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Do I expect too much?

Spent Sunday trying to track down an upper midrange rattle in my system - both channels but not necessarily exactly the same from side to side. I suspected loose or corroded connections but needed to move one of my Monitor Audio Gold 200 floorstanding speakers to access the back of my components. When I did I found a screw on the floor. The screw was only part of the footer and while it needed to be dealt with I don’t believe it was part of the issue. But that did get me to thinking about the speaker screws. These speakers have a unique driver mounting system where they are held in place by screws on the rear of the cabinet that physically pull the drivers into place. I checked them and on both speakers they were all significantly loose - one was about to fall out (my 19-year-old says it’s because I listen too loud but that is whole other string). 
So I looked in my MA manual and it didn’t even mention the screws. Next I went to the MA website and their contact us page allowed me to send an email to their North American distributor - Kevro. I asked for the torque spec. I did receive a prompt reply but was told, “there is no torque specification.  They should be tightened finger tight plus 1/4 turn. 
I expected more - am I wrong?  For one thing I am pretty sure my finger tight and oldhvymec’s finger tight are 2 very different things. For another these screws (maybe they are bolts - it’s a close call) have a broad flat head with a 4 mm hex inset - they aren’t really finger tightable (is that even a word?). 
Also any advice on how to proceed would be appreciated. I recall OHM saying he torqued the hell out of all his speaker screws (or some words to those effect). 
Thanks,

Matt
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Showing 4 responses by feldmen4

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feldmen4 OP
108 posts
 
@arch2 - I swear it skips a generation.  Both my boys are like my mom. 
@russ69 - Appreciate the input.  I’m sorry but the engineer in me is curious what defines a nut?  Does a nut have to be able to move independently?  Does a helicoil count as a nut? I haven’t pulled any of the drivers on my speakers but I imagine there basically a cage behind the cone with struts that start on the back of the driver rim and converge to a threaded orifice centered behind the voice coil. Is that a nut?  I am guessing yes?
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feldmen4 OP
108 posts
 
@fuzztone - appreciate the advice. I’ll need to think about that with this unique mounting arrangement. Would hate to end up with red 271 drips on my cones. 
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feldmen4 OP
108 posts
 
Lots of good advice. I really appreciate all of the thoughtful responses. 
There does seem to be some misunderstanding about how these drivers are mounted. Each driver has a single bolt/screw that secures it from behind. There are no bolts/screws around the rim of the driver - just the one pulling it into position from behind. Thus no torquing pattern is possible. 
I didn’t realize this until I was tightening them on Sunday. Given this single relatively insubstantial screw/bolt per driver getting the torque right seems imperative. The fact that they were as loose as they were is evidence of this need. 
I know how much damage over tightening can do so I don’t want to go there. Give that @erik_squires indicates finger tight would span up to 1/8 turn and the instructions are to only turn it 1/4 turn once finger tight this allows for as much as a 50% difference in bolt/screw stretch depending on judgement. I’ve been involved with the design of mechanical systems for years and understand the difficulties in actually measuring torque accurately, but this much variability seems excessive. 
@johnfritter - it is a little comforting, in a contorted manner, that at least the advice is consistent. 

Matt
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feldmen4 OP
108 posts
 
@russ69 - not clear to me how “Torque angle is a very accurate way to apply torque settings.” in this case when it can vary by 50% based on where the finger tight starting point is?  Since I have no intention of actually removing the screws different lubrication conditions are not a concern. 

@johnfritter - Your responses are very much appreciated. I was frustrated that MA sent me to their distributor for questions rather than allowing me to ask questions directly from the home office. It may be a way of dealing with language barriers but in this case the speakers are designed in the UK so there aren’t any such barriers. It does at least provide some piece of mind that the instructions are consistent. I sort of felt like they were just blowing me off so a stock answer is at least better than that. 
It’s interesting that you only had a couple of bolts whereas all of mine were loose. This includes the bolt that holds the plate with the speaker connections - one of this was also about to fall out - and bolts in the footers. 
Do you still have your MA speakers?  If so which ones?

Matt

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