They both wear out faster if you don't let them rest.
Any trainer will tell you that if you overwork a muscle group, the results will be extreme fatigue, rendering that muscle group painfully unusable for a while. The same result happens to your reeds when you overwork them. When you play only one reed, rather than rotating it with other reeds, it will stop working from fatigue. Your muscles recuperate and get stronger when you let them rest. Your reeds recuperate when you allow them to dry out a little and regain some of their stiffness. The best way to let them do that is with a quality reed case with humidity control, like the Vandoren Hygrocase. There they regain their moisture equilibrium and are ready to give you the sound and response you expect from Vandoren reeds, over and over again. Think of it as a strong start to a long and happy reed life.
Making Your Reeds Last Longer
You invest a lot in your reeds – not only in dollar cost but in time breaking them in and using them in rehearsals – all in preparation for that really important performance.
Rotating reeds is a great way to make your reeds last longer. By using a different reed for each different practice your reeds have a chance to rest and recuperate from the rapid vibration you put them through.
When you store them, try and keep them in a humid environment of around 50% humidity. You will want to experiment with this humidity level based on where you live and how much you play. Some musicians like it a little dryer and some a little more wet, but 50% is a good place to start. When you keep your reeds humidified, the reed will warp less. Warping occurs when the reed begins to dry out. If it dries out too much it’ll start to warp and then you have all sorts of problems with performance. If this occurs you can reflatten he backs of your reeds with sandpaper, or the Vandoren Reed Resurfacer. Doing this will allow your reeds to once again seal completely flat against the mouthpiece the way they were originally intended. But if you keep your reeds humidified, you’ll have much less need for resurfacing.