Speed is more of a perception than a reality. A music passage at the recording has a certain speed or tempo. After reading the music info from the recording and by the time we hear the tempo at the speakers, it should be near impossible to exactly match the tempo of the music embedded in the recording. It should also be near impossible for any two playback systems to play a music passage at the exact same tempo, even if the playback systems appear identical.
The reason for this is distortions. Every system contains various distortions to one good degree or another. Distortions corrupt the fidelity of the input signal and the more distorted the playback presentation the more the music notes are less distinct seemingly run together and hence the slower the perceived tempo. Playback systems with less distortions make each musical note more distinct and separate from the next music note and therefore, the perception is a faster tempo.
I remember a reviewer out of TAS maybe 15 years ago when reviewing a CDP, ask the reader why does one component have a perceived faster tempo than another as he was concerned about this unit's perceived slow tempo. But cables can also change the perceived tempo just as does the noisy AC coming from the street.
Also, before I forget. Superior main speaker placement within the room has as much or more to do with perceived tempo as any/all other distortions. Finding the optimal location for your full-range speakers will have as much or more impact on bass than other distortions elsewhere as it is here where the fastest, tightest, deepest, and more well-defined bass is found and ultimately has a large impact on tempo.
Things really don't change much when it comes to lower frequencies, woofers, mains, and subs. The tempo at the speaker mains is basically WYHIWYG (What you hear is what you get whether fast or slow). The main speakers will generate a speed based entirely on their own placement, their own engineering, as well as the designed engineering and all the associated distortions generated from the speaker drivers back to the service panel.
Assuming we're talking well-enough designed/engineered subwoofers, hopefully we're not really talking so much about speed per se. Rather we're talking about getting the subwoofer's input signal to match or sync with the main speakers' input signal so that the music is flowing seamlessly into the room regardless of the frequencies.
Perhaps your speakers are well-positioned and your system induces less distortion than average, so you perceive your main speakers to be fast. But based on all the above, speed really should be irrelevant to your question. Hence, I suspect what you're really asking is, which subwoofers allow the greatest opportunity to match their speed or tempo to my main speakers, whether fast or slow? Or better yet, how do I increase my chances to match a given subwoofer to the sound from my mains?
If that is your real question (if not I apologize), then here's a few policies that I follow to increase the probability of properly syncing a sub(s) to the mains:
1. Ensure your interconnects or speaker cables to the sub are the exact same make and model used elsewhere in your system. Different cables induce different distortions and it just so happens that they also induce different tempos. Hence, using different cabling to the sub is a rather sure-fire way to almost guarantee a certain amount of disjointed sound.
2. If you're using aftermarket power cables, line conditioners, etc, elsewhere, then for the same reason as #1 above, you should do likewise with the sub. Remember that when trying to sync any 2 things everything matters and hopefully the days are gone where we've been taught that we can treat our subs different than the mains because they only handle the lowest frequencies, etc.
3. Ensure the subwoofer is well-anchored to the floor. Hopefully just like everything else in the playback chain already is. This has a good deal to do how musical the bass will be.
4. Though I've not tried it, I have my doubts about high-level inputs from the main amps to the sub. Among other things, this implies the input signal has already been processed through one amplifier, including its associated distortions, must now be processed through a second ampifier which also induces its own distortions. So not only are we talking doubling up on potential distortions at the sub induced by 2 amplifiers instead of one, we're also talking potential timing issues since the sub's input signal must be processed through 2 amplifiers instead of one. Yes, I realize some subwoofer companies like REL insist on high-level connections. But then REL also provides their own high-level subwoofer cables which IME is a big no-no. See #1 above.
5. Ensure your main full-range speakers are optimally placed within the room first before ever turning on the subwoofer. Once you're satisfied with the main speakers placement measured by how pleased you are with their musical bass, then it's time to syncronize the subwoofer.
6. Like the main speakers, ensure the subwoofer is optimally placed for fastest, tightest, deepest, most well-defined bass.
7. Buying the right subwoofer. Tee hee. By this I mean, to ensure that your subwoofer has enough of the right dials, knobs, and/or switches to configure and contour the bass to sync with the mains. The more levers and dials, I presume the greater the chances to match the mains.
In the end, it's all hit and miss. Your main speakers may be optimally positioned but your subwoofer is not. Or vice versa. And finding the optimal location for main speakers and subwoofer can be rather painstaking and sometimes seem impossible. Really, it's more art than science. But if the planets are in alignment and one is able to cross into the promised land where the bass is astonishly "quick", tight, deep, and well-defined and flat out musical, and merges beautifully with the mains, this alone will set a given playback system apart from most any other. Then again, with the right main full-range speakers and optmal placement, this same fabulously musical bass can also be achieved without a subwoofer at least down to 23Hz or so - depending on the main's range.
Hopefully, some of the bullet items I mentioned above can minimize some of the guesswork and pain associated with this most rewarding art.