Help Trouble Shooting Sound Delay on Sonos System...?

[MattHooper]

Hey folks,

I'm trying to help out a non-audiophile pal. He's got an old Panasonic plasma TV with very limited connections. Below the TV he has a Sonos ZP 120:

https://www.mislimited.co.uk/Uploads/1279112867_Sonos_Zoneplayer_120.pdf

Which is powering a pair of KEF LS50 speakers. He wants to send sound from the TV to the KEFS through the SONOS, so he can listen to movies using the KEFs.

The Panasonic plasma TV has only an optical out for sound output, and the Sonos only has one set of RCA inputs available, so I told him to grab one of these optical to RCA converters:

https://www.amazon.ca/Neoteck-Converter-Optical-Digital-Amplifier/dp/B01MRII0D1/ref=sr_1_5?crid=31CETPW2K7QLM&keywords=optical+digital+audio+output+to+rca&qid=1706663663&sprefix=optical+digi%2Caps%2C87&sr=8-5#customerReviews

He's hooked it up, but he's getting about a 1 second delay in the sound from the speakers relative to the TV picture.

Anyone speculate as to why? Would it be a delay produced by the conversion in the cable splitter itself? Or perhaps something the Sonos streamer/amp is doing to the signal?

I suppose an alternative would be to send the sound to the Sonos streamer directly from the sources, in his case a ROKU box and a Blue Ray player. Though since he only has one set of RCA inputs on the Sonos, it would require RCA splitters to get both sources in to the single RCA inputs.

 

[Martin Takamine]

It should be easy to determine if the converter setup is causing the delay.
1. Connect Roku directly to the Sonos.
2. Connect the Blu-ray player directly to the Sonos.
If configuration 1 and 2 perform without delay then there is an issue using the TV optical out.
But whether the problem is caused within the TV audio conversion or the Neoteck conversion can only be determined with direct optical-to-optical connection.

 

[Rottmannash]

I assume there is no audio delay adjustment in the tv? I have an old Panasonic plasma but haven't hooked it up in years. They are so energy inefficient and hot I can't imagine why anyone would use one these days. And not very bright nit-wise.

 

[GXAlan]

No good options. Some of the modern Sonos setups have a 75ms delay and the optical to analog conversion adds additional latency. (Because those inputs can then be beamed over to a random Sonos speaker anywhere in the home).

The WiiM setups are apparently 50 Ms of latency. With modern HDMI eARC, there is an auto latency calibration, but for an older TV, the best bet is an old AVR.

The good thing is that you can get really good classic AVRs for not a lot of money…

 

[MattHooper]

It should be easy to determine if the converter setup is causing the delay.
1. Connect Roku directly to the Sonos.
2. Connect the Blu-ray player directly to the Sonos.
If configuration 1 and 2 perform without delay then there is an issue using the TV optical out.
But whether the problem is caused within the TV audio conversion or the Neoteck conversion can only be determined with direct optical-to-optical connection.

Yeah, that was going to be one of the moves, but they are luddites and I'm trying to help "over the phone" so first getting an idea of what might be going on with this first method.

I assume there is no audio delay adjustment in the tv? I have an old Panasonic plasma but haven't hooked it up in years. They are so energy inefficient and hot I can't imagine why anyone would use one these days. And not very bright nit-wise.

The TV still works. They aren't videophiles and are not prone to caring about the latest things.

No good options. Some of the modern Sonos setups have a 75ms delay and the optical to analog conversion adds additional latency. (Because those inputs can then be beamed over to a random Sonos speaker anywhere in the home).

The WiiM setups are apparently 50 Ms of latency. With modern HDMI eARC, there is an auto latency calibration, but for an older TV, the best bet is an old AVR.

The good thing is that you can get really good classic AVRs for not a lot of money…

Well, that's interesting. I think a classic AVR is not going to be what they want.

It seems to me that if we try the Wiim Amp and there is too much latency when taking the optical feed from the TV, then the other option is sending the audio out separately from the Blu Ray player and Roku box to the WiiM Amp. I haven't looked at every connection, but I presume that would be possible.