Audio Systems: Mixed house of 70v and 8U / QSC Audio, qsc audio, watt amp

Question
I've inherited a restaurant with a combination of (4)70v speakers and (8) 8 ohm that are powered by a QSC CR-302 and CR-302v amps mixed by a Allen-Heath controller. Being the wires are into the walls and ceiling, How can I trace them out and add 4 more to the system without removing each from (13') the ceiling ?  
I need to add 4 more to another room, presently unserved.
I have no skematic, and the installers are long gone.
The Mixer sends some audio ( CD and DMX ) to the CX-302, and a DJ's / mic to the 70v  QSC- CX-302v. The speakers are Martin-Audio ( England)

Answer
You shouldn't have to remove anything since the speakers are meant to be daisy chained. That means that you should be able to attach other 70v speaker to either the terminals of an existing speaker or accross the terminals of the amplifier.  The way 70V systems work is that the speaker loads (wattages) should all be equal in order for the volume level to also be balanced. 70Volt speakers usually have transformer taps that can be changed to set the wattage of a speaker. My recommedation would be to add only speakers that have adjustable taps (as do most Martins) so that you can change the wattage to balance the sound from the existing speakers to the new ones. A total of 8 speakers should not be a problem since that amplifier is a 250 watt amp. It means that you could conceivable get about 30 watts to each speaker