Grunt (Dean): Acoustically Transparent screen isn't an option for me. Most of them have too much texture and this is a MAJOR concern because my whole theater is run from an HTPC (Home theater PC). A white browser page like this forum will reveal ANY texture and imperfection in a screen.
I understand and agree with your concerns. Picture quality issues was one reason I ditched the idea of and AT screen.
Your advice regarding 7.1 is something I thought of initially and I agree. My Pioneer 1019 does support 7.1 audio but I thought there wasn't much point given that DTS and Dolby are only 5.1 audio paths. Does the receiver automatically duplicate the rear surrounds to the sides with 5.1 content?
In my last room 12x14 I thought that 5.1 actually sounded better than 7.1 leading me to believe that 7.1 or more was just marketing hype. Now that I’m in a longer room 13x21 I’ve found that 7.1 is a huge benefit in creating a seamless rear soundstage even when using Dolby PLIIx or Neo 6 on 5.1 and 2.0 sources. I’ve even found that using DSX wide speakers in a 9.1 configuration really helps fill the gap in the transition from the front to the side soundstage now that I’m in a longer room.
There are several ways that Dolby and Neo 6 derive the rear speaker channels depending on how the recordings were mastered. In some cases a rear channel is “matrixed” in with the surround channels allowing it to be decoded and played in the rear. In other cases various algorithms are used to “pull” audio information out of either the surround channels in the case of 5.1 or the L/R channels in 2.0 and rout it to the surround and rear speakers. How effective this is depends on how the recordings were made. In all cases I find they greatly improve 5.1 sources in my longer room. As for 2.0 sources it all depends on how they were recorded. Some benefit while others seem to do nothing. In those cases I often use “All channel Stereo” mode which just duplicates the L/R channels down each side of the room. Although not “surround sound” it does create a more full and engaging audio environment for 2.0 sources like many TV shows. Again having 7.1 even benefits this in my longer room.
Multiple subwoofers may be in the long term plan. I was debating ordering the Axiom Master System 7.1 and using the SVS 10 with the Axiom 500. I'm not sure about the Axiom 500 vs an SVS 12 though. My desk is behind the second row of seating and right now the sub is between the wall and the desk (behind the right side of the couch). See photos linked at the top to get an idea.
Generally I think it’s considered best to use identical subwoofers when running multiple ones. Though many people have had great results using very different ones. I think using different subs together may become less of an issue as more receivers allow for separate subwoofer outputs like “7.2” or more. My opinion is that if you are happy with the sub you have just get another of the same later unless you feel you are missing something on the very low end. Just understand that if one sub goes much lower than the other it won’t benefit as much at that lowest level from having another sub to even it out.
Subwoofer placement confuses me. In such a long theater with concrete all around I can't figure out why some people recommend the woofer on the screen wall. That's 9+ feet from the nearest seating and 12+ feet from optimal seating. By putting the woofer next to my desk behind my couch my LFE is startling for only a 10 inch sub. Lovin' the SVS! It's so good now I can't imagine a second 12 inch sub. My dog is going to hate it!
Welcome to the club, subwoofer issues still baffle me. I always thought that multiple subwoofers were better than one until I recently tested that premise with a couple subs borrowed from Sean. Turns out in my “L” shaped room one subwoofer works better than 2.
As for placement there are so many variables from room/seating layout to personal preferences that IMO most generalizations break down leading to experimenting being the only way to really get things right. Still general placement guidelines are still useful for many who can’t tweak their setups and also as a common stating point from which to tweak.
I found that doing the “subwoofer crawl” allowed me to find the best locations in my room to place my single subwoofer:
http://www.youtube.com/watch?v=AV3oLLMgS-MIn my last room the best place I found for my subwoofer was right behind my center seat. In my present room it’s up in the far right corner. I’ve found that room/seating layout, subwoofer output and personal preferences for bass play the biggest roles in finding the best subwoofer locations.
Note that bass is not omni-directional. I have been knocked on my ass in the direction of travel of very low frequency waves from explosions. People generalize that below 80Hz bass is non-directional because in an enclosed area bass produces standing waves (bass waves bouncing off room surfaces) making it hard to tell their original direction of travel. The smaller the room the higher the frequency these wave start to seem non-directional while the larger the room the lower the frequency before this happens. A rule evolved that 80Hz and below is “non-directional” in part because this is generally true for average sized HT rooms.
However, for many people myself included, even at or below 80Hz where the bass is coming from can be noticeable. That’s why many people recommend placing the subwoofer up front near the mains/center. Since most of the bass not in the LFE channel that is getting routed to the subwoofer by your receivers bass management settings is coming from the main left and right channels. Placing the sub near the mains minimizes the chances of “hearing” the bass coming from the wrong direction.
Some general thoughts. The closer the sub is to a wall more so a corner the greater some low frequencies are reinforced. This can help the output of a small sub in a large room but often at the expense of overemphasizing certain frequencies and causing “boomy bass.” the closer the subwoofer is to your seat the more you will feel the “mid-bass punch” (especially if it’s path to you is not blocked) but at the risk of localizing the subwoofer.
Sorry that I just took a lot of time to say all that. To put it simply the best way to place your subwoofer is to do the subwoofer crawl to find the spot that give the flattest frequency response and then experiment with placement among the best locations you find to see which also gives you the best low-bass rumble and or mid-bass punch. The difficult thing is that most locations will maximize one at the expense of another. So in the end experiment to find where the sub sounds/feels best.
Cheers,
Dean
