Hi, this is Dan Wright from ModWright. I read your post and felt that I should at least share my $0.02.
The audio market is a tough one to break into and finding your niche is the best route. I can't tell you what that niche would be for you, but don't be daunted by the fact that you don't have a PHD in Electrical Engineering or something similar

. I am a Mechanical Engineer by degree and have simply worked hard and taught myself what I needed to know. There is no substitute for hard work, research and just getting your hands dirty. Follow your heart and do what you enjoy and are passionate about. If you do this, you will succeed.
As far as the business end of things, speaking from experience only, this is what I would recommend:
1) Treat the customer right and treat all customers the same.
2) Offer a good product/service that represents a good value.
3) Don't sell yourself too cheap! Good value doesn't have to mean 'cheap'. Bottom line, you have to make a profit to stay in business.
4) Align yourself with other people in the industry that share your values and business plan. I.e. networking is VERY important.
5) Keep your OVERHEAD LOW!
6) Follow your heart...
I hope this helps. It has served me well and I a happily in business today after 7+ years since the inception of ModWright LLC, now ModWright Instruments Inc.
In case you don't what we do, we started out doing digital player/DAC mods and now do this as well as manufacture our own products and do some consulting. I don't miss my day job in consulting engineering

.
Take care and good luck!
Dan Wright