Yes
I guess mostly it does so. . Especially if talking cheap woofers.
But there is a big advantage of these drivers + LEDs: measure the THD at 100 Hz without an LED at > 90dB...
Ok, this will make it somewhat sensible to build LEDs in the speakers: He will see if the music is playing still in a few years when his hearing´s gone....
Thats not the point, those megawatt caraudio guys loose something different....
as a wrote, i did the experiment. And at my speakers the LED did not cause audible THD - but also did not gife any light, at reasonable levels.
Once i have seen a schematic for a guitar amp, using LEDs for adding distortion to the signal...
see above
Re: wow you guys stumbled onto something else for me!
So THAT's why audio-appreciating people don't like modern music !? 😉
Hmmm... maybe I'm hopelessly old-fashioned with the age of 30, but since when has distortion been an indication of quality?
Do we possibly have a link here to the subject of hearing loss, and LED's to indicate accoustic activity, which is audible to the inhabitants of the nearest 4 blocks, but barely noticed by the occupants of those mobile 2 m3 boom-boxes, some call vehicles and use for transportation?
Then again, maybe the excessive movement of air inside a car, causing 20 sq.feet of useless fabric to sway in the wind, is the only way to make baggy-pants look cool? 😀
MrCheeks said:
So THAT's why audio-appreciating people don't like modern music !? 😉
Hmmm... maybe I'm hopelessly old-fashioned with the age of 30, but since when has distortion been an indication of quality?
Do we possibly have a link here to the subject of hearing loss, and LED's to indicate accoustic activity, which is audible to the inhabitants of the nearest 4 blocks, but barely noticed by the occupants of those mobile 2 m3 boom-boxes, some call vehicles and use for transportation?
Then again, maybe the excessive movement of air inside a car, causing 20 sq.feet of useless fabric to sway in the wind, is the only way to make baggy-pants look cool? 😀
...20 sq.feet of useless fabric to sway in the wind, is the only way to make baggy-pants look cool?
hmmm..ever seen a scottish golfer?
Don't take offense guys-I'm enjoying what I consider a light hearted discourse
hmmm..ever seen a scottish golfer?
Don't take offense guys-I'm enjoying what I consider a light hearted discourse
*Laughing my a*** off*
No, I haven't seen a scottish golfer - do they really look worse than baggypants, held up by a a string to a heavy (fake?) gold chain around a hip hop'ers neck?
Jennice
No, I haven't seen a scottish golfer - do they really look worse than baggypants, held up by a a string to a heavy (fake?) gold chain around a hip hop'ers neck?
Jennice
Preliminary results.
Okay. I tried 4 different circuits.
1. LED in series with speaker.
This was horrible, no two was about it. Even at very low volumes settings this was completely unacceptable. I started trying a higher volume pass on this circuit, just to be complete, but thankfully (for my ears, and I think the woofer cone) the LED blew before 60dBA. In a word, YUCK!
2. LED in parallel with woofer.
This was also very bad, and caused the protection circuit in my amp to trigger, probably because the diode started registering a dead short. The protection circuit in the amp triggered before the diode blew, so at relatively small leakage currents. There was a definite harsh edge to the sound
3. LED with a 4 ohm 10W resistor in series
The LED lit, and distortion at low levels was okay. There were artefacts on the waveform where the LED was conducting. At high volumes the sound was almost okay. I wasn't sure if I was actually HEARING the distortion, only only expecting it, so I watched the waveform recording it with a mic. There was a tendancy for the wave to want to go a bit square where the LED was conducting, but it was minor. The LED blew at elevated levels.
4. LED with 470 ohm 1/4W resistor in series
Low distortion, perfectly acceptable (ie not audible), but the LED didn't light until there was a LOT of power going through the woofer. I would be a lot more likely to consider this circuit with a higher value resistor as an overdrive indicator. Set it up so that the LED will light about the time that the amplifier starts to clip.
Test parameters:
Speaker: Phoenix Gold 10" woofer in 1 cubic foot sealed enclosure
Amplifier: Pioneer 150W connected to a spare car battery
Source material: PC sound card with NCH tone generator. Test tones generated as 60Hz, and 100Hz sine waves, and a 20Hz to 100Hz sine sweep, played at 10%, 25%, 50% and 75% volume.
I used LEDs purchased on eBay of unknown brand, rated at 6000 mcd (red)
Okay. I tried 4 different circuits.
1. LED in series with speaker.
This was horrible, no two was about it. Even at very low volumes settings this was completely unacceptable. I started trying a higher volume pass on this circuit, just to be complete, but thankfully (for my ears, and I think the woofer cone) the LED blew before 60dBA. In a word, YUCK!
2. LED in parallel with woofer.
This was also very bad, and caused the protection circuit in my amp to trigger, probably because the diode started registering a dead short. The protection circuit in the amp triggered before the diode blew, so at relatively small leakage currents. There was a definite harsh edge to the sound
3. LED with a 4 ohm 10W resistor in series
The LED lit, and distortion at low levels was okay. There were artefacts on the waveform where the LED was conducting. At high volumes the sound was almost okay. I wasn't sure if I was actually HEARING the distortion, only only expecting it, so I watched the waveform recording it with a mic. There was a tendancy for the wave to want to go a bit square where the LED was conducting, but it was minor. The LED blew at elevated levels.
4. LED with 470 ohm 1/4W resistor in series
Low distortion, perfectly acceptable (ie not audible), but the LED didn't light until there was a LOT of power going through the woofer. I would be a lot more likely to consider this circuit with a higher value resistor as an overdrive indicator. Set it up so that the LED will light about the time that the amplifier starts to clip.
Test parameters:
Speaker: Phoenix Gold 10" woofer in 1 cubic foot sealed enclosure
Amplifier: Pioneer 150W connected to a spare car battery
Source material: PC sound card with NCH tone generator. Test tones generated as 60Hz, and 100Hz sine waves, and a 20Hz to 100Hz sine sweep, played at 10%, 25%, 50% and 75% volume.
I used LEDs purchased on eBay of unknown brand, rated at 6000 mcd (red)
if you want to protect the led a current source
LM317 / 7805 etc + one resistor might work.
fet?
You then need to consider not exceeding the max voltage input
(zener across the led/current source combo?)
also the power dissipation in the current source at max volume
also the power dissipation in the zener at max volume
LM317 / 7805 etc + one resistor might work.
fet?
You then need to consider not exceeding the max voltage input
(zener across the led/current source combo?)
also the power dissipation in the current source at max volume
also the power dissipation in the zener at max volume
An externally hosted image should be here but it was not working when we last tested it.
A (very) old Maplin design, once available in kit form. A series of transistor switches that trigger at different voltages to give a rough idea of wattage, a zener limits max voltage to each stage.
For 8R speakers,
25W - R9=1k5, R13=1k
50W - R9=1k, R13=820R
100W - R9=820R, R13=680R
Takes its power from the speaker terminals. I've built single stage versions to indicate when low-wattage outdoor speakers are in danger.
An externally hosted image should be here but it was not working when we last tested it.
and then.....THERE WAS LIGHT!!
I had initially assumed using a resistor might actually light the LED but didn't have anything of a usable value.
After reading through the posts again, it occured to me that I had a bunch of 2 meg audio pots lying around.
I cranked it wide open, connected an LED and vwal-la, I had not only lit the LED but it responds to the musical peaks.
I wired it in parallel to the terminals and it produced no distortion that I could notice by ear.
.....I'm actually assuming that if you wire it in parallel there should be no noticable difference in volume or generated distortion.You guys would know better than me though with your gadgets and gizmo's......
I had initially assumed using a resistor might actually light the LED but didn't have anything of a usable value.
After reading through the posts again, it occured to me that I had a bunch of 2 meg audio pots lying around.
I cranked it wide open, connected an LED and vwal-la, I had not only lit the LED but it responds to the musical peaks.
I wired it in parallel to the terminals and it produced no distortion that I could notice by ear.
.....I'm actually assuming that if you wire it in parallel there should be no noticable difference in volume or generated distortion.You guys would know better than me though with your gadgets and gizmo's......
It's late at night here so this could be silly, but how using an inductive circuit to trigger an LED driver run off a 9V battery OR alternatively, tapping off the low-pass?
🙂ensen.
🙂ensen.
How do I calculate what value of resistor to use?
I am having trouble figuring out what value resistor to use.
I was able to light my LED's using a 2 meg audio pot that was wide open.
I didn't have a speaker load on the amps output so I ended up frying the pot....smoked it and all!
....I also REALLY cranked the volume.
I have actually used these pots as a limiter on my PA speakers tweeters.
Never had a problem with frying them since speakers were in the equation.
ANYWAY, just wondering if anyone knows how I should calculate the resistor value or has a general idea of a range of values I should experiment with.
I can add something to this project though. The higher the MCD rating of the LED, the less wattage it takes to get them to light up.
I used a 3,000 mcd LED and was getting light flickers at about 15-20 watts RMS.
In my experiments with speakers, wiring the LED and resistor in parallel on the speaker terminals had no affect on the sound.
I am having trouble figuring out what value resistor to use.
I was able to light my LED's using a 2 meg audio pot that was wide open.
I didn't have a speaker load on the amps output so I ended up frying the pot....smoked it and all!
....I also REALLY cranked the volume.
I have actually used these pots as a limiter on my PA speakers tweeters.
Never had a problem with frying them since speakers were in the equation.
ANYWAY, just wondering if anyone knows how I should calculate the resistor value or has a general idea of a range of values I should experiment with.
I can add something to this project though. The higher the MCD rating of the LED, the less wattage it takes to get them to light up.
I used a 3,000 mcd LED and was getting light flickers at about 15-20 watts RMS.
In my experiments with speakers, wiring the LED and resistor in parallel on the speaker terminals had no affect on the sound.
Re: How do I calculate what value of resistor to use?
So a 50W/8R amp, V= +/-28V.
LED resistor = (Supply volts - LED forward voltage)/Led current, so a 2V 25mA red will need a 1040 ohm resistor, use 1k. It's dropping about 20V RMS at 25mA so a 1W rating is advisable. (That's why your pot smoked 😉 )
A LED is a diode so will block the reverse 28V. But it will only stand about 5V PIV, so needs a silicon diode (1N400x, 1N4148) in inverse parallel or series to bypass or block any reverse current from the negative cycle. (a second inverse parallel LED could be used instead).
If the LED is too sensitive to volume, you could increase the volume it comes on at with a series Zener diode.
LEDs are very unfussy about current, they'll glow right down to about 0.5mA
All you need to know is the peak line voltage, and you can calculate that from the amp RMS wattage into your speaker resistance, W = VxV/R, multiply by 1.414 to get the peak.MrCheeks said:
So a 50W/8R amp, V= +/-28V.
LED resistor = (Supply volts - LED forward voltage)/Led current, so a 2V 25mA red will need a 1040 ohm resistor, use 1k. It's dropping about 20V RMS at 25mA so a 1W rating is advisable. (That's why your pot smoked 😉 )
A LED is a diode so will block the reverse 28V. But it will only stand about 5V PIV, so needs a silicon diode (1N400x, 1N4148) in inverse parallel or series to bypass or block any reverse current from the negative cycle. (a second inverse parallel LED could be used instead).
If the LED is too sensitive to volume, you could increase the volume it comes on at with a series Zener diode.
LEDs are very unfussy about current, they'll glow right down to about 0.5mA
step-up transformer...
how about using a step up transformer
U can use a mains adaptor trafo w secondary as input and will save your hears since led will start lighting at low P
Gajanan Phadte
how about using a step up transformer
U can use a mains adaptor trafo w secondary as input and will save your hears since led will start lighting at low P
Gajanan Phadte
What about an inductive pickup (a coil) placed somewhere on the speaker?
With enough windings the coil should generate enough voltage to drive an LED and if not you could always throw a 1-transistor amp and a battery in there.
With enough windings the coil should generate enough voltage to drive an LED and if not you could always throw a 1-transistor amp and a battery in there.
Xmer...
A potentiometer has to be used with a series resistor before the secondary winding
Gajanan Phadte
A potentiometer has to be used with a series resistor before the secondary winding
Gajanan Phadte
http://store.qkits.com/moreinfo.cfm/fk101
http://store.qkits.com/moreinfo.cfm/fk102
http://store.qkits.com/moreinfo.cfm/K4307
http://www.techsys.co.kr/techsyskits/kits/k4307.htm
I'm moderately sure I found a manual for the K4307 display online someplace once, and it had just about enough info to build your own without the kit. Still, the parts list gives some clues (zener values...). I wouldn't want it on my home speakers (too distracting), but on my party speakers they'd give the speaker-huggers something to look at.
http://store.qkits.com/moreinfo.cfm/fk102
http://store.qkits.com/moreinfo.cfm/K4307
http://www.techsys.co.kr/techsyskits/kits/k4307.htm
I'm moderately sure I found a manual for the K4307 display online someplace once, and it had just about enough info to build your own without the kit. Still, the parts list gives some clues (zener values...). I wouldn't want it on my home speakers (too distracting), but on my party speakers they'd give the speaker-huggers something to look at.
Found it... no pictures of the traces, but there's a schematic and the component overlay. So, it'd be pretty much join-the-dots to create a pc board layout, or to wire it up on perfboard.
http://www.velleman-kit.com/Downloads/0/Manual_K4307.pdf
http://www.velleman-kit.com
http://www.vellemanusa.com/
http://www.velleman-kit.com/Downloads/0/Manual_K4307.pdf
http://www.velleman-kit.com
http://www.vellemanusa.com/
i saw some woofers who drives a noen lamp without a problem.
consider the amp giving them 500-1000W....
consider the amp giving them 500-1000W....
Simplicity does the job
I got great results by simply using a resistor.
Wired a high wattage sandstone resistor in sereis with the LED's. Then wired to the speakers terminals in parrallel.
They light up just fine and respond to the musical peaks.
Way cool effect guys and absolutely NO alteration of your sound when wired in this manner.
The only way I've experienced any change in sound was when wiring this simple circuit in series on the positive lead of the amp.
Wiring in parallel on the terminals has proven most effective.
I got great results by simply using a resistor.
Wired a high wattage sandstone resistor in sereis with the LED's. Then wired to the speakers terminals in parrallel.
They light up just fine and respond to the musical peaks.
Way cool effect guys and absolutely NO alteration of your sound when wired in this manner.
The only way I've experienced any change in sound was when wiring this simple circuit in series on the positive lead of the amp.
Wiring in parallel on the terminals has proven most effective.
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