Do I expect too much?

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.

"...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