You'd have a better shot if you told us what speakers you own and the model number of the driver you think it is. Many use off the shelf, some have custom ones made.
4 responses Add your response
Dave, some manufacturers do customize drivers and some do not. If the part number matches the driver you need EXACTLY then I would say that it's probably safe to circumvent the manufacturer to save money. If there is even one difference in a letter or number on the driver, then the manufacturer MAY have had the driver custom made just for them.
If you are uncomfortable contacting the manufacturer, then you could contact Scanspeak and ask them if the driver is a "drop in" replacement, just to make sure.