H Dustcap Explained
What is an 'H' dustcap?
The term "dustcap" refers to the small dome-shaped part of the speaker in the very center of the cone. The dome is there primarily to keep dust and debris out of the speaker's voice coil gap, but a secondary function is how it affects the high frequency response. For typical guitar speakers, we have chosen the standard dome that makes the most musical sense, as well as preserving vintage characteristics.
Sometimes a player will want a speaker with a diffused or reduced high frequency response. For this purpose, some speakers may be ordered with the 'H' dustcap. This is especially true of harmonica players, who want to reduce the high end to help prevent feedback and abusive tones. Hence the designation 'H'