Originally Posted by antiprnt
My Father is going to take delivery of his first pair of SVS Pb13 Ultras thanks to a fellow forum member letting it go for a very reasonable price. My father was intended to put one in each front corner of his room, where his current dual MFW15's sit. Now, if it were me, I'd find a way to place the MFW15's near field, possibly being the couches, but I think for WAF purposes, he's not going to do that. He did throw around the idea of co-locating the subs in those corners, as he has room for dual's in the corner. With that being said, for aesthetics's purposes, he intended to do that by having one PB13 + one MFW15 side by side in each corner. Has anyone co-located subs like this before? Where you have two different models/manufacturer subwoofers co-located together? They're both ported, but obviously have different tuning frequencies. What's the worse case scenario here? I'm guessing the other option is putting two of the PB13's together in one corner co-located, and putting the pair of MFW15's in the other corner. It'd look weird from a proportionality standpoint, but not sure if my mother would have an issue with that.
On a similar note, has anyone co-located two ported but different model SVS subs and had success? I currently have a PB12-NSD and a PB12+/2. I was thinking about co locating the two in a nearfield corner. If I had space on the opposite corner, I'd definitely split them up, but that's not an option at this point. Anyone have any feedback about doing something like this? If so, were any measurements done?
Those are interesting questions. If your father lives in the Tampa area, I know whom he bought the subs from, and they were a very good buy. I looked up a review of the MFW-15's, and they give up a great deal of low frequency response to the PB13's. My advice to your father would be similar to yours--to stack (or collocate) the two older subs behind him, in an attempt to more nearly equal the low frequency output of the PB13's. Failing the ability to do that, I probably wouldn't use them at all.
If the option to use them nearfield just isn't in the cards, I don't see any harm in trying the MFW-15's on top of the PB13's in the front corners of the room. Mutual coupling, as I understand it, occurs where the frequency response of two subwoofers is very similar (or identical). Where the frequency response is quite different, I'm not sure how effective the subs will be in reinforcing each other. Something I would definitely not do is to pair the older subs in one corner, and the PB13's in the other. The disparity in performance between the two pairs would be very significant.
Frankly, my advice would be to simply try the Ultras for a while, and enjoy the upgrade. They may give him just the additional low frequency extension he was looking for. If he is not exceeding their output capabilities, by over-boosting them with high volumes (which is pretty unlikely), that will give him a much better chance for improved sound quality. Once he has a good listening baseline established, he can always try adding in the two MFW15's, but I am skeptical that the combination will work as well as the Ultra's playing by themselves.
We all want to utilize/re-purpose older audio equipment, when we add new equipment. But sometimes, that sort of defeats the purpose of adding the new equipment, in the first place. More, mismatched subs, is not always (or even very often) preferable to a sufficient number of matched subs. And, his Ultra's may very well be sufficient, in this case. I know that there are exceptions to that general statement, regarding matching subs, particularly where someone has measuring and DSP capabilities. But, as a general statement, I think it's reasonably valid.
As for collocating a PB12-NSD and a PB12+/2, you would just have to try it to see what you think. You already know that the latter sub is more powerful, and that ideally you would want to have it further away, with the PB12-NSD nearfield. But, the theory of what works best, and what you actually observe when you try something, may be different. So, you will just have to give it a shot.