Originally Posted by dvdwilly3
I have 2 rows of seats in my home theater. The first row is on the floor and the second row is on an 8" riser.
So while my fronts and center are on the same plane as the front row, they are below the second row. The tweeters fire at ear level for the front row, but, obviously, not the back.
Would I be well served by putting my front towers on something like Primacoustic RX9s? Not necessarily for the acostic treatment, but to get them closer to ear level for the back row (around 4" thick...).
Anyone with multi-rows tried anything like it? That is, raising the fronts?
I would try a little experiment.
Have people sit in all seating positions. If every person can't see all of the speakers, then you should adjust positions until they can. The biggest problem is usually the center channel speaker which most place below the screen. There is almost no way a second row can see this speaker. This is bad and will result in poor dialog as second row does not have a clear line for the sound. Unlike light, sound will bend around objects a bit, so it is not a complete kill, but there will be a very distinct difference in the sound that the person who can see the speaker and the person in the shadow of an object or other person is able to hear. For left right front and side surround speakers, you may be able to move them side to side and front to back in the room to get a clear shot to all listeners with them still at the lowest possible height, but in many cases, a small increase in height can do an even better job of getting the best sound to all seats.
Depending on the size of your screen with a flat screen TV, you may find that the speaker above the screen will work much better. For a front projection system, behind the middle to top 1/3 of an acoustic transparent projection screen is the best for coverage as well as placing the sound source in the right place for the image.
For those who think the sound level from the middle to the end of a couch is no big deal, keep in mind that sound level drops off with the inverse square law. If you double the distance from the speaker, the sound drops 6 db. This is a hug drop for a fairly small change in a small room. A person on the end of a couch in a 10 foot wide room could easily be just 2 feet from the near side surround speaker and 8 feet from the far side surround speaker. This 4 x difference in distance works out to 12 db in level shift. A combination of moving them either up and/or to the side, and aiming them at the further listener can greatly reduce the level difference. Ear height in my room with my couch measures at 43 inches. My front L, C, R speakers have the HF horns at 63 inches behind an AT screen. 1.25 x 43 inches is about 54 inches. I will probably end up a little higher than that. Trying to stay under 60 inches.
In a perfect world, which does not exist, having the speakers at a true ear level does in theory give you the ability to pan a full 180 degrees from left to right over your head and front to back as well, and the full 360 around you, so that is the idea. If I raise the speakers to 5 feet (60 inches) on my 12 foot wide room, the center seating position has a pan range of 154 degrees. That is not losing much at all for the far better coverage on 2 rows of seats. With my current screen size, the 63 inch high front speakers have the horns very close to the ideal 2/3 up the screen. Lowering the front speakers to "Ear Height" would not only hurt the room coverage, but it would also make the sound no longer come from the ideal area of the screen.
As for which top speakers to use....
Think of it like this. The speaker names and angles are relative to a perfect main listening point. If your couch is against or near the back wall, and you use "top front" and "top rear" even thought the rear ones are basically straight above you, then it is just like sitting a little behind the MLP in a movie theatre. To make the pans correct, you should also have your side surround speakers ahead of you a bit to land close to mid way between the front and rear top speakers. A sound panned halfway back in the room will be evenly between the top front and top rear speakers, but will be directly in the side surround speaker. Front wide speakers appear to render close to the top front speakers as far as angle, or distance back in the room.
Due to the shape of my room (12 feet wide and 18 feet long with an 8 foot ceiling), I am thinking a bit unconventional. The front pair seems easy, I think I will use the "Top front" and have them about 6 to 7 feet back from the front wall. This does place them close to the correct angle in my 18 foot long room with the couch back 12 feet from the screen. The angle from straight forward is 36 degrees up, and from center channel, it is still 28 degrees up.
For the rear height position, I am really leaning at going to "rear height" and just using my existing rear surrounds for that purpose. They are just 9 inches below the ceiling at the back of the room now and the right distance apart too, with ball mounts, and aimed down to my front row seated ear height. From my front couch listening position, this places the rear height speakers at 31.4 degrees up behind me, close to the same angle as the front height is up. This is the same as 148.6 degrees from straight ahead, which is also in range for "rear height" speakers. I will then just add new back surrounds under them. Since my second row of seat will be on a riser of about 8 inches, I will put my new back surround at 63 inches like the screen channels. Seated ear height with the riser comes out to 52 inches. This 11 inches will keep the speakers from blasting into the heads of the back row seats.
for complete curiosity, I ran the trig on the front row seat for the front to back overhead pan angle range and I came up with 156 degrees of angle from front screen over my head to back surround.
I so wish I could afford a unit that could do 9.1.6