May 9, 2005, Baltimore, MD–Today speaker manufacturer Polk Audio announced the first model in a planned line of premium priced, premium quality mobile audio products dubbed Signature Reference series.

The affordable Polk Audio Signa S4 soundbar and subwoofer is a fantastic way to experience immersive audio, but it can’t be upgraded with additional speakers, and you’ll have to do without Wi-Fi.

We earn commissions from purchases you make using links in our articles. Learn more. If you’re looking to buy a new aftermarket car stereo for your car, you’ll have a lot of things to consider. Many ...