Break in period

Gregm,

I have a very old pdf of a paper that Billy Woodman published which explains his driver construction philosophy. It includes plots of speaker distortion and discusses IMD distortion and the advatanges of active versus passive designs. Unfortunately, speaker distortion measurements are pretty sobering stuff - I doubt most audiophiles realize the relative amounts of distortion coming from speakers compared to the rest of their gear. (Certainly not those who spend $4 K on speaker cables and an amplfier and only $1 K on speakers.)

Yes, Shadorne, I have always wondered how people can hear the difference between 0.002% THD on SS amps and 3% 'natural' harmonic distortion on tube amps over speakers with some 5-10% THD and sometimes up to 100% when the speaker 'doubles'! Methinks that they are hearing differences due to frequency response differences which are quite discernable even over 10%THD of the speakers.
Salut, Bob P.

Methinks that they are hearing differences due to frequency response differences which are quite discernable even over 10%THD of the speakers.
Salut, Bob P.

Agreed. I expect you are referring to the higher output impedance of a tube (with ouput transformer) coupled with a typical bumpy speaker load. This results in a different frequency response/presentation from a tube/speaker combo versus an SS/Speaker combo.

Shadorne -- that mustn't be what I'm referring to. I distinctly remember them comparing distortion figures (3%) I think between two ATC models at specific spl levels...Oh well.

the higher output impedance of a tube (with ouput transformer) coupled with a typical bumpy speaker load. This results in a different frequency response/presentation from a tube/speaker combo versus an SS/Speaker combo

Normally, yes. But one thing that is important in a spkr -- and one thing we do NOT know -- is the strength of each driver's magnet. A very "strong" driver (e.g. a Lowther, etc) paired with a SS will be overdamped and sound like Donald Duck unless tamed (i.e. at xover level). A hi output impedance paired to a very strong (i.e. electrically damped) driver may provide the optimum marriage...

Gregm,

IMHO, although high damping factors is a "pushed" feature of SS amps....I think it is really over rated.

Frankly the driver Qes and Qms coupled with the box design almost entirely dominates driver response...above a damping factor of about 5 a higher damping factor really makes almost negligable difference to the driver response, as the voice coil and magnet size dominate the driver electrical damping. (A good speaker design should be as close to critically damped as can be achieved given a host of other compromises)

I suspect most differences heard with low damping factors are more related to frequency presentation, as a high output imepdance device acts as a filter when coupled with a variable load (speaker)....