As the speakers are situated on either side of the dance floor which is usually in front of the main table it is better to seat the older guests further back so that they won't suffer with the loud music. That way they enjoy themselves a lot more.
When catering for the Videographer, Photographer & DJ it makes the room look much nicer if they are seated at a smaller table together & not crowding at the DJ table or seated with your guests.
Suggested Sequence of Events
Guests arrive at the venue.
DJ plays background music from when the first guests arrive.
Bridal party have photographs taken.
Ask the venue's maitre'd to signal to the DJ when you are ready to enter the room so that he can play the bridal march or your choice of music for your entrance.