Firstly, happy New Year!With mine, it's more of a pop than a crinkle. Take the headphones off and press the pads against each other. You should hear a distinct popping noise coming out of the back of the driver. It's almost certainly the diaphragm flexing / popping. My question is whether or not it's a design flaw that contributes to the high driver failure rate for the LCD series.
Second, not sure why you’re trying to blow your drivers?
The LCD driver membranes are thinner than a human hair. It’s both their biggest strength, and biggest flaw - but only if you don’t look after them. That crinkle or pop noise is the driver flexing - it has a certain built in tolerance for this, but by forcibly making them flex you’re just asking for trouble. I strongly suggest you put them on and take them off very gently, almost peeling them off your ears when taking off, and gently setting them on your ears when putting on. Otherwise, one day soon, you’ll hear the pop for one last time before one or both drivers stop working.
Take care of your LCDs, handle them carefully and gently, and they’ll continue serving you well for years to come.