Custom door sound

The door sound manipulation works exactly like the one in the button sound tutorial. Create a bigger caulk box outside of the map, place caulked fake brushes, which represent the door, UNDER the real brushes into the box and convert the visible and the invisible brushes into a new door.
It should look like this:

Since we have 2 doors (one for the left, one for the right side) select first the 12 brushes (sumed up the original and the fake ones in my brain) from the left and create a func_door. Then, do the same with the right ones. Add these lines in each door entity window:

I used the "crusher" flag and a lower speed value, because this is a heavy rock wall and furthermore it fits better to the sound effect. Connect the target_fragsFilter to the left and the right part of the door.

Here comes the sound source again. Place a target_speaker in front of the door. Then copy the target_speaker once, twice or thrice for a louder sound. Select all speakers and type in following key and value:

Keeping all of the speakers selected copy them and place them into a second row. Now add a target_delay next to the target_fragsFilter. Deselect everything. First select the target_fragsFilter and then connect it with one of the row of speakers (one after another). Then do the same with the target_delay and the second row. For the last step select the target_fragsFilter and connect it with the target_delay.

Add a "wait" key and a value of "5" to the target_delay entity window:

Perhaps you are a bit confused now what happens here. Let me summarize it for you:
You press both buttons, activating their sounds and their target_scores. This adds up to a score of 2. Now the target_fragsFilter comes into action. It activates both parts of the door, 4 of the target_speakers and the target_delay. When the door closes again after 2 seconds (default value), but slower than normal because of the lower "speed" value, the target_delay plays its targets after its "wait" value of 5 seconds. The wait key in the target_delay sets the time when the triggered entities get activated after the delay's activation (see target_delay entity notes).

Again some aspects to mention: Because of the sound being played when the frag filter counts two frags the player could activate the 2 buttons faster than the door closes and therefore activate the sound during the closing process. So the whole construction only works if the player activates the buttons once or after the door has been shut again. You need to add some doors which hinder the player to activate the buttons again or you have to fine-tune the "wait" values.

For Q3A: Here it's a bit simpler. Select the button (Ctrl+Alt+left mouse button onto one of the button parts) and connect it with both door parts. Then select the button again and connect it with one row of the target_speakers (one after another). After that, just connect the button with the target_delay and you'll have the same effect like in Defrag. Unfortunately it's only possible with one button.