Help me diagnose this weird audio problem on my parents' HDTV

February 27, 2018 5:55 AM

I have been visiting my parents recently, and have noticed a weird issue with the audio on their 3-5 year old SCEPTRE HDTV. I have not been able to determine its specific make and model, and they live (and the TV was purchased) in the USA, if that makes any difference, but the problem seems generic enough that I suspect it's not really related to the specific model.

The substance of the issue is that when the audio coming out of the built in speakers reaches a certain level, loud, but not too loud, it will very quickly diminish to almost inaudible. It will then proceed to climb back up into the normally audible range of volume until something else comes along to boost it over this mysterious threshold, after which the process repeats, faster or slower depending upon the native volume of the audio program of the broadcast. It has a little bit of a saw-tooth wave quality to it, climbing gradually and then dropping suddenly. Over and over and over.

I initially thought the issue was that they had the audio set to "dynamic" level out the highs and lows, but the TV was not set to that value, and in any case, I detect this behavior for any audio setting.

I know almost nothing about electronics, so I'm completely stumped as what the issue might be , or where to even start looking, and so throw myself upon the ministrations of the MeFi hive-mind.

posted by hwestiii to Technology (3 answers total)

My initial thought was that they definitely hit something accidentally in the menu, but your description of the saw-tooth thing sounds like maybe something is actually wrong with it.

However I did a search on SCEPTRE HDTV volume problems and there were a lot of suggestions. Seems this is a fairly common problem and not a lot happy solutions.

Suggestions from the world to try:
Turn off "AVL" (auto volume leveling, sounds like a different setting than what you listed for dynamic level)
Go to settings, to sound, to expert settings, to HDMI Input Audio Format, change Bitstream to PCM.
This thread seems to suggest you'd have to open the back and disconnect the side buttons, as the issue is caused by them.

Good luck!
posted by clone boulevard at 6:52 AM on February 27, 2018 [1 favorite]

That is exactly what my Vizio's automatic volume setting does. It also has a dynamic range compression feature that doesn't change the overall loudness, which may be what is now off on your parents' TV.

If it's a failure, it's not a hardware failure, that's for sure.
posted by wierdo at 11:22 AM on February 27, 2018

I have experienced exactly this, and fixed it. I don't remember the exact details, but I think the problem was resolved by changing from a Surround Sound audio mode to Stereo.

Does this problem happen with multiple video sources (e.g. cable box and disc player)? If it only happens on one device, check that device's surround sound settings.
posted by reeddavid at 1:30 PM on February 28, 2018