If you have stripped any amount of CAt5e, you would/should have noticed that the twist rate of the Brown pair was lower than the others.

Cat6 is different, in several ways.

From the link below, "The twist rate (also called pitch of the twist, usually defined in twists per meter) makes up part of the specification for a given type of cable. When nearby pairs have equal twist rates, the same conductors of the different pairs may repeatedly lie next to each other, partially undoing the benefits of differential mode. For this reason it is commonly specified that, at least for cables containing small numbers of pairs, the twist rates must differ.[2]"

[Link: en.wikipedia.org]

And, since we're discussing twist rate, this-

[Link: en.wikipedia.org]

That doesn't make it part of the spec. That makes it the way my SKU of choice has been made.


...and nothing is mentioned about which color gets most or least twists.


The photo shows a UTP where brown is the least twisted, though it also shows a brown stripe on part of the white/green wire. The photo of the F/UTP shows a cable where blue appears to have the least twist.

The words "brown" and "green" are not in the text of this article, and there's no picture naming which colors are twisted most and least. The closest you get here is "the twist rates must differ."


Thank you for that:

You rest my case. Thanks.

We all forget a lot of info through the years/decades, but this is covered in the CEDIA Installer I test. Having been forced to take it 12 years ago, it's fresh in my mind. :D

Yeah, but it's not that it's not fresh in your mind. Is a person who is adamant about something that's not true just unable to remember it?

The info about twist rate IS fresh in my mind, but memory is an odd thing- many things just don't go away. Someone who's adamant about something remembers, just not correctly in all cases.

However, some sites are a good way to find info quickly and use them as a way to check one's memory and Wiki works as well as any for network info.

I used a different cat6 and I thought the problem was solved. Last night she emailed me again that it is still happening with the same speaker. Buzz for 10 sec then it goes off, then on again and repeats. Could it be interference from an LED driver in the ceiling? I'll play with the line in level adjustment on the Sonos as well; the hard part is that when I'm there it is working fine.

If you have a Radio Shack near you, buy one of these and connect it to the end that connects to the Sonos. If the buzz remains, it's RFI/EMI and if it stops, measure voltage from the RCA cable's shield to the Sonos' shield. If you see more than a few millivolts, you may need an isolation transformer or the kind of balun we linked to. Make sure it actually has a transformer- they don't need to be very expensive, but the good ones won't degrade the signal. Jensen and Edcor are two of the better brands.

highfigh, buy one of what?



It sounds like we have some new data that's more important than what wire is being used: does this problem occur only at particular times of day that happen to be NOT when you're out there? That's a strong clue to help pin down the source.

I doubt that there's an LED driver in existence that does something for ten seconds, then stops, then does it again, over and over.

You need more need data: does it buzz for ten seconds over and over? Or just once or twice? At what time of day or night does it stop happening?

The weirdest problem I've seen was that a guy lost his satellite signal that we modulated and ran throughout the house on his TV antenna system. Turned out that it started when his garden lights came on at 7:00 PM every night. He snooped around and found that one of the PAR lamps had a strange audible buzz. He removed that one and got his channel back.

Second weirdest was a client's DirecTV, which did not receive HD programming until about ten minutes after the morning sun hit the LNB. Too cold, it wouldn't work.

Sorry, I was involved in a call to ATT Wireless and got so pissed off that I forgot to provide the link.

I guess they may have discontinued their amplified speaker- battery powered, so it was isolated from the rest of the circuit and it's a great way to find noise sources, or prove that it's not coming from a device.

I would like to hear the noise- I have heard some sounds come from cell phones and device controllers, but only when a call was coming in or when the controller was sending commands.

I missed the part about Sonos Line-In. I encounter lots of ground loops with Line-In. Try adding a ground breaker to the cable feed. I always assume that the cable feed is the ground loop driver until proven otherwise.

It happens, especially with some of those jerks.


I use a test telephone as my wetware interface. If there's hum in a line level or louder signal, you'll hear it on a test telephone set to the monitor position. Radio Shack also has had, for years, a small 9-volt powered amp that's good for this.


There's SO MUCH you can learn by hearing the noise! ! ! This is a great suggestion, especially as it breaks ground loops.

As buzz says, ground breaker. But put the entire system together before you even think about hum. I once moved a big system for a guy and he was concerned about hum when we were half done. I wisely asked him to hold on for a day... when I finished connecting everything, there were so many grounds and ground loops that there was no noise!

The main reason I was so pissed is that, once again, the call ended unexpectedly. A few minutes in wouldn't be so bad, but it was over a half hour after I called and I didn't have a chance to agree to the offer she made. If my phone can't hold a call when I'm sitting in one place and using WiFi and their phone system can't maintain a connection, why should I use ATT for my cell phone and internet?

If you're referring to the off-white amplified speaker, that's the one I was trying to find on their web site, but couldn't. I found it on Amazon and some other sites, but not on RS, even if I used the part number. Doesn't really matter- any battery-powered amplified speaker or device with an input and headphone jacks will work.