Hello I am building a pair of bluetooth/fm headphones mainly just for the experience and I have accepted that this will probably be more expencive than just buying a pair. I am using a pair of high quality passive earmuffs (NRR 31db) as a base because i mostly use headphones while working in the shop with power tools.

Thanks in advance for any help

I have a few questions about the components I should use

Any tricks i can use to make better sound

I was thinking of using 5w speakers to compensate for some of the louder tools i use but i am not sure how loud this would actually be. Would 3w suffice?
What is the effect of physical size and Ohms on the sound?

would i get better quality using multiple smaller speakers in each muff? Is it worthwhile to aim for 5.1 or 7.1 audio or is this tech lost in a headphone environment. ( I have above average but not excellent hearing. Probably top 25%)

What kind of amp should I use if any? I understand amps from an electronics perspective but i am clueless as to there effects on audio quality other than making it louder.

If i can i would like to not pierce the earmuffs to retain its NRR rating. to this end I am thinking of using a lipo battery with qi wireless charging in each muff and stow the on/off switch and fm controls inside the muff.

Can anyone suggest a wireless strategy to drive both speakers from the amp or bluetooth pcb (i would assume better quality audio would be produced with an amp in each muff therefore wireless off the bluetooth board would be preferred.)

I was thinking of potting the boards in to some electronics safe silicone as occasionally the earmuffs will get knocked off and fall to the cement floor.(I accidentally knock my earmuffs off a couple times a month). Would the potting cause issues with the amp overheating or should I ensure the amp remains out of the potting.
Is there a better shock absorbing potting material better than silicone?