Originally Posted by dgrizzard
First, thank you for taking the time to read the below and please see attachments for a visual. I have a fairly small room 14Lx11Wx10H which ends up being a mixed use of my office and a personal theater. Only one seating so just the MLP - there can only be one! My problem is that I've done the sub crawl, test tones from 20-80hz, and moved the sub all over the room. The place it sounds the best is near field on the left side of my seating position. In general I don't have a problem with this, but it can feel localized. Sometimes I'm not sure if it is actually localized or if it is just my mind knowing the sub is just to the left of me.
So based on that I went down the road of should I get dual subs to maybe help the FR (I don't always get that hit me in the chest feel that I have had with this same sub in a different room) and eliminate the localization. I have a UMIK-1 on order and it should be here Wed to get an idea of what my current environment is. But for now I started playing with the Room Sim - and this is where things went down hill. What it shows in the room sim does not at all line up with what I am hearing/feeling in my room. The room sim (see attachments) says the best place should be in the front corners. But in reality if I do that I barely feel anything at all. I think this may have something to do with all of the "stuff" in my room as opposed to room sim thinking it is an empty room/blank walls. The other issue is room sim doesn't seem to show dual subs near field at the MLP will help, the SPL for the 15-30hz range actually slopes down as compared to a single sub in my current position.
My main questions are:
Will I truly benefit from dual subs or is room sim right? I am coming up on my 1 year SVS upgrade time (currently have a single PC13-Ultra and looking to get dual PC-4000s) and I need to make a decision soon to upgrade or not. I don't want to buy something and then end up in the same place I am today.
Does the stuff in my room affect room sim this much?
I have several observations. First, the room sim may or may not be a reliable predictor of the best subwoofer location. I have seen results all over the map on that. Second, the stuff in your room should not affect the overall frequency response that much. I like the suggestion to try putting your existing subwoofer directly behind your seating position. That would be even more in the nearfield, where room modes would have less effect, and it might help with localization.
We can sometimes get localization cues from bass sounds and sensations, so I wouldn't assume that your occasional ability to localize or "notice" bass coming from the left is entirely psychological. If you aren't getting the chest punch you used to get, it may be that you have some cancellation occurring in about the 60Hz to 80Hz range, or from the position of the MLP. (More later on that.)
But, if you have a UMIK coming Wednesday, then I would put all of the speculation on hold until you have had a chance to measure the room and see what you actually have now in the way of a frequency response. If you do have some cancellation occurring near the crossover to the speakers, you may be able to address that with a sub distance tweak, or by adjusting the phase on your PC13.
I would measure with your sub where it is now, and both listen and measure with a rear nearfield placement, making whatever tweaks are required. But, I also wouldn't totally rule-out upgrading to dual subs yet either. Matching the left-wall sub, with a right-wall sub, would give you a potentially workable location for dual subs. Opposing mid-walls can often work well. And, there are other placement combinations you could try. I just think it's a little too early to tell whether you need a second sub yet, until you have had a chance to work with REW a little.
One thing that I see in your drawing that concerns me a little, if it's rendered accurately, is the location of your MLP. It appears to be awfully close to the center of the room's long dimension. If so, you could be getting some cancellation just due to your MLP location. If you could move the MLP back a foot or two, to get a little further off that center line, it might help, irrespective of other factors. There are also some things that you can do to enhance your mid-bass chest punch, but I would start with better MLP positioning, and REW, first.