cornfedksboy Posted November 8, 2011 Share Posted November 8, 2011 This topic came up briefly in the "Lets see your Home Theater" thread. I wanted to explore it a little further. Here's a diagram of the THX recommended sub placement: Note the "middle" location. Here's a quote courtesey of RodRocket that is in regards to a TUBA design: Quote from Bill Fitzmaurice on placement for the TUBA design. "Boundary loading should be used whenever it’s practical to do so. Having subs next to a wall gets you 6dB of additional sensitivity below about 80Hz, and putting them in a corner an extra 12dB. In most cases you’ll have best results with the cabinet mouth on the floor against one wall, about 18 inches from the adjacent wall. If the cabinet mouth is a quarter-wavelength from a boundary there will be up to a 24dB deep cancellation at that frequency. Within the nominal bandwidth of the THT a quarter-wavelength ranges from 19 feet at 15 Hz to 2.8 feet at 100 Hz, so middle of room placement usually won’t work well." I know that every room is different, and that even low end subs, set-up properly, can perform exceptionally well. I guess that what I want to know is: Does center placement of a sub create a "null" location at the MLP? Are there certain frequencies that one should target for maximum oomph, and are those increased by corner loading? Is it a good idea to corner load a traditional front firing ported sub for HT? For music? This should probably be in the subwoofer forum, but that forum is manily for broken subs and/or horn subs. Anyways, I'm curious. Quote Link to comment Share on other sites More sharing options...
StephenM Posted November 8, 2011 Share Posted November 8, 2011 Something to read that will give you a few insights: http://www.harman.com/EN-US/OurCompany/Technologyleadership/Documents/White%20Papers/LoudspeakersandRoomsPt3.pdf Quote Link to comment Share on other sites More sharing options...
formica Posted November 8, 2011 Share Posted November 8, 2011 I personnally don't feel it's a bad idea... but rather I feel it's hard to have a single "one size fits all" solution for subwoofer placement given the location of the room modes will vary greatly according to room geometry and dimensions. As mentioned in the other thread, putting the sub in your listening position and crawling around to find the best spot is quite an effective way of placing it optimally. I feel standards are there to facilitate placement for those who aren't overly concerned with "ideal" and tweaking it isn't their cup of tea. In that case, corner placement will be the loudest due to boundary gains... and mid wall will generally be flatter... but not necessarily so. You should give Todd Welti white paper on subwoofer placement a read, as it gives a very detail comparison of many placement options. http://www.harman.com/EN-US/OurCompany/Technologyleadership/Documents/White%20Papers/multsubs.pdf Another interesting read would be this collection of placement articles : http://forum.blu-ray.com/subwoofers/48286-guide-subwoofers-part-ii-standing-waves-room-modes.html And with all that said, my subwoofer mouths are on either side of my centre channel since I use corner horns and wanted to have symmetrical placement of my subwoofers up front. I may not benefit as much from room gain, but I make up for it with displacement. ROb Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted November 8, 2011 Share Posted November 8, 2011 From Dr. Hsu. What is the best place to put a subwoofer?Due to certain principles of acoustics, the corner of the room is almost always the ideal location to place a subwoofer. The next best location to place a subwoofer is along a wall. Home theater aficionados may like to place the subwoofer to the side or behind the seating, near the listener, as this will provide better upper-bass impact. For the best experience, avoid placing the subwoofer or your seating in the middle of the room, because there is a bass void there. I believe SVS states pretty much the same thing but their FAQ is currently down. Quote Link to comment Share on other sites More sharing options...
cornfedksboy Posted November 8, 2011 Author Share Posted November 8, 2011 Good read Stephen. Also look forward to the read from Formica. So two early questions as I move forward. Who doesn't sit very near the center of their room (right to left) as that is the best listening position? Why do I need a 3db gain via the corner placement? I already turn my subs WAY down. Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted November 8, 2011 Share Posted November 8, 2011 Who doesn't sit very near the center of their room (right to left) as that is the best listening position? The middle of the room, side to side is fine. You don't want to sit in the middle of the room side to side AND front to back. Ideally you should be about 2/3 back in the room (2/3 of the room in ft and 1/3 of the room behind you.). Quote Link to comment Share on other sites More sharing options...
mark1101 Posted November 8, 2011 Share Posted November 8, 2011 It depends on your application. For Home Theater maybe you want that extra gain from wall or corner loading. I use 2 Bill Fitzmaurice Titan 48s........but for music, not HT. See my avatar. There they are right in the center. I have measured many times using an RTA setup and "curved" my system...........so I know exactly what it does. Sure, I might get more bass output if I put them in the corner or against a wall. They sound excellent right there in the middle. I am running them in stereo as well. When you go to a concert where do they put the subs? They sure don't stick them in a corner or along a wall............they point them forward and set them on the floor or on stage usually. It's application based on how to use and where to locate. Quote Link to comment Share on other sites More sharing options...
cornfedksboy Posted November 8, 2011 Author Share Posted November 8, 2011 After some extensive reading I gathered that as long as you have enough sub, that center placement is pretty darn good; especially if you have a row of seating. With two subs, it appears that front and rear center are best with front corners being next. Also, I think that 2 subs placed 1/3 in from the sides on the font wall (like I have) should be close to as good as center placement. Anyways, I don't see any issues with center placement. 2 is better than 1...and thanks for the articles! Quote Link to comment Share on other sites More sharing options...
StephenM Posted November 8, 2011 Share Posted November 8, 2011 Who doesn't sit very near the center of their room (right to left) as that is the best listening position? Depends on how you qualify it in my case; a set of stairs throws things off a little bit. Why do I need a 3db gain via the corner placement? Why not? Corner loading costs nothing, and if you gain an additional 3dB, thats less work your sub has to do for any given output level. Quote Link to comment Share on other sites More sharing options...
cornfedksboy Posted November 8, 2011 Author Share Posted November 8, 2011 I have to agree Mark. I had just recently seen many comments stating to put the sub in the corner per a posted pic. You'll gain a little efficiency, but it appears room dimensions are much more important to "empty bass" than corner loading. Obviously it's more complicated than that, but I'm starting to get a better picture. Quote Link to comment Share on other sites More sharing options...
nezff Posted November 8, 2011 Share Posted November 8, 2011 Seems like I read this somewhere, maybe audioholics. Quote Link to comment Share on other sites More sharing options...
cornfedksboy Posted November 8, 2011 Author Share Posted November 8, 2011 Who doesn't sit very near the center of their room (right to left) as that is the best listening position? Depends on how you qualify it in my case; a set of stairs throws things off a little bit. Why do I need a 3db gain via the corner placement? Why not? Corner loading costs nothing, and if you gain an additional 3dB, thats less work your sub has to do for any given output level. After reading 60 pages on the subject, it seems much less important than room acoustics. Quote Link to comment Share on other sites More sharing options...
Chris A Posted November 8, 2011 Share Posted November 8, 2011 Does center placement of a sub create a "null" location at the MLP?See enclosure.excerpts from Subwoofers in Small Listening Rooms.pdf Quote Link to comment Share on other sites More sharing options...
StephenM Posted November 8, 2011 Share Posted November 8, 2011 After reading 60 pages on the subject, it seems much less important room acoustics. No argument from me there. Quote Link to comment Share on other sites More sharing options...
Gorm Posted November 8, 2011 Share Posted November 8, 2011 I have my two subs right in the middle, facing each other, with the one in the rear at 180 phase. They are gained maybe 1/4 of the way up, and still produce great bass, which I have measured at 115+ db. I have seen no drawbacks from placing the subs in the middle of the room. Quote Link to comment Share on other sites More sharing options...
cornfedksboy Posted November 8, 2011 Author Share Posted November 8, 2011 Does center placement of a sub create a "null" location at the MLP?See enclosure. Good point in there about it being easier to turn down the EQ on a sub that is corner loaded than increasing the EQ for a null location. Quote Link to comment Share on other sites More sharing options...
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