Most speakers do not need a great deal of 'damping' to achieve their design goals. A high damping factor is another way of saying 'low output impedance'.
However there are two schools of thought about what is meant by low output impedance! One school has it that you have to use a lot of loop feedback to achieve it. This is the path taken by most transistor amplifier manufacturers. Not all do though and they are noteworthy has having made some of the finest transistor amplifiers available: Nelson Pass, Ayre and Ridley Audio are the names that come to mind.
However, funny thing- there are a good number of tube amplifiers that IMO/IME play bass better than the transistor amps with high 'damping factor'. These amps do so with 'damping factors' between 2 and 20. Tubes are inherently lower distortion than transistors and so need far less feedback to make the resulting amplifier circuit linear- in fact a good number of tube amps do this with no feedback at all. As Kijanki points out, feedback has very audible detrimental effects.
Our ears use the 5th, 7th and 9th harmonics as a means of determining loudness. We are more sensitive to these harmonics than just about **anything else** in audio! So if these harmonics are emphasized by distortion at all- we will hear it. Audiophiles use the terms dry, hard, harsh, brittle, clinical, chalky, white and the like to describe very slight enhancement of these harmonics.
While loop feedback will reduce overall distortion (when listening to sine waves, the jury is out on whether this is true of a constantly changing waveform), these harmonics in particular are actually **enhanced** by loop feedback. The result is that lots of feedback in an amp will result in an amplifier that will never sound natural.
for more information see
http://www.atma-sphere.com/papers/paradigm_paper2.html
However there are two schools of thought about what is meant by low output impedance! One school has it that you have to use a lot of loop feedback to achieve it. This is the path taken by most transistor amplifier manufacturers. Not all do though and they are noteworthy has having made some of the finest transistor amplifiers available: Nelson Pass, Ayre and Ridley Audio are the names that come to mind.
However, funny thing- there are a good number of tube amplifiers that IMO/IME play bass better than the transistor amps with high 'damping factor'. These amps do so with 'damping factors' between 2 and 20. Tubes are inherently lower distortion than transistors and so need far less feedback to make the resulting amplifier circuit linear- in fact a good number of tube amps do this with no feedback at all. As Kijanki points out, feedback has very audible detrimental effects.
Our ears use the 5th, 7th and 9th harmonics as a means of determining loudness. We are more sensitive to these harmonics than just about **anything else** in audio! So if these harmonics are emphasized by distortion at all- we will hear it. Audiophiles use the terms dry, hard, harsh, brittle, clinical, chalky, white and the like to describe very slight enhancement of these harmonics.
While loop feedback will reduce overall distortion (when listening to sine waves, the jury is out on whether this is true of a constantly changing waveform), these harmonics in particular are actually **enhanced** by loop feedback. The result is that lots of feedback in an amp will result in an amplifier that will never sound natural.
for more information see
http://www.atma-sphere.com/papers/paradigm_paper2.html