Well, the limit in the upper range is indeed a technical limitation we have, due to the used pitch tracker technique (we are going for the maxima, not for the fundamental). So, we could precisely and fast track frequency’s up to 1000hz (B5). The tuner could track higher frequency’s, true, but lost precision then, so we cut of the result (not present).
On the down side, I cant reproduce the issue, the tracker works for the range from 20hz to 1000hz, so I could track easily, fast and precise the A0 (27,5hz) here.
There isn't any user setting for the tracker range, as the full possible range is in use anyway.
Using a other technique will result in a much higher CPU usage for the tracker, and, will be a way slower. You could check out X42's tuna
, which use the fundamental technique, which expand the upper range, but have it's cost.