Are two smaller subs better than one larger?

I will give this a "maybe" in response. Here is why one might be better than 2 (since the very valid reasons 2 might be better than 1 have been laid out above, in particular the emergence of stereo effects at 80Hz or so, and the potential of 2 subs to minimize room nodes):

1) The quality of the single sub is much better. I moved from dual NHT subs to a single REL Storm III, and this was definintely an improvement in my room. Related to the quality of the sub is the quality of the intergration a sub can achieve with mains. For the REL that came through their speaker level connections, but I could also imagine that single subs with DSP (digital signal processing) options could also work better than dual subs without DSP or with lower quality DSP.

2) You don't need a high crossover point. My NHT pair was originally purchsed when I needed an 80 Hz crossover point. My single REL was crossed over at 35 Hz.

Most likely yes. If you read this white paper from Harmon on the number and placement of subs for optimal listening, you would conclude that at least two subs properly positioned will give you a smoother response in your room than one. If you are the only one in the room, then you can position the one sub for optimal listening. On the other hand, if you move from that spot, or there are other positions in the room that you want to optimize, then more than one sub is required. The quality of the sub(s) will matter, but the positioning of them is most important, but difficult if more than one is involved. It may require a computer program to perfect, whereas one involves a more simple approach, trial and error. This is the white paper:

http://www.harman.com/EN-US/OurCompany/Technologyleadership/Pages/WhitePapers.aspx?CategoryID=White%20papers

Good luck, have fun, and always listen to the music (not the experts/reviewers/posters/self-proclaimed golden ears)!!

If you know where to shop, you can get two $1200 subs for about $500, which should take good care of both HT and music. Go to vanns.com and do a search for Infinity subs.

I'm running dual subs in both my HT and 2-channel analog-primary stereo
rigs.

Generally speaking, I definitely like two smaller subs for stereo music. My
music-only subs are a pair of small (9" cube) Mirage MM-8 subs. They
are not for deep-deep bass; they're strong to about 35 Hz. But so many mid-
sized speakers aren't putting out real extension below 50-60 Hz, or
sometimes a small tower is in a slightly too-large room and can't put out the
low bass amplitude to occupy the space. That's where these small subs come
in. They totally occupy the 35-60 Hz zone, but best of all, the sealed
enclosures (with dual passive radiators), very high internal power (1200w
peak), high excursion surrounds and very light (aluminum) diaphragms make
for very "fast" woofers, with short rise times and quick settling,
making for an excellent blend with the light'n'lively 5-1//4" woofers in
my small towers. Plucked string bass is full and lush, yet quick and lively to
match fast bass passages.

The better Martin-Logan subs are also great at blending for music. Given that
their subs are intended to blend with their electrostatics, keeping up with
cones is pretty easy for them.

If you have the coin, I don't think you can do better than JL. A pair of F112s or
F113s would not only make the music come alive, they'll also give you true
strong bass down to 20 Hz with no bloat, resonant peaks, or overhang.

As much as I lean toward dual subs, I have heard excellent 2.1 sub setups.
Particularly I heard a pair of B&W PM1 minimonitors paired with one carefully
integrated wilkins.com/Speakers/Home_Audio/Subwoofers/PV1D.html>PV1D sub
and the resulting sound was seamless and transparent. The PM1s shined for
their even, timbre-correct tonality, seductive transparency, and stunning
imaging while the single PV1D sub supplied a foundation that completely
integrated with the stereo image from the pair of monitors. So it can definitely
be done.

In fact, that PV1D was a kick-ass sub and should be on your short list. Small
and fast, but goes deep and takes 2-channel input.

Rel isn't a cheap sub and nice sounding but 2 x Vandy 2Wq can beat that for less price paid than for single REL.