How Cable Management Mistakes Can Lead to Big Headaches. Tips to Avoid Interference from Cables.

Hey, so we're here to talk about mistakes that really well-intentioned people make. In my left hand, I've got an AC power cord. This is a weapon of noise. In my right, I've got a standard REL high level cable for those of you who know REL well. This goes to, the blue speak on socket goes into the subwoofer. These go to your amplifier. So this is where people who really value aesthetics get it wrong and they create headaches for themselves and they wind up causing dissatisfaction phone calls. People who are working in stores don't understand what's going on. Suddenly there's hum and buzz in their system like they've never heard before. It worked fine and now doesn't. And it's a very dilute kind of an approach. Nobody's going, okay, I did this and then this happened. Never gets reported in that way.
When you plug a power cord into the wall, you think that power is going through the copper. What you're not realizing is there's about a three inch column all the way around it. That is an electronic field. It's called an E-field. And in that E-field, you actually have current exploding back and forth rhythmically in an invisible column right around this cable. So here's where things get goofy. I'm gonna undo this guy, can actually be my own worst enemy here. Alright, so I've got my thing plugged in, unplugged it. So, I really wanna make these cables. It's just this rat's nest of cables. I'm gonna make this look really nice. And what they do is, here we are, we've got this close, plugged into the sub. We've got this and we got all this cable here. And you know what they do?
I see this in stores too. Shame on them. And you listen to, you go, you've got a really noisy 60 cycle or 50 cycle hum field going in your REL. What are you doing? So, they run a bunch of tie wraps down and they make sure that these are in intimate contact with each other. You know where this is going. There's that three inch column of an E-field that's making energy back and forth. And by putting it either into the low level interconnects, if it's a 0.1 LFE cable or into a high level right next to it, get this all nice and neat and tied together. And then they usually take it with the excess. Here's what they do. They bundle it up and they really make sure that it's a really small thing because then we can tuck it and we can put a black sock over it.
Then you won't see anything. It's awesome. At which point you actually have created an electrical component called an inductor, which is a coil. It's used for all kinds of things. It's used in crossovers. It generally rolls off high frequencies. So now you're actually affecting the crossover on your subwoofer. Just a gentle suggestion. Please don't ever freaking do this again. Keep them separated. If you want it to look pretty, great, no issues. Plug it in. Run this to an AC sock, for example on this side, the amplifiers on this side, and keep these things separated to every extent possible. Now, that's not to say you can't have some overlap, but if you do, try and have them cross at 90 degree angles to each other, right, or at just any kind of something other than pure parallel for 4, 5, 6 feet of length, that's where you get the induction hum.
But if you come across at just a slight angle and you're only crossing it an incident point, you're fine. But I see this in stores all the time. They wrap them with about 40 different tie wraps, then they put a big piece of black grill cloth to wrap the whole thing up, drop it into sort of the shadow boundary at the boundary between the wall and the dark carpet. And they're going out. We can't seem to get the hum out of our systems. Yep, yep. Gonna happen a hundred percent of the time. That's the way physics works. Okay? So just keep these things separated as much as possible, whether it's your low level interconnects or high level cable, keep them away from the AC and you'll be fine. It's a really quick tip to keep a system clean, well-organized, quiet, and you'll so much appreciate not having to try and chase down hum gremlins in your system that were induced by coupling between the two cables.

[@berj79]

One of the main reasons i go for aftermarket shielded power cables 🙂

[@jondu-sud274]

I can hear your pain .........very well explained, thank you

[@artmaltman]

These are superb videos (as are your products!) but PLEASE no music!!!! The music is annoying and distracting. Trust your content!

[@totalplonker824]

Maybe I'm a little sensitive to unwanted background noise! But it's taken me years of trial and error to get rid of all my noise (noise floor) or should I say cable interference noise. From my listening position, I don't pick up on any noise anymore. Just to make it clear. Nothing to do with grounding / distortion or any kind hiss or buzz. What I'm referring to is the sound of the room! In fact, I would imagine the vast majority of HT owners are probably not even aware of the faint background signal noise, and that's ok. And there are probably a few who are aware of it. And yet it doesn't bother them, and that's ok too. But for me, getting rid of the background signal noise has been a journey within itself. After all, it's not as if one can pinpoint where the noise is coming from. It's almost as if the room itself has a faint electrical current sound. (Poor description) Even after I auditioned three separate mid-priced AVR's, the same unwanted noise was still present. It was only after I changed my cables for a third time. My noise floor came down to such a level, my sensitivities we're finally satisfied. I'm running an arcam avr20 with a couple of matching high-performance 4 channel power amps (front stage/Atmos) which are driving my Sonus Faber speakers in a 5.2.4 configuration, which also includes a stereo pair of Rel subwoofers for my 4 × 3.5m (13 × 11.5ft) livingroom. I have to say it was only when I purchased quality shielded speaker & RCA cables. The room became exceptionally quiet! My room is now so quiet their are occasions without opening my eyes, I'm actually unable to differentiate whether the system is switched off or if it's switched on. The room is really that quiet. If one is looking to get rid of that so-called ambient sound of the room. IMO, shielded cables are the only way to go. And btw they don't necessarily have to be expensive. However, the better the Shielding, the quieter the room. Bear in mind this is coming from someone who's changed his setup and cables multiple times. It was annoying at times, but hey, isn't that part of the journey 😁

[@seano218]

Actually, the rule in the field is less than a foot in parallel for more than 3 feet will generate inductance. The rest about crossing at 90 or at the very least 45 degrees is correct. This is very real and very true as I have witnessed voltage increases to the point that sensitive low voltage equipment literally gets fried on numerous occasions! Thank you for making a video about this!!!

[@deadline7610]

Nicely Done.

[@dixonbuttes6564]

Now, John ... there's another way to get hum with your sub, and that is to plug the subwoofer's power plug into a different outlet than your receiver. Since RELs use a three prong power plug, the act of plugging the subwoofer in over there, then the amplifier in over there ... there's hum there, too. But your message is well taken on this one, and users should know ... the REL is a nice piece of equipment, and requires best practices, or else it //will// hum.

[@joeritota9073]

I love it!! Hopefully users will finally get the benefit from what John is saying here!! I love my REL sub! Great job John!

[@clementajaegbu6660]

Ok, and even if there is minimum contact (from cables criss-crossing) ==> still get that tell tale hum ; thanks for the suggestion !!!!

[@warrenmayo5905]

Thanks John, good information!

[@Jim90wa]

Thank You Sir.

[@flargosa]

How about bundling audio cables and power cables in separate bundles? So you have audio cables bundled together and power cables bundled together.

[@RELAcoustics]

Thank you for reaching out. This is typically fine to do, since the main concerns is having audio signal cables run parallel with power cables. If the audio cables do need to cross power cables, then it is best to do so at 90 degree angles rather than letting them run parallel.

[@srkgv]

Thank you

[@gp4533]

Question: Is it the same with power cable and xlr? Or does the symmetrical nature of the xlr compensate the influence of the power cable? Thanks for your work!

[@brianhoggard3763]

The design of XLR is for overcoming noise on the cable, but I can tell you from experience that it doesn't work miracles, and you still want to avoid these types of cable overlap and coiling that he spoke about. Good habits are good to stick with all the time.

[@RELAcoustics]

Thank you for reaching out. The balanced design of an XLR cable will help to prevent some noise, but the guidance provided in this video is good practice to follow with any cables, regardless of their type or connectivity.

[@ptg01]

Electromagnetic Field (EMF) ?

[@MaharionPendragon]

Omg I've been doing this for ages. So, does this principle apply to all cables, such as ethernet and hdmi cables? I hope someone answers me please

[@RELAcoustics]

Thank you for reaching out. The cable interference that John describes in this video more commonly occurs with analog signal cables, such as an RCA or our High Level cable, and is less common with digital signal cables such as ethernet or HDMI.

[@MaharionPendragon]

@@RELAcoustics Thank you ever so much for this answer. Your customer service is truly the best. I'm now saving up for REL Tzero, and it's going to be good :)

[@user-br8qc5yh7o]

what about the long speakon cables provided? do we coil it up or better to cut them? thanks....

[@brianhoggard3763]

Speakon is actually just the connector. It's a branded end type by neutrik for live event production and doesn't change quality of anything. It's there as an quality of life and to lessen wear and tear. It's just just basic signal cable with the speakon connector at the end, so trim or leave as you see fit.

[@RELAcoustics]

Excess length of the High Level cable that comes supplied with your subwoofer can be coiled if needed, or if you prefer then you can trim the cable once you have finalized the positioning of the subwoofer in your room.

[@hkraytai]

@@RELAcousticsSo the length of the cable will not affect the sound? I’d rather not cut it but if a shorten cable can have a positive impact then I will.

[@RELAcoustics]

@@hkraytai That is correct, unless you use a cable that is far longer than the 10 meter one supplied with the subwoofer, in which case there can be some signal loss.

[@samidebs3559]

Hi Mr Hunter can I connect the high level straight to my speakers binding post!?

[@brentcollins9727]

That’s what I did and it sounds great.

[@samidebs3559]

@@brentcollins9727 I’m gonna try it this evening!

[@RELAcoustics]

It is possible to do this when running a stereo pair of subwoofers, and if your amplifier uses a Class A/B output stage design, though if using a single subwoofer or if you are using a class D or balanced/differential power amp then it will be best to connect the High Level cable to the amplifier's output terminals.

[@samidebs3559]

@@Burphy42 i do have a short cables with a dual rel T7x with AB amplifier,it sounds great 👍

[@samidebs3559]

@@RELAcoustics I am running a stereo rel T7X and I did tried it sounds great 👍 thank you for responding!

[@paulcomeau6]

If you see this in a shop, walk out asap. They don't understand high end electronics.