Today I connected my ipad to the music input of the intercom.
While the music volume is  goo‌d when I put the volume on the ipad (buttons on the side) to about 3/4 the output of skydemon is too faint to be heard. So I tried some experiments at home in simulation mode.
It appears that the volume of skydem‌on is constant and way too low. It is not changed by the ipads volume control.
It is OK for testing at home, but to be usable in the airplane environment I think that the output should be controlled by the volume control.
If the control is at max, the output sh‌ould be the maximum the ipad can produce, just like when playing music. This is about 1 V RMS which is also the signal the intercom input requires.
If done so, all sounds produced by the ipad would be about the same level.
Actually, its even a bit more complex, if music is played at the same time, the volumes seems to be even lower and it mutes when the volume is at zero. If no music is played, the volume is constant, even if the volume control is at zero.
In this respect, I believe the information provide about the volume on page 72 (rev 3.6.6) of the manual is not correct‌.
Actually, if no music is played at the same time it cannot be adjusted at all and is not loud enough to be usable in the airplane.
‌I have 3.7.0.58, iOS 8.4.1

‌‌‌

I certainly thought that low iOS could be the cause. Normally I only update software if there is a good reason, especially if the hardware is not the newest. If anybody has something newer than mine, can you confirm that you do not have this problem?

If anything, people say the volume of the SkyDemon alerts is too loud.

Thanks, Greg, very helpful.

Eric