polaris26 Posted June 18, 2013 Share Posted June 18, 2013 Hello All, A while back I bought a a pair of Chorus II's and sold my Chorus I's because I prefered the sound of the II's vs. the I's in my setup. I noticed sometime afterward that one of the passive radiators in the Chorus II seems to be sagging or tilting somewhat upward. That is, the bottom of the cone is pressing out slightly and the top is more inward. By comparison, the other speaker's radiator is perfectly level, the way I would expect it to look. I don't hear any strange buzzes or rattles coming from it, but I am wondering if I should be concerned, and if so what can I do about it? Thanks, Dave Quote Link to comment Share on other sites More sharing options...
Mongo171 Posted June 18, 2013 Share Posted June 18, 2013 Give it a Botox injection. Seriously, no need to fret unless it is producing a sound. Make sure it still moves smoothly. No need to be concerned right now. It may need to be reconed in the future. Quote Link to comment Share on other sites More sharing options...
moray james Posted June 18, 2013 Share Posted June 18, 2013 The proper service adjustment is very simple. Rotate the passive (and your woofers too) 180 degrees do that every ten years and you won't ever have a problem. Best regards Moray James. Quote Link to comment Share on other sites More sharing options...
polaris26 Posted June 19, 2013 Author Share Posted June 19, 2013 Wow the fix was so obvious it escaped me - I rotated the passives. I don't see (or hear) any problems with the woofers... so I didn't rotate them. Perhaps I should? thanks! Dave Quote Link to comment Share on other sites More sharing options...
moray james Posted June 19, 2013 Share Posted June 19, 2013 Thank god gravity has no bias. Rotate your woofers they have been sagging just as long as the passive units have. Every ten years is a good time frame to flip them and this will prevent the suspensions from becoming distorted. Leaving them longer can result in stretching your suspension well past its range and you don't want to do that. A small dot of nail polish on the frame will allow you to identify your flip point. Best regards Moray James. Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted June 19, 2013 Share Posted June 19, 2013 Same reason I make my wife stand on her head every night. Quote Link to comment Share on other sites More sharing options...
Mongo171 Posted June 19, 2013 Share Posted June 19, 2013 I have owned my Chorus II's for over 18 years and the passives don't sag. They are still perky. If they did sag, I would get them reconed. Sagging is a sign that the surround has lost its function to perform at the tuned freq. Flipping the passive will not cause it to function properly. It will just sag in the other direction, if the whole surround is shot. Quote Link to comment Share on other sites More sharing options...
moray james Posted June 19, 2013 Share Posted June 19, 2013 you are wrong they have sagged you just have not noticed it, not much escapes gravity. I imagine that there are a number of climatic factors envolved with the process of sag but it is normal and companies such as Altec and JBL used to recommend regular rotation to insure that drives were kept centred on their suspensions. This is a normal process, rubber suspensioms can sag too just not as much. Drivers in long term storage must be properly rotated or they will be ruined. Best regards Moray James. Quote Link to comment Share on other sites More sharing options...
Mongo171 Posted June 19, 2013 Share Posted June 19, 2013 If a tire is low on air, rotating it 180 degrees isn't going to fix it. You have to put air in the tire to bring it into spec. Here is my passive. I just got new glasses, so please tell me where it is sagging. Quote Link to comment Share on other sites More sharing options...
Mongo171 Posted June 19, 2013 Share Posted June 19, 2013 I was wrong. I bought these new in 1995. The build date is 95. Quote Link to comment Share on other sites More sharing options...
Mongo171 Posted June 19, 2013 Share Posted June 19, 2013 Next I will be told I have to rotate drivers between speaker boxes. Quote Link to comment Share on other sites More sharing options...
oldtimer Posted June 19, 2013 Share Posted June 19, 2013 Some are more ocd than others. Plus, climate conditions are different for all of us. While gravity may be a relative constant, conditions are not. If you notice a problem, deal with it. If not, either measure it with the most accurate micro gauge you can find, rotate it anyway, or keep enjoying. My first set of forte IIs from 1989 look and sound ok. There is wisdom in the if it isn't broken, don't fix it, because you just might do more damage trying. Quote Link to comment Share on other sites More sharing options...
moray james Posted June 19, 2013 Share Posted June 19, 2013 did you really think about this? This is not a tire. This is a weight on a spring all be it a distributed spring it cannot help but sag to some degree over time. Read what said there are a number of factors which will come into play and your passive may well be very happy where they are but sure as god made little green apples they are not where they were twenty years ago. If you care to look into Altec for example you will read over at the JBL Lansing Heritage forum accounts of the suspension dope migrating over time from the top of the suspension toward the bottom. Just one of the factors involved with some of the Altes drivers. Suspension dopes have been improved over time as have other aspects of design but the simplest solution is to rotate or flip the driver from time to time if that is an issue. After twenty years even the spring on your car get soft and sag a little. I don't see the point you are trying to make other than your passive radiators are just like new. So ok yours are just like new be happy. I don't have any more to offer this thread. Best regards Moray James. Quote Link to comment Share on other sites More sharing options...
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