Koss Corporation is not ready to hang up its headphones. The Milwaukee-based audio maker says it will appeal a federal judge’s decision that threw out its final patent infringement lawsuit against Skullcandy, keeping a long-running legal fight alive that has followed the company since it launched a focused patent enforcement push in 2020. Koss says it plans to take the battle to the next court.
On March 25, U.S. District Judge David Barlow granted Skullcandy’s Rule 12(b)(6) motion and dismissed the consolidated Utah case with prejudice. He found that earlier litigation had already resolved the key patentability issues, leaving Koss barred from trying to relitigate claims that had been deemed invalid. Those conclusions are detailed in Justia Dockets & Filings.
Company Says It Will Appeal
Koss told local reporters it will ask the U.S. Court of Appeals for the Federal Circuit to overturn the preclusion ruling. The company maintains that some of its claims were never fully aired in prior cases and argues they should survive on appeal. That stance was reported by Milwaukee Business Journal.
How the Case Began
The current dispute traces back to July 22, 2020, when Koss filed a cluster of lawsuits accusing Apple, Bose, JLab, Plantronics and Skullcandy of patent infringement, according to the company’s 2025 Form 10-K filed with the U.S. Securities and Exchange Commission. Local business coverage has linked that enforcement campaign to licensing deals and settlements that brought Koss millions of dollars in recent years, a thread that has shaped how investors and Milwaukee business watchers track the company.
Judge Relied on Earlier Invalidation
In his written decision, Barlow leaned on an earlier Northern District of California ruling in the Plantronics litigation, where representative claims from several Koss patents were found ineligible under 35 U.S.C. §101. Because that dismissal had merged into a final judgment, the Utah court applied issue preclusion and concluded there was no point in allowing Koss to amend its complaint. The court’s reasoning is set out in the memorandum and order available at Justia Dockets & Filings.
Appeal Path and Timeline
Any Koss appeal would go to the U.S. Court of Appeals for the Federal Circuit, which handles questions about patent eligibility and issue preclusion. Those appeals often take many months, and the Federal Circuit’s treatment of representative-claim and §101 issues has already played a major role in related Koss matters, leaving both timing and outcome uncertain. For a sense of how the court has approached similar questions, see analysis from Gibson Dunn.
Local Stakes for a Small Manufacturer
Koss, headquartered in Milwaukee, reported in its 2025 Form 10-K that patent enforcement efforts and related legal costs helped drive up selling, general and administrative expenses, even as enforcement also generated notable revenue. That mix of heavy legal spend and periodic licensing windfalls has become central to the company’s recent financial story, and local outlets have tracked how it has affected the bottom line. See Koss's 2025 Form 10-K and coverage in BizTimes.
Koss has reiterated that it intends to press ahead with an appeal and ask the Federal Circuit to revisit the preclusion finding. Whatever the appellate court decides is likely to determine which of Koss’s patents remain in play and how much leverage the company has in any future licensing talks. Milwaukee Business Journal reported that Koss plans to take the case up on appeal.
