Italian to English Tech/Engineering Electronics / Elect Eng Sound Equipment

Still working on the description of a series of high-performance speakers and related sound equipment. The sentences in which this phrase is used include:

AUDIO COMPANY ha sviluppato due diffusori a gamma estesa....

I diffusori possono essere utilizzati in ... gamma estesa o, come sistema di sala o stage monitor.

Since this isn't my area of expertise, I wanted to know what phrasing for "gamma estesa" (including, perhaps, the most obvious literal translation) others thought was workable here. Nothing I'm coming up with sounds very English.

Thanks!