In the mid-’70s, UREI founder Bill Putnam—unhappy with the sound of the Altec 604 monitors in his United Western Studios—worked with UREI’s Dean Austin and Dennis Fink on ways to improve the 604. They replaced Altec’s multicell horn with a wider dispersion design and added a 15-inch Eminence woofer to boost LF output. Ed Long applied his Time-Align™ crossover techniques to achieve time- coherent, true point-source performance.
Engineers and producers mixing on the system were so enthusiastic about its sound that UREI started producing the monitors as a commercial product, with the first UREI 813 debuting in 1977. Typically soffit-mounted, these large, double-15 monitors were ideal for the larger, higher-SPL control rooms of the time.
UREI founder Bill Putnam Sr. tests a very early 813 prototype.
Two years later, Altec replaced its Alnico 604-8H with a ferrite model, requiring modifications to the 813 design, including a foam diffraction buffer, crossover mods and small Helmholtz resonators in the horn flare. This 1979 model was the 813A, followed by the 815A (a 604, plus two extra woofers) and the single-driver 811A, but the 813A was far more popular.
Financial and QC problems at Altec led UREI to find a new driver source, now mating PAS coaxial 15 to a JBL 2425 compression driver. The new 813B version debuted in 1983. Later that year, Putnam sold the business to Harman, with UREI becoming a division of JBL Professional; the 813C, a new model with all JBL drivers, launched in 1984. But in its various incarnations, the UREI 813 was the most successful large-format studio monitor ever made.