One of these days I'm gonna have the wherewithall to upgrade my current sub to Axiom. As I fantasize about that, it occurs to me that -- due to the rapidly esacalating prices of the larger and/or DSP-enabled models -- it would actually be cheaper to get two smaller subs, rather than one larger model. Say, for instance, two EP175s as compared to one EP500. I've often read about (but never experienced) the benefits of two subs in a room, to level out some of the quirks of room response.

I know I'd give up a few hertz at the very bottom end, and I know the DSP in the EP500 goes a long way toward leveling out frequency response. Nevertheless, it seems intriguing.

BTW, I've got a pretty big great room, about 20 by 20 with a vaulted ceiling that peaks at 20 feet. I'm using M22s with a VP150 and QS8s for surround. My current sub (a Klipsch) does a decent job of filling the space, but it's easy to localize. I can't help thinking that two smaller subs might end up providing a better soundfield over all.

And before you suggest it, I know two EP500s would be the best answer, but that's not even in the realm of the possible.

Whaddya'll think?

Whip, I strongly lean toward favoring the two smaller subs if economics don't allow for the two bigger ones. Two widely separated subs do provide a 3dB higher volume and when correctly placed(basically, at the mid-points of either the side walls or the front and back wall, or in diagonally opposite corners)significantly smooth the bass response by reducing the effect of room modes.

Incidentally, I hope that you'll enjoy that Dvorak symphony disc.

For me, I would go with the large sub option if use was primarily movies as the lower frequency extension is more important to me than max spl. If it were primarily for music, I think I would lean toward 2 smaller subs because not a lot of music plays extends below 35-40 hz (barring electronic stuff like dubstep or huge pipe organs).

My personal opinion....strictly based upon anecdotal postings here... is that two 175s still won't approach the capabilities of one 500. Two 350s might have a shot at it, though.

Again, my opinion only is that your current sub is maybe being localized because it's outputting higher frequencies. If you were able to shift the crossover point lower so the sub is only outputting the lower end of the bass spectrum, and not the mid bass, localization would be less of a problem.

To me, this is the concern of using M22s in a big room. They may go loud enough, but they can't put out enough bass to take ANY duty away from a sub... they are absolutely reliant upon that sub (especially for movies).

BTW- when I say that this is anecdotal, I mean it: I've never heard the 22s, the 175, the current 350 or the 500. Seriously, it's all just theory.

While two smaller subs will give better room coverage, they won't give you that very low end (>20Hz) that is so wonderful and makes all the difference.

I have an EP500 and a 10" Polk and use both. When I do my calibration the difference in the very low end is huge.

I'm also in the camp that small subs can't provide deep low end . . . which is very important if you like your movies. If you go with the bigger sub, you can always add on another big sub in the distant future . . . at least you'll be able to hear the LF that the movie is supposed to have. Two small subs will always be missing the lowest frequencies.

BTW, I use M22s, QS8s, a VP150 and ended up with the EP500 after trying the EP350. The 500 just goes lower and sounds better with this speaker combo.

I have been using a larger sub for years, and I have been very happy with it. However, I have all of the "guts" to build an almost identical DIY sub to match it for smoother bass. So I had the investment into a single good sub in the past, and now that I have the money for a second sub (DIY for me, others may just buy a new factory one) I am going to smooth out that low end bass.

Thanks for the interesting interplay of ideas. Of course, one approach would be to keep my Klipsch and add a second, large sub. However, I really want to move the Klipsch to my basement TV set up, which currently doesn't have one.

As for movies vs music, I keep trying to find that fine line that marries value with sound quality (music) and SPL (movies). I'm only going to have one really good set up and it has to do double duty, so to speak.

Although I realize it's a feeble argument, I can't help thinking that I won't miss that last half octave that I've never heard, so I find myself leaning toward the 2 smaller subs option. Either way, though, it's now gonna happen any time soon.

I have the 175 and 500 (in two different places). I don't have two 175's, but I can't imagine two 175's coming anywhere close to EP500.

Yeah, going by the the comments I've seen, I wouldn't consider two 175s any kind of substitute for one 500. As Mark said, two 350s or one 500 would be my choices, but of course I'll defer to anyone who has actual experience with dual 175s.

The answer depends on a few things. How capable are the two smaller subs. From personal listening experience, the 175 just does not reach low enough to compete with the 500. The 350 does.

The other is the characteristics of your room. In may case I get very little difference in response from my sub regardless of where it is places. I believe this to be because I have what turns out to be a square room at the subsonic level. My case is unusual though.

I vote for the ep500. Two 350s would be another good option

Definitely 1 EP500. I've tried an EP175, and currently have an EP350. If I upgraded, I'd go for a single EP500 over 2 EP350.