Meridian Unplugged - Powered by MrTechGuy.co.uk Forums Discussion Meridian - Systems Tightening screws in the tweeter possible?

I've just done this after running in my 7200.2 for a few months. I don't want to make it sound like a surgical procedure but I did wear some DIY latex gloves as it improved grip (otherwise try doing it without getting sweaty hands!) and stops fingernails catching anything! Grip wise, what worked for me was index finger left hand in the 3 o'clock indent and right hand finger nails to lift the grill outer edge as others have suggested. The depressing bit was after all that not one of the bolts needed tightening!

Finally.

After been trying all tips I found and given up several times during the years. I today found a way of removing the grills inspired by this thread. I used the back end of a spoon with a very smooth shape. Over the spoon end I mounted self-adhesive velour. The velour made sure that:

1. No marks were done on the cloth
2. The spoon did not slip during the process

Using both hands over the spoon and the thumbs on the cabinet the grills came of with some effort.

(My first "sucess" was done using the spoon without the velour mounted, this resulted in glossy marks on the fabric and a cracked grill ring.)

The screws could be tighten between 1/4 to 0 turns.

Not really what I wanted to hear.
Managed, by touch, to locate the indentation on the "Mid" driver on 7200 but not on the two units below.
If a customer spends between �10K and �20K on a car, recommended torque settings for critical fixings are known to competent technicians.
I cannot remove the grilles on my speakers without applying what I consider to be an inappropriate force.
They still sound fantastic after more than 2 years, therefore I will leave it to the professionals, as and when the need arises.
Hector

Don't give up Hector! I think that it is really worth persevering.

Years ago, when I first got my 7k2.1s (now traded in), I also could not remove the grills which were very tight indeed. After advice here I learnt to feel for the indents and used the thin end of a coffee spoon to prise off the grills. The grills soon became looser and use of the spoon handle was no longer needed.

I ma sure that regular but gentle checking / tightening brings worthwhile benefits; even though, with 8ks, it is more of a time-consuming job.

I too would be very interested to know the recommended torque settings.

Also is it not possible to use Loctite?

I recently checked my M60's and all was well.

The trouble with a torque setting is that it will be very low and difficult to measure without an expensive accurate low torque tool.
The other problem with using torque wrenches is that you have to rely on the equipment and don't learn "The Feel".
If torque settings are critical then by all means, use a torque wrench, but in this case "Firmly Nipped" would be the torque I would suggest.
If in doubt, leave it alone, do not over tighten.

Just my opinion, Chris

One mans firmly nipped is another mans......

But you take my point Chris

That's why "the Feel" is a skill that needs to be learned and honed over time. Exclusive use of torque wrenches prevent this.
Don't learn "the Tricks Of The Trade", learn "The Trade". Chris

You are right Chris, feel is the best way, but I have a torque wrench I use on my mountain bike. Never thought I would use it on a speaker!

What about Loctite, no one came back with an answer.

I tightened my drivers (by feel) and what a difference!

Thanks

There are two reason why the screws can get loose.
The vibration of the sound can loosen the screw(turn it) or the chassis/box material can get compressed over the time and so the screw have less force(its loosen).
Loctite will prevent that the screw will turn(be carefull which color you use as every color have a different fixing force)
but not when the materials get compressed.
So you can only mark the screws and look after about one or two years if the screws have turned-then use Loctite.
If the material get compressed only tihtening the screws agin will help.
When metall rings are mounted direct on the chassis via screws
only vibration will loosen here the screws as the material dont get compressed.
If the metall rings is glowed to the cabinet then there should be no compression when the glow itself dont get compressed.
If the chassis is screwed direct on the wooden cabinett, some kinds of compressions would appear.
Only a practical test as described will tell you the truth...

Not sure that I agree with you entirely on the use of "loctite".
This is a case of material plasticity v elasticity. If a material has a predominantly plastic quality it will deform under pressure over time. A "loctited" screw will appear tight due to locking quality of the product used but does not take into account the permanent deformation of the compressed material with plastic characteristics.

If vibration (and screw loosening) is the major cause of performance degradation over time why does the manufacturer not use "loctite" in production?

If plastic material relaxation is the cause, then the secondary application of "loctite" seems to me inappropriate.
JMPOV.

Still can't get the grilles off. Maybe it is the Orange RAL 2009 sticky paint

Hector

Yes thats logic, maybe that is also a reason for the metal rings on SE models even the box mount/flange is still not metal.

But M moves on here, also every material have his own sound that have to fit or better say don't decrease the quality of the "remaining" box.