Sprint Tempo

Yay, first post. I'm about a decade out of college swimming give or take and i've competed on and off the past 10 years or so to different results. Recently I started working out on my own and have started to plot my comeback to competition. Without a coach or really anyone to ask advice of at the moment, I turn here. I'm starting my comeback up with 50 and 100 freestyle events. I'm reasonably sure my 100 is good to go (it was always my strong point) but I've had problems with my 50 even through college. Advice from coaches back in college seemed to indicate that I need a high stroke tempo above all else in the 50. ( It also seemed that no matter what the result the only response was "good swim" so this advice is questionable to me) Whenever I try to up the tempo, it feels like i'm just spinning the wheels so to speak. High tempo never feels like i'm going as fast as I could and also seems to throw off the balance, technique, and turns. When I try to back down the tempo to something that feels more productive like my 100 pace the 50 time seems to slow down drastically. I guess the answer I was hoping for would be a good description or indication of how to select the correct stroke tempo for a 50? Is it just trial and error or is there a decent way to measure what type of tempo a person should be at with a given armspan/height? I've tried to watch a lot of youtube footage of top notch sprinters and nearly all of them are high tempo, though sometimes it's hard to see anything but splashes ;) Just figured I'd ask here and see what people abroad have to say about it.