M-Audio 61es midi keyboard volume too low

I have connected an M-Audio 61es keystation to my iMac but its volume in Garageband seems very low. I have to really crank up the levels until I get a volume that comes even close to the volume of the GB loops.

The volume I get from GB soft keyboard [apple-K] is much louder.

The 61es volume slider is on maximum. Audio Midi Setup correctly identifies my keyboard.

I am wondering if I have missed a setting somewhere.

Any ideas?

Thanks, Paul