Who makes the drivers?

In lieu of another thread I posted, one made mention of a particular company that makes drivers for speakers. That led me to wonder, do most companies make their own drivers or contract out? If they contract out, is there a lot of companies making drivers or a select few making them for the majority?

Is there a way to tell who made those in your speakers by viewing them?

Just curiousity questions!
B&W makes their own for one. Nautilus type tweeter and the Kevlar mid/bass drivers are unique. There are now some other companies now using Kevlar; they are also very different.
Most companies do not make their own drivers. There are some, mostly high end companies, that do make their own drivers, such as Theil and Dynaudio. The ones that contract out drivers, generally write the specs for the drivers they need, then try several different brands. When they find the driver that maximizes price and performance--that's generally what they do. The drivers that are made to specification for the company generally are not sold individually to consumers--but rather exclusively to that company. Therefore replacement parts (drivers) can usually only be purchased from the speaker manufacturer--not the driver manufacturer. Some speaker manufacturers stick to one driver manufacturer. If I'm not mistaken Wilson uses Focal drivers. If you open up your speaker and look at the drivers it is unlikely you will find the driver manufacturer name on it, but you will usually be able to find a model number. If you research model numers of different driver manufacturers you will typically see a pattern, and that will lead you to which manufacturer it is. I have actually called one high end speaker manufacturer and asked them who they used, not only did they tell me who they currently use, they told me who they had used in the past, and who the manufacturer was of the vintage of speaker I had. Calling is obviously the easiest--but I can't guarantee all manufacturers will be so eager to share that information. I hope that helps.