People are confusing reviewers and editors here. Most reviewers don't have any inside knowledge about advertising because they don't actually work for the magazine. Almost all reviews in the audio mags are done by freelancers. And those freelancers don't decide what gets reviewed. They can propose something, but it's the editor's call.
And you can be very sure that the editors know perfectly well who's advertising in their publication, and how much. It's certainly been the case in the past that advertising has led editors to request review samples from a company. There's no guarantee, but a smallish, newish company can certainly up its odds by advertising.
That said, the primary purpose of reviews is to sell magazines. By and large, editors are going to want to review the products that readers most want to read about. Having an exciting or "different" product is a much better bet than advertising. If all you're offering is the latest iteration on the basic 12-gauge copper cable, an editor is going to yawn, no matter how much advertising you buy.
