Mix and match subs?

What is your goal with the addition of another sub? Listening to 2 channel music on a dedicated 2 channel stereo, or both, home theater and music listening through an AV processor? If it’s 2 channel, whatever sub you decide to acquire (makes good sense to use same, however, not a show stopper…check out a pair of SVS Micro 3000s for a little added punch in the lows while saving space), you should measure the in room response to see what settings have an effect at the listening position. You will get the crawl, low crawl, hang em high, recommendations, but why? Use technology to see on a display as to how the sub settings can be smoothed out by changing certain parameters to get an ideal and smooth curve.


More subs allows you to balance those bass room interactions to a certain degree and get away with smaller subs to boot. You should still use bass absorption judiciously if required to further help room issues, in particular smalle rooms. Smaller rooms are way more complicated than larger rooms, so multiple subs aids a lot in smoothing out bass modes. Larger rooms are more forgiving because, well, they allow the lower frequency to travel farther thus reducing the amount of bass frequency propagation, although their is still some and you need to again measure. REW makes a great application to measure your room.



For home theater and fire and forget use, just use the built in room measuring equipment built into your processor if so equipped. You may still not like it’s results.
The reason I suggested the SVS Micro 3000 is that if all you are looking for is some bass assist, and a means to control the sub, these little powerhouses are ample enough, while being subtle in size to add that extra flair to bass without messing up the stereo image if used properly. They are equivalent to nearly 12” woofers with their dual 8” size. I may or may not be testing a pair in my very large room with very large speakers:)

Thanks all for the helpful input—okay SF Sub is scratched off the list. My use will be 2-channel music only and I do love deep bass. My room is 16x18 with vaulted ceilings (family living room so treatment is not an option).
I have certainly looked at SVS and been intrigued by their subs and like the home trial option.

I ended up with the Paradigm because of a good deal through a local dealer and have been impressed with its performance. It has room correction and an app to control all settings which is really nice.

So sticking with Paradigm seems like a good plan. 
Then the question becomes should I go with the x12 to get the extra extension, or a second x10 for easier integration as many of you have suggested? 

I see no real value in having them match. Obviously. https://systems.audiogon.com/systems/8367 In fact, the main benefit of multiple subs is more small modes adds up to smoother bass. So to the extent they are different this creates even more variation in response, which for low bass is good. That is why mine were made 2 ported, 2 sealed, and they work beautifully together with the one ported isobaric Talon Roc sub. That is 5 subs of 3 different types. Just running out of new things to say about how misplaced an idea it is to talk about the importance of matching, integrating, timing, etc. There is a grain of truth to it. But it is so much less important than sheer numbers of subs as to pale in significance.

Then the question becomes should I go with the x12 to get the extra extension, or a second x10 for easier integration as many of you have suggested?

Depends on what kind of music you listen to and how loud. If your current X10 is loud enough on its own, you will be fine adding a second X10. If you need the deeper extension, then you should sell the X10 and go with two X12's. Integration happens at the crossover point, so mis-matched subs won't matter, but the benefit of multiple subs only happens in the frequency range that both subs share. So if you have music that goes lower than the X10 can reproduce, then you will not get the benefit of having two subs in that range.

No, it does not work that way. One of the many things people realize when they get a DBA is how much extreme low end information there is even on recordings with zero low bass that can be heard as such. Similar to the way extreme ultrasonic high end cannot be heard as such, yet does create a greater sense of realism on all recordings, extending all the way down into the low bass region.

These simplistic views of sound and what we can hear are really, uh, simplistic.