When people say that they are going to blank the tape, they are essentially using the wrong terminology. That would mean stripping off the magnetic coating in which case you would not be able to record at all. Setting the proper bias for your tape means that you will be aligning the magnetic particles in a straight line in preparation for recording. Bias is extremely important when recording. If your deck does it automatically then you're lucky although you should check to make sure it is correct.
Sound reproduction is directly related to the above two categories.
Not selecting the right bias will result in a terrible recording. The amount of energy that the tape can handle is important as well. A tape that can handle high magnetic energy will usually also flaunt its capabilities for delivering a high dynamic range and frequency reproduction. It usually does not matter whether or not you have a Sony or a Luxman deck as long as they have bias selection and a manual recording level on them. Most important is how well you maintain your equipment.