JBL 4429, deep bass ?

Bought the 4429’s a couple of months ago and WOW!!  They are absolutely amazing speakers...so much life and unforced detail.  Bass is actually some of the best I’ve  ever experienced...and I’ve had the big boys from Wilson, B&W, Dynaudio etc...deep, complex and visceral!  Feeding them with Krell 400/4ohms, Yamaha Ref SACD ans using new Transparent Super cables.  

Have a pair of 4429s. When they were new, they had very little bass below 50/60 Hz. Took a good year for the suspension to loosen up. Bass seams to be fairly flat into the 30s in my room. Anechoic response will always show a rolloff around a 100 Hz. Depends on the baffle loading. I have to agree with Dave_B. These are the best I have ever heard at my place. Talk about realism and detail, these have it in spades. My system consists of a Schiit YGGDRASIL feeding a Yamaha A-S3000 integrated amp. Balanced off course! The Schiit uses four medical converters - two per channel to feed the balanced outputs. Converters are guaranteed to be monotonic to 22bits. Put on Yanni "Live at the Acropolis" the other day. Had not heard it on this system. Good recording for being live. Sounded completely different then I remember it on my systems of the past. Wow. The harp sounds real and back in the distance. Dave_B, pick up the Schiit if you can. It is a serious converter, and the 4429s sound incredible with it.       

It is very hard if not impossible to make a driver that is effective at 18 Hz go all the way up to 800Hz gracefully. This is why subwoofers exist. You can make a midrange driver that makes it down to 100 Hz especially if you use them in multiples such as in a D'Appolito array. Then you can go right down to 12" subwoofers and skip the standard woofer altogether. 
This design approach Is used by several companies the Goebel Divin Nolesse is a great example. God knows what they cost. I have not seen JBL do anything really creative in home speakers in a while. Back in the day they were ahead of the curve. Anyway there is not speaker of this design type that makes it very low with authority. Real bass is a beautiful thing.