My chamber choir performed last weekend in perhaps the most acoustically dead church I've ever been in. Small, round, and fully carpeted. I decided to try the 22cm 4006 pair again (this time with Rens Heijnis modded preamps) knowing that I'd need to add some reverb in post.

Once again I arrived at a very similar EQ curve that sounded good, close to Gerzon's recommended low corner of 140 Hz, but only a 10 dB boost. His recommended boost of 14 dB made things much too thick, as did raising the low corner frequency to 245 Hz which the 5.4/d (cm) formula would suggest.

3 versions of each are below. ORG is nothing but gentle master bus compression. SHF adds shuffling EQ. MIX adds some light reverb (I went with a 1.4s room to not make it sound like a completely different place).

Let me know what you hear. The balance issues are personnel related: We were missing a tenor and a bass for this performance.