Primus speakers feature the patented Plus Oneâ"¢ polypropylene woofers which feature more radiating cone area for increased output and edge-driven tweeters for better high frequency dispersion. Speakers are super clear at the top with vocals, horns and strings and deliver big bass with plenty of slam. Long story short: superior sound top to bottom. True 4 ohm architecture gives the amplifier room to reach peak power for increased depth and detail.