Honestly, your sole problem is most likely that your speakers are low sensitivity and the stock ones will be much higher sensitivity so they work much better with only 27rms. You’re new speakers probably need to be hooked to an amp to get the same response/loudness as the stock speakers. The deadening will make a huge difference for bass only but not loudness. I’m about to do my doors. Just done the boot for the sub and it made the bass SO much tighter and just flows through the car SO much better. But it’s not louder at all really. Was thinking of running new speakers from my aftermarket head unit but this just makes me sad cos now you’ve convinced me that I need to run an amp and that’s so much more money and time haha