I wonder about DF importance for different types and kinds of speakers.
For example I am sure that Electrostatics "don't care" about DF at all as they do not generate any BACK EMF. Planar magnetics almost the same, as they have almost pure resistive impedance and do not generate BACK EMF either, or almost none.
Conventional dynamic speakers do generate BACK EMF and the overall damping of such speakers consists of their mechanical damping ability plus the electrical DF.
It is obvious that for different dynamic speakers their ability to perform damping as a result of electrical damping is different for each and electrical DF does not contribute the same given the same amp DF.
It is a pity that speaker manufacturers do not publish a figure that is the ratio between the mechanical damping and the electrical damping (say for a theoretical infinite amp DF i.e. zero output impedance) Such a ratio of mechanical VS electrical DF effect for a given speaker would have given us a good insight of how much DF is really important for a particular speaker.
For example I am sure that Electrostatics "don't care" about DF at all as they do not generate any BACK EMF. Planar magnetics almost the same, as they have almost pure resistive impedance and do not generate BACK EMF either, or almost none.
Conventional dynamic speakers do generate BACK EMF and the overall damping of such speakers consists of their mechanical damping ability plus the electrical DF.
It is obvious that for different dynamic speakers their ability to perform damping as a result of electrical damping is different for each and electrical DF does not contribute the same given the same amp DF.
It is a pity that speaker manufacturers do not publish a figure that is the ratio between the mechanical damping and the electrical damping (say for a theoretical infinite amp DF i.e. zero output impedance) Such a ratio of mechanical VS electrical DF effect for a given speaker would have given us a good insight of how much DF is really important for a particular speaker.
Damping factor is a poor way to try to specify output impedance of the amplifier (Rout). If your loudspeaker has a reactive load (ie the impedance curve goes for a wild ride), you need a low Rout amplifier (high damping factor) so as to avoid issues with the impedance curve imposing itself on the FR casuing imbalance. If the impedance is flat then Rout makes little to no difference in that respect.
ESLs may not generate back EMF but are highly capacitive (reactive) and given that P = V x A x cos(pahse angle between the two) it is critical that the voltage amplifer is capable of delivering large extra amounts of current as the capacitive load can make cos(pahse angle between the two considerably less than 1.
dave
ESLs may not generate back EMF but are highly capacitive (reactive) and given that P = V x A x cos(pahse angle between the two) it is critical that the voltage amplifer is capable of delivering large extra amounts of current as the capacitive load can make cos(pahse angle between the two considerably less than 1.
dave
Will the ratio of Qes/Qms yield a figure that represents the need for an amp with a higher DF?
Will it suggest that when ratio gets higher, a higher DF amp is required?
Planet 10 (Dave ) is right about electrostatics the first Quad electrostatic had the Quad 303 specially designed to be able to control them with stability .
I used to own a Quad 303 .
I used to own a Quad 303 .
Typically one looks for a very low Qms for a driver with a small or non-existant resonant peak, but all to often it is the impedance variations caused by the XO that are the bigger issue.
So if you were choosing a FR driver you could look at the Qms if looking for a speaker system that can work well with a high Rout amplifier. Do keep in mind that some speakers are designed for use with high Rout amps despite having high Qms.
dave
So if you were choosing a FR driver you could look at the Qms if looking for a speaker system that can work well with a high Rout amplifier. Do keep in mind that some speakers are designed for use with high Rout amps despite having high Qms.
dave
№5: Not significant (see No. 3).
Negative output impedance of the amplifier is possible. Used to change Qes.
Negative output impedance of the amplifier is possible. Used to change Qes.
They cannot give such numbers. Even for the reason that in multi-band speakers such data will be different for each frequency band. In general, the dumping factor affects not only the braking of the mobile system but also the intermodulation distortion of the speaker. Often these distortions are reduced at a higher output impedance, and usually at medium frequencies.
I can give in personal mail a link to an article in Russian on this topic, where these intermodulation distortions were measured.
I can assume that good speaker manufacturers such as JBL, Cabasse, B&W and others know this problem and solve it with filters too. You just need to choose the right speaker cables or adjust the output impedance of the amplifier if possible.
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Damping factor is defined into an 8 ohm resistive load. It doesn't have anything do with individual speakers whatsoever, by definition. What you're interested in is output impedance of the amplifier and the Z of the actual speaker.
Negative output impedance affects more damping coefficient.
Practically used to reduce the quality factor of speakers at low frequencies.
At low frequencies, there is a way to dampen speakers using electromechanical feedback (like Velodine or Phillips). A speed or acceleration sensor is installed on the speaker. The signal is processed by a special circuit. There are developments with an optical sensor.
Practically used to reduce the quality factor of speakers at low frequencies.
At low frequencies, there is a way to dampen speakers using electromechanical feedback (like Velodine or Phillips). A speed or acceleration sensor is installed on the speaker. The signal is processed by a special circuit. There are developments with an optical sensor.
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Bass reflex. This the main problem for amplifier output impedance. If you design by yourself a bass reflex ,the resonator will have a Q calculated by formulas/software considering 0 ohm source impedance. For domestic use of 8 ohm, 2.5m speaker wire is estimated to be 0.5 ohm including connectics. For Audiophile use, it can go to 0.2 ohms with high expense. This said, the bass reflex resonator already lower in Q, If the amplifier goes more than 0.5 ohms, the punch (transient response) start audible less , if you increase further, the double resonance impedance of the speaker start polluting , and the power at resonator frequency decreases. With tube amps it was settled to be DF of more than 16, that is 0.5 ohm for 8 ohms, whereas triode output amps as 300b with 2 ohms/8 output , requires specially designed bass reflex.
Four-wire Kenwood power supply and load wiring diagram
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Different requirements. At low frequencies, zero or negative output impedance. At high and medium-current output. Bi (multi) amping.
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Different requirements. At low frequencies, zero or negative output impedance. At high and medium-current output. Bi (multi) amping.
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