Switching Units - Q. What is the technical definition of 'transmatch'?
Answer:
For the 5 way speaker switch we don't use parallel or series switching, using use transformer coupling instead. Again you have to use 8 Ω speakers
minimum if your amp is a 4 Ω minimum amp. The impedance is then matched
by the transformer, so that a net 1.6 Ω load (all 5
sets of 8 Ω speakers switched on) is converted back to a 4 Ω load. One
pair of speakers (A) is not connected to the transformer, but is directly
connected to the amp, these will be the main speakers. The four B pairs
are connected via the transformer.