How many brands use own drivers?

Some Spendors ( D-line).

As far as I know, ALL electrostatic (many) and magnetic-planar (Magnepan, Eminent Technology) drivers are manufactured in-house. If not, each company's are made for them exclusively, unlike most speakers employing dynamic ("cone") drivers, Vandersteen being, as others have stated, a notable exception.

@cleeds :
I am disturbed that I am the only one here who speaks fluent gibberish! :D

Sorry, what I meant to say is that Bose does the business task of discovering what consumers besides me will pay for very very well, and it results in table top radios that cost hundreds of dollars. To those who shell out the money, clearly they are getting equal or better value for their cash.


At the same time, I can't imagine a table top radio being worth more than $40

This question has been asked before. But since you asked: Tannoy.

One reason I find knowing which mfgs make their own drivers
is that it strikes me that those companies can do a lot more trial and error than a company who sends off specs and hopes the final result
is somewhat close to their goal.