After extensive research that concluded the show was too “subtle” to build an audience, FX has muzzled “Terriers” after one season.

Exec produced by Shawn Ryan and Tim Minear with series creator Ted Griffin, “Terriers” averaged 746,000 viewers during its 13-episode run from September through Dec. 1. The series, which starred Donal Logue and Michael Raymond-James, bagged a disappointing 1.6 million viewers for its premiere, then never reached seven figures again.

For comparison, past FX dramas including “Damages,” “Dirt,” “Over There” and “The Riches” were all considered ratings-challenged — yet each averaged at least 50% more viewers than “Terriers” in their first seasons.

Nevertheless, FX prexy John Landgraf took the unusual step of holding a conference call with reporters to explain the cancelation of the series, which drew increasing critical support over its run. Landgraf said that FX commissioned a post-mortem a mere three weeks after the show’s disappointing launch to understand why it wasn’t catching on.

“People thought that the show was compatible with the FX brandbut not similar to other FX shows,” Landgraf said. “And to the extent that it was dissimilar, they felt it to be a little less edgy, a little less sexy, a little less suspenseful.

“The things people liked about the show tended to be more subtle … and I don’t know if subtlety is something that the American public is buying in droves today.”

Landgraf noted that only a sliver of the 14 million who sampled the series (7.5 million in 18-49) some time during its 13 episodes became loyal viewers. In addition, “Terriers” averaged a 47% audience loss from its lead-in and a 16% loss during the show itself from the first minute to the last. Conversely, in their first seasons, such FX series as “Sons of Anarchy” and “Justified” built dramatically upon their lead-ins.

In the process of his call, Landgraf also defended FX’s marketing department. While the marketing for “Terriers” has come under fire — particularly billboards that emphasized a mascot that had little to do with the series, at the expense of highlighting the actors or buddy-detective show premise — Landgraf said that those ads were seen only in New York and Los Angeles, and that the bulk of the country was told directly what the series was about.

“I think if I legitimately believed … we failed to describe to the audience what the show was about, that would have been a reason to renew it,” Landgraf said. “The question is was the marketing campaign fair to the show? There’s gonna be lots of people who drove by various billboards and say, ‘no,’ but that doesn’t relate (to what we showed around the country).”

Landgraf concluded that he couldn’t find a reason to believe the series “would miraculously triple or quadruple its ratings, which is what it would need” to survive.

DirecTV rescued “Damages” after FX parted ways with that show earlier this year (as the satcaster had previously saved NBC’s “Friday Night Lights”), but senior entertainment and production veep Chris Long recently said DirecTV was moving away from such series-saving efforts.