Pioneer Electronics (http://www.pioneerelectronics.com) has expanded its line of USB-powered computer speakers with the introduction of the S-MM251. The company has also introduced new wireless music speaker systems.

The S-MM251 (pictured) offers a built-in audio DAC and a cool bass-reflex enclosure designed to enhance lower bass frequencies. The S-MM251 is designed to connect quickly to virtually any laptop. It’s convenient to use with a simple plug-in through a USB port, without the need for AC power or batteries, according to Chris Walker, director AV marketing and product planning for the Home Electronics Division of Pioneer Electronics.

The S-MM251 has a modern form factor that resembles small domes, and features 1.75-inch metal drivers and control buttons for volume up, volume down and mute. For increased low frequency response, the speakers use bass-reflex enclosures.

The speakers are connected and powered using an included USB cable, and the integrated blue LED in front of each speaker indicates a proper connection. The Pioneer S-MM251 will be available in July with a suggested retail price of US$79.99.

The XW-SMA1, XW-SMA3 and XW-SMA4 wireless speaker systems are equipped with the latest wireless technologies including Appleā€™s AirPlay, DLNA 1.5 and Wireless Direct. All three models were specially tuned by Pioneer sound engineer Andrew Jones to provide high volume output with excellent sound quality. The Pioneer SMA Wireless Speakers will be available in August with suggested retail prices of US$299 (XW-SMA1), $399 (XW-SMA3) and $399 (XW-SMA4).