(Arthur Grossman is the excellent and frequently-recorded bassoonist [solo bassoon and strings and wind quintet] of the SONI VENTORUM Woodwind Quintet in residence at the University of Washington.)
I have for years kept on my reed desk a huge, oversized tuning fork in a resonating box. I have counseled my students to do the same or to use a suspended tuning bar with the striking hammer tied back. My reasoning was that if one struck either the fork or the tuning bar, one's sensitivity to pitch would cause one to make the necessary embouchure adjustment to match the heard pitch. Whereas, with my system, the fork or bar was acting as a passive device, thus responding to the bassoon sound itself, therefore ensuring that one's reeds would be in tune.
I have also possessed for a few years a KORG Tuning Standard (electronic tuning instrument. Editor ) which I have used for other purposes, but until recently never in conjunction with my tuning fork-in-resonator. Imagine my horror when I did so for the first time and discovered that the fork would vibrate sympathetically to any "A" between 435 and 445 vps! Of course, it would not so respond when fed the pure sine wave signal of the KORG's tone generator. But when activated by the bassoon sound, it did.
My theory about this is that there are enough partials which are sufficiently out of tune that the tuning fork will respond to one of them within these limits (and perhaps farther). The clear message is that by using this method, one is not indeed ensuring that one's reeds are truly in tune; and the sensation of feeling that one has to adjust when in the real playing situation while using a reed which had caused the fork to ring beautifully is not an illusion.
My tentative recommendation is to use a KORG or a similar device. Play the reed first, with eyes closed. Then observe the result on the KORG indicator dial. A further elaboration which I find most useful is to play all octaves of the same note while leaving the KORG set for the note of the lowest octave. Follow this with the playing of all arpeggios while the tuner is set in this same mode. These tests should give a true picture of the reed's stability and should prevent the need for a great deal of performance adjustment, not to mention pain.