REMINDER: tighten up your loose screws

But don't lock down your cartridge screw with Herculean force.
The threads in the cartridge body are very delicate.  Many have been ruined and needed re-building.
Only a quarter turn beyond finger tight.

To get the best improvement in sound quality on tightening driver fixings, don't use a cheap screwdriver, whatever you do.  This will undo all the good work in the factory -  the makers of the best speakers only use costly screwdrivers, many with gold-plated finish.  Their handles are usually painted blue, although some favour a darker shade of purple.

my wife says I need to do that..... :-)

The question is, did the manufacturer use threaded inserts or "T" nuts or did he just use wood screws and expect the MDF to hold. If just MDF you will strip the threads. Take a screw out. If it is a machine screw (the tip is flat) you can tighten them up to 10 nm safely. If they are wood screws (sharply pointed tip) you are in danger of stripping the wood and just snug is all you should do. Some companies use a compressible gasket under the driver. I take them out and put a very thin bead of silicone around the periphery of the driver and tighten the screws to 25 nm to firmly seat the driver and seal the silicone.

nasaman,

You may want to compliment your new brass screws with more brass 

https://www.mapleshadestore.com/