I've decided that it is worth investigating the construction of and HL97 horn for use in my center channel. The horn will make use of an existing H91 and the perforated plate from the HL87. The result will be a horn that has the length of the HL92, but the dispersion plate of the HL87. This will be accomplished using a wooden extension that mates the H91 to the perforated plate. A diagram of the extension is included.

I have a friend that is a woodworking craftsman and he said he should be able to whip this out.