Hadean is a house brand of Rondo Music, a family-owned American music retailer based in New Hampshire. Like Rondo's other in-house lines (SX, Agile, Douglas, Brice, Omega), Hadean instruments are built to Rondo's specifications by overseas factories in China, Taiwan, and Korea, then sold direct through rondomusic.com and through resellers such as Guitar Center, Musician's Friend, and Reverb.

The Hadean catalog spans budget-oriented electric guitars, acoustic and classical guitars, basses, ukuleles, bass ukuleles (U-Basses), folk instruments, and small tube amplifiers. Notable models include the EG-462 electric, a headless electric guitar, and the Hadean Bullet tube combo amp offered in black, white, and tweed finishes. The brand is generally positioned at the entry-level and value end of the market, aimed at beginners, students, and players looking for an inexpensive second instrument.

Hadean has a quiet, retailer-driven presence rather than an artist-endorsement profile, and discussion of the line tends to live on community forums like TalkBass, The Gear Page, and the Telecaster and Squier-Talk forums, where players trade impressions of specific models and modifications.

Hadean has 3 products cataloged on Equipboard, including Solid Body Electric Guitars and Ukuleles.