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Reducing RFI at Home From Lighting Fixtures? 126

Posted by Cliff from the less-noise-more-candelas dept.
amper asks: "I'm in the process of building a new home recording studio. When I originally moved into my new (very old) house, I decided that in the interests of conserving energy, I would replace most of the incandescent lighting fixtures or lamps in my home with fluorescent fixtures or compact fluorescent replacement lamps in those fixtures which could not easily be replaced. Unfortunately, these fixtures are creating a massive amount of radio frequency interference in my home. The worst culprits seem to be the dimmable fluorescent fixtures in my living room. Barring replacing all my fixtures and lamps with conventional incandescents, can anyone point me in the direction of alternatives? Is it possible that the decreasing quality of most home goods has led to a decreasing quality in fluorescent ballast systems that are much more noisy from an RFI standpoint? Some of these fluo's are so noisy, they even emit audible sound! It's gotten so bad that I can't even play an electric guitar without turning off all the non-incandescent lighting in my house, which pretty much limits me to playing and recording during daylight hours (when I'm supposed to be out making money)."
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Reducing RFI at Home From Lighting Fixtures? More

Reducing RFI at Home From Lighting Fixtures?

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  • By the very nature of there operation Fluos will be electrically noisy. Audiable noise is due to loose fitting of the ballast and surrounding items. First post ?
  • well you could allways start playin blues.

  • Focus on ground loops, not on RFI sources. (Score:5, Informative)

    by hankwang ( 413283 ) * on Friday December 03, 2004 @07:03AM (#10984408) Homepage
    I come from a physical laboratory where we have to measure small signals with an acceptably low noise despite the presence of laser flash lamps, or even high-voltage discharges in more or less open air. The best way to avoid RF interference is not to remove all RF sources, but to design the electronic circuits correctly.

    The main thing that makes electronic circuits sensitive to noise is ground loops. Often, signals travel through cables that have two wires or a central wire with a shield surrounding it. Normally, equipment (whether it is an oscilloscope or consumer-grade audio equipment) has a common ground, which means that the neutral wire of each and every input and output is connected. If you have more than two pieces of equipment interconnected, it is likely that there are loops in the ground wire, for example the cable from mixer to some effect generator, and the wire back. All these loops acts as antennas that can pick up noise. Having shielded cables doesn't help because it is the shield, that acts as ground wire, that causes the problems.

    The first and simple step is to have all wires bundled as close together as possible, such that the area inside the loops is as small as possible. The next step is to upgrade your equipment to stuff that has balanced inputs, with those big XLR connectors. Here the shields are really shields against RF interference, while the signal is carried by two wires inside the shielded cable. Balanced signals means roughly that the equipment measures the signals on the two signal wires completely independent from the ground.

    • Its also important to point out that with balanced connections one of the wires carries a signal that is a "mirror image" (180 degree out of phase) of the original signal. The wire carrying the actual signal is normally termed "+", or "non-inverted", and the wire carrying the phase inverted signal is normally termed "-", or "inverted". "Phase inverted" means inversion of "plus" and "minus" voltages and currents - an exact mirror image.

      • Re:Focus on ground loops, not on RFI sources. (Score:4, Informative)

        by rhild ( 659603 ) on Friday December 03, 2004 @08:51AM (#10984904) Homepage
        To expand on that, any RF noise that gets into the cable will appear in phase on both signal conductors, which will result in it being cancelled out in the input circuit of the device the cable is feeding, if the device has balanced inputs.

        CMRR (Common Mode Rejection Ratio) is a measure of how well an input circuit cancels out this kind of noise. When looking at the specs for gear this is one of the important but often overlooked numbers to check out.
    • If it's a very old house, as he states, it likely has knob and tube wiring instead of shielded 3 wire NM cable. K&T generally does not use a common 3rd wire ground.
      • Um, the NM stands for "Non-Metallic." It's not shielded. Go to Home Depot and take a close look at the NM cable there, it's non-twisted pair, non-shielded. Ripe for RFI/EMF. The same goes for knob-and-tube, but those conductors are spaced further apart, compounding the problem. Not to mention that the insulation is probably old, brittle, and falling off the wires creating other more serious concerns.

        Armored cable (AC, MC, or MC-lite) or conduit are, effectively, shielded wiring systems.
      • The knob and tube can be a problem because of the separation of conductors, not the shielding, but it can definately cause some serious issues with enough harmonic distortion.

        In general, the biggest problem with dimmable ballasts is when they are not properly grounded. Check the grounds, make sure they are installed with the phase conductors, and make sure that they run with the phase and neutral wiring.

        Also along these lines, if you have three-way switching check and make sure the switch leg properly in
    • There are very few guitars with balanced outputs that I know of. Not that it hasn't been done, but you start getting into the "seriously boutique" area when you start asking for this.

      For fx processing and stuff, yeah, but you're probably still going to have an unbalanced signal from your source.
      • There are very few guitars with balanced outputs that I know of.

        There's no need for that because the cable from amplifier to guitar is a "dead end", that cannot participate in a ground loop. I'm not that much into indie rock, but I assume that a guitar is nothing more than a microphone from an electrical point of view. Just a device with two wires coming out of it. Guide those two wires through a shielded cables and voilà, you have a balanced signal.

        • Most guitars are very badly wired themselves, with ground loops and terrible sheilding, and rewiring them can cut a lot of noise.
        • The average electric guitar has a high-impedance unbalanced (one "hot" one ground) output and the average guitar amp the same kind of input, and the cord in between has a center conductor for the "hot" side and the shield around that is the ground.

          If the OP would care to email me at coastalnet.com I'll explain to him how his guitar can be fairly easily modified to greatly reduce the interference which it picks up, which may or may not be due to his lighting.

          Light dimmers, incandescent or flourescent, are no

    • I also had a problem with ground loops on the computer I put in my car (a whine that increased in pitch with the egine speed). I got a ground loop isolator on ebay and the problem completely disappeared. It connects in-line to the audio cable running from my trunk to the head. Maybe something like this could help with your guitar equipment if a ground loop really is the problem.
      • "...a whine that increased in pitch with the egine speed..."

        Almost certainly caused by electrical noise from your alternator rather than a ground loop.

  • You have fluorescent lights in your livingroom?

    I'm shocked.
    • They have flourescent lightbulbs at the approximate size and shape of "regular" lightbulbs. I'm using them in my house where-ever I can.

      Here is an example of some:
      http://www.lightbulbsdirect.com/page/001/CT GY/Mini +Spiral

      There are also ones like this, closer to form (via plastic cover)
      http://www.lightbulbsdirect.com/page/001/C TGY/CF+F resh
    • You have fluorescent lights in your livingroom?

      I'm shocked.

      Was that a lame attempt at a pun? Because I can't comprehend why you're surprised that people have flouros in their living rooms. Compact flourescent light globes are incredibly common. They have lower power consumption, they last longer, and the new ones have a similar light to incandescents. My entire house is fitted with compact flouros.

      • I've heard somewhere that fluorescent bulbs has a high UV emission.

        Don't really know if it is true, but it would be interesting to know, since we've could be giving ourselves the potencial to develop skin cancer while sitting on the light of these bulbs.
      • My Entire Bedroom is fitted with them.

        The other rooms however, need more decorative lighting, and thus unsuited to the industrialised look of the flouros.

        But I leave all my lights off most of the time anyway.

        Good point about RF interference as I am looking for a best solution for a wireless remote for my PC, for myth and for xmame, going through one wall. I am buying an RF set to connect my TV out PC card to my TV, and xmame on a 12" B&W portable here I come!

        OK, so it will be a 42 plasma maybe. or 3
        • if you have the space and the power doesn't concern you, go CRT

          If you don't have the space, is a cost/quality thing - big plasma looks great from further away, but grainy (even on $7000 sets in my exp) close in. LCD can be better quality and also consumes less power and produces less heat than Plasma.

          Enjoy - I'll continue saving up for the upgrade from my 14" crt...

  • Flourescent lighing (Score:2, Interesting)

    by madaxe42 ( 690151 )
    Flourescent lighing is inherently noisy - it essentially relies on a large oscillating rf field in a mercury vapor filled tube - no matter what you do, it'll produce noise, electrical from the field, and audible from the tube resonating with the field.

    You could replace your fittings with LED based fittings - the power consumption is lower, the light can be better & brighter, and the bulbs (LEDs) last longer. Also, they run off DC, so no noise!
    • Flourescent lighting - for when you can get enough of that wheaty smell! mmmmm flour....
    • mercury vapor filled tube

      No, that's mercury vapour lamps (don't get in my way, I just got off a 3-hour interferometry lab dealing with the bastards). Fluoresecnt tubes tend to be filled with noble gases, e.g. Neon.

      • No, that's mercury vapour lamps (don't get in my way, I just got off a 3-hour interferometry lab dealing with the bastards). Fluoresecnt tubes tend to be filled with noble gases, e.g. Neon.

        Fluorescent lights are filled with a mercury vapor. So are "Mercury Vapor" lights. Though the two operate differently.

        See http://science.howstuffworks.com/question293.htm [howstuffworks.com]

      • Fluorescent tubes are mercury vapor - they rely on excitation and emission of mercury vapor, and a mercury oxide coating on the interior of the tube, which fluoresces at a white light frequency - mercury vapor lamps operate at higher voltages, and work on a direct excitiation principle - like sodium vapor lamps.

        Interferometry lab. Mmmmmm. Prisms... So glad I finished my phys degree last year.

      • Re:Flourescent lighing (Score:3, Informative)

        by DAldredge ( 2353 )
        he following introduction is from a publication by the National Electrical Manufacturer's Association (NEMA) entitled "Fluorescent Lamps and the Environment". This publication and a lot more valuable information can be found at the NEMA website devoted to proper lamp disposal called www.lamprecycle.org. An Adobe Acrobat PDF version of the publication can be downloaded from www.nema.org/lamprecycle/nemafluorfinal.pdf

        If you need more information about properly disposing of lighting waste click on the link at
    • Perfect solution, except for the price. You'd have to take out a second mortgage on your house to buy enough of them to be effective.

  • RFI Solutions (Score:5, Informative)

    by Ed Almos ( 584864 ) on Friday December 03, 2004 @07:19AM (#10984440)
    As a radio ham I have similar problems, try the following.

    1) You can get ferrite rings of various diameters. Try winding a couple of turns of the cord leading to the light through one of these rings. The ring should be as close as possible to the fixture.

    2) Wire RF chokes in series with the fittings. These work in a similar way to the ferrite rings but are more effective.

    3) It's possible to obtain capacitors that are rated for 110/220 volt operation. Have a look inside a PC power supply and you may see one, they are normally encased in yellow transparent epoxy. Wire one of these across the fitting.

    And finally.........

    4) Ask for help from the right people. Try and find either a local radio ham or (even better) a local ham club. These guys will be experts at fighting RFI and will help you out.

    Ed Almos
    Budapest, Hungary
    • [geek awe]

      Dude, please tell me you are accessing slashdot through a RF connection, using some antenna made out of bean tins and dust-bin lids.

      Awesome...

      [/geek awe]
    • If you are going to mess with line current, chokes or anything of the sort, you should know enough to know what component types and values to use, how to connect them safely and how to package them so that they will not exceed their temperature, voltage or other limits in operation.

      An educated layman can do this, but if you aren't up to passing the electronics portion of a ham test you should probably defer to people who know more than you do. This may mean as little as finding good designs on the web... b

      • Agreed, somebody carrying out these modifications should know what they are doing, but I think my post and your reply requires some clarification.

        A 5000mfd capacitor rated for 110/220 volt operation would probably be about the same size as the light fitting. Disc ceramic capacitors MIGHT work if you are very careful about the voltage rating but the devices I was referring to are known as X2 rated capacitors (I've now had a chance to look this up). The X2 rated capacitor I am looking at now is rated to 275
        • The X2 rated capacitor I am looking at now is rated to 275 volts AC and is self healing with an epoxy case. It has a value of 0.22mfd, somewhat bigger than your 5000mfd example .
          Bigger? Try about 1/22500 of the size.

  • Cables? (Score:2, Insightful)

    by metatruk ( 315048 )
    Are you using good audio cables? for example, balanced instead of unbalanced? Are you using good quality connectors?
    Is all of your equipment properly shielded and grounded?
    These would be the first things I'd check.
    • Do you work at best buy? Sounds like you're hocking those $5,000 Monster cables...
      • Overpriced cables like monster are a stupid waste of money, but he did not hawk a brand there. You can't just wire everything up with unshielded 24awg wire and expect to get away with it. Proper cabling is very important in any setup - phone, video, electrical, audio, etc. A lot of the cheap cables really are cheap and do not do a good job of eliminating interference. Good connectors are important too. I ran into the connector problem when wiring the coax for cable tv in my last house. I got decent RG-6U co
    • Have you seen any guitar outputs that used a balanced XLR connector? Have you seen a guitar amp with balanced XLR inputs?

      You are recommending the replacement of all his gear to go to a balanced sound board instead of a guitar and amp combo.

      Using 100% shielded cables is a big improvement in noisy environments, but they rarely have the flexibility and durability of a typical guitar cord. A typical guitar cord uses a braided shield, not a 100% foil shield with a drain wire.

  • Since you're "building" your own studio, I'm guessing your're going through and soundproofing the walls and the like.

    Why not try making the walls a faraday cage. Line the interior of the walls with a good layer of aluminum foil or fine brass screening.

    • Why not try making the walls a faraday cage. Line the interior of the walls with a good layer of aluminum foil or fine brass screening.

      It's much cheaper and just as effective to install rigid conduit to all the fixtures. Let the wire be noisy inside the conduit. Put a few Cornell Doubler noise filters between the dimmers and the breaker panel. This isolates the noisy branch from everyting else.

      Look for people who do Tempest power conditioning. They do a good job killin the noise radiation.
  • Use the fluorescent fixtures when you don't care about interferance and the incandescent ones when you're recording.

  • Many before in the discussion have said that reducing eliminating ground loops in your equipment will eliminate RFI from being picked up in your equipment, however I doubt you are a Electrical Engineer. My suggestion is to replace all the flourecscent bulbs in your studio with these Led Floodlights [slashdot.org], these would be easy to install, more efficient than flourescent, and will be the way everything is lighted years from now ( geekstat +1 ).

  • Ditch the dimmers. (Score:4, Informative)

    by david.given ( 6740 ) <dg@cowlark.com> on Friday December 03, 2004 @08:45AM (#10984867) Homepage Journal
    Trying to dim fluorescent lamps is a really problematic process; see here [misty.com] for a discussion. You can't dim them by reducing the voltage, and have to pulse the power supply instead. This will, as you have discovered, interact oddly with the ballast and the tube itself and is probably what's making the bulk of your radio noise.

    (The article mentions a number of problems, including the fact that you might be significantly reducing the lifetime of your tubes by dimming them. YMMV.)

    What I have in my living room are some long-live fluorescents to provide the bulk of the light, and some incandescents to change the colour and make the illumination more interesting. You might be able to do something similar without having to hook the tubes themselves up to the dimmer.

  • How about Faraday Cages? (Score:3, Informative)

    by VernonNemitz ( 581327 ) on Friday December 03, 2004 @08:59AM (#10984950) Journal
    Get some wire mesh and surround each light fixture with it, and "ground" the mesh. The size of the mesh-holes will depend on the frequency of the interference (higher freq -> smaller mesh). Chicken wire is fine for some things (60-cycle AC hum) and window-screen mesh might be needed for others (but associated with lessened lighting, alas). If you can find mesh with holes as large as those in a microwave-oven door, that will probably be more than small-enough. (Of course, if this is really a good idea, then I expect some comment from some expert who KNOWS exactly what size of mesh is sufficient. :)
    • Get some wire mesh and surround each light fixture with it, and "ground" the mesh.

      Well, in principle, the mesh size should be much smaller than the wavelength of the radiation you want to shield. For example, a microwave oven: 2.5 GHz, 10 cm wavelength, 3 mm mesh size. Now if you want to block audio frequencies, 20 kHz frequency, 15 km wavelength, so a 450 meter mesh size should be enough...

      The problem is that you are much closer to the source than the wavelength, i.e. in the near field. You have to blo

      • Regarding the near field, that's something I didn't know. But what about the fact that chicken wire and window-screen wire is often made of steel? Your post implies a copper mesh. Magnetic fields don't usually pass through a surrounding layer of iron/steel, and steel, while not as good a conductor as copper, is nevertheless conductive enough to ground induced milliamps. Or am I missing something else?
        • But what about the fact that chicken wire and window-screen wire is often made of steel? Your post implies a copper mesh. Magnetic fields don't usually pass through a surrounding layer of iron/steel, and steel, while not as good a conductor as copper, is nevertheless conductive enough to ground induced milliamps.

          I'm quite sure that a small magnet will pick up paper clips right through chicken wire. :-) A reasonably thick layer of iron without holes will probably shield low-frequency magnetic fields. Howev

        • OK, then I guess the key question is, What Frequency do those fluorescent ballasts run at? Because that's the frequency we want to shield. I wouldn't be surprised if it is more than 60Hz (yet that would be my first guess, especially for older-model straight-tube fluorescents), but I would be surprised if it was more than, say, 250Khz, even for the newer incandescent-replacement devices, with convoluted glass tubing.

          Maybe all the guy needs is a Faraday Cage surrounding himself and his recording system....
          • As I recall, flourescent light ballasts double the line frequency (presumably using a tuned resonant filter--I'd guess an LC tank) to 120 Hz (or perhaps some other multiple of 60 Hz). <nit>BTW, Electromagnetic interference in this frequency range is not in the radio frequency (RF) range (ELF transmissions notwithstanding); its correct designation is "EMI".</nit>

            Now for the bad news:
            a surprisingly vast amount of professional audio gear uses 1/4" unbalanced connectors. Of the synths, samplers, a
  • > I'm in the process of building a new home recording studio. When I originally
    > moved into my new (very old) house, I decided that in the interests of
    > conserving energy, I would replace most of the incandescent lighting fixtures
    > or lamps in my home with fluorescent fixtures or compact fluorescent
    > replacement lamps in those fixtures which could not easily be replaced.

    There are two places where fluorescent lighting really doesn't belong: a
    recording studio is one of them. (The other is a
  • ...just how much are these flourescent lights saving you?

    I mean they emit horrid RF noise, if you have sensitive hearing which I imagine you do as a recording engineer they sound terribly annoying, and they make everything look wrong (though I suppose some folks are more bothered by that than others).

    Personally if I lived in a house with all flourescent lighting, I would just want to go outside all the time, and I would be kind of grossed out by how people, artwork, and even food looked...but that's me.
    • Personally if I lived in a house with all flourescent lighting, I would just want to go outside all the time, and I would be kind of grossed out by how people, artwork, and even food looked...but that's me. Let's talk about you.

      The new ones that replace regular bulbs have a much more balanced spectra. They look much more like natural light. They also don't cause CRT flicker (although I have found some that do).

      --
      Evan

  • Energy saving bulbs don't save you money.

    The EPA and state environmental agencies are interested in reducing peak load on the power grid to avoid building power plants without brownouts.

    This often doesn't translate into net savings for the consumer. While a 13W fluorescent bulb emits light similar to the 40W incandescent bulb, it also costs 4-10x more, depending on bulb quality.

    To top everything off, you're now living with all of the disadvantages of fluorescent light. Rip out of the fluorescent crap and

    • I guess you've never toted them up. (Score:4, Informative)

      by Engineer-Poet ( 795260 ) on Friday December 03, 2004 @12:25PM (#10987211) Homepage Journal
      I use a bunch of circle-tube CF's installed in table lamps. They are rated at roughly the same light output as a 150 W incandescent but they use only 34 watts on full (they're 3-way). They will run at least a year between tube replacements and these units cost about $20 new. Figuring 2000 hours of operation @ 34 watts and 8 cents/KWH and $20 up-front, the total cost for those 2000 hours is $25.44. That's assuming that you have to throw away the whole lamp after 2000 hours instead of just replacing the circle tube; if you replace the tube every 2000 hours at $5 each the cost for each incremental 2000 hours goes down to $10.44.

      Lifespan of a 150-watt incandescent is what, 200 hours or less? Figuring 10 bulbs at $1 each plus 300 KWH of electricity @ 8 cents, the same 2000 hours of light would cost $34. Looks like your approach is penny-wise, pound-foolish.

      • "Lifespan of a 150-watt incandescent is what, 200 hours or less? "

        Maybe in my shop light, because it gets slammed around a bit.

        I usually have to replace my porch light every 6 months because I forget and leave it on most times... so let's see:

        4 months = 2880 hours. I'd say I get probably 2500 hours out of the porch light.....

        Typically CFs last longer, or so I thought that was their claim to fame....
        • I just replaced a tube over the weekend (2-3 years on that tube) and checked the new GE 3-ways at the hardware store. They claim 10,000 hours on a tube for about $25 (not a big-box store, prices are higher). The 150-watt 3-way incandescents across the aisle were $2.29 and claimed 2000 hours. Figuring 33 watts for the GE going flat-out, over 10,000 hours it will use 330 KWH at a cost of $26.40 for a total cost of $51.40 sans taxes. The 5 incandescents would cost $11.50 in toto and use 1500 KWH at a cost of $
    • Power at $0.12/kWh:

      60W incand: Bulb $0.50 / 1000h + elec $7.20/kh = $7.70/kh

      13W c.flor: Bulb $4.00 / 8000h + elec $1.56/kh = $2.06/kh

      CFs are great, need little replacement (especially good for ceiling fans). But dimmers are noisy even on incandescents, and horrible on CF.

    • They are energy saving bulbs. Meaning that they save energy, not necessarily money. They also don't run nearly as hot so can further reduce the thermal load on air conditioners, but they don't help heat in the winter either.

      The actual breakdown of the bulb's TCO will vary from bulb manufacturer to manufacturer, bulb type, as well as usage. Flicking a light on and off can decrease the usable lifetime compared to a bulb that is just left on or only turned on/off limited number of times.

      Typical usage for

  • That's easy! (Score:3, Funny)

    by Datoyminaytah ( 550912 ) on Friday December 03, 2004 @11:50AM (#10986671)
    > ...I can't even play an electric guitar > without turning off all the non-incandescent > lighting in my house, which pretty much > limits me to playing and recording during > daylight hours (when I'm supposed to be out > making money). Well, that's easy! Just make your money by playing your guitar. When you figure out how, be sure to let me know. :)
  • 1) Run a seperate ground/power block, just for your recording studio.

    2) Make sure your equipment itself doesn't have ground loops. Check out this video on TaylorGuitars.com [taylorguitars.com] about the importance of a good ground.
    • Can't do that, NEC electrial code prohibits installation of a 2nd ground spike for household systems. This creates what is called a floating ground, effectively causing a major shock hazard.

      No master electrician worth his salt would go and do that, but whould be more than glad to help you out with your problem... Odds are that the older wiring has issues with grounding and is in need of proper grounding... Call a electrician and let him deal with it.
  • Disclaimer: I'm a /. reader. This could be completely wrong.

    I'd guess that the interference is coming in through the power lines. Others have talked of filtering, ways of rearranging your lifestyle, etc. But nobody has mentioned the obvious: plug your audio equipment in through a UPS. Most UPSes have line conditioners built in. I'd expect that they would eliminate most line noise. Just a guess though. Still, it's worth trying since it's so simple.

    • I'd guess that the interference is coming in through the power lines.

      Any audio equipment worth its money ought to have a power supply that adequately prevents line noise from penetrating into the low-voltage circuits. I believe the main issue is that the primary and secondary coils in the transformer should not be too close together, as that would create a capacitative coupling between line voltage and secondary.

      Of course, a computer power supply is not rated for use in audio equipment. If you live in a

  • ...so i cant imagine the wiring being any good. check that everything is properly grounded. go to radioshack and buy yourself one of those miltimeter\electriction tool sets that have the modified plugs you stick into the walls, usually they have little LED's that let you know if the socket is even grounded at all. its also important to make sure that your audio equipment does NOT share a common ground with everything else in your house. this would call for a wirering overhaul. most of the studios i have wor
  • but the dimable lighting you havemight have to do with the transformer. You should be getting a loud humming noise when you turn on those lights.

    A fix would be to get a "shielded" tranformer.

  • Buy an online UPS (Score:3, Informative)

    by ponos ( 122721 ) on Friday December 03, 2004 @03:02PM (#10989639)

    I don't remember how much these things cost but an online UPS (one that converts AC -> DC feeds the battery and then feeds the PC/equipment from the battery) can reduce line noise significantly. It isn't the most elegant solution but feeding pc/sound card/sound equipment from a noiseless source can improve things considerably and it is very easy to install. APC has a specific solution for high-end audio/video systems that appears perfect for you (its called a power conditioner and is, essentially, an online UPS with very little battery time). Caution: the words "high performance AV system" usually mean $$$$$$. Check the link http://www.apcc.com/products/family/index.cfm?id=3 10&ISOCountryCode=US [apcc.com]

    Alternatively you may try balanced XLR->XLR cables that are used by professionals. I use these for my microphones (which provide a very low signal) and I am quite happy. Note that 4.5mm jack can also be balanced but you have to explicitly request it. Also bear in mind that a strong signal is much less sensitive. Long lengths of microvoltage-level signal are a not a good idea but line-level (-5/+5) signal is quite resistant. You may also buy ferrite cores for your cables (even power cables that have ferrite cores pre-installed!) and see if it makes a difference. Shielded cable may also be useful. Don't go spending a lot before trying.

    Finally, always remember: a very good power supply (as in expensive audio equipment) can handle noise quite effectively.

    P.

    • An alternate to online UPSes, usually less expensive: a line conditioner. Tripp Lite sells some good but inexpensive models: http://www.tripplite.com/products/conditioners/tra nsformers.cfm their 500VA unit runs about $150 (I have NO idea how much power the OP's equipment pulls).

      • their 500VA unit runs about 150$(I have NO idea how much power the OP's equipment pulls).

        Usually audio-video equipment is very demanding in terms of power consumption. An amplifier in the 2x100W RMS range can easily draw 400W of electrical power continuously, which would roughly require a ~800VA supply. (Yes, I know that in theory 1V*1A = 1W, but unfortunately UPSes do not always work that way ;-)).

        I'm a little suspicious about the *sonic* performance of line conditioners, unless they have been specif

    • Or you can make something like this [dansdata.com].
  • ... well, at least in cold climates they don't. The point is that 100% of the energy consumed ends up as heat, and all but that which gets out of the windows as light stays in the house. If you get a bulb that uses less power, your heating system has to consume more fuel to maintain the same temperature.
    • I am agreeing with you, BUT it may be that in his locale, it's cheaper to heat with another source of energy such as gas, coal, oil, kerosene, gasoline, jet fuel, hydrogen, or anhydrous ammonia than it is to heat with electric lighting fixtures.

      If he's using electric heat, then there's no point in using flourescents to save energy, since all the light that is produced eventually turns into heat anyway as it strikes objects in the room. As you said, a flourescent provides less thermal energy to the room, re
      • I do like the idea of one poster who suggested using flourescent for day-to-day living, and switching to incandescent when using the audio equipment.

        To go a step further-- get some incandescent lights that run off 12V DC. There are fixtures that use wires or tapes that you screw small lamps into (with MR16 spot or flood bulbs). They have a transformer unit and a bunch of wire that you run where you wan to put the lights, and you can put bright light right where you want it. The 12VDC won't cause any in
  • What about switching everything over to halogen lighting? Or LED's?
  • Before investing a lot of money in reduced-energy lighting, you should (have) spent it on insulation for your "very old" house.

    Sealing drafts and insulating walls, floor, and ceiling to the greatest practical degree will provide a greater energy cost savings per unit of currency spent than high-efficiency lighting fixtures or any other "energy efficiency" exercise. It should always be your first course of action.

    Put another way, you can spend $500 to squeak out one extra mile-per-gallon in your car, but i
  • Remember that all the solutions to powerline noise will also block powerline transmission of data. If you were thinking of using X10, power line networking, or any other transmission over the power lines it will be blocked.

    That's not necessarily a bad thing, unless you've already invested in this technology. :-)
  • In my studio, the only noise problems we ever had were the sounds of a road a block away being picked up by the microphones when enormous amounts of gain were in use. In other words, it was electrically very quiet.

    We only used incandescant lighting. There were several switchable lighting circuits in each room with only a couple of smallish fixtures on each one; "mood" was controlled simply by turning lights on and off. Some of the lights were purposefully colored, but most where whatever we could find c
  • You could hook up one of these fancy balanced power systems [furmansound.com]. The National Electrical Code [equitech.com] has the basic details. Unfortunatly, these [djhardwares.com] are [yahoo.com] not [simplycheap.com] cheap [audiomidi.com]. The bargain solution is to get some nice incandescent table or floor lamps and use them when you record.
  • I couldn't reply sooner because I've been on the road working on a large project halfway across the country...

    1. I am not an EE, but I did go to Carnegie-Mellon for Theatre Production as a Lighting and Sound Design student. I am a fairly knowledgeable person, however, so I do understand most of the basic electronics concepts that have been addressed, especially the audio concepts. Plus, I've done quite a bit of studying on electronics since college (if I had it to do over, I'd probably go EE!).

    2. Yes, the

  • In a college recording studio I used, we simply switched off the fluorescents and used a couple (non-dimmed) incandescents while we were recording.

    The noise from the fluorescents may not be RFI in the over-the-air sense. It may be introducting spikes into your power lines. Use high-quality surge supression and, if possible, power your audio gear with a dedicated circuit that's isolated from the one running the lights.

    Standard fluorescents (I don't know about the CFs) create noise primarily at the A/C

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