Reply to thread

Message

<blockquote data-quote="Mark DeArman" data-source="post: 73474" data-attributes="member: 950">Re: What is the audible result of damping?For a voltage drive amplifier,The transfer function from Voltage to displacement, given a simplified linear model, has a Q valueQ = sqrt(km)/(b + (BL)^2/Re)So what I&#039;ve noticed over the years, BL will typically be the dominate factor in pro-audio systems. For example, High BL speakers will have an over damped frequency response, rolling off at around 6dB/oct way above Fs of the system.&nbsp; Adding series resistance can be quite noticeable if you start sticking large values in there. Adding excessive amounts of series resistance could, cause the cabinet tuning to go bad on an HP enclosure.&nbsp; Normally when the Q gets big the Frequency response will become under damped, which is what we perceive as that &quot;floppy&quot; sound.I haven&#039;t tried it yet, but if a passive network is built to compensate for the resonance in a HF driver, adding the series resistance could cause the network to not function properly anymore at the crossover region.Obviously there are a lot more variables involved in the total Voltage/SPL transfer function.&nbsp; But the simplified model does match what you will observe if you grab a variety of magnets and resistors.PS.&nbsp; This is also why if you start taking passive networks out of boxes and converting them to biamp you should also be checking the porting on the enclosure.</blockquote>

[QUOTE="Mark DeArman, post: 73474, member: 950"] Re: What is the audible result of damping? For a voltage drive amplifier, The transfer function from Voltage to displacement, given a simplified linear model, has a Q value Q = sqrt(km)/(b + (BL)^2/Re) So what I've noticed over the years, BL will typically be the dominate factor in pro-audio systems. For example, High BL speakers will have an over damped frequency response, rolling off at around 6dB/oct way above Fs of the system. Adding series resistance can be quite noticeable if you start sticking large values in there. Adding excessive amounts of series resistance could, cause the cabinet tuning to go bad on an HP enclosure. Normally when the Q gets big the Frequency response will become under damped, which is what we perceive as that "floppy" sound. I haven't tried it yet, but if a passive network is built to compensate for the resonance in a HF driver, adding the series resistance could cause the network to not function properly anymore at the crossover region. Obviously there are a lot more variables involved in the total Voltage/SPL transfer function. But the simplified model does match what you will observe if you grab a variety of magnets and resistors. PS. This is also why if you start taking passive networks out of boxes and converting them to biamp you should also be checking the porting on the enclosure. [/QUOTE]

Verification