yes! i definitely had that same experience when i play the organ in every service.
A couple of weeks ago when i was playing the organ, i could barely hear myself, but that is because the leslie was in the wrong spot. The Leslie was further from me.
Also, the guys at my church play tremendously loud. The bass guitarist and the pianist was basically showing off; the drummer was fine but sometimes he shows off too. The saxophone is pretty ok.
There were some cases where i couldn't even hear the piano nor the organ; i just hear the loud bass and saxophone and drums.
It is really not good to show off, thinking you are all that great. Just play to the honor and glory of God.
Also, i think each instrument should have a volume monitor to monitor the volume. So if it is too high, it can be decreased.
Another reason is where the amp is facing; if it is facing towards the congregation, the musicians will not know that they are playing so loud, since they can't really hear it that much. So the amp should be facing slightly towards them so they can easily monitor.
The drums are really hard to control the volume because basically the drum is a loud instrument. Sometimes, when you feel the Holy Spirit or when you're feeling the music, it makes you want to play louder and play harder. lol. It is difficult to control the way how you play the drums. I believe the drums should be hook up to the sound system so that the sound men can monitor and adjust the volume of the drum.