Multiple Subs - mixing models

I recently bought a second REL that is of the same generation as my original Q150e. The newer one is a Q108 MKII that is a "down firing" 100 watt 8" instead of the 150's 150 watt front firing 10. I bought the 108 to stick in my window to help my deck purposed speakers (I stick those in the windows also…firing out onto my deck with their dedicated amp, and take them out of the windows when not in use…a thing that works). The 108 when not serving the deck now adds to my 150 and the combination is fabulous (both subs get the same signal from my main tube amp, as hey…I'm not an idiot!). I think the multiple sub thing tames some standing waves, adds to what already was a balanced sound, and makes me seem like I really care, although nobody else seems to care until I point these things out. Still, worth it.

Two subs can exacerbate what might be a bass heavy room, especially rooms with flat ceilings and parallel walls…you just never know. However, a second sub can sometimes have the effect of canceling or minimizing standing waves as it may be somewhat out of phase with the waves rolling around the room…this is what happened in my Essentially Sacred Listening Chamber of Wonderfulness. I think you simply have to move subs around some to see what's up, but I'm also still a proponent of using one sub as it's often plenty. Note my listening room has a slanting ceiling that is around 9 feet on one (the hifi rig is on the shorter wall) side and 15 feet or so on the back wall…that could be what saves me.