Walmart offers the Xpress 3-Way Universal Premium Car Speaker Pair
, model no. XP577, for $16
. Opt for in-store pickup
via Site-to-Store to dodge the $1.97 shipping charge. That's the lowest price we could find by a $12, outside the mention below. These 5" x 7" x 3" speakers feature a frequency response of 30Hz to 22kHz and balanced dome tweeters.
A close price: mwave offers them for $17.29 with free shipping.