Hi Scott,
First, you need to determine if this is a 70V system or 8 Ohm. 1) If it's a 70V system, you'll need a mono volume control such as our OSD MO70V. Make sure the speaker has a 70V tap (check out our 70V speakers) and then connect the volume control in the nursery before connecting to the speaker. Note: if this is a two-conductor connection (+/-), then it is most likely 70V. 2) If this is a four-conductor connection (+/-, R & L), then the SVC100 should work (8 ohm system). Make sure to set the impedance matching switch to 1/2X.
TL/MA