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
Ag insider logo xs@2xfeldmen4
"...For another these screws (maybe they are bolts - it’s a close call)..."

If it has a nut, it's a bolt. No nut, it's a screw. FYI: An angular torque measurement is actually a very good way to properly torque (stretch a screw).    
@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?
There are many kinds of nuts but inserts are not nuts. Basically a screw goes into a blind hole and bolts have nuts. So the use of the screw/bolt changes it's name but it can be the same part.  
A nut, bolt and washers, sandwich materials together. We can measure torque to yield, bolt stretch, or torque plus. Long stock "torque to tone"

Screws and washers, hold one surface to another. They do not sandwich top to bottom, only surface to surface.

We use helicoils to increase the cross section of the securement.
EX: A Stainless bolt is used to secure two aluminum pieces together.
For more surface area (thread to material) a helicoil is used. The coil is harder than the hubs of hell. The bolt is hard, the washers are hard, the coil is hard. BUT the materials being joined are softer. The outside of the coil is much larger that the SS bolt..

See where this is going.. Small bolt, lots of tensile strength (so they DON'T stretch). Aviation standard.

The manufacture (in some cases because of warpage), will increase the number of securements on the face. The head of the securement is all you have to bind with.. I'd use a binding SS star washer under the head and a thread locker. Blue (Loctite) and a binding head aught to do it. Let it dry overnight. Red is metal to metal, white, is loosen with heat only.. Blue can be used with wood.. This is where the driver manufacture are coming from.

A great cheap way is interrupted threads. Different thread count (very minor) via nut and bolt. A wider binding HEAD (cap bolt or screw) is a good idea too. Wider binding area under the bolt head.

OP, I have very gentle hands, that can pull inch pounds or (LOL) 1600 foot lbs.. Yup I use to torque without torque multipliers to 1600 + with a 6 foot cheater, Spreading track..

Finger tight is finger tight PLUS 1/4. That is a torque Plus method.
Believe it or not, it works because you do recheck it many times.
With loctite, you don't recheck, you just go over the pattern several times BEFORE the binder dries..

If you keep up with the maintenance, they should stop backing out, once you get it "TIGHT".  Could take several times over a month or so. A cross pattern, then around the clock, two more times..

Back to, brass screws.. sonic difference? Better ears than mine!

My stuff don't come loose unless I want it to. Simple as that. :-)

Regards
I expected more - am I wrong?


Yeah, most of us would know what that is. Finger tight is not as tight as you can possibly tighten them. It's about when your fingers start feeling resistance and the torque needed shifts from nearly nothing to really something. That range is about 1/8th of a turn.  Anywhere in there is fine.  Get there and add 1/4 turn.

However, if you are worried, mayhaps what you should rely on is not the pressure but Loctite.

Add some to the end that attaches to the driver. You’ll get a permanent lock that won’t strip the screws. If you ever need to remove it, you can, but vibration won't cause them to loosen again.