Enclosed are pics of two 2214H-1 badly done front refoams done with a mix of thick white glue or urethane / silicone adhesive. You can see the heavy duatcap glue lines and the excess edge glue which has likely soaked and hardened into the cone material. It unlikely the surround can be removed without damage. Replying to front would restore much of the integrity minus any cone fiber loss.
It’s not ideal but sometimes it’s unavoidable. I have a number of 2235H’s and a few 2214H, all older of course, where the surrounds were replaced probably in the 90’s when the narrow roll thinner foams were not available. So generic 15” and 12” foams respectively, thicker w/wide rolls were used. If not a JBL knowledgeable shop, back then the easier and faster way was to put it on the front side, sometimes very poorly indeed.
It literally wasn’t till the early 2000’s when properly designed and made JBL model and come specific foams became widely available for use. Then the issue of cone or driver rest position offset with front vs OEM JBL rear mounting became a theoretical and practical consideration and one had to ask for reformers to rear mount. Another improvement was subbing polyether for polyurethane foam surrounds really improved longevity and reliability, particularly in hostile climates.
Unfortunately, trying to take off a front glue mounted foam frequently leads to front edge cone damage or layer delamination. Looks bad, may weaken the cone too. If putting the foam on properly back OEM mounted, the damaged cone edge is unsightly. Some have suggested light spray painting (but color matching and theoretical cone mass gain are issues), maybe consider a way to fill with a matte filler or watered down PVA binder, or other cosmetic improvement? Or just keep the grille on, or use in a subwoofer only application?
Otherwise, option to replace foam onto front of the cone looks non-OEM but preserves the original cone/voice coil and saves money which for many is a primary concern vs the cost of an OEM JBL Rec one kit, if even available, or going to an aftermarket kit of unknown performance aside from a few well known pro resources.
The front mount can offset the rest position of the voice coil in gap center, and spider est position by a millimeter or two down (thickness of cone plus surround?) depending on the thickness of the cone and surround plus it’s springiness compared to the elasticity or stiffness of the spider. Most thin foams will give way before a spider will but the slight difference in up/down surround resistance with cone motion may affect linearity. A soft, tired or heavily used spider would be affected even more but that should be examined by the shop and replaced at the time of service. Again, labor vs total recone costs.
It just dawned on me that an unavoidable front surround remount could mitigate the rest offset issue by raising the frame outer surround landing/glueing zone by a similar offset height. A 1-2mm thick ring of card stock or a similar thin foam ring (cut from the outside of another surround?) could lift the outer surround edge enough to balance the offset down by the front mount! This would allow the spider to be level & flat rather than maybe brought below level - and the voice co to remain centers in the gap.
We’d have to schematically draw this out and then practically see how it needs to work - a lot to save an OEM cone I admit and it still looks incorrect but it could preserve originality aside from appearance and more importantly, proper performance. Otherwise, you’re looking at a recone cost which may or may not be attractive to some.
I’ll ask my pro sources about this idea!
