JBL 4429, deep bass ?

Dave B which amp are you using with the JBL. What kind of stands are you using. 

Does anyone know or seen the impedance/phase graph? I want to use a 300b 8 watts amp.

FYI, the frequency range of an acoustic base is 40-400hz!  

Update!!  My 4429’s sound even better now...got some anticables involved which are by far the best cables I’ve owned (owned $20k speaker cables).  Coltrane LIVES!!  For the would be audio cognoscenti, they play with greater dynamic freedom, realistic visceral bass, extended non fatigue inducing high’s and wide soundstage the competes and in most cases beats my previous Wilson’s and B&W’s to name just 2.  

It does not look like I can insert the PDF file here. The rolloff starts at 40Hz, but judging from the file date the speakers were only a couple of months old. I know the bass improved quite a bit after a year.

Zowie. I would think the cabinet volumes are close. But you could research that. I have a plot of the response of the 4429s' in my listening room. I will look for it and submit it if I can find it. To my ears the 4429s' seem to dive into the 30 range. It took awhile before they went that low. Probably a year before the suspension loosened up. That woofer has a dual spider setup.

Well, the porting is different, the cabinets are different, and I don't know but wouldn't be surprised if they cross over differently.

You know that the L100 Classic and the 4429 share the same woofer. One has a white damping material sprayed on the front. The other is sprayed on the back. Low end should be the same.

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.

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.       

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.  

JBL 4429 and "deep bass" don't belong in the same sentence. I worked at an audio store in SoCal several years ago, and after playing some test and demonstration records through the typical JBL formula--horn plus oversized ported woofer, the frequency sweeps clearly showed that these big 12" and 15" woofers were starting to roll off at 100 Hz, which would explain why they're down 6 dB at 40 Hz.

Most of the perceived bass on this design is overtones. It's mostly midbass thump with little true extension. It sounds impressive on '70s rock and pop, but less so with deep synth tones, and the constant barrage of high frequency sizzle, blaring midrange, and upper bass thump gets fatiguing, even on the music it does fairly well.

And acoustic classical music easily shows its shortcomings.

People often use the term "deep bass" when what they really mean is a speaker with a high midbass output. Juke boxes are a good example. Tons of midbass, but no real low bass. But people love jukeboxes. They’d probably be happier with one than their current hifi system.