This series of posts will follow the construction of a pair of customer Rhapsodys so that we can share all the work and care that goes into making and testing these loudspeakers.
To start with, a few photos always helps Firstly, some of the components which go into each pair of ‘speakers:
Each set of drivers is measured for impedance curve data, acoustic measurements are taken and the crossover values for each are individually selected for very close matching before final assembly. Some minor tweaks may be necessary upon completion of the speakers as each set is individually re-measured following a break-in period. Only the finest quality components are chosen for the signal path and the tolerances of each are individually checked to be within 1%. All inductors are over-sized and wound down to exact values:
Matched speakers response curves (these taken from our own demo set): Note that left/right speakers are matched to within 1dB for most of their frequency band. Mic sensitivity looses accuracy at 20Hz so in reality, a fairly steep roll-off starts somewhere around 30Hz in this case. The graph here uses industry standard 1/3 Octave smoothing:
Selecting the veneers, in this case, selection of appropriate (premium) quality Crown Cut Walnut:
Next: Timber preparation for cabinet construction (to come)