Soundgarden’s stay at the top of the pop chart was certainly a short one. The A&M grunge band’s “Superunknown” album, which debuted at No. 1 last week, takes a back seat this time to “The Sign,” the first Arista release from dance act Ace of Base.According to SoundScan sales figures obtained by an industry source, “The Sign” sold 106,000 copies, up from 98,000 last time, moving from No. 2 to No. 1 in its 17th week on the chart. The album’s title song is enjoying its fourth week at the top of the pop singles chart. “Superunknown” sold 103,000 copies this week, down from 162,000 last time, still good enough for a No. 2 listing. Soundgarden is currently in Germany as part of its European tour. U.S. dates are expected in early summer. Top performers also included Bay Area folk-rock band Counting Crows, which jumps from No. 7 to No. 4; new-ager Yanni, whose Private Music recording “Live at the Acropolis,” this week’s largest gainer, leaps from No. 26 to No. 11 on third report sales of nearly 70,000; and Canadian band Crash Test Dummies, which moves from 17 to 15 on sales of 63,000, up 20%. That band’s current single, “Mmm Mmm Mmm Mmm,” crashes the top 10 of the singles chart at No. 8. Top debut for the sales period ending last Sunday is the self-titled Elektra release from L.A. hard rockers Motley Crue. “Motley Crue,” its first issue since the firing of original singer Vince Neil, sold an estimated 87,000, placing it atNo. 7. The group’s last studio album, the quintuple-platinum (5 million sold) “Dr. Feelgood,” peaked at No. 2. Surprise debut of the week comes from The Benedictine Monks of Santo Domingo de Silos. The spiritual group’s new Angel/EMI release, “Chant,” enters the tally at No. 47 on sales of nearly 23,000. Moving in the wrong direction this week were “The Downward Spiral,” the second TVT/Interscope effort from Nine Inch Nails, at No. 12 after a No. 2 bow last week, and “Funky Headhunter,” the latest Giant album from Oakland rapper Hammer. It dropped from a No. 12 debut to No. 22 last week to No. 28 this week.