This happens on mine also. Very annoying. A bit of searching shows it is a common issue on these sound bars. Stay well away from these.
I think it is due to overzealous power saving in the sound bar that mutes the sound during quiet parts of a film etc. You'll find that if you switch to your TV speakers when this happens, the sound is normal.
BTW sorry for the necro bump. I realise this is an old post but Internet searching for a solution to this problem brought me here.
Has anyone received a satisfactory response from BT or JBL on this annoying fault? Thanks to those from the forum who gave attempted a solution. Unfortunately none works.
I have a Sony Bravia TV connected to the JBL Sound Bar received as a gift for upgrading my account.
Is it just a case that we accept this poor device because it was free?
I had exactly the same issue and phone JBL support today (01612223325) - found the phone number here. Very helpful - they checked my serial number, and sent me an appropriate firmware update. They said it's a known issue.
They include a PDF with instructions, and a .bin file which is the update itself. The only issue I had was that the first USB stick I tried to use (Sandisk cruzer) wasn't recognised by the soundbar. The second one worked fine (a generic cheapo stick).
I've played a few video clips and haven't had the issue yet... but I'll need to give it time to be sure.
I rang the number you supplied and like you eventually got an email with firmware and instructions. Have the serial number ready else it might be a frustrating call.
Any info regarding the existence of the upgrade or the upgrade itself cannot be found online, a phone call is the only way.
The new firmware is version 42.37. It loaded ok but please follow instructions using buttons on unit, not the remote control.
I checked the firmware version after upgrade and it seemed to have worked. Note that I left it upgrading for a couple of hours ( not the 14mins it says) and it still did not indicate the upgrade was complete.
It's been a day now and I have not had a reoccurence. I will update all if that changes
I have the same soundbar which I got from BT it now doesnt work. All of a sudden it has decided to turn itself off (orange light) almost immediately after turning it on. It also doesnt respond to the provided remote. It worked fine one minute then this is there any fixes ??