Would normally put this under "Ask Win" but the DIY community seems more appropriate as it's home workshop related.

I've watched several informational videos on ensuring bandsaw blade tension is set correctly. I know the proper tension varies with the size of the blade, so for reference this is a 10" saw with a 1/2" blade.

When cutting anything thicker than half an inch, I often run into what I can only describe as an intermittent whirring sound. It only shows up when feeding wood into the blade, and while it would seem to be related to trying to feed the wood too fast, there often is not a steady increase in the sound, but more than it suddenly starts and then only goes away when I stop feeding the wood into the blade all together.

The denser the wood, the more likely this is to happen as well. Guide bearings are not spinning during this process, so it's not that the blade is deviating side to side or pushing back due to feed rate and riding on the back bearing.

Is this an issue with the blade tension not being enough?

Additionally, was resawing a 2x4 of about 10" in length today, cutting it into two 1x4's, and the blade deviated by about 1/16" off course and then back. After the cut was done, it had done this deviation around a knot that was in the wood. I don't know that I've cut a whole lot of wood since I got the bandsaw last year, probably 20 feet of wood total has gone through it, most of it less than 1" thick. Is this just a case of the factory blade being cheap garbage and it is now getting to dull?