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Old 01-14-2018, 12:15 AM   #31
SPL_Krayzie112

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To disambiguate it in short terms, the higher the damping factor number is, the better cone control?
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Old 01-14-2018, 04:54 AM   #32
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Quote:
Originally Posted by SPL_Krayzie112 View Post
To disambiguate it in short terms, the higher the damping factor number is, the better cone control?
Yes, but if I wanted good cone control, damping factor would be the last spec I would look for. Low impedance, strong motor, flat BL, cone area, xmax and enclosure would all be more important in my mind.
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Old 01-14-2018, 08:03 AM   #33
SPL_Krayzie112

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For me it'd be Sensitivity, S/N Ratio, THD and Damping Factor
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Old 01-14-2018, 11:50 AM   #34
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Quote:
Originally Posted by SPL_Krayzie112 View Post
For me it'd be Sensitivity, S/N Ratio, THD and Damping Factor
That's interesting. Exactly how does S/N ratio affect control? If S/N ratio is a major concern, then should we all run line drivers or only sources with high preamp voltages?

I'm not sure how THD impacts cone control. Any decent amplifier and even a lot of crappy ones have THD below the human threshold for hearing, some are just farther below the threshold than others. What if I choose to clip the amp, which is when our "decent" amps will have enough THD to be detectable to the human ear. Are you saying the amplifier loses control of the cone when clipped? What if I'm clipping at a power output when the sub is still well within it's xmax spec?

Are you suggesting amplifier input sensitivity somehow affects the amplifier's ability to control cone motion, is this related to your theory regarding S/N ratios? Are you saying we should run amps capable of accepting higher preamp voltages. If higher preamps voltages lead to better control, then should we just skip use the preamp and wire our systems using the high level outputs on our source units and high level inputs on our amps?

Or are you referring to driver sensitivity? Are you saying a driver with higher sensitivity is easier to control? Since driver sensitivity can be measured as 1 watt/1 meter vs 2.83v/ 1 meter, which spec should we use? If damping factor is a major concern, then are you suggesting we wire our systems in a manner to increase damping factor at the expense of output power and/or sensitivity or do you prefer amplifiers with regulated outputs capable of delivering the same output over a range of loads?

Last edited by Jimi77; 01-15-2018 at 06:28 PM.
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Old 01-15-2018, 10:37 PM   #35
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Don't know if you came across this table, but looking at the decay times at various damping factors, you can see why so many people consider it an insignificant spec. In the hypothetical case presented in the article any damping factor <10 looks acceptable to me.

http://www.audioholics.com/audio-amp...ystem-response

And looking at this hypothetical with attached chart, George Augspurger, of JBL fame and who has forgotten more audio than I'll ever know, concluded >20 is more than enough Damping Factor.

http://www.butleraudio.com/damping1.php

There are only a few amplifier designs that would have damping factors under 10-20 and those aren't used in car audio.

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Old Yesterday, 07:22 PM   #36
SPL_Krayzie112

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Quote:
Originally Posted by Jimi77 View Post
That's interesting. Exactly how does S/N ratio affect control? If S/N ratio is a major concern, then should we all run line drivers or only sources with high preamp voltages?

I'm not sure how THD impacts cone control. Any decent amplifier and even a lot of crappy ones have THD below the human threshold for hearing, some are just farther below the threshold than others. What if I choose to clip the amp, which is when our "decent" amps will have enough THD to be detectable to the human ear. Are you saying the amplifier loses control of the cone when clipped? What if I'm clipping at a power output when the sub is still well within it's xmax spec?

Are you suggesting amplifier input sensitivity somehow affects the amplifier's ability to control cone motion, is this related to your theory regarding S/N ratios? Are you saying we should run amps capable of accepting higher preamp voltages. If higher preamps voltages lead to better control, then should we just skip use the preamp and wire our systems using the high level outputs on our source units and high level inputs on our amps?

Or are you referring to driver sensitivity? Are you saying a driver with higher sensitivity is easier to control? Since driver sensitivity can be measured as 1 watt/1 meter vs 2.83v/ 1 meter, which spec should we use? If damping factor is a major concern, then are you suggesting we wire our systems in a manner to increase damping factor at the expense of output power and/or sensitivity or do you prefer amplifiers with regulated outputs capable of delivering the same output over a range of loads?
To clarify the matter, if it's not damping factor I'm looking for, it'd be those parameters. On another note, yes, I'd say those parameters CAN control cone motion, damping factor aside.

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Old Yesterday, 08:06 PM   #37
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Quote:
Originally Posted by SPL_Krayzie112 View Post
To clarify the matter, if it's not damping factor I'm looking for, it'd be those parameters. On another note, yes, I'd say those parameters CAN control cone motion, damping factor aside.
I guess I'm just confused as to how sensitivity (and whether it's amplifier sensitivity or driver sensitivity) contributes to cone control. For example, are we looking for amp's with higher input sensitivity or lower input sensitivity.

If it's driver sensitivity that would should be concerned with, then should we look for drivers with higher or lower sensitivity? How does sensitivity contribute to cone control? Since amplifiers are basically considered voltage sources, and DVC drivers can be wired for lower or higher sensitivity at a given voltage, should we be wiring for higher sensitivity or lower sensitivity? For example, if we wire a 2 ohm DVC sub to 4 ohms will control increase vs wiring for 1 ohm.

How does S/N ratio contribute to cone control? Generally, we look at S/N ratio as way to reject noise that gets inducted into the signal chain; I've never heard it hypothesized that s/n ratio contributes to cone control....
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Old Yesterday, 08:50 PM   #38
crapola

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Useful info at a very useable car audio tech website:

http://www.bcae1.com/dampfact.htm

In terms of who publishes the actual damping factor for their sub amps, my research tells me that less that 10% of amplifier manufacturers publish this data. While not publishing the numbers does not mean that specific amp is bad or poor audio quality, but manufacturers known for sound quality, or just overall quality and customer care, will publish these numbers.

Here is a short list of manufacturers I know of that publish Damping Factor numbers, and not in all cases (such as all different quality/featured product lines):
Audio Control
JL Audio
Rockford Fosgate
Alpine

Last edited by crapola; Yesterday at 09:18 PM.
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Old Yesterday, 09:26 PM   #39
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Quote:
Originally Posted by crapola View Post
Useful info at a very useable car audio tech website:

http://www.bcae1.com/dampfact.htm

In terms of who publishes the actual damping factor for their sub amps, my research tells me that less that 10% of amplifier manufacturers publish this data. While not publishing the numbers does not mean that specific amp is bad or poor audio quality, but manufacturers known for sound quality, or just overall quality and customer care, will publish these numbers.

Here is a short list of manufacturers I know of that publish Damping Factor numbers, and not in all cases (such as all different quality/featured product lines):
Audio Control
JL Audio
Rockford Fosgate
Alpine
I think a lot of companies don't publish it because most solid state amps have a DF of close to or above 100. And of course there's the matter of how DF was measured. The PPI Phantom P1000.1 lists DF as 91 - at 1 ohm that's not bad, but at 4 ohms DF is getting "dangerously" close to 20. Unfortunately, PPI doesn't tell us what load they used to calculate DF.
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