Quoted from ovfdfireman:It seems opinions vary, some insist on one over the other. But for any speaker to sound great, the sound track is key. In fact, some machines don't offer a substantial sound difference after being upgraded simply due to lack of sound quality in the sound chip itself. That said, comparing a Williams System 11, to a current Stern, there is a difference, and some even from one game to another (of the same era).
Pricing is comparable on complete kits, Pinball Pro has been custom making kits for years, and we are happy to build kits minus volume control (which saves money) and we have simple factory replacements options, also have kits that work with Pinsound upgrades (simply a kit minus crossover and wiring). But the full kits are comparable in price. We have just opted not to put every option on the website, but can easily customize.
Give us a try you will be glad you did....Pinball Pro offers full tech support, and our speakers are built to our specs to offer the best performance in a pinball machine. If you are not satisfied for any reason we will return it for a refund. I know you will love the sound! Happy to answer any further questions you may have, and thank you for considering Pinballpro.com
Greg Mockenhaupt
http://www.pinballpro.com
PPS dealer/Stern Dealer
I've always used FF, but I'll tell you what...this is one of the most honest and well-said responses I've read in a while. And it makes me want to try PP in the future. 
