M40.1: final measurements (outside)
A nice sunny Saturday afternoon - what better than to make some nearly final measurements of the prototype M40.1 outside to verify the in-room measurements and computer simulations.
To save the inconvenience (and danger!) of clambering up and down the step ladder with a hot soldering iron, the crossover has been wired out on extension cables and sits on the table. The reason for the side panels on the cabinet is simply because this is the grey pro cabinet that has been used (more immune to knocks and bumps ) and the metal handel cut-outs have been blocked-off.
Note: all acoustic measurements are made with the grille on since the frequency response is flattest - thanks to Harbeth's unique SuperGrille technology.
Minutes after this picture was taken, the master prototype M40.1 nearly toppled off the stand ..... I just managed to catch it. And guess what - as I was grappling with it above shoulder height and wondering exactly how I was going to safely get it to the ground .... the mobile phone in my pocket started to ring to tell me my youngest son David (19) was at the railway station awaiting collection. How one must suffer for ones art!
PS. Since this session, I found a way to simplify the crossover by 6 components and to increase overall sensitivity by 1dB or so by restructuring the crossover section that drives the bass unit.
Alan A. Shaw
Harbeth Audio UK