1. Our recent in-person meeting
with Leo Ayzenshtat of Orchard Audio had many graphs of his
products' performance. One caught my eye, labeled THD versus
Level. It showed the characteristic apparent rising distortion
at low levels of a THD + Noise plot. The definition of THD is
a sum of specified number of harmonics and does not include
noise. Unless there is crossover distortion the plot will show
diminishing distortion as the level is dropped, until the harmonics
fall into the noise. A narrow band analyzer can be used to chase
the harmonics below the noise.
I contacted Audio Precision, the maker
of the hardware/software he's using, and got an opaque and evasive
reply. Not satisfactory for a company of their reputation.
2. The new issue, V43N1, of the
BAS Speaker will be published shortly. It features AXPONA and
CES reports and is the first issue under my editorship. I hope
you enjoy it.
email me here