Originally Posted by EndersShadow
Seeing pictures of my space, does that at all change your recommendations?
I'm also open to other DIY kits such as ones from Madisound, Meniscus and GR Research, however the flatpack enclosures from DIYSoundGroup would just make it SOO much easier........
As a back story, I used to build and even design conventional speakers based on typical "home" drivers. I thought they had superior performance, lower distortion, and the best possibility for good sound staging. I'm a sound stage nut, its the single most important thing for me next to overall response smoothness. Then I met Earl Geddes who turned me onto the possibilities of professional drivers in home applications and he taught me a ton about driver integration with regard to the polar response (and importance of CD). After not only building the Gedlee Abbey's for myself, but also my own hand at some other high efficiency waveguide designs, I'm totally convinced its the only way to go. I'm yet to hear a different approach equal what I get with the Abbey's. Having said that, truly following through on the findings of really solid research on what sounds best to the majority of people (be it Harman, Geddy's, etc.) means BIG speakers. You can't easily replicate the ideal CD behavior of a perfect speaker with really small speakers right now. In addition, while I think large waveguide speakers have the best sound I've heard, I've also heard some really spectacular systems using other approaches. I said that because I think the DIYSoundGroup designs are in line with what I like, the others are not. For that kind of money I think you get a better value kit from DIYSG.
Now not all waveguide speakers are created equal and a waveguide doesn't make a speaker better. The entire point is to create a response that falls at a constant rate off to the sides and does so in a perfectly linear fashion. An ideal speaker would fall off as perfect flat lines at all frequencies, but in small rooms, bass is non-directional and so it can't fall off to the sides. Instead, an ideal speaker in a typical room will fall off as a perfect flat line angled from a central point at the Schroeder frequency out to the upper limit of 20khz or so. Not every waveguide profile does this and not every DIYSG speaker does this.
This is an example of one they sell that really is well behaved, its not perfect, but its really good. Much better than most speakers.
Here is one I like the sound of but actually doesn't really conform to this property as well as it should. Still better than most:
In either case you can see that the speakers roll off fairly smoothly, but one is rolling off smoother over a wider range of angles.
I know that doesn't help you much, but I mention this because I want you to know my bias toward these kinds of controlled constant directivity speaker. I think even for small speakers I would seek this general attribute on a smaller scale, especially when being used in a room where people might be sitting in a variety of places. Any array of drivers has an impact on the directivity of the speaker, this is why line arrays exist, to control vertical directivity. The directivity is only impacted in the area where drivers operate at the same frequency, hence why a woofer doesn't really impact the directivity of a tweeter. That means the Quad4's will have some kind of vertical directivity constriction, and if you are too close, some lobing. The Fusion 6 and Fusion 8 I don't believe will have the same issues, they should have a wider vertical dispersion with a more even vertical response even closer up (All speakers lobe at some distance when there is a crossover involved). They also can crossover lower due to the larger waveguide and larger driver. I like the 8 best because its the biggest, its closet to the larger designs that get you closest to the ideal design.
Waveguide speakers typically are higher in efficiency and capable of more output with lower distortion. However, that isn't always true and often their total output is constrained by the low crossover point of the compression driver. In some of the DIYSG designs, I think the midbass driver might actually constrain the total output, but I'm not sure of that. In either case, they should all be capable of as much more output to any other similar sized speaker, which is to say, painfully loud.
The biggest negative with improperly designed waveguide speakers using compression drivers is that the tweeter will be bright to the point of pain. They are irritating to listen to. Harman did research into why this is, and Earl Geddes has done some similar and different research into the same phenomena. Both concluded that a general tilt in the response is desirable, and that with CD horns, the honk comes from the diffraction slot (so hence why we prefer a well designed waveguide). The waveguide needs a special eqed crossover using typically 2-3 tank filters (notch filters). I know nothing about the crossover schematics of the DIYSG speakers, so I don't know if these have that, but worst case scenario, they could be added if you found the response not flat and the sound irritating. It can be added via external DSP as well.