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Yerboogieman
Nobel Prize Winner
USA
577 Posts |
 Posted - Apr 26 2010 : 8:16:29 PM
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| I can't remember it, but I need a subwoofer crossover circuit. |
If you don't have the time to do it right, when will you have the time to do it over? |
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audioguru
Nobel Prize Winner
Canada
4218 Posts |
Posted - Apr 26 2010 : 8:58:38 PM
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| Because the sub-woofer frequency is low, the inductor in a passive LC crossover is huge, expensive and steals power. Therefore it is best to make an active filter with an opamp. Here is a site with a sub-woofer active filter and many other audio projects: http://www.sound.westhost.com/index2.html |
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wasssup1990
Nobel Prize Winner
A Land Down Under
2261 Posts |
Posted - Apr 27 2010 : 02:12:40 AM
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| Ah yes. This Ozzi website is goood! |
When one person suffers from a delusion it is called insanity.
When many people suffer from a delusion it is called religion. |
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Aaron Cake
Administrator
Canada
6718 Posts |
Posted - May 01 2010 : 10:11:00 AM
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| That site has a great discussion on light bulbs. I'll be printing it out for everyone who says CFLs are the cure for all the worlds problems. |
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audioguru
Nobel Prize Winner
Canada
4218 Posts |
Posted - May 01 2010 : 12:44:20 PM
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Most CFL light bulbs are made poorly in China. They fail much earlier than they should.
My Sylvania CFL bulbs usually fail in 2 years but say they last 5 years so I phone them and get a coupon for the replacement each time. |
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wasssup1990
Nobel Prize Winner
A Land Down Under
2261 Posts |
Posted - May 01 2010 : 11:37:58 PM
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| I want to convert every light in the house to LED. Prefferably so I could change the colour temperature too. Mixed RGB in other words. Sounds fancy but I want too give it a try and see how well these LEDs can mix together to produce all the visible color spectrum, but I'm so busy with Uni. Those Cree LEDs look good. |
When one person suffers from a delusion it is called insanity.
When many people suffer from a delusion it is called religion. |
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Aaron Cake
Administrator
Canada
6718 Posts |
Posted - May 02 2010 : 10:01:28 AM
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quote:
Originally posted by audioguru
Most CFL light bulbs are made poorly in China. They fail much earlier than they should.
My Sylvania CFL bulbs usually fail in 2 years but say they last 5 years so I phone them and get a coupon for the replacement each time.
I've had about the same result. Except that I've had at least 4 fail on fire. Another two failed by bursting the tube. Yet I can't remember the last time I have replaced an incandescent light. I'm just glad that I was in the room when the CFLs failed because if I was not, it could have started quite a fire. |
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wasssup1990
Nobel Prize Winner
A Land Down Under
2261 Posts |
Posted - May 02 2010 : 8:42:20 PM
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| My sister's CFL turns off and on intermittently. |
When one person suffers from a delusion it is called insanity.
When many people suffer from a delusion it is called religion. |
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Aaron Cake
Administrator
Canada
6718 Posts |
Posted - May 09 2010 : 10:59:28 AM
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That means it is probably about to fail. All of mine did that before they burst into flames.
What is also wonderful about these CFLs is that when they do break, you now have a cloud of mercury in the air. |
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audioguru
Nobel Prize Winner
Canada
4218 Posts |
Posted - May 09 2010 : 11:35:19 AM
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My electical utility company gave away CFLs for free. One of mine dripped burning plastic on the table.
They were all recalled and replaced because the Chinese manufacturer copied the certification label from his competitor so they were not certified and were not safe. |
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BEatonNo1
Nobel Prize Winner
USA
1133 Posts |
Posted - Jul 29 2010 : 10:49:59 PM
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Wasssup,
I tried to make a lamp that would change color temperature to match what is outside (to help the dreariness of the cube-farm :P). The problem is if you look at the spectrum output of the LEDs you end up with dips. This is why you are starting to see RGBY controllers, leds and products. Also heat is a big problem unless you are willing to buy very expensive LEDs.
Also good to know about CCFLs are about to catch fire when they start to flicker off and on....I have a couple that are doing that. The big disadvantage to them I think is the Mercury, I don't think any green organizations have really adopted them because of this. Only the power companies. |
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wasssup1990
Nobel Prize Winner
A Land Down Under
2261 Posts |
Posted - Jul 30 2010 : 04:37:08 AM
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| Interesting. I haven't got the time to research them but does the extra color really fill in the spectral dips and why are spectral dips a problem in room lighting? |
When one person suffers from a delusion it is called insanity.
When many people suffer from a delusion it is called religion. |
Edited by - wasssup1990 on Jul 30 2010 04:37:54 AM |
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audioguru
Nobel Prize Winner
Canada
4218 Posts |
Posted - Jul 30 2010 : 09:59:28 AM
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When two colours are added together then they fill-in and make a 3rd colour.
When R, G and B are added together in the proper ratio then they make pure white with no dips in the colour spectrum.
My RGB mood lights slowly fade and brighten R, G and B LEDs and make millions of colours including pure white.
One Japanese TV manufacturer is adding yellow to the RGB screen (maybe as a gimmick). |
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wasssup1990
Nobel Prize Winner
A Land Down Under
2261 Posts |
Posted - Jul 30 2010 : 8:50:27 PM
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| That's what I was thinking too, it probably is a gimmick. We only need RGB on a black background or YMC on a white background to produce the full visible color spectrum. I havn't done the research but I don't see how yellow will improve apon anything. |
When one person suffers from a delusion it is called insanity.
When many people suffer from a delusion it is called religion. |
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Aaron Cake
Administrator
Canada
6718 Posts |
Posted - Jul 31 2010 : 10:41:45 AM
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It most certainly is a gimmick. Since yellow isn't part of the transmitted signal, it must be synthesized. There was an article in Maximum PC that explained how absurd adding another colour is:
http://www.maximumpc.com/article/features/display_myths_shattered
I guess if you like over saturated yellows at the end of the spectrum, get a Sharp TV.
As for the CFLs, I wonder how many of those enviro-weenies pushing them really through the whole thing through. The fact that they contain mercury makes for a disposal disaster if they all end up in the landfill. Many are made in China where there are minimal environmental controls, and minimal worker protection for those handling hazardous substances. And what about all those perfectly serviceable incandescent bulbs which are now in the landfill? |
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audioguru
Nobel Prize Winner
Canada
4218 Posts |
Posted - Aug 01 2010 : 9:44:28 PM
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A CFL contains a very small amount of murcury. Most people don't eat landfill.
I heat my home in a furnace with inexpensive natural gas, not expensive electricity in incandescent light bulbs that don't last long. The air conditioner must work harder to remove the heat from incandescent "heaters". |
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Aaron recommended a circuits site to me.
