multi-channel LPCM and HD audio down-mixed to 2.0 LPCM, also see the explanation of AC3 transcoding a bit further down)

Keep in mind to disable “Sync playback to display” under Settings/Player/Videos for passthrough to work!

Sort of says I can’t do more than 2 channels via the optical output (S/PDIF) ?? Is this correct? Or I misunderstood?

As it states in the wiki article, S/DIF can only do 2.0 LPCM channels. Surround LPCM can only be passed through transcoded to 5.1 Dolby Digital.
Besides LPCM 2.0 S/DIF can pass through Dolby Digital streams and DTS, but no HD-audio streams.

Thanks for your reply, I’m a bit of a noob (been hiding under a rock for a while now, so only understand basic concepts).

I can see from some of the specs that my receiver (VSX-920) can do DTS, but still doesn’t work??

Your optical cable is capable of carrying either two channel PCM (uncompressed), Dolby Digital, or DTS. If you set your audio settings in Kodi to 2 channels and turn on passthrough for DD and DTS then your system will play surround sound for any source that is DD or DTS and stereo for any other type of audio source. If you also turn on transcoding then all non DD or DTS audio sources will be converted into DD and output to your receiver as 5.1 surround sound…ish. I believe the way this works is that all channels that are not in the source are muted. The result of this would be that on a two channel source your AVR sees a 5.1 signal but only output audio on the two channels. This may cause issues if you use Pro logic or other early surround formats for this type of material. You may want to play around a bit to find out if the transcode option is suitable for you.

Also are we talking about optical going from the vero to the AVR or the optical going from the projector to the AVR? Not all display devices allow DTS signals to pass through them.

This is not correct. Only sources that are not DTS or Dolby Digital themselves and not PCM 2.0 are transcoded to a Dolby Digital stream. A stereo PCM source will be passed as PCM 2.0.

Having said the above… This won’t be an issue. Most users will probably only play stereo or 5.1/7.1 surround content.

Many displays don’t allow any passthrough except passing on a PCM 2.0 downmix of any incoming audio. For that reason we wouldn’t recommend using a TV as an audio passthrough device at all.

Please do upload logs so we can see your audio settings. And please explain your setup in detail - is your Vero connected to the projector via HDMI and the AVR to the projector via S/PDIF or is your Vero connected directly to the AVR via S/DIF?

Sure I’ll upload logs tonight!

Thank you everyone for the replies, the projector is a Sony VPL-VW520ES, it is solely connected to the vero via HDMI on port 1 the vero then connects to the receiver via the S/PDIF.

Not feeling too hopeful about the outcome at this point haha. Really don’t want to spend more to get a better receiver. This one has served me well for a while.

I stand corrected. I could have sworn I read that in the documentation somewhere but I must have been mistaken. I just tested it myself and with transcoding turned on all stereo source formats are output as 2.0 LPCM and non passthrough surround source material is transcoded to DD. This means that Pro Logic and equivalents work as they should, which is great.

I would disagree a bit about passthrough on a TV. Although for the OP’s situation a direct connection is the right choice, there are situations where it is the optimal choice (legacy AVR without enough appropriate inputs, Pi with non-HDMI soundbar, etc.) The reason I assume DD passthrough support is because ATSC required DD support and therefore it is common in the US for HDTV’s to allow passthrough of DD even though they will not normally pass DTS. Perhaps that is different outside of the US.