Is America all sung out?

The latest entry in the singing-competition series genre, Fox’s much-anticipated “The X Factor,” opened Wednesday night with numbers that would be considered very good for any other premiering series but are modest compared to the genre’s heavyweights — and certainly below Simon Cowell’s own standards.

The “X Factor” creator made life tough on the Fox PR team this week bysaying that anything short of 20 million viewers for the show would be a disappointment. “X” fell considerably short Wednesday, with its 12.49 million viewers and 4.4 rating/12 share in adults 18-49, less than half what Cowell’s former show, “American Idol,” bowed to in January; the demo rating is also below the 5.1 that NBC’s “The Voice” garnered with its April bow.

So while Fox may have something that can keep its Wednesday and Thursday popping in the fall, the competish can breathe a sigh of relief, knowing that it may not have to deal with another “American Idol”-type ratings monster.

ABC’s “Modern Family” beat “X Factor” head-to-head in all categories Wednesday and hit series highs to stand as the night’s No. 1 show. The net also saw its new 10 p.m. soap “Revenge” get off to a pretty good start.

CBS had a solid night with time-period gains for its crime dramas, but it was a struggle for NBC’s “Free Agents” and “Harry’s Law” — with the former rookie already on cancellation watch.

For Fox, Wednesday’s two-hour opener of “The X Factor” logged the net’s best premiere-week numbers on the night in 13 years among adults 18-49 and 16 years among total viewers (back to the “90210”/”Melrose Place” days). The net placed second to ABC head-to-head from 8 to 10 p.m., but Fox’s overall average was higher than ABC’s (4.4 to 4.2) to win the night.

Much of the blogosphere was quick to label the opening-night “X Factor” numbers disappointing, but that wasn’t Fox’s take.

“It was a relief, actually,” Fox reality honcho Mike Darnell said upon seeing the early ratings Thursday morning. “There were crazy expectations that had nothing to do with reality. Fall is very tough us, and (Wednesday) was such a competitive night. … If we can maintain close to this rating for 40 hours of television this fall, that would be wonderful.”

Darnell doesn’t think the singing-competition genre — which includes NBC’s newcomer “The Sing-Off” — suffers from having so many shows airing year-round.

“I don’t think there’s singing fatigue,” he said, “but there are a lot more bad ones than good ones. The good ones stick around.”

Elsewhere on the opening Wednesday of the season, ABC was up sharply year to year as “Modern Family” hit series highs (6.1/15 in 18-49, 14.53 million viewers overall) a few days after picking up its second Emmy for best comedy, and leadoff hitter “The Middle” set series highs as well (3.1/9 in 18-49, 9.74m). The “Modern” demo score was the best for an ABC half-hour laffer since “8 Simple Rules” in November 2003.

And at 10, “Revenge” narrowly won in 18-49 (3.3/9, 10.02m) with the net’s best preem in the hour since 2007. It will have to do without a “Modern Family” lead-in next week as “Happy Endings” takes over the 9:30 p.m. slot, but it’s already clear that the new soapy drama is an improvement over last year’s dud “The Whole Truth,” which opened to a mere 1.5 demo score.

CBS was sturdy as usual, with “Criminal Minds” (4.1/10, 14.14m) up a bit vs. last year despite facing “X Factor” and a bigger “Modern Family.” The timeslot debut of “CSI” with new lead Ted Danson (3.2/9, 12.74m) was down a from its Thursday opener of last year and up vs. the Eye’s Wednesday 10 p.m. drama “The Defenders.” “Minds” beat “X Factor” in total viewers, and “CSI” led its hour by that measure.

At 8, “Survivor” (3.2/9, 10.46m) dipped 6% week-to-week and 20% year-to-year but is a still-solid performer in its 23rd edition.

It was a tough night for NBC, but leadoff comedy “Up All Night,” which drew good numbers with its preview last Wednesday, showed some spark (2.4/7 in 18-49, 6.05m) — up over last year’s “Undercovers” and the net’s best performance for a regular show in the timeslot since December.

Auds quickly turned elsewhere at 8:30 p.m., however, as “Free Agents” had a meek time-period bow (1.3/4, 3.88m). Things stayed quiet at 9 o’clock for the Peacock with the second-season premiere of “Harry’s Law” (1.2/3, 7.53m), whose low numbers made life difficult for “Law & Order: SVU” (2.4/6, 7.63m), which ran a distant third at 10 o’clock and was down sharply from last year.

And CW barely registered with “Hater” (0.4/1 in 18-49, 1.04m) and the once-vital “America’s Next Top Model” (0.7/2, 1.60m).