I heard bottom of the unit heat up - did you try to flip it upside down? ; )I bought the HT-A9 one month ago.
Great system but I have one complaint : the fan noise.
Starts to spin after 1H25 of used and lasts 10 minutes then stops then starts again one hour later for ten minutes.
The noise is quite noticeable in the evening when the volume is low.
Does anybody who own this system could check if they have the same noise coming from the fan after about 1 hour and 25 minutes.
I have recorded the fan noise with my iPhone close to the control box here
To give you a comparaison the fan noise is quite the same than the noise coming from the PS5 which have the worst fan.
And one last thing my SA-SW5 subwoofer makes a strange noise at some moments : like first moment of the HBO logo and at the beginning of Blade Runner 2049 at 1 minute and 45 secondes before the first image on the eye. Sounds like a saturation as if bass were too powerful.
Does anybody with a SA-SW5 could make the same test ?