Musings on color management, CHROMiX products and services and other relevant topics.

Monday, May 9, 2011

Can speakers ruin a monitor?


If you have speakers sitting on your desktop, next to your computer screen, can they damage your monitor or affect its color?

The thought is that audio speakers have magnets in them, and these magnets if they are too big or unshielded can have an immediate effect on the color of a monitor that uses magnetic fields. Colors and shapes will be bent into strange patterns near the location of the magnet. Sounds scary, doesn't it?!

While there is a measure of truth to this rumor, here are a few points to keep in mind:
  • This problem only effects CRT displays, not the modern LCD which uses a completely different technology.
  • This only happens when the speaker has a big enough magnet and is close enough to effect the CRT.
  • You can tell immediately if this distortion is taking place, and remove the speaker from the proximity of the display.
  • If you notice any lasting effects of this magnetic interference, you can run your CRT through its "de-gaussing" routine, and it should come back to normal (newer CRTs run a degauss every time they are turned on.)

5 comments:

  1. Tell me a digital imaging pro, that still uses a CRT ?

    /Sven W

    ReplyDelete
  2. You're absolutely right - I can't think of a single one! But just this week I talked with a customer who 'had heard' that speakers could harm a monitor, so I thought I'd throw the information out there.

    ReplyDelete
  3. I work in a video post-production facility. One of the functions we perform is Color Correction. One of the problems we are running into is that LCD monitors simply do not have the necessary color accuracy for Color Correction work. Our colorists are constantly fighting over our remaining CRT (glass) monitors. This problem is going to keep getting worse as the electronics industry is no longer producing broadcast standard CRT monitors suitable for CC work.

    ReplyDelete
  4. I'm not familiar with the video world, but professional photographers have successfully switched over to high quality LCDs in the last few years. It takes an IPS-panel display with built-in graphics processor like the CG series of Eizos or the like, but they can produce good sharpness and precision of color that meets or exceeds the CRTs. They are pricey, naturally. I don't know if the image response time of these models is sufficient for video work.

    ReplyDelete
  5. Pat- in my experience, an LCD is perfectly suited to do color correction. High-end post houses have been using LCD for some time now. Look at the monitors that come with Autodesk Smoke, Flame and Lustre color grading systems for example. The problem can be that the CRT (especially the Sony’s) have been the reference, and it is not push-button easy to make a LCD look like one. Also, a CRT in any form is analog, old, and to some level, not fully accurate. Nevertheless, and practically speaking, it is the reference. But a good hardware calibrated monitor with 3D LUT (which does better color space emulation) can do this. Response time and video are generally incompatible because desktop LCD’s run at 60Hz. Video and film tend to run at 24fps, 30fps and 50Hz for broadcast. An LCD performs better with an expanded frequency range that synchs up to these frequencies. Trouble is you need a graphics card that allows wide frequency. There are only a very few monitors available that have the color accuracy, adjustment sand enhancements that can do this. These run from $1000 to $3000 (in 24”- which you would want for 1080HD resolution. You would likely want a signal converter from Blackmagic or AJA to port HD. Certainly, the ability to handle HD signals and signal types puts you in a higher-end monitor class. These broadcast monitors either have less than adequate color quality, or are pretty expensive (above $10000).


    Tom Gadbois
    Color Graphics Specialist - Eizo Nanao

    ReplyDelete