The two pairs of 5-way binding posts, on the rear of your Polk speakers, enable bi-amplification and bi-wiring the speaker system.
To bi-wire, you’re going to run two sets of speaker wires from the same output connection on your receiver/amplifier to each speaker. (If you’ve already connected the receiver to the speakers, you can leave that connection in place and merely add a second set between your amplifier/receiver connections and the empty binding posts on the speaker). First, you’ll need to first remove the gold-plated binding post jumper plates to isolate the upper and lower posts. The goal is to have two separate audio paths from the receiver/amplifier’s speaker outputs, one to the upper set, and one to the lower set of binding posts.
You might well ask, “What does that accomplish? How is that any different from what the jumpers were doing?” There are many audio enthusiasts who feel that bi-wiring an already great-sounding speaker can make a subtle improvement to the way middle range sounds are produced. They often describe the effect as “lifting a veil from the mid-range,” or that “voices seem clearer, more distinct,” and less “muffled.”
While no one, to date, has definitely proven what might be happening, one plausible theory says that bi-wiring is to speaker connections as “Star Grounding” is to electronics connections. When a piece of audio equipment uses a single circuit grounding point for all of the electronic sections, rather than connecting “daisy-chain” fashion (one circuit ground plugging into the next in a chain), this is called “Star Grounding.” The integrity of each ground path is maintained by individual connections to a low impedance point.
In bi-wiring, the same thing happens. Each “section” of your Polk speaker (sometimes just the tweeter and its portion of the crossover, other speakers have the tweeter and mid range joined as one section) is connected, independently, to the low impedance point (the output transistors) in your receiver/amplifier. Whatever might be happening between the electromechanical operations of your Polk woofers (called “back EMF") is kept isolated from the delicate motion of the tweeters and mid range drivers.
Hence, the bi-wired feeling that music with well-recorded vocals is a wee bit closer to sounding “live.” Worth a try!
This article was last modified Mar 12, 2014