I have heard of the Summas, and I am aware that Earl Geddes is at the forefront of waveguide tech for diy'ers, but from a few who have compared them to the sp's and heard both, they are seriously NOT in favor of Gedlee's creations.
Here is one such comment:
"Thanks for the comments. I too was very interested in the Gedlee Summa's as well. In my investigation here is what I found on the matter.
I asked one manufacturer what he thought the Summa's sounded like at RMAF two years ago, and I trust what he says cause he calls it the way it is. If it sounded good he would tell me.
"Well, I really don't want to take anything away from Mr. Gedlee. I think he is a brilliant man, but my impression of the speaker wasn't real favorable.
I heard it at the RMAF last year, or was it the year before? It might have been the year before last.
I was cruising some of the rooms with a few colleagues. They had gotten ahead of me and were coming out of that room as I was going in. They all told me at the door not to waste my time with this one as it was horrible. Regardless, I still wanted to hear them. They were right. It did sound pretty bad. I hate to say it, and if it were great, I'd say they were great.
However, Mr. Geddes was demonstrating that one didn't need all that high end gear and fancy cables to get great sound. He was using a cheap CD player and a receiver or something. All cables were generic Walmart type stuff. Unfortunately is sounded just like all the gear. It sounded like a radio from a car and the highs sounded like they were playing through a rolled up sock.
I am sure those things can sound a lot better than what I heard, but from what I heard almost anything at the show would have gunned them down before they could get their guns out of the holster."