Use of subwoofer with bookshelf speakers

I heard demonstrated a Pair of Canalis Anima speakers and they were awesome. I'm using full range speakers now (ML Odysseys) which have developed a significant problem and am considering purchasing these Canalis speakers when I can put together enough money to do so.

My question has to do with using these with a Vandersteen sub. Vandersteen recommends using this sub with speakers having effective capability down to 40 Hz. I think the sub has an upper cutoff of 250Hz. Will I be able to use them together and have an acceptably smooth sounding transition between them?
I'm really not familiar with Vandersteen subs, but it does seem odd that they would recommend their use only with speakers that are just about full range. 40hz is pretty low and in the borderline territory of not needing a sub at all or just occasionally.

Still, according to the specs on the speakers that you're looking at, it seems that you are right in the ball park.

I'd say, give it a try. In any case, I wouldn't buy speakers to fit a sub. I'd get the speakers that I like and then match a sub to the speakers.
Thanks, Tonyangel. I agree that Vandersteen's advice seems a little odd and that's what prompted my question. I think that I could live with the Canalis speakers by themselves because I am using my stereo system mostly for guitar music and light jazz. However, we do have our TV in this setup and we do watch movies and some of these need the lower frequencies for realistic sound. As far as choosing the main speakers first I can only say that I have made my choice in these by Canalis so, you're advice is appreciated.
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Sell the Vandy sub and buy a REL sub.
For music, the Rythmik sealed subs look really interesting. Due to furnishings, I've been limited to small speakers for a while. Over the course of the last year or so, I've run System Audio 505s, Paradigm Studio 10s and am now running a very small pair of Silverline Minuets. The are all good sounding speakers that are fast, but need help with the lows.

I've run a little REL T3 with them and it's been easy to integrate and keeps up with them very well. I've seen them go for around $300 or so, if you can find them. Heck, for that low of a price, you could get two and have stereo subs.
I have the Sonics Anima -- very similiar to the Canalis version -- paired with a REL Strata III sub, and they sound great together. I had been using the Animas sans sub for a few months and mostly didn't miss the bass <60hz, but then I got the sub and really noticed what I was missing. The sub fills in that last bit of the picture and adds more scale. Get a sub (REL or perhaps an Audio Physic one would fit nicely) but first get a good pair of 24" stands.
However...I believe Vandersteen( and others) recommend crossing over an octave full range speakers would be x-over at 80hz...most speakers are -3db down or more at their LF cutoff point...thus the rationale for x-over higher...and anything above 80hz is usually directional in nature...hence the full range recommendation...
I think Vandersteen's approach calls for a gentle-slope crossover between mains and sub(s) - maybe even first order, I'm not sure. Nothing wrong with that, you just gotta have the right speakers for it. Well okay one possible drawback is that you have to keep the sub(s) near the main speakers, because they will still have audible (and localizable) output well into the upper bass region. Obviously not an issue if you plan to place the sub(s) near the mains anyway.

There are so many variables--you simply have to experiment with different c.o. frequencies and find what works with your situation. That's the only way to know.
I agree with Bob Reynolds here. You have to look at the bass rolloff characteristics of the Canalis to correctly match it to a subwoofer. He's also correct about the Vandy's crossover slope of 6 dB/octave. Here are the specifications.

One thing the Vandy has going for it is that it uses 8" drivers, giving it a higher ratio of flux density to diaphragm size, which is better both for transient response and for less cone breakup. With a 5" woofer, you want a subwoofer with great acceleration--transient response--to keep up with the 5" woofer. The Canalis 5" woofer is aluminum, so it would be particularly fast and rigid and need a fast sub to keep up. Not too many subs are great at both matching to mini-monitors for music and also having the bass extension and dynamic range for home theater. It appears that the Vandersteen was designed to cover both applications, and the gentle 6dB slope should make blending it with the satellites a bit easier.

If you didn't already have the Vandersteen (I assume), I'd recommend you get a pair of small, sealed subs. I match a pair of (now discontinued) Mirage MM8s with my Mirage OMD-15s. The MM8s are 9" cubes housing an 8" aluminum driver augmented by two 8" aluminum passive radiators. They don't go very deep, but they are very easy to match up musically with bass-shy speakers. They have lots of power and a crossover that can be adjusted from 50 Hz to over 200.

Although the Mirages are discontinued there are several good small sealed subs with similar configurability. They're easy to blend with decor and match up with small speakers well, but they generally aren't designed for room-filling 20Hz bass as the Vandersteen is.
Johnnyb, I like what you say about the relationship between the bookshelves and sub, especially as regards mating the acceleration of the fast fast 5" woofers in the bookshelf and relatively fast acceleration of the Vandersteen sub speakers. This speed was my reason for buying this subwoofer years ago, in the first place. The other responses are valid and much appreciated but I, at least, have a bit more confidence that the Vandy will work out as I very much enjoyed this sub when it was in use with my Focals and I would like to minimize expenses as much as I can. It will be awhile before I can justify/afford the speakers I want so I have time to kick this around for a bit. Thanks.