CarAudioForum.com


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

Registered User
 
Join Date: Jul 2001
Posts: 2,534
SPL_Krayzie112 will become famous soon enough



To disambiguate it in short terms, the higher the damping factor number is, the better cone control?
SPL_Krayzie112 is online now   Reply With Quote

Old 01-14-2018, 04:54 AM   #32
Jimi77

Registered User
 
Join Date: Oct 2002
Location: Denver, CO
Posts: 27,669
Jimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond repute



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.
Jimi77 is online now   Reply With Quote

Old 01-14-2018, 08:03 AM   #33
SPL_Krayzie112

Registered User
 
Join Date: Jul 2001
Posts: 2,534
SPL_Krayzie112 will become famous soon enough



For me it'd be Sensitivity, S/N Ratio, THD and Damping Factor
SPL_Krayzie112 is online now   Reply With Quote

Old 01-14-2018, 11:50 AM   #34
Jimi77

Registered User
 
Join Date: Oct 2002
Location: Denver, CO
Posts: 27,669
Jimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond repute



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.
Jimi77 is online now   Reply With Quote

Old 01-15-2018, 10:37 PM   #35
Jimi77

Registered User
 
Join Date: Oct 2002
Location: Denver, CO
Posts: 27,669
Jimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond repute



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.

Last edited by Jimi77; 01-16-2018 at 12:05 AM.
Jimi77 is online now   Reply With Quote

Old 01-16-2018, 07:22 PM   #36
SPL_Krayzie112

Registered User
 
Join Date: Jul 2001
Posts: 2,534
SPL_Krayzie112 will become famous soon enough



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.

Last edited by SPL_Krayzie112; 01-16-2018 at 07:24 PM.
SPL_Krayzie112 is online now   Reply With Quote

Old 01-16-2018, 08:06 PM   #37
Jimi77

Registered User
 
Join Date: Oct 2002
Location: Denver, CO
Posts: 27,669
Jimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond repute



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....
Jimi77 is online now   Reply With Quote

Old 01-16-2018, 08:50 PM   #38
crapola

Chief Pessimist!
 
Join Date: Oct 2000
Location: Arlington, Texas
Posts: 371
crapola is on a distinguished road



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; 01-16-2018 at 09:18 PM.
crapola is offline   Reply With Quote

Old 01-16-2018, 09:26 PM   #39
Jimi77

Registered User
 
Join Date: Oct 2002
Location: Denver, CO
Posts: 27,669
Jimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond repute



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.
Jimi77 is online now   Reply With Quote

Old 01-20-2018, 05:15 PM   #40
SPL_Krayzie112

Registered User
 
Join Date: Jul 2001
Posts: 2,534
SPL_Krayzie112 will become famous soon enough



Quote:
Originally Posted by Jimi77 View Post
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....
Sound minus noise = subjectively positive cone control.
SPL_Krayzie112 is online now   Reply With Quote

Old 01-20-2018, 06:16 PM   #41
Jimi77

Registered User
 
Join Date: Oct 2002
Location: Denver, CO
Posts: 27,669
Jimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond repute



Quote:
Originally Posted by SPL_Krayzie112 View Post
Sound minus noise = subjectively positive cone control.
That's a good one. .

I must be the idiot of idiots for spending all that time looking at KMS, CMS & BL curves, paying attention to inductance, enclosure design, etc.

Last edited by Jimi77; 01-20-2018 at 06:53 PM.
Jimi77 is online now   Reply With Quote

Old Yesterday, 09:31 PM   #42
SPL_Krayzie112

Registered User
 
Join Date: Jul 2001
Posts: 2,534
SPL_Krayzie112 will become famous soon enough



It's not the end of the world. On the positive side...try using the mathematical equations of each parameter. Maybe you'll come to the "golden ratio" of SQ-dom.

Never really delved into specific sound quality topics until recently so you'll have to pardon the gray arguments.
SPL_Krayzie112 is online now   Reply With Quote

Old Yesterday, 10:26 PM   #43
Jimi77

Registered User
 
Join Date: Oct 2002
Location: Denver, CO
Posts: 27,669
Jimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond repute



Quote:
Originally Posted by SPL_Krayzie112 View Post
It's not the end of the world. On the positive side...try using the mathematical equations of each parameter. Maybe you'll come to the "golden ratio" of SQ-dom.
That's why I was so confused about sensitivity since that's both an amplifier and driver spec. And is higher better or lower?

Quote:
Originally Posted by Jimi77 View Post
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.
Jimi77 is online now   Reply With Quote

Old Yesterday, 11:30 PM   #44
SPL_Krayzie112

Registered User
 
Join Date: Jul 2001
Posts: 2,534
SPL_Krayzie112 will become famous soon enough



Now I'm thinking if you're being sarcastic.

Speaker damping factor would be dictated by Qms or Qes? I wonder if you can have a speaker parameter that will match a source's damping factor.

Equipment compatibility almost comes hand in hand with similar branded/packaged equipment. I wonder if matching all the speaker's and source's (separate brands) T/S parameters quid pro quo/tit for tat will ALWAYS yield THE best results.
SPL_Krayzie112 is online now   Reply With Quote

Old Today, 02:09 AM   #45
Jimi77

Registered User
 
Join Date: Oct 2002
Location: Denver, CO
Posts: 27,669
Jimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond reputeJimi77 has a reputation beyond repute



Quote:
Originally Posted by SPL_Krayzie112 View Post
Now I'm thinking if you're being sarcastic.
No, I'm seriously confused by your reference to sensitivity since both the amp and the speaker have a sensitivity spec and in many cases sensitivity is variable on pieces of equipment.

Zed Minotuar is highly regarded and has high input sensitivity (8.6v). PPI Ice Amps are considered decent amps, but run about 25% the cost of a Zed and only have 6v input sensitivity. Or you referencing the low end of the amp's input sensitivity; in which case the Zed is at .25v vs .1v for the PPI Ice.

Or are you referencing the speaker's sensitivity and if so, is higher or lower better. For example, with comps I tend to like "hi-fi" style comps as opposed to the more pro-audio style comps. The PA stuff has better power handling, lower moving mass and higher sensitivity, so it can get as loud with less power and get louder if you're willing feed them full RMS. While lower moving mass does have it's downsides, obviously the less moving mass the motor has "fight", the better it can control the cone. I tend to like heavy damp cones myself.

Quote:
Speaker damping factor would be dictated by Qms or Qes? I wonder if you can have a speaker parameter that will match a source's damping factor.
Damping factor is a ratio of the speaker's impedance divided by the amplifier's output impedance. Qms & Qes would only be relevant if you wanted to map out the speaker's impedance curve so that you would know the damping factor at any given frequency. In that case you would actually need the impedance curve for the driver while in the enclosure to be truly accurate. From that data you could derive a damping factor curve, but I think there must be a reason nobody bother's doing it. Most of the guys I know accept that if it's a decent solid state amp, then it will have more than enough damping factor.

You cannot (by definition) have a speaker parameter that will match an amp's damping factor, since (by definition) an amp cannot have a damping factor without a speaker/load connected to it. We do know that higher impedance loads yield higher damping factors (because of the equation). I guess one could look for subs with peaky impedance curves to increase damping factor as FS, however a lot of the SQ crowd attempts to flatten the impedance curve. For example, Richard Clark's methodology for tuning Aperiodic Enclosures was based on getting the flattest impedance curve, which would result in lower damping factor at FS.

Quote:
Equipment compatibility almost comes hand in hand with similar branded/packaged equipment. I wonder if matching all the speaker's and source's (separate brands) T/S parameters quid pro quo/tit for tat will ALWAYS yield THE best results.
I don't know how you could possibly match a speaker's T/S parameters to a source, since the only T/S spec the amp "cares about" is impedance. If you give me a sub, I can give you dozens of good amps that would be a good match for said sub.

Last edited by Jimi77; Today at 02:55 PM.
Jimi77 is online now   Reply With Quote

Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT. The time now is 06:51 PM.
Powered by vBulletin® - Copyright © 2000 - 2018, Jelsoft Enterprises Ltd.
Copyright 1996 - 2011 by CarAudioForum.com - all rights reserved.