The “sub crawl” is a little-known way you can optimize the placement of your surround sound system’s subwoofer.

At 2:20 p.m. ET / 1:20 CT / 11:20 PT on Oct. 4, cellular devices, televisions, and radio systems across the U.S. will sound off as part of a national emergency alert test designed to ensure that ...

The test will feature a one-minute siren tone and a simultaneous Emergency Alert System audio broadcast in partnership with local broadcasters. No drills or exercises will accompany the test.

The first nationwide test of the most recent version of the Emergency Alert System took place on November 9, 2011, at 2:00 p.m. ET.

We test the vanilla Audi, BMW, Ford, Lexus, Porsche, and Tesla in-car stereos against the optional high-end versions to see if you really should trade up.

It also requires a speaker system that supports 5.1 audio. Last June, YouTube TV announced that it would bring 5.1 surround sound to “select devices.” ...