Proslushivat noise from audiostrobe
Posted: Tue Dec 19, 2006 22:27
Hello all.
Started to listen to the gate drives through the Inner Pulse and was faced with problemkoy:
With headphones listens noises in time with the blinking LEDs. To describe the nature of the noise gives the best fit to the word "Cherkasy" noise.
The noise level is not very large, but clearly bugged and frankly interferes with this delicate process, as the occurrence of ISS.
A few simple experiments made it clear that:
1. Noises occur at the output of the player.
Connected the headphones directly to the output of the player.
2. Noises occur when you listen to all the disks in varying degrees, and sometimes masked the main theme of the composition.
The audibility of noise on the discs:
"Brain Machine" - clearly.
"Healing" - clearly.
"Endorphins" - the first 30sec.
"Polar Lights" - places.
"Fractal Dance" - sometimes.
"Children of the Universe" - not everywhere.
The noise level in two - three times lower than the lapping of the water on the disc "Healing". With the CD "Endorphins" is another story - it seems it uses a noise signal as the background and its spectrum similar to the spectrum of noise from audiostrobe. In the beginning of the disk first 30sec noise audiostrobe bugged, and then starts the theme and the background noise of the theme disguises the noise from audiostrobe. On disks "Brain Machin" and "Healing" theme is very homogeneous, that noises were heard.
3. Noise arises not only when listening on a specific player (Panasonic SL-SX430). Tried on the car magnitola Kenwood and on the computer at certain EQ settings. Put the experiment on the computer: Stick the disc "Healing", open it in Windows Media player, switched to the view with the graphic equalizer, click on the button the way the engine plant - "individually", move the leftmost and rightmost sliders up until it stops and after two seconds listening to the sounds from the headphones or speakers. On the computer the noise is more sharp - transistor. Full atas is obtained if EQ pull from end to end in the "tight group". Get kriemadis the sounds in the beat signals audiostrobe really fading out after ten seconds.
Some idea what's going on: When digital filters of high order can occur spectrum shift audiostrobe signals in the low frequency region due to parasitic oscillations at the poles of the filters. Any troubles with the number. The fact that Windows Media player plays fine without noise drives when the equalizer presets by default, all sliders in middle position. Now, portable player, it seems that there is a source filter that cuts unnecessary (not audible) range. Here it is so disgusting itself, and is in relation to the signals of audiostrobe that are close to the cutoff frequency of the filter and apparently have not a small amplitude.
In fact, in view of the upcoming purchase of a new player
question:
Who is any player sits, and hears, and what is not?
What to buy something?
Started to listen to the gate drives through the Inner Pulse and was faced with problemkoy:
With headphones listens noises in time with the blinking LEDs. To describe the nature of the noise gives the best fit to the word "Cherkasy" noise.
The noise level is not very large, but clearly bugged and frankly interferes with this delicate process, as the occurrence of ISS.
A few simple experiments made it clear that:
1. Noises occur at the output of the player.
Connected the headphones directly to the output of the player.
2. Noises occur when you listen to all the disks in varying degrees, and sometimes masked the main theme of the composition.
The audibility of noise on the discs:
"Brain Machine" - clearly.
"Healing" - clearly.
"Endorphins" - the first 30sec.
"Polar Lights" - places.
"Fractal Dance" - sometimes.
"Children of the Universe" - not everywhere.
The noise level in two - three times lower than the lapping of the water on the disc "Healing". With the CD "Endorphins" is another story - it seems it uses a noise signal as the background and its spectrum similar to the spectrum of noise from audiostrobe. In the beginning of the disk first 30sec noise audiostrobe bugged, and then starts the theme and the background noise of the theme disguises the noise from audiostrobe. On disks "Brain Machin" and "Healing" theme is very homogeneous, that noises were heard.
3. Noise arises not only when listening on a specific player (Panasonic SL-SX430). Tried on the car magnitola Kenwood and on the computer at certain EQ settings. Put the experiment on the computer: Stick the disc "Healing", open it in Windows Media player, switched to the view with the graphic equalizer, click on the button the way the engine plant - "individually", move the leftmost and rightmost sliders up until it stops and after two seconds listening to the sounds from the headphones or speakers. On the computer the noise is more sharp - transistor. Full atas is obtained if EQ pull from end to end in the "tight group". Get kriemadis the sounds in the beat signals audiostrobe really fading out after ten seconds.
Some idea what's going on: When digital filters of high order can occur spectrum shift audiostrobe signals in the low frequency region due to parasitic oscillations at the poles of the filters. Any troubles with the number. The fact that Windows Media player plays fine without noise drives when the equalizer presets by default, all sliders in middle position. Now, portable player, it seems that there is a source filter that cuts unnecessary (not audible) range. Here it is so disgusting itself, and is in relation to the signals of audiostrobe that are close to the cutoff frequency of the filter and apparently have not a small amplitude.
In fact, in view of the upcoming purchase of a new player
question:Who is any player sits, and hears, and what is not?
What to buy something?