I've been wondering, all this talk about damping factor, and how it affects cone movement and the higher the damping factor, generally the tighter the bass because of the greater control over the cone's movement. So I thought i'd ask you guys. So if I used an amplifier, say a bridged Crown K2 which has a damping factor of 3,000 on one of my subs, and then I used one side of a Crown XTI6000 (just an example) which has a damping factor of 500 to power my other sub, would the average person be able to tell any difference in tightness of kick drums or sub basslines? I'm talking set up so both subs are outputting the same spl. Also say cable length of 3 metres for both amplifiers because my speaker cable lengths are never longer than 3 metres. Plus interconnection cables (XLR) are no longer than 3 metres from the dj mixer to the loudspeaker management system and 1 metres patch cables from the loudspeaker management system to amplifiers.
Does damping factor have any noticeable effect?
- Thread starter Richard Stringer
- Start date
Re: Doe damping factor have any noticeable effect?
Take this stuff outside and find out.
Steal your neighbor's old 100' extension cord, cut off the ends, attach whatever connectors are needed to drive the sub and let it rip. Swap it out with your normal 3 meter cable and let it rip again. Swap out amps and let it...
Thoughts:
1. You'll be doing well to keep the damping factor above 20.
2. Ray Rayburn has the best spreadsheet available on this.
3. Keep the round-trip resistance of your loudspeaker cable </= to 5% of the nominal load impedance you are driving.
4. Fix the extension cable and give it back when you're done.
Hi Richard:Richard said:
Take this stuff outside and find out.
Steal your neighbor's old 100' extension cord, cut off the ends, attach whatever connectors are needed to drive the sub and let it rip. Swap it out with your normal 3 meter cable and let it rip again. Swap out amps and let it...
Thoughts:
1. You'll be doing well to keep the damping factor above 20.
2. Ray Rayburn has the best spreadsheet available on this.
3. Keep the round-trip resistance of your loudspeaker cable </= to 5% of the nominal load impedance you are driving.
4. Fix the extension cable and give it back when you're done.
Re: Doe damping factor have any noticeable effect?
There have been many articles written about this (I think I wrote two myself), but short answer for modern solid state amps is.... wire will typically make a bigger difference than amplifier DF spec.
Note: some solid state guitar amps intentionally degrade the DF to enhance cabinet/driver resonance interactions with the amplifier.
JR
Noe
There have been many articles written about this (I think I wrote two myself), but short answer for modern solid state amps is.... wire will typically make a bigger difference than amplifier DF spec.
Note: some solid state guitar amps intentionally degrade the DF to enhance cabinet/driver resonance interactions with the amplifier.
JR
Re: Doe damping factor have any noticeable effect?
When you say wire, do you mean thickness? Like 14guage when compared to say 10guage
When you say wire, do you mean thickness? Like 14guage when compared to say 10guage
Re: Doe damping factor have any noticeable effect?
Wire gauge and length. Since wire resistance is in ohms per unit length, take that unit resistance times the length. Don't forget that the current has to travel both to and from the speaker, so it's the resistance of both wires.
JR
Wire gauge and length. Since wire resistance is in ohms per unit length, take that unit resistance times the length. Don't forget that the current has to travel both to and from the speaker, so it's the resistance of both wires.
JR
Re: Doe damping factor have any noticeable effect?
As others have said-the wire will have the greatest effect on the overall "sound" of damping.
Historically-amps with higher damping factor have had "tighter" bass. This is generally attributed to a better designed amp (stiffer power supply-lower output impedance/damping factor and so forth)
Of course people just want a "simple" answer-so the amps with the best sound had higher damping factors-so it was "obvious" that the damping factor was sole factor.
However that is not the case any more. I have played around with some cheaper amps that have high damping factors-and they are not as "tight" as amps with much lower damping factors..
You have to look at the WHOLE chain-to figure out the damping of the SYSTEM. That includes the amp-the loudspeaker (impedance)-the wire-the connectors and so forth-anything with weries resistance.
As others have said-the wire will have the greatest effect on the overall "sound" of damping.
Historically-amps with higher damping factor have had "tighter" bass. This is generally attributed to a better designed amp (stiffer power supply-lower output impedance/damping factor and so forth)
Of course people just want a "simple" answer-so the amps with the best sound had higher damping factors-so it was "obvious" that the damping factor was sole factor.
However that is not the case any more. I have played around with some cheaper amps that have high damping factors-and they are not as "tight" as amps with much lower damping factors..
You have to look at the WHOLE chain-to figure out the damping of the SYSTEM. That includes the amp-the loudspeaker (impedance)-the wire-the connectors and so forth-anything with weries resistance.
Re: Doe damping factor have any noticeable effect?
You might want to give this a read.
http://bennettprescott.com/downloads/dampingfactor.pdf
You might want to give this a read.
http://bennettprescott.com/downloads/dampingfactor.pdf
Re: Doe damping factor have any noticeable effect?
Is there a point of diminishing returns? Like is using 6.0mm speaker (which I think is 2 guage) worth it? I've heard if you use cable too thick, power can get lost in the cable.
Is there a point of diminishing returns? Like is using 6.0mm speaker (which I think is 2 guage) worth it? I've heard if you use cable too thick, power can get lost in the cable.
Re: Doe damping factor have any noticeable effect?
IF you will actually read the links various people have proviced-you will quickly realize that it is not so much the size of the wire-but the LENGTH (and the size) that determine what is best.
In some cases 18 ga will work fine. In others you should use 2 ga. It depends.
And NO-the electrons will not get "lost" in large wire-as if they can't find their way.
IF you will actually read the links various people have proviced-you will quickly realize that it is not so much the size of the wire-but the LENGTH (and the size) that determine what is best.
In some cases 18 ga will work fine. In others you should use 2 ga. It depends.
And NO-the electrons will not get "lost" in large wire-as if they can't find their way.
Re: Doe damping factor have any noticeable effect?
It's exactly the opposite. Power will be lost in too thin wire. Imagine the extreme case where the speaker wire has 4 ohms of resistance and the speaker is 4 ohms. The wire will dissipate as much power as the speaker, so fully one half of the amplifier's output power is "lost" in the wire.
This is more of an issue with loudspeakers distributed around very large buildings, like background music systems. The strategy used there to reduce wire losses is to step up the amp output voltage to 70V or 100V nominal and use higher impedance speaker loads, so the current flowing in the wire is less.
JR
It's exactly the opposite. Power will be lost in too thin wire. Imagine the extreme case where the speaker wire has 4 ohms of resistance and the speaker is 4 ohms. The wire will dissipate as much power as the speaker, so fully one half of the amplifier's output power is "lost" in the wire.
This is more of an issue with loudspeakers distributed around very large buildings, like background music systems. The strategy used there to reduce wire losses is to step up the amp output voltage to 70V or 100V nominal and use higher impedance speaker loads, so the current flowing in the wire is less.
JR
Re: Doe damping factor have any noticeable effect?
Thanks for the links, i've read the links and saved the info on my computer so I can learn more about it. And thanks for your replies to, i'm glad i've got this ironed out about power supposedly being lost in the wiring.
Thanks for the links, i've read the links and saved the info on my computer so I can learn more about it. And thanks for your replies to, i'm glad i've got this ironed out about power supposedly being lost in the wiring.
Re: Does damping factor have any noticeable effect?
Hi Richard,
My take is that any discussion of "damping factor" that concentrates on amplifier output impedance is focusing on the flea and ignoring the gorilla on which it's sitting. (In any amplifier you're likely to use, the output impedance is insignificant in comparison to the loudspeaker impedance and cable resistance.)
Simply try to keep the round-trip cable resistance to no more than about 5% of the loudspeaker's nominal impedance. If you put that in a formula, you should aim for a cable cross-sectional area of L/(1.5*Z) mm^2 where L is the cable length in metres and Z is the loudspeaker impedance in ohms. So for a 10m cable to an 8ohm loudspeaker, aim for 0.8mm^2. For a 30m cable to a 4ohm loudspeaker, aim for 5mm^2. Thicker does no harm other than consuming money and adding weight.
Nick
Hi Richard,
My take is that any discussion of "damping factor" that concentrates on amplifier output impedance is focusing on the flea and ignoring the gorilla on which it's sitting. (In any amplifier you're likely to use, the output impedance is insignificant in comparison to the loudspeaker impedance and cable resistance.)
Simply try to keep the round-trip cable resistance to no more than about 5% of the loudspeaker's nominal impedance. If you put that in a formula, you should aim for a cable cross-sectional area of L/(1.5*Z) mm^2 where L is the cable length in metres and Z is the loudspeaker impedance in ohms. So for a 10m cable to an 8ohm loudspeaker, aim for 0.8mm^2. For a 30m cable to a 4ohm loudspeaker, aim for 5mm^2. Thicker does no harm other than consuming money and adding weight.
Nick
Re: Does damping factor have any noticeable effect?
Indeed DF is an archaic specification from back when tube amps exhibited significant output impedance. Now it is just a superfluous specification that marketers flog to try to create the impression of differences where little really exists.
JR
Indeed DF is an archaic specification from back when tube amps exhibited significant output impedance. Now it is just a superfluous specification that marketers flog to try to create the impression of differences where little really exists.
JR
Re: Does damping factor have any noticeable effect?
I use speaker cable runs of 3 metres each to my mid/high cabs and a 3 metre run to one of my subs, then a 1 metre run from that sub to the next sub. Cable diameter is 4.0mm on all cables, according to the American Wire Guage it's 7awg. So it's 2 x 4.0mm cable i'm using because i'm not bi-amping the mid/highs.
I use speaker cable runs of 3 metres each to my mid/high cabs and a 3 metre run to one of my subs, then a 1 metre run from that sub to the next sub. Cable diameter is 4.0mm on all cables, according to the American Wire Guage it's 7awg. So it's 2 x 4.0mm cable i'm using because i'm not bi-amping the mid/highs.
Re: Does damping factor have any noticeable effect?
Seriously? According to my calculations, that 4mm wire is closer to 6AWG. That is WAY overkill. Those kinds of wire sized shouldn't be needed for anything other than feeder for small/mid size PA and power distribution for larger PA systems. I could understand if you were using very long speaker cable runs. But that thick of a wire size is an excess in terms of cost, weight, and trunk space. How do you get the ends into standard speaker connectors like Speakon?
Greg
Seriously? According to my calculations, that 4mm wire is closer to 6AWG. That is WAY overkill. Those kinds of wire sized shouldn't be needed for anything other than feeder for small/mid size PA and power distribution for larger PA systems. I could understand if you were using very long speaker cable runs. But that thick of a wire size is an excess in terms of cost, weight, and trunk space. How do you get the ends into standard speaker connectors like Speakon?
Greg
Re: Does damping factor have any noticeable effect?
Hi Greg,
I think Richard means 4mm^2 (cross-sectional area), not diameter. According to Google, that's about 11 of your American AWGs! Still overkill, though.
Nick
Hi Greg,
I think Richard means 4mm^2 (cross-sectional area), not diameter. According to Google, that's about 11 of your American AWGs! Still overkill, though.
Nick
Re: Does damping factor have any noticeable effect?
This is what cable i'm using :
http://www.clearly-av.co.uk/images/items/300x300/vd_blue_40.jpg
It just says 2 x 4.0mm, what does cross sectional area mean?
Edit :
Right, I just took one of the wires out the speakon plug's terminals and measured how thick the total strands are at the nearest part to the edge of the cut jacket of the cable where the cable leaves the jacket, it measures 3.8mm from side to side, so each side of the cable (red and blue) measures 3.8mm diameter.
This is what cable i'm using :
http://www.clearly-av.co.uk/images/items/300x300/vd_blue_40.jpg
It just says 2 x 4.0mm, what does cross sectional area mean?
Edit :
Right, I just took one of the wires out the speakon plug's terminals and measured how thick the total strands are at the nearest part to the edge of the cut jacket of the cable where the cable leaves the jacket, it measures 3.8mm from side to side, so each side of the cable (red and blue) measures 3.8mm diameter.
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Re: Does damping factor have any noticeable effect?
Hi Richard,
If you cut a slice through the cable, the cross-sectional area of a conductor is simply the area of copper exposed. In the UK at least, this is the fairly universal way in which cables are described. The units of area are square-millimetres, or
, or mm^2. Cross-sectional area is sometimes abbreviated as CSA.
Your cable is Van Damme "Blue series" speaker cable, two cores, each 4mm^2 cross-sectional area. The seller is calling it "4mm" cable as a shorthand.
VDC, another seller, show the specs for the range of cables like this:
The "conductor stranding" bit means the cable has 227 strands of copper, each 0.15mm in diameter (and here the convention is that it is the diameter that's stated!). Given that the area of a circle is given by Pi times the square of the radius (and the radius is half of the diameter), the overall conductor area is 227 * 3.1416 * (0.15/2) * (0.15/2), or 4.01 mm^2.
The bottom line is that, for the lengths you're using, your cable is fine.
Nick
Hi Richard,
If you cut a slice through the cable, the cross-sectional area of a conductor is simply the area of copper exposed. In the UK at least, this is the fairly universal way in which cables are described. The units of area are square-millimetres, or
Your cable is Van Damme "Blue series" speaker cable, two cores, each 4mm^2 cross-sectional area. The seller is calling it "4mm" cable as a shorthand.
VDC, another seller, show the specs for the range of cables like this:
The "conductor stranding" bit means the cable has 227 strands of copper, each 0.15mm in diameter (and here the convention is that it is the diameter that's stated!). Given that the area of a circle is given by Pi times the square of the radius (and the radius is half of the diameter), the overall conductor area is 227 * 3.1416 * (0.15/2) * (0.15/2), or 4.01 mm^2.
The bottom line is that, for the lengths you're using, your cable is fine.
Nick
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Re: Does damping factor have any noticeable effect?
Thanks for that Nick, I apreciate it, a couple of years ago I used to use 2 x 6.0mm of the same van Damme cable but they stopped selling it.
Thanks for that Nick, I apreciate it, a couple of years ago I used to use 2 x 6.0mm of the same van Damme cable but they stopped selling it.
Re: Does damping factor have any noticeable effect?
Richard - it seems you're overbuying your wire, both from a cable gauge standpoint (3m cables aren't very long) and from a "quality" standpoint - there's no need to pay for "ultra-pure oxygen free" or whatever other junk is sold as "premium speaker wire". Regular power distribution cord of appropriate gauge (what we call SJO cord) is just fine.
As several folks have said, you want your cable resistance to be <5% of your load impedance. If you are running 4ohm loads, then you want your cable resistance to be .2ohms or less.
Here's a table of resistance per foot. Units are American AWG and per foot:
4 .000292
6 .000465
8 .000739
10 .00118
12 .00187
14 .00297
16 .00473
18 .00751
20 .0119
22 .0190
24 .0302
26 .0480
28 .0764
Assuming no connector loss, you can accomplish a damping factor of >20 with 18-ga wire (.823mm^2 area) for your 3m lengths. I'm not suggesting you do this, but as you can see, you have a lot of headroom.
Most US pro audio has standardized on 12 gauge cable (3.31mm^2 area) for runs of up to 75' or so as it is cheaply available and relatively easy to work with. Longer runs are minimized to the degree possible - amp racks on each side of the stage, etc.
Richard - it seems you're overbuying your wire, both from a cable gauge standpoint (3m cables aren't very long) and from a "quality" standpoint - there's no need to pay for "ultra-pure oxygen free" or whatever other junk is sold as "premium speaker wire". Regular power distribution cord of appropriate gauge (what we call SJO cord) is just fine.
As several folks have said, you want your cable resistance to be <5% of your load impedance. If you are running 4ohm loads, then you want your cable resistance to be .2ohms or less.
Here's a table of resistance per foot. Units are American AWG and per foot:
4 .000292
6 .000465
8 .000739
10 .00118
12 .00187
14 .00297
16 .00473
18 .00751
20 .0119
22 .0190
24 .0302
26 .0480
28 .0764
Assuming no connector loss, you can accomplish a damping factor of >20 with 18-ga wire (.823mm^2 area) for your 3m lengths. I'm not suggesting you do this, but as you can see, you have a lot of headroom.
Most US pro audio has standardized on 12 gauge cable (3.31mm^2 area) for runs of up to 75' or so as it is cheaply available and relatively easy to work with. Longer runs are minimized to the degree possible - amp racks on each side of the stage, etc.