Thanks so much for the great questions! Right up my alley!
The answer to the second question about perceived 'pace' will inform your understanding about the first question regarding dynamics and punch. Each is a big subject with plenty of rabbit holes so I'll work on them separately and try to condense, but am happy to welcome a deeper discussion about any aspect.
The three common problems that create the perception of slow pace are poorly aligned vented enclosures, cheap drivers and some elements that cause poor electrical damping.
To open a discussion of the first cause, let's refresh a little bit on bass system engineering. Most conventional bass systems are vented boxes (VBs). They are designed to extend LF performance; to get more output at lower freq's than an equivalent closed box (CB). They do this by tacking on an additional resonant system, the port, in series with the ones that already exist in the basic CB.
The point, here, is there is no free lunch; you don't get deeper bass without giving something up. VBs strike this bargain by storing energy and releasing it later. Think of striking a bell. The initial energy of the hammer strike is absorbed then reradiated later. The more resonant the bell, the more it will ring on. That's the whole idea.
(If you'd like to try a fun mechanical demonstration that reveals how VBs resonant systems work using stuff that's in your desk, just let me know.)
In a well designed VB the added 'warmth' created by the system's resonances sounds quite nice as it is not so severe as to trigger your perception's objections. For others, that's not the case. The designer who's hell-bent on getting the lowest possible F3 will fall right into a trap; a system that sounds nice cornering at 45Hz can sound sloppy and wet cornering at 40Hz. But if you're the kind of guy who wants to sell on specs (and who has the kind of customers who buy on specs), you go with the 40. It's the ringing-on that makes the bass. That's the whole idea. The system takes some time to get going, then even more time to settle. The net is the added extension.
(Sad but true, the ubiquitous use of FFT analyzers to acquire FA measurements has made for a generation of guys looking at F/A plots on computer screens and tweeking for low F3s. They're measuring at the wrong things simply because it's easiest. Bud Fried and Paul Klipsch didn't face that impediment.)
As for cheap drivers, the single most expensive part of a driver happens to be out your sight as a customer, hence it's a great place to save money: the motor. Cheap wimpy motors. Pretty, flashy cones that you can brag about in your ads....but cheap wimpy motors.
And, as you know - heavier bells play lower notes - heavier cones get you a lower F3.
It should not come as a surprise to you that the very common strategy of combining these two bad ideas causes trouble. That wimpy little motor will have to keep pushing on that heavy load a few times to get it going (like you pushing a child on a swing) then, once the signal is removed, it will have trouble bringing the swinging mass to rest.
Obviously, the inverse is the the answer: to make the cone to respond quickly you'll want a light cone (more accurately: a low mass moving system) and plenty of force. Isaac Newton stated: F=MA, force equals mass times acceleration. Law. Again, no free lunch: never mind the higher cost, the lighter moving system will naturally result in a higher F3 plus aligning the VB for a high performance driver is quite a bit trickier; the errors more obvious. I hate to use the"sports car v.s. dump truck" analogy...but you get the idea.
Third, we rely on a close coupling with the amplifier to take advantage of electrical damping. If you'd like to actually feel what is going on just do this: disconnect your speaker from the amp and articulate the cone. Then reconnect, amp on, and compare the force required. If your system is well coupled you'll find that the driver is much harder to move when the amp is "fighting" you. The grip the amp has over the position of the voice coil is critical to commanding the coil to "follow orders". This is THE reason we want low output impedance from our SS amps and why we want plenty of copper in the output xfmrs of our tubies.
Of the things downstream from the amp that can diminish that control are parasitic impedances like long or crappy cables, crappy internal wiring, poor connections both inside and outside the speaker and, the most common and by far the worst culprit : lossy crossovers. Just me, I keep those losses to a dead-nuts minimum....even to the detriment of other issues. But the typical production speaker is designed with devilishly nasty filters before the bozos upstairs in Cost Accounting demand yet cheaper parts, making things even worse.
All of those impedances are in series so they SUM. It's like you're pushing that child on the swing through a big, soft spring instead of gripping her directly.
So, looking back, you can have both an enclosure's port/internal air resonant system that doesn't want to get moving then doesn't want to stop coupled to the driver's motor/cone/air/suspension system has the same failings. Then you give up the amp damping you need to get what little grip might remain. Result: the system takes several cycles to come up then several cycles to shut up. The output is delayed.
I used to joke that: "You're getting all the bass you paid for - just a bit late."
At the core of these issues is one well worn aspect of inaccurate signal tracking: poor rise and settle times. My next blurb about dynamics and punch will include some less discussed and amusing ideas about signal tracking that lie closer to the frontier.
Ain't Life Grand?
