I've got an install where we have a TV and 2ch ceiling speakers.

The ceiling speakers are also used for distributed audio, when the TV is not in use, the speakers are powered via a multi zone amp.

There are some other TVs in the install running off the same video matrix that have 5.1ch surround sound.

The problem im having is that in one of the zones, the TV audio is very quiet. If you turn it up there is noticeable distortion on the audio. The distortion only happens when the TV audio is active (including if you pause the video source).

We have other rooms where we have a different Samsung TV + 2ch speakers running through the same multi zone amp, but we don't get the same distortion.

I have done further multi variant testing and can definitely segregate the issue to the TV audio output.

Currently we have the TV configured as follows :

4k Video Source (RACK) -> HDbaseT matrix (RACK) -> HDbaseT Receiver (ROOM) -> TV (ROOM) -> Optical audio out extender over cat6 TX (ROOM) -> Optical audio out extender over cat6 TX (RACK) -> Multi zone Amp (RACK) -> Ceiling Speakers (ROOM).

The TV in question is a Sony 55” X85C. I have set the Sony TV to output over optical in various audio formats, but it doesn't seem to make a difference. There is also an option for optical audio PCM out volume, but it doesn't make a difference.

My first idea was to break the audio out at the rack just after the HDbaseT matrix (which is not straightforward as the matrix doesn't have a 2ch stereo out per zone, although could be achieved by using an additional HDMI output on the matrix, bonding it to output whatever the TV zone in question outputs, then breakout the HDMI from it using an HDMI to 2ch Stereo breakout device). I'm not a huge fan of this idea, I feel it could work on paper, but may cause lip sync issues in the real world.

Any other ideas on how i could rectify this distorted audio issue ?

Or if i did you my idea as above, any idea on how to mitigate lip sync issues ? From what i can see the Sony TV does not have a lip sync settings, although the multi zone amp dose, but this would only add a delay to the audio, it could not speed up the video.

You say that testing indicates the issue to be with the TV optical output. Are you suggesting that the output is defective on this particular unit? If the issue is for sure upstream of the optical audio extender, I’m inclined to think it’s a setting with the TV.

Anyway, another option is to break out the audio between the HDBaseT RX and TV and return the audio from there.

The exact details of the wiring of the two different audio sources is not clear to me. Are you connecting one analog audio source to another analog audio source, and connecting that combination of signals to an amplifier?

Looking at it another way, is there a point where three things connect together: one analog audio signal, another analog audio signal, and an analog audio input?

This is a great way to get distortion as well as low volume. Please detail this, if it's the way things are connected.

In an effort to think outside the box slightly, have you checked the optical path is clean and the optical cable unbroken? Possibly missed digital data could result in this?

Otherwise I would presume it’s either the optical out on the TV or the optical in stage on the optical to balanced converter.

I am assuming however that:

1. You have successfully tested the integrity of the cat cable.
2. You have successfully tried a different source device into the DA Amp

In any event I would just try substitution of each element of the chain one by one until you positively identify the cause.

I just noticed something similar with a 65x900f. Trying to use the apps on tv and feed sound to the avr. I’m using an AV Pro edge extender with optical input and output. Not getting any sound either and have tried every audio setting available. My next step is to bring a source with optical out and test through the extender. If I’m getting sound, then I think the Sony’s are having an issue.

dopey question for all: do you update firmware at installation?

I always update unless I have prior knowledge that there is something wrong with the latest. And, if possible, I turn OFF automatic updates because unit updates will sometimes break the control system. Otherwise, a middle of the night update could result in a flood of calls in the morning.

Some newly released units are shipped with known issues with the intent of fixing the issue while the shipment is in transit.

OP- take a soundbar with an optical input with you and plug into the optical over cat box at the rack.


and at the tv itself

James, where are you?

We had a similar issue with a Sony TV and Integra soundbar. The ultimate fix was to use the analog out of the TV to run the soundbar.

Was this ever solved?