Guest daveshel Posted January 14, 2006 Report Share Posted January 14, 2006 Not long ago I replaced the surrounds on my large Advents (not the older masonite ring modles, there were called the "New Advent Loudspeaker" and I purchased them in 1978 or 79). I used a kit I bought on ebay - I think it was from simplyspeakers.com. The operation was not difficult, and the results were more than satisfactory. More recently I found this site and learned about sealing drivers when I rehabilitated an AR-4x set. I never used any putty or anything on my Advents. Do I need to do so, and are there any Advent-specific techniques of which I should be aware? I also bought a set of the masonite-ring models last year that had previously been refoamed. I may need to check those as well. Link to comment Share on other sites More sharing options...
Doug G. Posted January 15, 2006 Report Share Posted January 15, 2006 Sealing the woofers and any other leak is critical to getting the correct sound from Advents or any other acoustic suspension system. This is because they depend on the air trapped in the enclosure to act as the restoring force when the cone is displaced by a signal.They won't sound anything like they are supposed to if you don't do this. The bass will be severely lacking in the lowest octave and there will be too much in the midbass region. This will make them sound "honky."You can test for leaks by pushing gently in on the woofer cone. There should be considerable resistance to your doing this and the cone should return fairly slowly to its original position. If the cone pushes in easily and returns almost immediately, you have a leak. Use of Mortite or other sealing method is a must.So, yank those woofers back out and get them sealed. You will amazed at the change this will effect. Then put on a source with known low frequencies (between 30-50 Hz.) and listen, and feel, these speakers reproduce them.By the way, this is my first post here so hello everyone.Doug Link to comment Share on other sites More sharing options...
Doug G. Posted January 15, 2006 Report Share Posted January 15, 2006 Oops, forgot.Advent used Mortite, a kind of clay-like sealer that has been around for, seemingly, centuries on the early masonite woofers. Run a bead around the rear side of the frame flange where it meets the speaker board, position, and screw down.The later all metal woofers use a gasket that works just as effectively. I would think that your New Advents would have this on them already so they may be sealed well.I suppose you could use either method on either version.Doug Link to comment Share on other sites More sharing options...
Guest Edeit Posted January 17, 2006 Report Share Posted January 17, 2006 I just got done resealing my LA's and SA's. I used a compound called "Electrical Putty". In the trades it's known as "Monkey Shi*". It can be found at Lowes or Home Depot in the electrical departments. It comes in a block and looks like clay. Cost is $2.00 and one block will easily do your speakers.Remove the old Mortite then carefully roll the Electrical putty out into long strips the diameter of a pencil. Apply and screw down. Works well. Link to comment Share on other sites More sharing options...
Carlspeak Posted January 17, 2006 Report Share Posted January 17, 2006 >I never used any putty or anything>on my Advents. Do I need to do so, and are there any>Advent-specific techniques of which I should be aware? I also>bought a set of the masonite-ring models last year that had>previously been refoamed. I may need to check those as well.Yes, you should use putty or foam gasketing, both of which are available at low cost from Parts Express. They have 1/4 inch wide by 36 inch strips (part #269-300) which are like monkey shi_. Each is a mere 98 cents. Also, self adhesive foam strips are available (part #260-540). A 3/8 inch wide strip, 50 ft long sells for a mere $4.23.I have used both on my customers speakers.CarlCarl's Custom Loudspeakers Link to comment Share on other sites More sharing options...
Guest daveshel Posted January 18, 2006 Report Share Posted January 18, 2006 Thanks, guys. The Ace Rope Caulk Weatherstrip worked just fine on the New Advents. The older ones had some putty of some sort that I could see around the edges of the metal frame, so I haven't torn into those yet, but they woofers do seem a bit looser. In these older masonite ring models, it occurs to me that there may be another surface that needs to be sealed - is it necessary to seal between the driver and the masonite? Link to comment Share on other sites More sharing options...
Doug G. Posted January 19, 2006 Report Share Posted January 19, 2006 You are correct, of course, that there must not be any leakage between the masonite ring and the metal frame. If they were glued correctly, however, they should be OK (I guess we can assume Advent glued them correctly; they used plenty of glue :^)If they are ever removed and replaced (like I have done when replacing surrounds)there must be a continous bead of adhesive applied here.You can still check for any leakage anywhere with the woofer cone push test as I outlined above.To add a bit, when the cone is released, it will move more quickly at first and then more slowly as it nears its normal position.Doug Link to comment Share on other sites More sharing options...
Guest daveshel Posted January 19, 2006 Report Share Posted January 19, 2006 I found that the (New) Advents, as opposed to the ARs I resealed last week, got a pretty decent seal all by themselves, probably by virtue of the wide flange. I didn't see a huge difference with the push test in the first place, but eventually decided the News were a little quicker than the old masonite ring woofers. After the reseal, the News are now a little slower than the olds, but by a smaller margin than I saw before. I'm sure I'll eventually see if I can improve the olds, but for the moment I think I'm in pretty good shape. Link to comment Share on other sites More sharing options...
Carlspeak Posted January 19, 2006 Report Share Posted January 19, 2006 >Thanks, guys. The Ace Rope Caulk Weatherstrip worked just>fine on the New Advents. The older ones had some putty of some>sort that I could see around the edges of the metal frame, so>I haven't torn into those yet, but they woofers do seem a bit>looser. In these older masonite ring models, it occurs to me>that there may be another surface that needs to be sealed - is>it necessary to seal between the driver and the masonite?Dave. The rope calk weatherstrip looks great at first when you apply it and install the woofer. It's soft like modeling clay and compresses nicely. I used it years ago myself when I first got into speaker building. However, over time, it will harden and become brittle. The sealers I recommended in a prior post will not.CarlCarl's Custom Loudspeakers Link to comment Share on other sites More sharing options...
Guest daveshel Posted January 28, 2006 Report Share Posted January 28, 2006 Carl - thanks for the tip. Should I redo them now or just stop using rope caulk and keep an eye (ear) on these? Link to comment Share on other sites More sharing options...
Carlspeak Posted January 30, 2006 Report Share Posted January 30, 2006 >Carl - thanks for the tip. Should I redo them now or just>stop using rope caulk and keep an eye (ear) on these?I don't know for sure how long it takes for those window calking ropes to harden. I think it may be a year or two, but it does happen. I say go with the Parts Express recommendations if you're planning to go the long haul with your Advents. Link to comment Share on other sites More sharing options...
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