Good questions, oxl. Welcome to the forum and congrats on the Invisa HTR-7000s. I think many of us here are considering the same solution and will monitor the response with interest. If possible, can you follow up with us once you have things in place to share your experience with us? So far, we haven't had a lot of feedback on the 7000s in an Atmos configuration. Pictures are always appreciated.

Regarding your question, it seems like there are a lot of variables out there. Besides variation from solution to solution, you also have room considerations such as seating positions and ceiling height. What type of ceiling are you installing these into? It seems this would be one advantage of a drop ceiling in that you could use a little trial and error to find the ideal position. I think all of the guidelines are simply that, and there is Some room for subjectivity and creative license.

Cheers,

T Cobe

oxl wrote: So my question is: How far off axis should the MLP be? Should I try to find a position that leaves the HTR7000s 31 to 44 degree off axis after compensating for the 30 degree firing angle? Should the axis "pass" above or below the MLP?

As T Cobe implied, lots of variables relative to your specific setup. If I (or your integrator/dealer) was standing in your room, looking at all the surfaces, seating positions, etc., I could easily point and say, "right there". From here, all I can do is suggest reading this thread (I just did, lots of good answers), the info on our website Atmos Systems section, and/or getting local assistance.

The GENERAL idea with the HTR 7000 as height channels is to have them deliver the height information without pointing straight down over your head from only a few feet away. By locating the HTR 7000s outside of the directly-overhead positions and pointing them towards the MLP, you get height effect (sound appears to come from above) but it sort of washes over you rather than drills through your head. To accomplish this the position needs to be LESS THAN the geometry required for the front LCR application. How much less really depends on the exact layout of the room and the seating positions. Our experience with setting these up has been to position the height channels, with HTR 7000s, in a typical 8ft-ish ceiling, just outside (L/R) of the listening area, and just in front for the front height and just in back (of the listening area) for the back heights - all angled toward the MLP.

Moderator Dude,

Has anyone experimented with enclosing these speakers inbetween ceiling joists. I have the ability to build an enclosure and install that between my joists if there would be an improvement in the low frequency handling/output. Thank you very much!

Cheers,

T Cobe

T Cobe wrote: Has anyone experimented with enclosing these speakers in between ceiling joists. I have the ability to build an enclosure and install that between my joists if there would be an improvement in the low frequency handling/output. Thank you very much!

I don't really know, but there's no reason not to do so as long as the created enclosure is large enough. Generally, the speakers perform best without an enclosure unless the enclosure exceeds the max volume needed for full frequency response. A 1.5 cu. ft. enclosure area gives you good performance down to a standard 80Hz crossover. For deeper bass extension, you need a larger enclosure (or no enclosure).

Ok, continuing this discussion. I wrote a long post about this topic, but decided it was too long so I’m posting a summary instead.

I’m hoping to have 2 rows of seats, with 3 seats in the front row (MLP is the middle seat) and 2 seats in the back row.

If I follow the placement as described by the Dolby spec and pick the smaller angle (30 degrees), in my setup the HTR7000 speakers will be placed 53” to the side (so just outside the listening area and aligned with the mains) and 36” to the front/back of the front row. After a little bit of linear algebra, I find that the listening positions will be at the following angles relative to the height speaker axes:

- the MLP will be 14 degrees off-axis (“under” the speaker axis);
- the left and right seats will be either 32 degrees or 10 degrees off-axis;
- the back-left and back-right seats will be 32 degrees or 20 degrees off-axis relative to the front height speakers;
- the back-left and back-right seats will be 50 degrees or 59 degrees off-axis relative to the back height speakers;
- the back height speakers will end up in a position between the front row and back row;

In this configuration, the MLP will probably sound good, but the back row will be severely compromised. I couldn’t find information about the dispersion angle of the HTR7000s to have an idea if the front row seats will also be compromised.

On the other hand, if I pick the wider angle in the Dolby spec (55 degrees), then the HTR7000 speakers will be placed 53” to the side (so just outside the listening area and aligned with the mains) and 89” to the front/back of the front row. This significantly improves the angles of the “surround” seats (the off-axis angles range between 12 degrees and 37 degrees, with the back height speakers properly behind the back row), but now the MLP sits exactly at the speaker axis (1 degree off axis), which I assume will completely kill the height effect at the MLP.

Unfortunately I cannot physically experiment with this without making my ceiling look like Swiss cheese, so I’ll continue doing math.