jimorf735 Posted August 11, 2016 Report Share Posted August 11, 2016 Hi_ Does it make a difference if a surround is mounted on top of the woofer cone or should it be underneath? I just purchase a pair of AR 38s (10 inch woofer) that had been re-foamed and the person put the inside edge of the surround on top of the cone. I noticed that underneath the cone are the remains of the old foam!! After I remove all of the old foam material I will re-foam the woofers. Is there a difference performance wise as to where the foam is attached? Link to comment Share on other sites More sharing options...
JKent Posted August 11, 2016 Report Share Posted August 11, 2016 Others may chime in here but according to our old friend John McPeak of M-Sound it makes no difference. -Kent Link to comment Share on other sites More sharing options...
DavidDru Posted August 11, 2016 Report Share Posted August 11, 2016 Similar to JKent, other can chime in but it may depend on the replacement you source. Also email rick cobb and ask him since he sells teh surrounds. Or Tom at my Audio addiction if you can't get McPeak. RoyC may also have a direct answer. Link to comment Share on other sites More sharing options...
DavidR Posted August 11, 2016 Report Share Posted August 11, 2016 When I refoamed the woofers from an AR94S one style of driver had the surround on the back side of the cone. The glue was proving very difficult to remove so I decided to mount it to the front face of the cone. The surround would not sit right until I made a shim for the basket surface. According to Roy it made no difference in performance of the driver. It sounds fine. Link to comment Share on other sites More sharing options...
djcheung Posted August 11, 2016 Report Share Posted August 11, 2016 When I repaired my pair of 38s, without much experience on refoaming, it was a tough job trying to stretch the surround with glue applied and glue onto the underside of the cone. After some more practice on woofers like DavidR's AR94S and the ARUK1, it became easier. Here is one ARUK1 woofer I finished a few years ago. Link to comment Share on other sites More sharing options...
JKent Posted August 11, 2016 Report Share Posted August 11, 2016 17 minutes ago, djcheung said: it was a tough job trying to stretch the surround with glue applied and glue onto the underside of the cone. It also depends on the type of glue. The water-based white glue M-Sound used to sell (and Aleene's Tacky Glue) is MUCH more forgiving than the solvent-based stuff. You can smear it with your fingers, wipe up goofs with a wet cloth, even pull it apart before it dries, wash it off and try again. -Kent Link to comment Share on other sites More sharing options...
ra.ra Posted August 11, 2016 Report Share Posted August 11, 2016 I am not familiar with the 10" woofer used in the AR-38s, but I think the first consideration is to always be mindful of how the original foam was installed (on top or below). The second consideration, since not all replacement foams are alike, is to ensure that the new foam is going to sit in a natural state once installed - - - in other words, you do not want to 'force' the pliable foam into a position where it feels stressed or stretched or pinched or creased or is not mating well with the adjacent surfaces to be glued. It is important to be comfortable with a "dry fit" before even reaching for the glue. JKent is correct that a forgiving, slow-set, white glue is normally easier to work with, and djcheung is correct that applying glue to the cone underside can be challenging. The only time where I installed the foam on the underside of the cone was this 8" woofer from an AR-28B (p/n 200050), and once the cone was shimmed in the "up" extended position, it was not difficult getting the surround around the cone perimeter, and then I lowered the cone to meet the inner surround for the glue to set up. Link to comment Share on other sites More sharing options...
DavidR Posted August 11, 2016 Report Share Posted August 11, 2016 I stretch/place the surround under the cone first and then apply glue. No fuss no muss. And yes, Aileen's Tacky glue is much easier/forgiving to use than the solvent based glues. Link to comment Share on other sites More sharing options...
lARrybody Posted August 12, 2016 Report Share Posted August 12, 2016 Just checked my 38s speakers I re foamed a couple years ago. Yes the original foams are glued to the back side of the cone. That's the way I replaced mine. What difference does it make? Not sure if it does. I just figure if that is the way AR did it originally there might be a reason. Reminds me of my first attempt at installing woofer foams, Original Large Advents with the Masonite rings. They are glued upside down (concave)to the back of the cone. The New Large Advent with the steel baskets which are glued to the front of the cone with roll convex. Link to comment Share on other sites More sharing options...
djcheung Posted August 12, 2016 Report Share Posted August 12, 2016 This is one I rescued with the surround attached to the top of the cone. Link to comment Share on other sites More sharing options...
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