How to Correctly Fig 8 Wind a Cable and it is not a Straight Figure 8

hello I'm Dave Rat and today we are going to listen to the difference between a speaker cable that's coiled up unspooled and I'm gonna dump it onto the floor and then I'm gonna coil it up in a figure 8 pattern and show you the proper way to figure 8 a wire or a cable there actually is a wrong and preferred way of doing it so let's start out on this setup if you watch some of the other videos are done with this speaker cable testing you'll be familiar I'll go over it briefly if you haven't watched them and you want to know more there's several of them out there while I describe to setup in depth but basically this allows us to listen to the actual loss or the difference between the input and output of a speaker cable we we have a speaker here a home hi-fi speaker that's wired up across one of the wires and any sound alteration that is caused by the speaker cable will be audible to us and visible to us on this analyzer peak noise I've got a 4 ohm load 100 foot 12 gauge cable and we're listening to one of the wires the losses will be doubled because there's two wires and if I'm gonna test the load there is no differential between what's at the front end of the cable in the back end there's no current going through so we hear nothing here output here across terminals and without touching the amp volume that's how much signal is being lost or the difference in drop from the beginning to the end of the cable with the 4 ohm load, I can put a 2 ohm load on there I am going to have to unplug it for a second and 2 ohm load and then 4 ohm load which is quieter because there's less drop with the higher impedance level so listening to this cable coiled up and on this analyzer here you should be able to see we see a 6.3K peak and from the other testing we found out that that's due to the coiling quite a bit of that's due to the coiling of the cable the inductive aspects of the coil so what we're trying to do is get rid of that peak because really what we want to see we don't really care about losses too much these lost in a fairly slice but what we don't want to see is that the losses are altering the frequency response of the signal arriving at the other end if there's a 6.3 peak theoretically we should have a 6.3 dip in the other end and it won't be flat if speaker cable attenuates all frequencies evenly and we lose a fraction of a dB who really cares we have other aspects that we do care about damping factor and transient response but one of those factors is that the frequency response is linear also coiling power cables AC cables can create inductive loads as issues with that as well so let's look at the difference between a coiled cable and spooling it out on the floor and I'll do that and I'll hush down so you can hear the difference and should be able to see it let's go ahead and store and then we should be able to be that later spooling out fun part oh I was gonna shut up so much for not talking during the spooling process but we can see it so now you should be able to see that we just have a slightly rising response we don't have that 6.3 although it's not ideal it is preferable not to have a narrowband peak there probably get a little better play all right so let's go ahead do it a figure 8 and see what happens so now I'm gonna do two different types of figure 8s first I'm gonna figure eight in a pure figure 8 where we just keep crossing in the middle and what's happening here though is the inductive load is caused by the coil the energy going in the same direction so the coil that I'm coiling right now continues to be constantly clockwise these coils will all be interviewed fooling around this way these coils are going so we plan to form the uniform direction and that's the opposite of what we really want to have occur just coiling a figure eight like this And it's almost done here there we go and we can see that the peak at 6.3 isn't as big as before it actually moved up to 8k but we've gained that peak back and basically clothing like this is really just the coil and we can see that it's come back that's been opened up and that's not the optimum set up so let's go ahead and go back and I will show you the proper way to coil a figure eight is actually think of an oval so we'll go around this oval here and we're making the first turn and the second turn and they were to cross over the middle and then we're going to go this way when the first turn second turn cross over the middle turn turn middle so you're forming a loop around the outside and then crossing so we cross to turn turn cross cross and the reason we're doing this is if we just do a figure eight everything continuously goes in the same direction but if we do this turn turn cross we go it's going counterclockwise counterclockwise in the second turn we cross over and now it's going clockwise clockwise crossover counterclockwise counterclockwise cross over so by doing that every other turn goes the opposite direction turn cross turn across try to think here turn turn but now look at this we have a figure eight setup and we've maintained the frequency response that we saw with an unspooled cable furthermore since we've got this every other thing goes up to direction even when we fold this properly wounds figure eight in half we still maintain the frequency response that we saw with a spoolled out cable alright so there's the proper way to figure eight a cable and a demonstration that it makes a difference and something you can hear cool hope you like it

Channel: Dave Rat

Views: 31,805

Rating: 4.9747434 out of 5

Keywords: soundtools, dave rat, actual loss in cables, rat sound, Sound, Audio, install, speaker, cable, loss, test, cable loss, pro audio, wire, speaker wire, speaker cable, Figure 8, Wind, Wind Cabl;e, Cable Inductance

Id: jgq8-4m133o

Length: 8min 52sec (532 seconds)

Published: Wed Apr 01 2020

Reddit Comments

[u/LookAtThatDog]

I randomly followed this guy (Dave Rat) on ig a couple years ago. His company handles sound for concerts and festivals. He has a bunch of interesting stuff on his YouTube channel and Instagram.

https://instagram.com/dratsound

[u/DonFrio]

A lot of his videos are neat because although they seem like audio voodoo bs at first they are all rooted in sound electrical engineering practice and practical suggestions. He’s a good dude who knows his theory and backs it up with listening and testing

[u/HD64180]

Fascinating. Thank you for posting this!

[u/senior_neet_engineer]

His other videos are also really interesting and informative. Thanks for posting.

[u/PicaDiet]

This information is valuable to live sound people who often have cables much longer than necessary at different gigs. You don't cut a cable to length when you might need it longer tomorrow.

But he's dealing with an 80'-100' speaker cable. At that length resistance and capacitance (and if you're coiling it, electromagnetism) would certainly come in to play. The typical lengths in home systems wouldn't exhibit this problem. The theory is interesting, but don't extrapolate too much.