I've been thinking about rebuilding my whole home theater setup for a while. Currently I have a Velodyne CHT speaker setup with
two sealed subs I made that use the 12" Dayton Titanic. I enjoy this setup a lot but it has some flaws that I think I can address.
Problems
1. Needs more mid-bass. The Velodyne speakers are two-way sealed speakers with a 4" woofer. While very good for what they are they don't have the mid-bass punch I want in my action movies.
2. Mains need to go lower. The Velodynes have an F3 of 90Hz. While this is fine with my setup (twin front subs keep the bass from being localizable) I'd really like to push that down so they are
flat to 80Hz or lower.
3. Center needs better dispersion. I've never been 100% happy with the center chanel. It is a typical MTM type and the horizontal dispersion is lacking. I've done everything I can do to fix this with positioning and it's good - but not good enough.
4. Sub(s) could go lower. Okay, this is probably always true. With EQ my current subs have an in-room F3 of about 21Hz. Bass shakers are all I really need for sub-sonic. I would like to have my subs go low without electronic EQ. This is low priority but something I'll probably address.
5. This isn't a problem but one thing I liked about the Velodynes is that they were pretty insensitive to room placement. I think part of this came from the small woofer and part because they were sealed with highish F3 points.
Philosophy
Since my theater is for movies only (music listening is done in a different room) I can stay a bit focused and not worry about having full range mains. These are nice (especially for 2 channel music) but I'm happy being able to pass all LF to the subs as long as #1 above is met. Right now I'm going to try to have all my speakers have the same F3 to simplify crossing over. This design choice allows me to use smaller drivers which tend to have better dispersion and should allow me to use smaller baffles and a higher x-over point (makes tweeter selection easier).
I've imagined building a set of 2-way speakers based on the
Dayton RS125S-8 and an as-of-yet-undetermined tweeter. My experiments with full-range drivers (all in the 3" and 4" range) have impressed me with their good dispersion and the bass that is possible with a modern small driver.
The front L and R speakes would be ported MMTMM's, the center a ported TMMMM that stands on the floor. The surrounds would either be of a similar design to the surrounds described in the Loudspeaker Design Cookbook (one woofer canted down with forward and rear tweeters) or similar to the GR-Research upwards firing surrounds. If I decide to go 7 channel I'll make simple ported TM 2-ways for the rear.
To try to keep these as insensitive to positioning as possible I plan to front port these (almost as good as sealed IMHO).