@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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Yes I understand "torque angle" quite well. No need to try and explain his question to you. It made perfect sense to me as I have been in his shoes. Just thought I would help a guy out since I actually knew what he was talking about from first hand experience.
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I do agree A torque spec would be great..."
Torque angle is a very accurate way to apply torque settings. This eliminates the differences between a dry fastener and a lubricated fastener or materials that have different surface frictions. They gave the OP the info he needed. |
@feldman4
I do agree A torque spec would be great. I tried and tried to get a torque spec from the only to get re-worded versions of the same reply. Maybe I will try and reach out to the home office and bypass the US. distributor. I have only had trouble with the upper two bolts and after tightening I haven't had any issues since. I do play at what could be considered "excessive" volume on a regular basis. I listen to a wide variety but I'm an old rocker by hart so......! |
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 |
I am familiar with your issue, I also received the exact same advice. You may have to use a hex key to turn the bolt to "finger tight". If this is the case use the long side of your hex key. Insert it into the bolt head using your thumb and forefinger to tighten the bolt until the head is snug to the back of the cabinet. By snug I mean just to the point you have full contact between the cabinet and the bolt head. At that point give it the extra 1/4-1/2 turn with your hex key. I say 1/4-1/2 because mine actually took a bit more than 1/4 turn before the bolts would no longer move side to side or up and down. This will make sense when you tighten them up! Hope you find this helpful.
Oh I would also recommend inserting the long end of your hex key in the bolt head when you make the final torque. This way you will have less leverage reducing the chance of accidentally over torqueing the bolt.
Have a good day!
JF |
You can always add a Nylock nut to the existing nut, tightened to the same 1/4 turn. Saves threadlocker (or drips), and isn't permanent.
And mind those bass line forays.... ;)
Nylock nuts ought to be a SOP for woofers, anyway....esp. sealed enclosures. |
I am sorry it sounds like another case of we sell it do not know what to say when questioned about the product syndrome but i would say that you want the bolts more than finger tight in a speaker that produces vibration or you would be tightening all the time.
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Maybe think about replacing the existing screws with treadlocking ones, something like these would stand a better chance of staying put. |
Follow the manufacture/distributors recommendation. Do not over-tighten. I would not use any thread lock either. Seriously, you’re trying to over-think a simple operation. |
I would only use the Loctite that is not permanent. What if for some reason down the line you want to remove a driver? |
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. |
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 |
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. |
@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? |
"...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).
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Feldmen4: “my 19-year-old says it’s because I listen too loud but that is whole other string”
I find that hysterical. When my daughter was a teen she would often come down into the music yelling “the music is too damn loud.” Every time it made me think of my mom when I was in high school. |
@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. |
Don't worry about torque. Just use thread locker.
I would break out the big guns and use red 271 myself. |
