With eight AA batteries and a Roland BA-330 portable PA System you can now pump out 109dB (equivalent to a jackhammer).

The Roland BA-330 has four 6.5-inch and two tweeters and on the reverse you get a four-channel mixer with XLR, 1/4-inch, RCA, and mini jack inputs, and an effects section for adding EQ, re-verb, delay, or a stereo-widening effect.

It also has a stereo link feature which allows you to wire two of these bad boy BA-330 speakers together creating and awesome system.

If you’ve ever encountered embarrassing feedback onstage, and most of us have, you’ll be pleased to know that the BA-330 is equipped with Roland’s advanced Anti-Feedback technology. With a simple switch, the BA-330 automatically detects the howling point and eliminates feedback.

• All-in-one portable digital PA system suitable for use anywhere
• Powerful high-quality stereo sound for audiences of up to 80 people
• No setup required, just plug in and go!
• Powered by AC power or eight AA batteries
• Four custom-designed 6.5″ speakers and two tweeters for wide stereo projection
• Built-in effects: EQ, reverb, delay, and wide (on/off per channel)
• Four-channel configuration: two channels for mic/instruments plus two channels for stereo inputs
• Stereo Aux input with dedicated volume-control knob
• Advanced Intelligent Anti-Feedback function
• Built-in tilt-back stand enables optimal monitoring angle
• Speaker-stand adaptor for mounting on a standard speaker stand

Available for $829 which is nearly as busting as the sound.

Via CNET