Thank you. Yes, I realise that you were referring to the 'pull the ethernet cable' test, but the underlying implication seemed rather serious. I have to say I'm amazed at your findings. I can't believe that what you've encountered is common. I once had a 'music centre' (all the rage 30 to 35 years ago) on which I made cassette tape recordings of FM broadcasts (you've guessed it - the top 40 countdown), and I used to regularly detect clicks and pops from the kitchen fluorescent lights being switched on or the fridge motor switching on. But it's been many many years since I've encountered any sort of extraneous noise through my hifi. Tell a lie - a couple of years ago I built a gutted SB2 into the same case as my home-built pre-amp, and careless routing of the wifi pigtail resulted in audible noise whenever the SB2 buffer refilled. But that was an isolated incident, and apart from that my hifi is gloriously immune to any kind of electrical noise or SQ degradation, even from my Mac Mini server running within a few feet of my amplifiers.
Results 21 to 28 of 28
2012-07-02, 13:38 #21
2012-07-02, 19:53 #22
- Join Date
- Jan 2007
A couple of thoughts...
First, my system has to share a room with lots of other stuff from modern life. Besides the Squeezebox Touch with an amp & speakers, there is a TV, Roku, laptop, switch, Kindle Fire, cell phones, a cordless phone, my daughter's iPad and occasionally her laptop. I control the volume with the Touch's volume control so the amp is set fairly wide open. Even with my ear to the speaker, I've never heard the slightest hint of EMI breakthrough on the stereo speakers. I've also never heard a change in sound quality in the system that I can attribute to which of the devices are present in the room or which ones are on or off. (The only breakthrough problem I ever had was when I had a turntable in the system and the guy a couple of houses away would broadcast on his shortwave radio through the antenna on the outdoor tower. The neighbor and his tower are still there but the Touch seems completely immune.)
Second, radio wave strength follows the inverse square rule, so even a foot or two is a lot of distance compared to having gear immediately adjacent to each other.
Third, I don't think it is a particularly unusual complaint that some high-end electronic devices willingly sacrifice some of the traditional signal isolation methods commonly used in the communications industry and scientific equipment. Some pieces of fancy equipment may indeed be more susceptible to interference than even middle market gear.
Finally, the effects that people claim to hear are often at the edge of perception and rarely are subject to any repeatable test criteria.
I know that I'm the biggest variable there is in my system. Perhaps it is just my aged hearing, decrepit mind or inferior system, but when I have to strain to decide if what I'm hearing is real or imagined, I've ceased to worry much about it. That makes it a lot easier to just enjoy the music. ;-)
2012-07-02, 23:29 #23
Cell phones can make it in if your close enough a feet as you say.
But something must be technically wrong if the rf from a wireless mouse find it's way in , are we talking tube hif here or ?
But a factor is weird audiophile grade equipment as you say , there was some fetish in having things with very high slewrate and thus ultra wide bandwith especially in power amps vs a more level headed company as Quad always have bandwith limited inputs to not get exactly those problerms we where discussing .
And even more daft stuff like no shielded casing is it not dnm that thinks metal cases "sounds bad"
There is another factor improper equipment setup especially grounding ,not all outlets have a ground prong (maybe in GB ) but some hifi is designed to be grounded some people don't install a grounded outlet to the hifi (but indulge in voodo power cables instead, eh).
I had an power amp that did receive FM radio I could not get why untill I've found out that the seller gave me the wrong power cable it did not have ground .
Another case of wrong grounding can be shielded cat6 cables, that is used in way that gives you ground loops, simply at home do not use shielded Ethernet it has an application in very harsh industrial settings
To be practical I don’t hear a difference pulling the plug SBGK did not hear a difference and many more forum members do not I think it is a valid enough test , there might be rare weird exceptions , but it is so audiophile to always seek the fringe explanation .
In most cases folks hifi equipment are not subject to subtle sq changes due to interference .
I have not upgraded hifi in years I also enjoy the music .
And lets not forget some basics that must be disproved before any subtle source mod is to be taken seriously .
There is not even a case for that we can hear a difference between *any* source component if the source is reasonably well designed and the DAC is reasonably well designed , if ie nothing is technically wrong all source components sound the same into a DAC .
This is usually the case in scientifically conducted tests , but this is a reasonable provisional fact imo .
So why not just use a suitable digital cable (BJ or similar not boutique stuff ) connect the unmodified Touch to your dac or processor and enjoy the music it works just try .--------------------------------------------------------------------
Main hifi: Touch + CIA PS +MeridianG68J MeridianHD621 MeridianG98DH 2 x MeridianDSP5200 MeridianDSP5200HC 2 xMeridianDSP3100 +Rel Stadium 3 sub.
Kitchen: Touch + powered Fostex PM0.4
Misc use: Radio (with battery)
iPad1 with iPengHD & SqueezePad
(in storage SB3, reciever ,controller )
server HP proliant micro server N36L with ClearOS Linux
2012-07-03, 03:44 #24
- Join Date
- Apr 2010
The typical squeezebox installation is surely a server in another room from the SB. I find it difficult to accept that a change to processes running on the server could perceptibly affect the sound of the stereo in another room either from changes in the amount of EMI from the computer, or from some mains borne interference.
Any such emissions from the computer would be pretty minute compared with all the rubbish generated by all the other devices (including those of your neighbours.)
IMHO one might as well postulate that the changes on the server processes affect the stereo by some hitherto unknown effect, which would be about as plausible.
Last edited by adamdea; 2012-07-03 at 09:36.
2012-07-03, 07:20 #25
2012-07-03, 11:54 #26
- Join Date
- Jun 2006
Note that I specifically said that the tests I had run were done in the same room as the stereo system, usually 6-8 feet away, NOT several rooms away.
These tests happened about 5 years ago when I took my SB3 over to a friends house to show it off, how nice it was to use and how good the sound was from such an inexpensive box, and that it could work well with his expensive DAC. I was running this off my laptop with the server on the laptop and using the web interface to control things. After listening for a while he said that he could hear a change in the sound when I was actively doing things with the computer (searching for the next song to play etc). Well that surprised me I had never heard that before. We then started doing some tests to see if it was related to the fact that it was the computer with the server or if it was just the laptop in general. We loaded the server on his Mac mini and sure enough, working with my laptop caused a change in the sound, even if it had nothing to do with the sound flow (server on another computer, playback from SB3). We tried this with one of his laptops and got similar results. Doing things with the Mac mini didn't cause any change, but it was not in the room with the stereo.
This got me thinking about how computers can affect things. I started running tests in my system, and other peoples systems. We did find that there was significant difference in sensitivities, some systems more than others. At this point I was not interested in a more rigorous testing to try and figure out correlations (what was it about a system that made it more sensitive).
The thing about the mouse was not a wireless mouse, just the increase in activity in the computer when moving the mouse. Interestingly the couple places I have heard this have NOT been on "audiophile" systems, but at peoples houses with "normal" systems. I was at one ladies house, she had the stereo on but the song had stopped playing, she was working at her laptop, we could definitely hear a grinding sound coming from the speakers, changing in concert with the movements of the mouse. I have heard something similar to this at another friend's house, again not an audiophile system.
Since this has little to do with the thread topic I'll shut up now.
2012-07-03, 12:14 #27
That will usually not have been the computer's activity itself but the screen's.
Old LCD displays used to still be line driven and could even be scanned from another room (you could make visible what they are showing in another room). They even developed special fonts to get around the effect for security relevant text.
It's not as dramatic as with old tube monitors (where, given a somewhat radiation free environment you could even reproduce their picture over hundreds of feet) but they are still radiating quite significantly.
Got much better with higher-resolution displays (due to the shift to higher frequencies) and LVDS but it's still probably more EMI then what comes out of the rest of your computer.---
learn more about iPeng, the iPhone and iPad remote for the Squeezebox and
New: Logitech UE Smart Radio as well as iPeng Party, the free Party-App,
2012-07-04, 04:40 #28
Then I bought $20 worth of copper tape off ebay, and lined the guitar cavities containing wires, pots and switches with it. The pickups cannot be shielded, though. Anyway, now I'm hard pressed to detect any PC (or fluorescent tube) activity through my guitar amp, no matter where I'm playing. The guitar is a Telecaster with single coil pickups, a 1950s design infamous for its ability to pick up electromagnetic noise. There was probably less EMI floating around in the 1950s, so Leo Fender didn't bother with shielding when he designed the first electric guitar. And the Fender company never upgraded the design with shielding since.
Anyway, the point of this anecdote is that shielding for audio frequency EMI seems to be a really, really easy, inexpensive and effective thing to do, but despite that, it is not always done. For reasons that elude me.