Yes that’s the only me. Thanks for clearing it up. I didn’t care who was right. Just as long as I know now...
Anyway it seems I’m making a mountain out of a mole hill with this one so gonna just Get in with it
Well the system keeps improving and I keep wanting more. I’m quite obsessive, but.i think I’m nearing that stopping position.
Room is rectangular and going to have one at front left and one at rear right.
It’s like walking a tightrope.
Too much subs.. no wife
Too much bass traps ... no wife.
Spend too much money.. no wife.
All of the above.... No wife and never see my kids again
Anyway it seems I’m making a mountain out of a mole hill with this one so gonna just Get in with it
Well the system keeps improving and I keep wanting more. I’m quite obsessive, but.i think I’m nearing that stopping position.
Room is rectangular and going to have one at front left and one at rear right.
It’s like walking a tightrope.
Too much subs.. no wife
Too much bass traps ... no wife.
Spend too much money.. no wife.
All of the above.... No wife and never see my kids again
Woofer Damping ratio, not the damping factor.
I was talking about the woofer damping ratio. This is typically tuned to be 0.707 by adjusting the series resistance, box volume and box stuffing. The added series resistance of the cable will have a very very very small effect on this. Changes in the woofer damping ratio are what would directly change the woofer low end frequency response, the thing you could hear. The woofer damping ratio is proportional to the total series impedance of the amplifier, cables, woofer and crossover. So if the woofer, amplifier and crossover impedance at the woofer resonant frequency is say 5 ohms, changing the cable impedance at that frequency by 0.1 ohms isn't going to change the damping ratio of the woofer enough to be audible. The amplifier damping factor is only one small component and not the dominant factor in the system sound.
I was talking about the woofer damping ratio. This is typically tuned to be 0.707 by adjusting the series resistance, box volume and box stuffing. The added series resistance of the cable will have a very very very small effect on this. Changes in the woofer damping ratio are what would directly change the woofer low end frequency response, the thing you could hear. The woofer damping ratio is proportional to the total series impedance of the amplifier, cables, woofer and crossover. So if the woofer, amplifier and crossover impedance at the woofer resonant frequency is say 5 ohms, changing the cable impedance at that frequency by 0.1 ohms isn't going to change the damping ratio of the woofer enough to be audible. The amplifier damping factor is only one small component and not the dominant factor in the system sound.
That’s very good to know and i didn’t know this. And I’m not sure on how to calculate this either.
But my boxes are tuned to around 0.57 dampening. (Wanted a shallower rolloff due to room gain and wanted a lower response)
Boxes are 140litres and subs are alpine 15” type R
One thing I’ve just realised is that both my subs are not the same. 1 is actually dual 2ohm and one is dual 4ohm
So if the one fairest away is wired for 8ohm and one closest for 4ohm. The overall dampening would be around the same.
Just wish I knew if 65 is reasonable or not. Doesn’t look like there is a simple answer. I hear above 20 is fine. Some say 50 some say 100.
Non of them probably have a clue lol
But my boxes are tuned to around 0.57 dampening. (Wanted a shallower rolloff due to room gain and wanted a lower response)
Boxes are 140litres and subs are alpine 15” type R
One thing I’ve just realised is that both my subs are not the same. 1 is actually dual 2ohm and one is dual 4ohm
So if the one fairest away is wired for 8ohm and one closest for 4ohm. The overall dampening would be around the same.
Just wish I knew if 65 is reasonable or not. Doesn’t look like there is a simple answer. I hear above 20 is fine. Some say 50 some say 100.
Non of them probably have a clue lol
Going back to your original concern, it is correct what people say.
Both of your calculated damping factors comfortably exceed 20. 🙂
That’s good then thanks. It’s going to be a big enough journey calibrating these 2 subs with my ls50 mains and setting it all up. Last think I need to think about is this really.
Now I know I can get in with wiring it up and building my sub box
Now I know I can get in with wiring it up and building my sub box
Woofer impedance at resonance.
The thing isn't mentioned is that the woofer impedance varies wildly with frequency. At resonance, that "2 ohm" woofer may have an impedance of 10 ohms or more.
It is possible to measure the damping ratio with and without your speaker cables. That will show you the final answer. No calculations required. Use the free Limp software (part of Arta) and a known resistor of 8 ohms or so, or if you have it, the woofer tester from Parts Express. I have done it and found that the change with and without cable in my system didn't move the the measurement as much as the measurement noise. I was using 22 AWG wire trying to force a difference. Good clean fun for a rainy day between football games.
The think I love about this hobby is that it is very complex.
The thing isn't mentioned is that the woofer impedance varies wildly with frequency. At resonance, that "2 ohm" woofer may have an impedance of 10 ohms or more.
It is possible to measure the damping ratio with and without your speaker cables. That will show you the final answer. No calculations required. Use the free Limp software (part of Arta) and a known resistor of 8 ohms or so, or if you have it, the woofer tester from Parts Express. I have done it and found that the change with and without cable in my system didn't move the the measurement as much as the measurement noise. I was using 22 AWG wire trying to force a difference. Good clean fun for a rainy day between football games.
In all due respect, you're more than a "little obsessed", obviously. You're human, and not a machine that can actually determine "room nodes" and trivial inaccuracies in audio/sounds.
For decades now, people have enjoyed their music systems mainly as the manufacturer has designed them, without even giving it a second thought.
(The bit of evidence)
Yes, some are more "picky" than others, and so they'll go to greater lengths (and costs) in order to please themselves. But there is a cloudy limit to things, and by worrying about trivialities, it will make you insane.
While watching a movie, do you honestly "get into" it, or are you pulled away from the plot because of straining your ears to find faults with the audio system?
Do you jump from seat to seat during a movie, to locate "the best" position?
Some of these things are considerably more worrysome than some possible fault in the audio chain.
Nothing, nothing, is perfect.
Seriously, losing a happy balance to life by allowing such things to proliferate is nothing more than a sickness, much like alcohol or drugs, or constant use of a cellphone app.
The wire resistance at those damping factors might make as much as 0.1dB difference (that can be calculated as well - it's a simple resistor divider ratio, then get the voltage dB of that ratio), hardly enough for the best ear to notice.
Use the same length of wire for both subs (the wire for the nearer sub can be coiled up with no issues), then you know they'll have the same damping factor, same loss in the wire, and the subs will have the exact same volume level.
Easy to acquire is welding 4 , 2, 0 and 00 ga from local farm/industrial supply. Skin effect is a factor so welding super stranded flex is a good price/availability/performance balance.
U could get fancy and use Anderson connectors but maybe not.
Make your own ferrals from copper tubing etc or buy.
I like the 2ga.
U could get fancy and use Anderson connectors but maybe not.
Make your own ferrals from copper tubing etc or buy.
I like the 2ga.
Attachments
Re: Damping Factor Debate.
That debate suggests that the DC resistance of the voice coil should be regarded as being in series with the output impedance of the amplifier when calculation damping factor (DF).
e.g. Take a speaker of impedance Z = 8 ohm with DC resistance Rdc = 6.4 ohm and amplifier output impedance Zo = 0.1 ohm. (Let's forget about the small cable resistance!).
By definition, DF = Z/Zo = 8/0.1 = 80
If we trust the debate then, DF = Z/(Zo + Rdc) = 8/(0.1 + 6.4) = 1.2
Doesn't seem right to me, but I'm willing to be educated!
That debate suggests that the DC resistance of the voice coil should be regarded as being in series with the output impedance of the amplifier when calculation damping factor (DF).
e.g. Take a speaker of impedance Z = 8 ohm with DC resistance Rdc = 6.4 ohm and amplifier output impedance Zo = 0.1 ohm. (Let's forget about the small cable resistance!).
By definition, DF = Z/Zo = 8/0.1 = 80
If we trust the debate then, DF = Z/(Zo + Rdc) = 8/(0.1 + 6.4) = 1.2
Doesn't seem right to me, but I'm willing to be educated!
Not taking sides, but voice coil d.c.r. IS in series with everything, including the linear electric motor which actually does the job of moving cone and air.
That total is, say, 7 ohms made out of 6.5 ohm winding wire plus 0.5 ohm long thin connecting wire or 6.8 ohm winding (slightly thinner wire) plus 0.2 ohm from shorter fatter connection wire should not matter much to the actual electric motor in the transducer which is actually current driven.
I think the main battle was fought LONG ago when infinite Z/constant current no NFB pentodes gave way to power Triodes ; and later to NFB pentodes.
Not sure damping factor of early Tube amps but if, say, around 1, that would have meant going fom unbearable NO damping at all to about half the maximum possible, so it was a HUGE step.
Then with SS, DF of 10 or 20 already reached >90% of the theoretical maximum, a lesser but audible step.
Anything above that? ... I fail to understand what audible difference it might make.
That total is, say, 7 ohms made out of 6.5 ohm winding wire plus 0.5 ohm long thin connecting wire or 6.8 ohm winding (slightly thinner wire) plus 0.2 ohm from shorter fatter connection wire should not matter much to the actual electric motor in the transducer which is actually current driven.
I think the main battle was fought LONG ago when infinite Z/constant current no NFB pentodes gave way to power Triodes ; and later to NFB pentodes.
Not sure damping factor of early Tube amps but if, say, around 1, that would have meant going fom unbearable NO damping at all to about half the maximum possible, so it was a HUGE step.
Then with SS, DF of 10 or 20 already reached >90% of the theoretical maximum, a lesser but audible step.
Anything above that? ... I fail to understand what audible difference it might make.
Firstly I want to thank all the helpful reply’s that I’ve had regarding this subject. It has given me a lot of reading and learning to do to aid the understanding of my “hobby”
Secondly, I want to address the comments by some that I may be obsessed to some degree..
Although I’m sure no offence was intended, I can’t see how people can come to a conclusion that I’m more than obsessed from a few posts..
There are posts on this forum that are way more obsessive than mine that have been met with no talk of obsession or anything like that,
There are people on this thread mentioning using welding cable, and getting deep in to the equations and calculations and sending me links to debates and articles regarding the subject
The subject that apparently I’m obsessed with because I asked a simple question. The only reason I’m asking is due to what I’ve already read on the internet.
I don’t move around to get the best sound out of my system, movies and series and music have moved me to tears in the not so distant past, so I do enjoy the music..I have 2 kids, a nice house and a good job and we visit my caravan every weekend.
I don’t have any room acoustic treatment, bass trapping and have ruined my living room in order to get the best sound possible.like some on here who don’t get called obsessed.
In all honesty, when I start getting too obsessed with something I’m more than capable of bringing myself back down to earth.
I just didn’t appreciate the assumptions
Secondly, I want to address the comments by some that I may be obsessed to some degree..
Although I’m sure no offence was intended, I can’t see how people can come to a conclusion that I’m more than obsessed from a few posts..
There are posts on this forum that are way more obsessive than mine that have been met with no talk of obsession or anything like that,
There are people on this thread mentioning using welding cable, and getting deep in to the equations and calculations and sending me links to debates and articles regarding the subject
The subject that apparently I’m obsessed with because I asked a simple question. The only reason I’m asking is due to what I’ve already read on the internet.
I don’t move around to get the best sound out of my system, movies and series and music have moved me to tears in the not so distant past, so I do enjoy the music..I have 2 kids, a nice house and a good job and we visit my caravan every weekend.
I don’t have any room acoustic treatment, bass trapping and have ruined my living room in order to get the best sound possible.like some on here who don’t get called obsessed.
In all honesty, when I start getting too obsessed with something I’m more than capable of bringing myself back down to earth.
I just didn’t appreciate the assumptions
I don't know about 'obsessed', but if I understand the goal, sure went about it wrong.
Wire size is chosen based on voltage drop over distance, so using same type wire, calculate for the two different lengths to get ~ the same voltage drop, i.e. ~ same dB loss, and all the rest is moot.
BTW, solid is most efficient, so has lowest resistance/ft/wire gauge/type, though at your distances it's such a vanishingly low difference to stranded that it can be ignored.
GM
Wire size is chosen based on voltage drop over distance, so using same type wire, calculate for the two different lengths to get ~ the same voltage drop, i.e. ~ same dB loss, and all the rest is moot.
BTW, solid is most efficient, so has lowest resistance/ft/wire gauge/type, though at your distances it's such a vanishingly low difference to stranded that it can be ignored.
GM
Sorry I mentioned the welding cable. It is frequently used in high power audio systems as well as stranded. Yes the DC resistance is higher.
I appreciate all the comments and don’t mind being told of how went about it the wrong way. I’m here to learn at end of day
When all said and done, that's right, what's important is what you have got out of it, sod everyone else's opinions, there are a lot of those here, and egos and business interests that need to be protected, by dogma much of the time. There are facts buried in there somewhere 🙂
When I read back at all these comments. I got the exact answer I was looking for and learned something along the way. Can’t ask for much more than that.
Walking on egg shells to be educated has a certain excitement to it I suppose
Walking on egg shells to be educated has a certain excitement to it I suppose
Silver wire for all the special exotic things they do with Copper you don’t even need solid silver he just needs to be coated Copper and it’s the same as Silver. With all the super special bells whistles and Snakeoil the price per foot of exotic copper wire exceeds that of silver. It’s only in the US and European markets due to capitalism marking up unnecessarily the price of copper that makes it so expensive. If you source your silver wire directly from a Chinese manufacture in China it’s cheaper than the exotic copper wire. And if you sourced your copper wire directly from China in person if you seen the true cost of good copper wire your jaw will drop it’s only a fraction of the actual price that were used to seeing before all the middleman. I only know because my last 20 years of traveling and living in China with my wife from Shanghai and sourcing products directly.
If so obsessed just use mono blocks located right at each speaker with two feet of wire. You have more to lose trying to push high current through 10 m of wire then if you had 10 m of sore signal wire to your amp. With only 2 feet of wire then you can afford to spend the money on 2 feet of Japanese manufactured produced mono Crystaline wire quadruple 0000 gauge where each foot of copper wire cost more than 1 lb of silver bullion.
If so obsessed just use mono blocks located right at each speaker with two feet of wire. You have more to lose trying to push high current through 10 m of wire then if you had 10 m of sore signal wire to your amp. With only 2 feet of wire then you can afford to spend the money on 2 feet of Japanese manufactured produced mono Crystaline wire quadruple 0000 gauge where each foot of copper wire cost more than 1 lb of silver bullion.
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