Hi All!

I have in my office a pair of 4435's that were built in 08-1986. They are original and the surrounds lasted just a few months shy of 30 years. One of them just started to crack, yeah I know, terrible design, only 29.5 years of trouble free service.

I have never re-foamed a speaker, I have always just re-coned them but I had seen on the bay these butyl surrounds from Japan and I figured if anyone was going to get this right it would be them. What the hell? What have I to loose? If they don't behave I will just re-cone them anyway so I bought four.

The first thing I learned is that if you value your time, just re-cone!

I haven't taken pictures yet but the roll is slightly smaller than the JBL surround. It fits the cone perfectly but leaves a slightly wider flat between the outer edge of the roll and the front foam gasket. This may not be noticeable to the average person but most of us would see it.

Other than that? Pretty close to perfection.

Name:  JBL  2234X3.jpg
Views: 1129
Size:  60.9 KB

The graph curser numbers didn't display so here is the rundown:

17 Hz Fs is with the original surround removed, no surround at all.

21.6 Hz Fs is with the original failing surround.

24.0 Hz Fs is with the new butyl surround installed.

Because I didn't want to be without music at all I re-coned four 2235's to 2234's while I went through this experiment. I swept all four of them of course and the average Fs of four of them is 24.4 Hz.

I will get these back in their original homes tomorrow during lunch and see if I can hear any difference from the new ones going back to these.

All the best,