I have bought a Bose SoundTouch 300 sound bar and wireless rear speakers Bose Virtually Invisible 300 - the only rear speakers on the market supported by the sound bar at the moment of the purchase in my country. It will never be told you by a reseller in an official shop, but these rear speakers have a very annoying problem. The problem presence is confirmed by the official Bose support in my country. The problem is - power units of the rear speakers make an annoying hissing noise close to ultrasound until they establish a firm connection with the sound bar. It basically means that once you switch your sound bar off, the connection is lost and the rear speaker power units start to produce an annoying hissing noise. It especially makes sense at night when every sound is audible. So, you have to switch the rear speakers off the power outlet every evening.
I can assume that this is an electrical circuit design problem which usually occurs if non-proper filtering is applied or filtering elements (capacitors) fail or there is a lack of noise suppression. Such noise is usually caused by a throttle or a transformer on an electrical circuit board. As the entire released batch can be affected, it is most likely the electrical circuit design issue. But manufacturers usually call it “a feature”, otherwise they would have to recall the entire batch.
You may be familiar with such a hissing sound – it is often caused by cheap impulse power supplies you may buy on AliExpress. But you never expect to meet this problem buying an expernsive Hi-Fi sound equipment!
I found a similar post in an archive:
There is a Reddit post as well:
And if you want to have a clue of what I mean just watch this video on YouTube:
At the moment of this writing I understand that there is nothing you can do with the problem except for returning the rear speakers back to the seller. The power units are monolith, there are no screws – one cannot open them and fix the problem (even if one knew how to fix it) without destroying the power unit box.
The actual question I want to ask is the following. The whole 300 series is discontinued now, including SoundTouch 300, Virtually Invisible 300 and Acoustimass 300. They are replaced by new products – Soundbar 500/700, Surround Speakers and Bass Module 500/700.
So the question is – do the new Bose Surround Speakers power units have the same hissing noise problem? And can the new Bose Surround Speakers be paired with the old SoundTouch 300 sound bar?