In that case, my recommendation is that you reconsider. No tiny speaker is going to be able to go low enough for a proper crossover with a subwoofer, and consequently you will either have a gap in your frequency response or you will be able to locate the subwoofer by the sound (or both, as with
these).
From a quick search of online reviews for the two models you first mention, the companies seem to essentially admit as much by the fact that they seem to not send them to reviewers who actually take measurements. Plus, of course, they do not seem to list proper specifications on their web sites, another sign that they have some unpleasant facts that they want to hide.
The absolute smallest woofer that I have ever encountered that goes low enough to be adequate for proper blending with a subwoofer at a low enough frequency to not be a problem is about 5". I do not recommend anything smaller than that.
If space is that much of a problem, I would recommend in-wall speakers instead, so that you will not have the problem of not going low enough to satisfactorily blend with a subwoofer. Or use headphones.