The math hasn't changes since the 80's. You should gain 3db every time you double your wattage. The "perceived" volume will double with an increase of 10db.
Speakers rated at 90db at 1 watt, will put out 93 at 2 watts, 96db at 4 watts, 99db at 8 watts and so on...
There's a lot of arguments out there about 1 watt at 1 meter and how that isn't accurate but it is consistent even though most people do not listen at 1 meter.
Personally, I'm more worried about dynamic headroom. When you overstress an amp, that will reduce musicality. Just my 2 cents.
Speakers rated at 90db at 1 watt, will put out 93 at 2 watts, 96db at 4 watts, 99db at 8 watts and so on...
There's a lot of arguments out there about 1 watt at 1 meter and how that isn't accurate but it is consistent even though most people do not listen at 1 meter.
Personally, I'm more worried about dynamic headroom. When you overstress an amp, that will reduce musicality. Just my 2 cents.