I was researching the power amp upgrade path for my full rangers, and was trying to figure out the logic behind current driven power amps. In the process I found some conflicting information that I would like sorted out by the electronics experts on this forum
For example this article (http://www.passdiy.com/pdf/cs-amps-speakers.pdf) seems to indicate that a power amp with high output impedance and low damping factor would work great with sensitive full rangers, when in fact it is commonly held that output impedance of source needs to be lower than input impedance of receiver by a factor of 10.
To summarize: "Full rangers are easily over-damped, resulting in excessive loss of bottom end. Over-damping has good transient bass control but also suffers a significant loss of bottom end response. This partially explains the preference for tube amps with such loudspeakers. Our amplifier had a high output impedance and thus no damping factor. The Son of Zen operates without feedback and has an output impedance of about 16 ohms. This nets a damping factor of 0.5, miniscule compared to the 100 to 1000 you can achieve with regular solid-state amplifiers... With the low damping factor, the Fostex became a totally different speaker. It suddenly had bottom end response and a better top end".
Contrast this with (Live Sound: Understanding The Relationship Between Amplifier Damping Factor, Impedance & Cable - Pro Sound Web)
A system where the damping factor of the entire loudspeaker/wire/amplifier circuit is very low will exhibit poor definition in the low frequency range. Low frequency transients such as kick drum hits will sound muddy instead of that crisp punch we would ideally want from the system
or this one (Amplifier Output Impedance Why It)
"The only way to achieve constant voltage drive with a changing load impedance is by having very low amplifier impedance... The lower the amplifier output impedance, the lower the speaker produced voltage is. The lower the speaker produced voltage, the less effect it has on cone motion. A good rule to follow it that amplifier output impedance must be at least ten times lower than speaker impedance for good control of cone motion."
So what design philosophy or type of product should I choose?
TIA
Regards
For example this article (http://www.passdiy.com/pdf/cs-amps-speakers.pdf) seems to indicate that a power amp with high output impedance and low damping factor would work great with sensitive full rangers, when in fact it is commonly held that output impedance of source needs to be lower than input impedance of receiver by a factor of 10.
To summarize: "Full rangers are easily over-damped, resulting in excessive loss of bottom end. Over-damping has good transient bass control but also suffers a significant loss of bottom end response. This partially explains the preference for tube amps with such loudspeakers. Our amplifier had a high output impedance and thus no damping factor. The Son of Zen operates without feedback and has an output impedance of about 16 ohms. This nets a damping factor of 0.5, miniscule compared to the 100 to 1000 you can achieve with regular solid-state amplifiers... With the low damping factor, the Fostex became a totally different speaker. It suddenly had bottom end response and a better top end".
Contrast this with (Live Sound: Understanding The Relationship Between Amplifier Damping Factor, Impedance & Cable - Pro Sound Web)
A system where the damping factor of the entire loudspeaker/wire/amplifier circuit is very low will exhibit poor definition in the low frequency range. Low frequency transients such as kick drum hits will sound muddy instead of that crisp punch we would ideally want from the system
or this one (Amplifier Output Impedance Why It)
"The only way to achieve constant voltage drive with a changing load impedance is by having very low amplifier impedance... The lower the amplifier output impedance, the lower the speaker produced voltage is. The lower the speaker produced voltage, the less effect it has on cone motion. A good rule to follow it that amplifier output impedance must be at least ten times lower than speaker impedance for good control of cone motion."
So what design philosophy or type of product should I choose?
TIA
Regards
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