Didn’t know where to put this post so I apologise in advance if it’s in the wrong place.
Not interested in exotic wire or getting in to anything that may be considered snake oil
I want to know if anyone has found a cable that has a lower resistance than the one I have already
4mm van damme shotgun cable at 4.7ohm per km
This is for my subwoofer build and have concerns at 7 meter long with overall speaker dampening.
Not interested in exotic wire or getting in to anything that may be considered snake oil
I want to know if anyone has found a cable that has a lower resistance than the one I have already
4mm van damme shotgun cable at 4.7ohm per km
This is for my subwoofer build and have concerns at 7 meter long with overall speaker dampening.
Your Van Damme cable will only introduce around 0.07 ohm (to your sub and back).
You have absolutely nothing to worry about as regards its effect on speaker damping!
You have absolutely nothing to worry about as regards its effect on speaker damping!
Worried, concerns, and obsessions about wire again?
I truely think that the internet, along with those fancy wire companies, is to blame for this.
I truely think that the internet, along with those fancy wire companies, is to blame for this.
The obvious answer is to go thicker section.
You currently have 0.0329 ohm resistance per wire; you can halve that by going to 8mm section.
You will probably have to use some Industrial type terminator at each end to fit whetever connectors you use, not sure Home type ones can fit that large wire, although I might be surprised.
That said, not sure how much can that affect audible response, but, hey, it´s your system.
You are right, no need for anything exotic, just plain old muscle.
You currently have 0.0329 ohm resistance per wire; you can halve that by going to 8mm section.
You will probably have to use some Industrial type terminator at each end to fit whetever connectors you use, not sure Home type ones can fit that large wire, although I might be surprised.
That said, not sure how much can that affect audible response, but, hey, it´s your system.
You are right, no need for anything exotic, just plain old muscle.
I’m really hoping that what I have is fine but my problem is that I have an identical sub at the front of the room less than 1 meter away from the amp.
I didn’t want them to sound different to each other
My amp is the inuke6000dsp
Output resistance is 0.057ohm
Speaker wire is 0.047ohm per meter
Speaker is going to be 8ohm load
7m distance
I’ve worked out this will give me a dampening factor of 88 for the rear sub
And much higher for the front sub
But don’t know if that’s any good or not
People say as long as it’s higher than 20 all is good but I don’t know
I didn’t want them to sound different to each other
My amp is the inuke6000dsp
Output resistance is 0.057ohm
Speaker wire is 0.047ohm per meter
Speaker is going to be 8ohm load
7m distance
I’ve worked out this will give me a dampening factor of 88 for the rear sub
And much higher for the front sub
But don’t know if that’s any good or not
People say as long as it’s higher than 20 all is good but I don’t know
(a) They will not sound different.
(b) I suggest you submit your method of calculation and quantify the term 'much higher'.
0000 welding cable (.000025 Ohms/ft), readily available in any length. Terminations, either screw on or hammer on are readily available. If you want the hammer on version I recommend going up to 350K circular mil lugs because the multi strand cable is hard to compress to fit into the connector. $16/ft for both conductors together no snake oil just the price of copper.
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I want them to sound different due to the different location. That’s exactly what I’m after..trying to smooth response in my room.
The only concern is that when I have 1000w going through a sub 7 meters away playing down to below 20hz sometimes during movies, that the amp is going to have control of the cone as is needed.
The calculation I used is
4.7ohm (per 1km) x 7m x 2 / 1000= 0.0658ohm
0.057 (amp) + 0.0658 (wire) = 0.1228ohm total resistance
8ohm / 0.1228 = 65df
I was wrong with 88. My bad. The closer sub is same but 0.5 meter from amp so
4.7ohm x 1 x 2 / 1000 = 0.0094ohm
0.057 + 0.0094 = 0.0664
8ohm / 0.0664 = 120.48df
Would this be a problem??
Thanks for all reply’s btw.
Did it Wong for the second calculation
Was meant to be
4.7ohm x 0.5m x 2 / 1000 = 0.0047
End result is 129.65df
Had a long day sorry
The only concern is that when I have 1000w going through a sub 7 meters away playing down to below 20hz sometimes during movies, that the amp is going to have control of the cone as is needed.
The calculation I used is
4.7ohm (per 1km) x 7m x 2 / 1000= 0.0658ohm
0.057 (amp) + 0.0658 (wire) = 0.1228ohm total resistance
8ohm / 0.1228 = 65df
I was wrong with 88. My bad. The closer sub is same but 0.5 meter from amp so
4.7ohm x 1 x 2 / 1000 = 0.0094ohm
0.057 + 0.0094 = 0.0664
8ohm / 0.0664 = 120.48df
Would this be a problem??
Thanks for all reply’s btw.
Did it Wong for the second calculation
Was meant to be
4.7ohm x 0.5m x 2 / 1000 = 0.0047
End result is 129.65df
Had a long day sorry
You're obsessed, clearly.
I've seen this happen before.
Put away the internet, the calculations, and ignore the hype of society.
Then, just enjoy the music.
I've seen this happen before.
Put away the internet, the calculations, and ignore the hype of society.
Then, just enjoy the music.
Calculate the change in woofer damping with added resistance
The best way to know if there will be a difference is to calculate the change in the woofer damping ratio with the added resistance.
The best way to know if there will be a difference is to calculate the change in the woofer damping ratio with the added resistance.
Damping factor = (loudspeaker Z + cable R)/amplifier output Z
So, for your 7m cable: DF = (8 + 0.0658)/0.057 = 141.5
So, for your 7m cable: DF = (8 + 0.0658)/0.057 = 141.5
I know it may seem a little obsessive,
All I’ve read is, “ if the overall dampening factor is not high enough, bass will sound muddy and one note”
What I really need is someone to say, you won’t notice a difference and everything will be fine... (with a bit of evidence to support it)
As for setup I own a very expensive anthem AVR with top draw room correction along with a separate calibrated microphone and all the rest of it.
So setting up isn’t an issue, i just wanted to avoid what could be a potential problem.
But if it isn’t then fair enough.
All I’ve read is, “ if the overall dampening factor is not high enough, bass will sound muddy and one note”
What I really need is someone to say, you won’t notice a difference and everything will be fine... (with a bit of evidence to support it)
As for setup I own a very expensive anthem AVR with top draw room correction along with a separate calibrated microphone and all the rest of it.
So setting up isn’t an issue, i just wanted to avoid what could be a potential problem.
But if it isn’t then fair enough.
So the website that states this must’ve wrong then? Damping Factor (DF) = Speaker DC Resistance / (Amplifier Output Impedance + Total Cable Resistance)
You are missing the bigger, far more relevant picture. https://www.tubetrap.com/bass_traps_articles/room-acoustics.pdf
If you are that worried use plate amps
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Thank you. It’s a good read.
I actually haven’t missed the fact that bass traps and acoustic treatment is the ultimate way forward.
However, since I started this project 4 years ago, I have had to basically try my best to get the most out of my system as possible by optimising speaker and seating locations, and utilising room correction and subwoofer
Time delays and phase adjustment. To get to am the best outcome possible
This second sub is the next step in the project.
I have a wife that will not allow such bass traps and room treatment as it needs to look like a living room.
I know it’s all relative and by no means am I saying my system is mega compared to some but I’ve measured the response and I’m quite happy apart from a few nulls that I’m going to sort with this second sub.
I actually haven’t missed the fact that bass traps and acoustic treatment is the ultimate way forward.
However, since I started this project 4 years ago, I have had to basically try my best to get the most out of my system as possible by optimising speaker and seating locations, and utilising room correction and subwoofer
Time delays and phase adjustment. To get to am the best outcome possible
This second sub is the next step in the project.
I have a wife that will not allow such bass traps and room treatment as it needs to look like a living room.
I know it’s all relative and by no means am I saying my system is mega compared to some but I’ve measured the response and I’m quite happy apart from a few nulls that I’m going to sort with this second sub.
Earl Geddes recommends three Using multiple subwoofers to improve bass: The Welti / Devantier and Geddes approaches - Acoustic Frontiers
Multiple Subwoofer after Geddes
Or if you have a perfectly rectangular room "Double Bass Array" It all depends how obsessed you are 😉
Sorry, I've seen both versions of the equation, but yours would appear to be the correct one.
You are probably referring to this link:
https://eaw-g9n1f8q3p5.netdna-ssl.c...on/StudyHall_and_TechNotes/Damping_factor.pdf
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