It's a long story but basically, the missus was not happy with the looks of the speaker. WAF is not important if you have a separate room to listen in, but if the system shares main living space with the rest of the household then it needs to be domestically acceptable.
The experimenting with scattergun tweeters was fun, and taught me a lot about omnis and their own peculiarities, so it was useful from a speaker development perspective. Experimentation was also relatively cheap, using cones, but because of the unnaceptablity in the living room, I had to find a way to get the treble right, with just the single SB Acoustics, ring radiator tweeter.
Replacing the Faital Pro 6PR110 bass/mid driver was not an option, as the whole cabinet and quarter wave line had been designed around
it specifically. Can't get the tweeter loud enough? Then you have basically two options:
1. multiple tweeters - done that. OK but not domestically acceptable in the format I used.
2. reduce the bass/mid level to allow the tweeter to breathe unaided and assert itself properly above the din from the rest of the freq range.
I chose the second option.
L Padding a main driver is not ideal, but needs must and apart from anything else, the Faital bass/mid driver doped with a little bit of shout removing PVA had such a good overall tone, I would have been a complete eejit to want anything else.
The whole speaker system now has an overall efficiency of around 91dB/Watt, so is still pretty sensitive as speakers go and the tweeter, being 94dB efficient, is now properly able to make itself heard.
The results are quite exquisite, which is all I'm prepared to say. These could go to any home based bake-off and not be found wanting in any way. I'm now confident I've cracked the semi-omni conundrum. Not an easy process, I can tell you, and all credit to Richard, for the sound of the his Cubes.
Having done something similar, I can appreciate the amount of work that must have gone into getting them right and also the fact that omnis don't play by conventional design rules. They need a huge amount of effort, thinking and empirical experimentation to voice up properly. No amount of measuring gear or computer plots is going to cut it. OK you could say the same about point and squirt speakers, but omnis are another level entirely in terms of the effort needed to get them right.
Probably why there aren't many about.
Sunday morning bliss: