I have not yet noticed this effect.
With the voice setting, dialogue is emphasised somewhat and with the night mode, the (sometimes somewhat exaggerated) dynamics are reduced.
Both help against the problem you fear.

Hello,
I have been using SONY HT-A9 for almost a year now and have been very satisfied with Bass and overall Volume levels in case of action scenes, Night sounds and general Dialogue delivery. After initial setup, I never had to adjust the volume controls during operating times. I did face volume control issues in our earlier home cinema systems but not anymore with Sony HT-A9. It works very well !!

Hello, I know what you mean. This was the case with my first sound system X years ago, where I had to permanently turn down the volume. With the Sony HT-A9, I couldn't notice this with the two films I've seen so far. After a short time, I got the Sony SA-SW3, which gives the HT-A9 even more bass and gets a lot more out of it. In retrospect, I would get the SA-SW5, which is a bit more powerful.

Hi Giusbian23,

you can adjust the volume of the speaker system, the bass volume and the volume of the rear speakers with the remote control. With the new BRAVIA TVs, everything can be connected perfectly. Control sound and volume settings with one remote. Check the audio system status on the go. Thanks to the built-in user interface, home entertainment system settings are automatically displayed in the TV's quick settings.
For clearer dialogue, you can switch the function on or off with VOICE. For more information, visit our support page.

Sony Support EN