Reply to thread

Message

Re: What is the audible result of damping?

Art, I'm not sure how I could have been any more clear, but I will try.

I started with an equation which models a behavior:
Q = sqrt(km)/(b + (BL)^2/Re)

And then, talked about implications of that equation. I guess I did assume some basic knowledge of small signal parameters. In response to your comments above:

I normally use Fs to represent the resonance of a speaker or a system, this might be confusing. I'll use F0, f0 or w0 for resonance of an individual component. Can we can agree that Fb will be the resonance of the enclosure/speaker system as related to Vas of the enclosure? If not, I'm not sure where your definition of Fb comes from?

#1
"The roll off above Fs", in fact does not have anything to do with Fs (even though I used Fs in the sentence of the original post) but with the Q of the loudspeaker. High BL leads to a very small Q, wide bandwidth, which results in an over damped SPL response. I did not think the use of the word Fs would be confusing, since I am talking about the Q equation.

#2
"Porting of the enclosure" is not just about Fb, but also about the total Q of the system. I'm not sure about you, but when building enclosures, I don't just look at the 'tuning' (meaning Fb) frequency when determining the porting. I am not talking about the tuning frequency in my original post. Changing Re will not change the value Fb of the enclosure/speaker system (small signal), but will change the Q of the system.

(edit) Well this is only true in the small signal sense. Fb changes with drive level in general soo.

Now to be fair I could have used a different word than 'tuning' later on in my post. I guess a lot of people call it 'alignment' when talking about the shape of the SPL response desired by adjusting the Q of a HP enclosure.

PS. Again, I know looking at the model for a single speaker not in an enclosure, is an over simplification, but it DOES bear well on what you will observe for a system when you modify the variables.

PPS. I'm done replying to this thread. This is way off topic now. If you want to investigate small signal models yourself go ahead. I'm not going to waste anymore time arguing over semantic issues when all of the models are well published. As are all of the more recent models which take large signals into account. Just search AES.

Mark DeArman

<blockquote data-quote="Mark DeArman" data-source="post: 73508" data-attributes="member: 950">Re: What is the audible result of damping?Art, I&#039;m not sure how I could have been any more clear, but I will try.I started with an equation which models a behavior:Q = sqrt(km)/(b + (BL)^2/Re)And then, talked about implications of that equation. I guess I did assume some basic knowledge of small signal parameters.&nbsp; In response to your comments above:I normally use Fs to represent the resonance of a speaker or a system, this might be confusing.&nbsp; I&#039;ll use F0, f0 or w0 for resonance of an individual component.&nbsp; Can we can agree that Fb will be the resonance of the enclosure/speaker system as related to Vas of the enclosure?&nbsp; If not, I&#039;m not sure where your definition of Fb comes from?#1&quot;The roll off above Fs&quot;, in fact does not have anything to do with Fs (even though I used Fs in the sentence of the original post)&nbsp; but with the Q of the loudspeaker.&nbsp; High BL leads to a very small Q, wide bandwidth,&nbsp; which results in an over damped SPL response.&nbsp; I did not think the use of the word Fs would be confusing, since I am talking about the Q equation. #2&quot;Porting of the enclosure&quot; is not just about Fb, but also about the total Q of the system.&nbsp; I&#039;m not sure about you, but when building enclosures, I don&#039;t just look at the &#039;tuning&#039; (meaning Fb) frequency when determining the porting.&nbsp; I am not talking about the tuning frequency in my original post.&nbsp; Changing Re will not change the value Fb of the enclosure/speaker system (small signal), but will change the Q of the system.(edit)&nbsp; Well this is only true in the small signal sense.&nbsp; Fb changes with drive level in general soo.Now to be fair I could have used a different word than &#039;tuning&#039; later on in my post.&nbsp; I guess a lot of people call it &#039;alignment&#039; when talking about the shape of the SPL response desired by adjusting the Q of a HP enclosure.PS.&nbsp; Again, I know looking at the model for a single speaker not in an enclosure, is an over simplification, but it DOES bear well on what you will observe for a system when you modify the variables.PPS.&nbsp; I&#039;m done replying to this thread.&nbsp; This is way off topic now.&nbsp; If you want to investigate small signal models yourself go ahead.&nbsp; I&#039;m not going to waste anymore time arguing over semantic issues when all of the models are well published. As are all of the more recent models which take large signals into account.&nbsp; Just search AES.Mark DeArman</blockquote>

[QUOTE="Mark DeArman, post: 73508, member: 950"] Re: What is the audible result of damping? Art, I'm not sure how I could have been any more clear, but I will try. I started with an equation which models a behavior: [COLOR=#333333]Q = sqrt(km)/(b + (BL)^2/Re) [/COLOR] And then, talked about implications of that equation. I guess I did assume some basic knowledge of small signal parameters. In response to your comments above: I normally use Fs to represent the resonance of a speaker or a system, this might be confusing. I'll use F0, f0 or w0 for resonance of an individual component. Can we can agree that Fb will be the resonance of the enclosure/speaker system as related to Vas of the enclosure? If not, I'm not sure where your definition of Fb comes from? #1 "The roll off above Fs", in fact does not have anything to do with Fs (even though I used Fs in the sentence of the original post) but with the Q of the loudspeaker. High BL leads to a very small Q, wide bandwidth, which results in an over damped SPL response. I did not think the use of the word Fs would be confusing, since I am talking about the Q equation. #2 "Porting of the enclosure" is not just about Fb, but also about the total Q of the system. I'm not sure about you, but when building enclosures, I don't just look at the 'tuning' (meaning Fb) frequency when determining the porting. I am not talking about the tuning frequency in my original post. Changing Re will not change the value Fb of the enclosure/speaker system (small signal), but will change the Q of the system. (edit) Well this is only true in the small signal sense. Fb changes with drive level in general soo. Now to be fair I could have used a different word than 'tuning' later on in my post. I guess a lot of people call it 'alignment' when talking about the shape of the SPL response desired by adjusting the Q of a HP enclosure. PS. Again, I know looking at the model for a single speaker not in an enclosure, is an over simplification, but it DOES bear well on what you will observe for a system when you modify the variables. PPS. I'm done replying to this thread. This is way off topic now. If you want to investigate small signal models yourself go ahead. I'm not going to waste anymore time arguing over semantic issues when all of the models are well published. As are all of the more recent models which take large signals into account. Just search AES. Mark DeArman [/QUOTE]

Verification

Top Bottom