Sony's party-speaker lineup is on sale, according to a WIRED deals roundup, with the flagship ULT Tower 7 priced at $548. That is $102 off the $650 list price, and WIRED describes the ULT speakers as being at their lowest price ever. The Tower 7 deal appears at both Best Buy and Amazon in the article.
Other ULT models are discounted too: the Tower 5 is $348 (23% off), the Field 7 is $448 (10% off), the Tower Max is $1,198 (20% off), and the Field 1 is $108 (23% off). For the Field 1, WIRED notes the price has dipped below $100 in the past, so this is not a lowest-ever figure.
WIRED recommends the Tower 7 for DJ use, with 420 watts of output, a 30-hour battery, and inputs for a microphone or guitar. The article also notes the speaker is heavy and large, and the reviewer says it lacks a retractable handle.