For over 15 years Graham Audio has produced loudspeakers based on a series of BBC designs, building on the extensive work of the BBC Research Department. The latest design is the LS3/1, which was originally aimed at use in outside broadcast (OB) settings. 

 

The drive units are similar to those in the Graham Audio LS5/1, which was the studio monitor version of the LS3/1. Unlike the LS5/1, the smaller cabinet volume is a sealed infinite baffle design, as this works better than the ported version with the combination of a large diameter bass driver in a smaller box volume. The bass driver has been modified from that in the LS5/1 to produce a combination of sensitivity and bass response which suits the reduced internal volume.

 

Unique among the BBC designs is the co-axial placement of the dual tweeters, giving a coherent response at closer distances which, although meant to suit OB settings, is also appropriate in domestic settings.

 

The bass driver is set behind a perforated metal plate, and the tweeters are mounted on a panel central to the bass driver. The slot width in front of the bass driver is similar to that of the LS5/1 and LS5/5 and improves smoothness of the off-axis response.

 

The design adheres to the BBC thin wall principle and again as all Graham Audio products is studio grade.