I so admire what and how Jeff does this. That is for somewhat selfish reasons because it is very much like my business model. I was sort of forced to retire a bit early from the movie-making biz after an accident left me with disabling injuries. I decided that I could probably bring something to the other end of the business designing screening rooms, dedicated HTs, and not-so-dedicated theaters. I used to spend hours in the finest screening rooms in Hollywood, so my approach is to bring that experience to every project. I’m always researching products that will allow me to do that best whether in data or auditioning them wherever I find them (CEDIA, etc). So, somewhat like Jeff, I only tackle as much as I can fully keep my arms around and deliver my “recipe” …sort of analogous to Jeff’s unique JTR voice.
I come from the professional side, but I’m also a residential enthusiast like all of you. I can’t totally shake either, and don’t want to.
Lest you guys think my annoying inquiry process is nuts, the process I'm pursuing is routine for commercial cinema design (and other venues). That's why professional divisions publish those detailed spec/data sheets. It enables us to predict certain necessary technical matters that are essential to design. I don’t want to choose a speaker that sounds bad, regardless of the what graphs and numbers say, but those can be really helpful.
I hope you find this next part informative. I’m offering it for your entertainment, not to make any argument.
Here is a link to the spec/data sheet for a JBL commercial cinema speaker. http://www.jblpro.com/BackOffice/ProductAttachments/3252N%20Spec.pdf
I chose this product because it is somewhat like the 212 in scale and general design approach. If you open it and scroll down to the directivity index/factor graph you will see some things that we all know: low frequencies have lower directivity than higher frequencies. This speaker has a Directivity Index of about 10 which is common for a cinema speaker, but rather high for our typical HT size rooms. If you only have one important seat, that’s fine.
Notice that the mid-range is quite smooth, but takes a bit of a dip at about 800 Hz. That is the two 15” woofers just beginning to beam. Notice that the directivity smoothly increases with frequency until the crossover point at 2 KHz where it takes a slight dip. This graph shows us that this is a pretty good speaker design that uses its components, waveguide design, crossover design to keep that directivity graph pretty much like we want it; predictably and reasonably smoothly becoming more directive as frequency increases. I suspect that Jeff has successfully accomplished similar results.
Take a look at this one by comparison. http://www.jblpro.com/BackOffice/ProductAttachments/SS3722.0509.pdf
Also a cinema speaker, but different enclosure, CD, and waveguide design, and lower crossover resulting in a little less smooth performance near the crossover, but smoother directivity in the highs due to the different CD/waveguide design.
In fairness to Jeff, I don’t know of any residential speakers that have that kind of data published. I'm sure that's because, like someone mentioned above, most residential customers would not care. They rely on their provider, or they audition and make a subjective/emotional decision...which is fine. The S in AVS does define us a bit here.
Jbrown15 mentioned the Klipsch THX U2 speakers. I know those speakers well, like them, own them, and have used them in a number of designs. I like their performance and output for their relative small footprint. They are not perfect, though. The heavy data exists on the KL-650-THX , but Klipsch doesn’t publish it publicly. I have seen the data on them. NDA won’t let me be too specific, but like many 2-way designs, they are imperfect at the crossover point. Their reasonably high directivity does help in many rooms, as each room has its specific needs. I do like them personally…which makes me think I’d also like JTRs.
So, back to JTRs. I just don’t know them, but I suspect they are very good and I might personally find them excellent and ideal for some designs I do where they are custom installed/concealed. At this time, they enjoy an entusiast (i.e. fun) niche. I'm also looking at them for practical utility reasons to meet design needs. The synergy of the two makes everybody happy happy happy. Edited by Cam Man - 10/12/13 at 12:03pm