Upgrading sub to get a live feel.

You Might try the Sub upgrade now..Many good ones out there.You could move up the SVS food chain and still be quite usable with your current JBL's.Those JBL 4367 are $15,000 correct?

My current short list of subwoofers are

JL F113 or Seaton Submersive

Most likely Seaton

I am hopping that the sub upgrade will hold off my 4367 purchase. 

thewatcher101,

     You may be able to improve the bass response at your listening seat just by repositioning them.  I'd suggest using the crawl positioning method sequentially for each.
     If this doesn't work and you have the room space, using three SVS-SB1000s, sequentially positioned using the crawl method, is virtually guaranteed to provide bass response at your listening seat approaching state of the art.  This is called a distributed bass array (DBA) system and it works amazingly well in virtually any room and with any pair of main speakers, even with faster and very detailed speakers like electrostatics and Magepans.
      The bass perceived is very smooth, detailed, as powerful and dynamic as the music requires, seamless integration with any pair of main speakers and an overall quality of effortless bass on music and HT.
      I use a 4-sub DBA system called the AudioKinesis Swarm in my 23'x16' room with large Magnepan panel speakers and it works like a charm.  The DBA concept usually requires four subs to function properly but works almost as well with three.  
     Here's an Absolute Sound review of the AK Swarm that gives a good explanation of how it works and what to expect.  The SB-1000 subs are ideal to use in custom DBA systems because they're very good subs and are relatively small.

https://www.theabsolutesound.com/articles/audiokinesis-swarm-subwoofer-system/ 

Tim 

Thanks a lot I will look into it.

i also believe that the mids and lf are the most important part of music.

i currently have the subs right under my main speakers. They image very well but still lack that physical presence.

Room acoustics and EQ matter a huge deal. More so than the sub hardware itself in a lot of cases.