I have been told that a center channel for the 938s will be available late this fall by a company rep here in Atlanta. I'd wait for it if I were you...
I don't think purchasing the upper module of the 938 is a good idea; the crossover point from the bass is at 230Hz. Maybe the HPS-906 may be a good solution, why not check if Hyperion is willing to sell just one for center channel usage?
Did you check with the company whether the voicing of one of their smaller model speakers would be a good match? Another more expensive option would be to purchase a single upper module of the Hyperion 938. The top treble-midbass module should be a suitable fraction of your original purchase price. It would be as if you were buying a replacement module when damage is limited to just part of this fine speaker. The company rep probably has the correct answer for you if you reach by telephone.
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