Sub placement

NVP,

Not IME. For the last 6 years, I've used a RTA to measure FR at the listening position. If the subs are in a good spot, I get good results irrespective of orientation. There may be small differences, but if you're setting up subs by ear, I wouldn't characterize the delta as significant.

Of course, different rooms and/or different ears might yield a different conclusion

Marty

Hi Marty, what you report it can certainly happen but it is not the general rule. Sometimes the interference fringes may be less affected when rotating and/or moving the sub. I am sure that you have often noticed while setting up your sub that moving the sub in one direction can induce significant changes while moving the sub in other direction has only a minor effect, if at all. Since one can never predict this, as it depends on the room and subwoofer, it is best to experiment like you have done. However, as I have mentioned in my previous post, this has nothing to do with our inability to detect the position of the source of law waves.

I've used a REL Stentor 3 (a down firing ported subwoofer) for four years and I have set it up in three different rooms. In one of them rotating the sub made very little difference, while in the other two the difference was significant.

I use a similar method as suggested by Polk432, except that I align the subs (2 15" sealed), facing each other from the outsides of the speakers. Basically, you will aim the subs towards each other across the sides and slightly to the rear of each main speakers. I use a Velodyne SMS-1 sub controller to address any issues. This could also aide in mitigating phase issues.

I have used this process for years with satisfying results. Also, the sound stage seems to open up greatly using this method. Observe that a cutoff below 60hz also removes localization issues associated with bass.

Integrating a sub into a system is utterly room and system specific so rendering suggestions on this is tough. Another reason why I can't get the "put your head where the sub sounds best" thing is that it takes the main speakers out of the picture...and the sub/main synergy is where the mojo lives.

Another reason why I can't get the "put your head where the sub sounds best" thing is that it takes the main speakers out of the picture...and the sub/main synergy is where the mojo lives.

Wolf_garcia, you are incorrect again. As I have mentioned in one of my previous posts, when putting the sub at the listening position one tries to find a place that is roughly the acoustic equivalent (for the low notes) of the listening chair. That means that 1) the bass will be very similar in the listening chair and in the place where you would like to put the sub, 2) all bass sources (i.e. room, main speaker and subwoofer) have been accounted for. (Only this paragraph is addressed to you Wolf_garcia.)

One has to realize that below 200 Hz, the listening room (and the neighboring rooms too!) has(have) a very significant effect on the sound that you hear in your listening chair. This is because the room can significantly amplify or absorb specific frequencies, i.e. the room modes. In fact, it often happens that when listening to big speakers what one hears below 100 Hz is dominated by the room response!

The main advantage of adding a subwoofer is that one can place the speakers in the position that gives the the best stereo image and most natural midrange, and place the subwoofer in a different place that minimizes negative bass resonances induced by the room.

I really do not want to be condescending and/or impolite, but people should understand that in order to properly integrate a sub into a system one has to understand how waves interact, i.e. the interference phenomenon. It is really not a difficult phenomenon (it is taught in high school), plus one does not need to understand the math to be aware of its consequences. (It is pretty much like with the water, one does not need to work out the theory or look at phase diagrams to understand that water can exist in different phases, e.g. solid, liquid and gas).