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Hi Guys,
Newbie here. I would like to know ways to reduce RF noise in my system. Where would be the likely sources in a typical bedroom. Besides my system, only other equipment I have in my bedroom would be my desktop, wireless router and a halogen lamp. Separate power conditioner for audio. Computer, router and lamp connected to a separate wall outlet...different line.
Thanks for your help.
Follow Ups:
The Upgrade Company has an extensive primer on EMI/RFI and most of their modifications address these 2 problems. I had them modify my $1,200 Marantz SA 8005 and it sounds much better than my old $2,500 SA 14.
One of my other hobbies is ham radio - both a victim and contributor to RFI!
One of the best pieces of advice I ever heard - although probably not very popular if you're married or have kids - is to shut down your power at the panel, and see what kind of difference it makes. It's amazing how noisy our homes are, internally.
Don't be scared by the math, but here's some good reading: http://audiosystemsgroup.com/RFI-Ham.pdf
Ferrite chokes are available at places such as Universal Radio, Ham Radio Outlet, Fair-Rite, and others.
Jim J.
No kidding!
We had a pole-pig melt down several years ago in the heat of late Summer. With no A/C, TV, Internet, suddenly all we were left with was... each other! So slowly everyone in the neighborhood crept from their houses and we were reduced to wandering around visiting with one-another and ultimately watching the linemen install a new transformer. It was great!
But once the juice started flowing again we all started looking around sheepishly and hemmed and hawed and shot back into our caves.
Maybe people are really better entertainment devices than machines? Just don't touch my iPad...
73, K7SNV
Drink the beer, before it gets warm! ;)
73 de KG4NEL
Jim J.
Welcome!
are you living on or off of a grid (major U.S. city)?
RFI/EMI is everywhere -
...is to place piezoelectric crystals on or near your speakers. Rough cut topaz is cheap and works well. The effects of quartz vary greatly from one stone to another, so I usually stick with topaz. Aqua aura works well, but it costs more than topaz. All of these crystals convert elecromagnetic waves into kinetic energy (they vibrate) and clean up the sound. The typical result is a larger soundstage and better detail.
Crystals work in all sorts of places: here is a picture of some that I've placed in my preamp:
Another way too absorb RFI is to use ERS cloth or Z-Sleeves near the cable inlets. I don't think that either product is made any more, and their effects aren't as strong as the effect of crystals, but I use Z sleeves on my speakers and they have some effect, even though it is a small one. One problem with Z-sleeves and ERS cloth is that they can deaden the sound if over-used.
I double checked the www.stillpoints.us website and they still list ERS as a product they distribute. The specifications for RFI absorption is clearly given on the website, and quite impressive, IMHO.
Many have commented that use of ERS dulls the sound, but that hasn't been my experience. However, I am not sure if ERS is suitable for the original poster, as application requires some patience and a lot of experience. .Indiscriminate application can produce negative results easily
Hi Unclestu. Yes, you are correct...I don't think I have neither the patience nor the experience to deal with ERS...:)
Just wondering...about crytals...ever had the blu tack or little plastic baggies melt on top of amp IE core transformers? Top of mine (chrome covered)run very hot.
Blue tak can melt, I doubt if the plastic baggies will, hower. You can pick up small zip lock ones at craft stores, BTW , about an inch square.
Another good storage device is contact lens holders, you can cut them in half with a saw, or come to think of it you could use a bottle cap and use the blue tack inside. The plastic is pretty permeable to EMI fields
I believe Mark Hampstead has sold the rights to another company which is manufacturing them
I like the Z sleeves placed on the cables themselves. In isolating the magnetic field of the cables from external influences it has been a major sonic benefit in my system. I use them on ICS as well as Speaker cables. On power cables sonic gains are smaller unless you can slide it over the actual ends, IMHE.
It is good to hear from you , though, and I am glad to see you still experimenting with crystals. The the dropping of the price of gold, aqua aura prices are dropping too, btw,
Another interesting crystal you ought to try is rutilated quartz. Rutile is titanium dioxide and is supposed to have certain catalytic properties. It is interesting stuff and love to hear your thoughts should you elect to try it. I buy mine from bead shops, BTW,
Hi Paul_A. Been hearing about effects of crystals. For for speakers and components...where would be a good place for them externally?
Thank you.
Pretty much anywhere can work, but areas where the radiation is highest work best. RFI travels along AC lines, so anything connected with power supplies is beneficial--near power transformers, rectifiers, or power supply capacitors. On speakers, I have had good luck with aqua aura as close to the drivers as I can get them. Here's a link to some rough cut topaz. It's cheap and works well. $10 should buy you a lifetime supply.
Thanks Paul_A..:)
In a plastic bag place them where the power cord enters the piece of gear (IEC plug)
ET
Thanks Awe-d-o-phile..:)
Your welcome and good luck!
ET
We live in a RF and gigahertz saturated condition. Routers, cell phone transmission, TV and radio. Some things dump noise back onto the ac line and also can enter equipment enclosures through very tiny holes and connectors. Moving the computer and router to another location might help. Shielded cables and input/output connector caps can help. But the simple fact is all these tech toys we now enjoy surround us with RF.
Maybe something is different in my scenario but I don't get much of any change unplugging the TWO routers I use (the ISP supplied unit has no external antennas and doesn't work well at the far edges of the house) and they are only 10 feet away from the gear. Perhaps all the things I am doing to combat grunge already play a role. I get more result when unplugging the laptop switching PS, what a noise maker!
ET
S
Since you already have a separate power line conditioner for your audio system, the next step is to use a separate power line conditioner for your computer gear and lighting that would suppress noise before it enters the AC line in the first place. An isolation transformer based PLC for the computer/lighting gear would be the most effective method for the task. However, a computer grade line conditioner such as a Tripp-Lite LC1200 features effective noise filtering and voltage regulation:
http://www.tripplite.com/line-conditioner-1200w-avr-system-automatic-voltage-regulator-power-conditioner-ac-surge-protector~LC1200/
Good prices can be found on eBay:
Hi Duster. Thank you for your input. Quick question...Do I need a separate PLC for my comp, router and lamp even if they are on a separate AC line from my audio system. My bedroom has 2 different AC lines for some reason. Presently, they are just connected to an el cheapo powerstrip.
The benefit of a dedicated line has to do with a high-current demand power amplifier being placed on a separate circuit from low-current demand components within an audio system. It is not about RF noise issues which still requires power line conditioning to address. It's often considered best to also filter noisy AC appliances themselves as well as use an audiophile power line conditioner rather than only relying on an audiophile power line conditioner to filter both power grid noise and in-home noise sources.
Somebody gets it.
Duster, your's is one of the first postings I've seen in years who understands the difference dedicated lines and line conditioning.
Not sure I understand the need for stated points in your last sentence, but, hey, nice to know ya'.
Thanks Duster, Unclestu and everyone for all the information. Really appreciate it.
Yes, will still help audio n help the computer stuff too. Evrn cheap Monster PLC power strip can make noticeable difference.
s
The three items that you mentioned are all sources of noise:
The desktop - I presume computer - will generate lots of EMI & RFI:
the spinning of a disk in either the hard drive or a CDROM reader will cause lots of spurious noise (all rotating equipment does), the router is a signal propagating device, by design; and lastly the Halogen light has a High Voltage supply to get the proper voltage for the lamp-
None of these devices were especially designed to minimize the radiation of RFI/EMI
some of them can be tweaked to emit less....
As Awe-d-o-file suggests, mine the forum
Happy listening
I think that you have already done a good job of reducing interference possibilities. At this point, unless you have some actual evidence of an issue, I wouldn't worry about it.
Regards, Rick
RFI is everywhere. I've spent lots of time to filter it, remove it and so on. The result is a big improvement. I like the speaker filter which helps filter/remove it from your speaker wire which acts just like an antenna. There are things that actively and passively remove RFI and EMI. Dealing with power delivery to your gear is hugely important as well.
I would search the Tweaks forum here and use terms like RFI and EMI and you'll find a TON of info to sift through. Put RFI in the line "with the topic title". Also I found both RFI and EMI sometimes come from unexpected and unidentifiable sources. The key is assume it is there and attack it.
ET
Edits: 10/17/14
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