Interestingly, sometimes they do really bad when you give them exactly what conventional wisdom dictates.
My bushes came with the property, but I have increase yield already this year (my second crop with them). They are growing in red clay and chert/fractured limestone. PH is neutral, maybe even alkaline a bit. It's a funny thing. Same for the blackberries. So I've just weeded and layered a little bit of garden soil, garden tone, Cascade minerals, Azomite and mulched with hardwood chips. Trying to give the feeder roots something happy to live in.
I had planted raspberries last year. Dug out a hole. Made a nice soil mix. Lightly fertilized and let it sit before planting. Stuck the Rasps in and they just didn't take off. I thought they had died. This spring Raspberry shoots popped up all around the holes where I planted them. They literally crawled out of the nice dirt and into the native, very compact and very rocky clay.
I confess I'm a bit puzzled and have not figured out the answers as to why they prefer the native. Or why they're all doing so well in 7.0+ PH, though I believe it has something to do with an abundance of a couple nutrients that would otherwise not be as available in neutral or alkaline soil.