A counter is configured to generate counts associated with different locations, within a smallest addressable unit of data, on a storage medium of a disk drive. A detector is configured to detect a change in a property of a signal sensed from the storage medium. A controller is configured to: determine a count of the counter corresponding to a location, within a smallest addressable data unit on the storage medium, at which the change in the property of the signal sensed from the storage medium is detected, and change a response of at least one of the detector, a read channel controller of the disk drive, or a servo controller of the disk drive based on (i) the count and (ii) the counter.