@nashvillehifi I will add my 2cents even though I know little about the inside of this industry. I am a successful entrepreneur and have experience in venture capital, though. I encourage you to follow your passion, but with some hard-stop caveats. Do NOT expect to draw a salary or take dividends for, say, three years. So, either have a pot of money at hand now to support yourself and your family for three years, or have a day job, or rely on your wife's income for that period (there is nothing wrong with this assuming she is supportive). Remember, you will need health insurance.
Second, the business will need working capital. Depending on the type of business you decide on the working capital needed could be substantial. Bricks and mortar (i.e., a lease), outfitting a showroom, inventory, etc. all take cash. Do NOT borrow from your IRA or pension fund. In fact, depending on your age, I would advise against starting the business at all if your retirement financing is not adequate and already secure.
View this endeavor as a labor of love (or fun). That pot of money I mentioned above? - You may never get it back. You will not be able to compete against Music Direct, Crutchfield's or Sweetwater, much less Amazon. Do not expect your small town to support your proposed business - your only realistic option is to target the Nashville market. That is where the money is. @meadowman and @lonemountain have given you some very good advice on easing back into the business. Start as a consultant or a sales representative and learn, learn, learn. Don’t bet the farm yet.
Here is something I have seen in multiple start-ups and experienced myself: what ends up being successful five or ten years down the road will not be what expect or plan for now. Let me put it this way, the only way to figure out what will work in your niche is to try it, but you need to be able to survive while you discover what exactly works and what doesn't. Learn and adjust; reinvent your business as needed.
I don't mean to be negative, just realistic. You might actually be able to make it work. Sincerely, best of luck.