Klipsch Epic CF4

After sealing inside cabinets with Gorilla Glue Silicone no more rattle.

Fun speakers, I wish I had kept my Gen 1's.  Wouldn't be my main speakers anymore, but while large... they were a fun speaker.

I'm still using a 48 lb Onkyo TX-SV919 (1993 and first consumer THX certified receiver with 51 RCA/phono jacks on the back and 35 push buttons under the front door) to push a pair of Klipsch Epic CF-4 speakers (~1994), a Velodyne sub, and Klipsch THX certified center speaker from the same era . The system is 25+ years old and still works great for blasting music you can hear at least two blocks away from inside the house, but for TV use with modern HDMI and codecs it could have used an upgrade over a decade and a half ago. It's the quality amps in the receiver and those extremely efficient and quality speakers that have kept me from doing so.

myccpay.com

I've got a beautiful pair of CF4's in the back closet. Bought them back from my ex for sentimental reasons. What big mother!

The back panels came loose on my KLF-30s and I used Titebond III to seal them up.  No more rattling.

Cabinet rattling is a somewhat common problem for some Klipsch of that era.  Typically, it is the rear (or front in some cases) panel  which is glued in becomes loose and rattles.  An internet search for Klipsch cabinet rattle will bring up lots of advice on some Klipsch specific forums... 

Some people will add internal bracing. I haven't tried it myself, but something to consider.

Good news after further testing the speaker is not bad cabinet is rattling will try to silicone it from the inside I am the original owner so I guess after 20 plus year the seal is not as tight .

Yes russ69, you are right. I own version 1 and I had heard that the bass drivers were changed after that as well as the port tubes. Thanks for the clarification.  

The Klipsch forum says:

Rev.3 – Summer of 1995 to end of production in 1996

1. These models had new lighter cone woofers (new vendor) (these cones aren’t nearly as stiff as the originals and can be deformed much easier by pressing on them)
2. Networks were changed to compensate for the new woofers

I don't think Klipsch will service them or that they have replacement woofers. They were made specifically for those speakers. Two ideas, call Madisound or any company that deals with driver repair, or scour ebay where you can sometimes find Epic drivers.