Build a wooden crate or use a cardboard box for Amplifier.

@oldhvymec, great advice there, voice of experience.

Hello, 
A lot of moving companies do not cover damage to electronics. I would crate. Also, use insulation foam panels instead of upholstery foam. Try to build a cardboard box. Use the pink foam to surround maybe even double to 2” if you are really worried and build the wood box around it. You could use a 1/4 hardboard just in case you have a puncture on the out side of the cardboard box then foam then crate. Also, make sure the transformers are screwed down tight. When the move they get damaged. You will be happy knowing they are ok. Plus, if you decide to sell they are ready to go.

The key with any shipping container is to ensure that the contents do not move around.This is a large part of the battle.However if these are going to be shipped, wood crates would be the logic and ground freight versus one of the one of the carriers that use the 4 foot drop test to see if the product is packaged properly.

Also if you can remove the feet on an amp, get the bolt size, insert a bolt through the bottom of the crating with appropriate washers. Tighten that down. that ensures it won’t move in the packing.

Then the “cover” just protects the top of the amp from puncture/crush possibilities. 

Special thanks to all.
I appreciate the input and the effortt
All the best

I would crate the cardboard. You need a crumple zone to absorb the impacts. If you build a solid crate and the amps are fixed in a solid position they will still take all the hits and vibration. Just like a car bumper and a bike helmet they absorb the impacts through a crumple or break away material. Good luck and enjoy the music!