my friends have never complained of me sounding quieter, the only way they know im using it is they say its clearer and tends to pick up less background noise
it shouldnt make a difference the age of the controllers it should work no matter what
for most people that is not a problem as generally people have newer consoles and/or newer controllers that have been bought so i expect few with have problems on that side of things
i believe the earpiece of the wireless headset can go louder than the wired one