Yes 4329 and the pro monitor the 708p are cheaper options. 
 

i would buy used or demos when possible. I understand why people don’t but it allows me to buy speakers above my price range. I bought my JBL 4367s new in the box for less than the JBL 4349 retails for, food for thought. 
 

here are audio mart is a good place to start looking. 
 

@tommyuchicago,

JBL Synthesis 4429 Pair see here!

Mike

@phusis  @james633

Yes I've considered the 4329Ps but this is where inexperience comes in -- the 4329Ps are regularly on sale for $3,500 which is way below my budget and I worry I would not be getting the same quality as something in the $5k+ range in passive designs.

I also would have no problem buying passives used but do worry about used actives -- just a lot more could go wrong with them. 

I have read on threads that the 4349s and 4367s can be purchased at good discounts from dealers, there's at least two Chicago dealers I've found for them including Music Direct that also carries the ATCs.

Volti Volti Volti !!

Talk about speed and dynamics. I’d bet these are the droids you are looking for. Yes it is true there is not a return policy. However if you are intentional and make an effort to listen to a pair, the return policy will be irrelevant. I’m sure there are plenty of Volti owners like me willing to welcome OP into their home to have a listen. Additionally one would have no problem reselling as they are sough after and rarely show up for sale used.

If you are within a drive of NE Ohio I’d be happy to host.

Yes Volti is a very good brand for delivering excellent dynamics and speed while still sounding relaxed and natural.  This is a far cry from a brand like Zu which is very fast and dynamic but also shrill and brittle sounding (to me anyway).  Volti horn systems are the rare examples of modern horn compression driver systems that I like.  However, there are MANY vintage systems and drivers that can sound as good or better than the Volti, although many are quite expensive.

JBL horn systems can also be quite dynamic, but, they don't have enough mid-bass weight for my taste so they sound a bit thin and slightly harsh; still many, like the Everest are very much worthy of top end systems.  Fyne speakers sound fast and reasonably balanced and just a touch harsh.  There are quite a few high efficiency wide-range driver systems (i.e., not compression driver/horn systems) that are also very dynamic, such as the single driver and two-way systems of Songer Audio, the single driver backloaded horn systems of Charney Audio, and the single driver and two-way systems of Cube Audio (I particularly like the two-way Nenuphar Basis model).

At a lower price point, the MoFi Source 10 is quite dynamic with only a slight bit of harshness.  It won't deliver the weight and sense of scale that the Volti speakers deliver, but, they are surprisingly capable.

A dealer in the Washington DC area, Deja Vu Audio, builds custom speakers using modern and vintage components.  These can be tailored to one's specific taste, which is a BIG advantage of a custom build.  They employ vintage midrange horns and compression drivers because there is very little out there that can match these old drivers except VERY expensive drivers from the like of G.I.P., ALE, Cogent and Goto.  These systems truly deliver excellent dynamics while retaining a sweet, natural and relaxed sound; the weight and sense of large scale is particularly good when very large format horns are employed (some of these horns are monsters).