Notifications
Clear all

Need help with a low volume issue

9 Posts
3 Users
3 Likes
478 Views
Dennis in Dayton
(@dennis-in-dayton)
Member
Joined: 2 years ago
Posts: 4
Topic starter  

I have an X-Kit 5 channel color organ that works very well using line input audio. I had to set the line level (thus volume) to medium level so the really loud music will not over drive the op amps and keep the lights on all the time or really bright.

The Problem is when the audio is low (like soft passages of music) the X-Kit doesn't have enough signal at the input to turn on the op amps. So there will be a period of time where there is no light. I have used an Casio organ to test the set up and as long as the output is mid volume everything works just fine. Excellent frequency discrimination between octaves !

I need to build (buy) a device that will amplify low line level signals but pass through the signals that are strong enough to turn the op amps on. I need the opposite of an audio leveling circuit that keeps sound from going too high to an audio amplifier. Can somebody point me in the right direction ? I am but a beginner, so I am not well versed in such things.


   
Quote
Ron
 Ron
(@zander)
Father of a miniature Wookie
Joined: 3 years ago
Posts: 6906
 

@dennis-in-dayton In audio tech, I see things like 'night mode' that drop the louder passages. Also a standard 'loudness' switch found on any decent grade audio amp will do the same thing. Maybe search for that circuitry and you should be set.

Here are a couple links I found https://www.circuits-diy.com/simple-audio-loudness-control-circuit/ and the theory is https://www.extron.com/article/loudnesscontrol_ts

 

First computer 1959. Retired from my own computer company 2004.
Hardware - Expert in 1401, and 360, fairly knowledge in PC plus numerous MPU's and MCU's
Major Languages - Machine language, 360 Macro Assembler, Intel Assembler, PL/I and PL1, Pascal, Basic, C plus numerous job control and scripting languages.
Sure you can learn to be a programmer, it will take the same amount of time for me to learn to be a Doctor.


   
ReplyQuote
(@dronebot-workshop)
Workshop Guru Admin
Joined: 5 years ago
Posts: 1075
 

The device you are looking for is an "analog audio compressor". These were very popular years ago, they used them with AM radio and analog television.

An analog audio compressor makes the soft sounds louder and the loud sounds softer.  They were used in AM radio to keep the signal above the noise floor, while avoiding clipping.

These days, it is more common to use digital devices that mimic the operation of the analog compressor.  There are many compressor applications, so if you can pass your audio through a computer first (or if that's the source to begin with) then you can easily do this.  If you have a Mac you could use Logic Pro if you have it, I use one of the dynamic compressors in Logic Pro when I produce my videos.  I'm not sure if Garage Band has one, as I've actually never used Garage Band.

Stand-alone analog devices can be pretty expensive, as they are usually of a higher quality than you'd require for a color organ.   I seem to recall that back in the 70s I made one with op-amps, perhaps you can find a similar circuit.

😎

Bill

"Never trust a computer you can’t throw out a window." — Steve Wozniak


   
ron bentley and Ron reacted
ReplyQuote
Dennis in Dayton
(@dennis-in-dayton)
Member
Joined: 2 years ago
Posts: 4
Topic starter  

@dronebot-workshop Hello Bill. I was quite surprised to get a reply from you !!! 

The source for the audio is iTunes on my pc (Windows 10) that is fed to old Archer stereo amp from 1978 with the audio split with RCA "Y" connectors so the color organ audio is not affected by the volume of the sound sent to the speakers. I have tried "sound check" in iTunes, but that tends to even all the volume levels, and that is not what I am trying to achieve.

I have an audio leveling circuit that does just the opposite (limits higher volume). I need to "flip" this to unlimit the high volume. I am thinking perhaps some kind of op amp arrangement that could be set up that will detect the low volume, amplify it, and simply pass the usable (higher) volume through to the color organ like it is now.  I hope I am making sense... Dennis


   
ReplyQuote
Ron
 Ron
(@zander)
Father of a miniature Wookie
Joined: 3 years ago
Posts: 6906
 

@dennis-in-dayton I think what we are trying to explain is that raising the lowest to be closer to the high is IDENTICAL to lowering the high to be closer to the low then increasing the total volume.

First computer 1959. Retired from my own computer company 2004.
Hardware - Expert in 1401, and 360, fairly knowledge in PC plus numerous MPU's and MCU's
Major Languages - Machine language, 360 Macro Assembler, Intel Assembler, PL/I and PL1, Pascal, Basic, C plus numerous job control and scripting languages.
Sure you can learn to be a programmer, it will take the same amount of time for me to learn to be a Doctor.


   
ReplyQuote
Dennis in Dayton
(@dennis-in-dayton)
Member
Joined: 2 years ago
Posts: 4
Topic starter  

@zander Hello Ron, thank you for your input. I had not thought about doing this because I did not want to "clip" the higher volume and thus limit the brightness of the lights. The X-Kit does a splendid job of using volume and frequency to change the brightness and color of the lights.

I am kind of scared to mess with the current setting. It will involve reseting the volume levels of the sound system and that was a two day process in the beginning. BUT, I will look back at my notes from the original setup and see what I can do to remedy this issue. Maybe you are on to something. Maybe I need to think outside my very small box. LOL


   
ReplyQuote
Ron
 Ron
(@zander)
Father of a miniature Wookie
Joined: 3 years ago
Posts: 6906
 

@dennis-in-dayton Sometimes I am thinking outside the box because I don't have a clue where the box is. Seriously though, I think I share an interest. I have a strip of multi-colored LED's (RGB?) that I want to feed some sort of music signal into and cause them to light in tune and beat etc with the music. My first cut research tells me it can be done, I just need to figure out the interfaces. Keep us informed of your progress please.

First computer 1959. Retired from my own computer company 2004.
Hardware - Expert in 1401, and 360, fairly knowledge in PC plus numerous MPU's and MCU's
Major Languages - Machine language, 360 Macro Assembler, Intel Assembler, PL/I and PL1, Pascal, Basic, C plus numerous job control and scripting languages.
Sure you can learn to be a programmer, it will take the same amount of time for me to learn to be a Doctor.


   
ron bentley reacted
ReplyQuote
Dennis in Dayton
(@dennis-in-dayton)
Member
Joined: 2 years ago
Posts: 4
Topic starter  

@zander For about $43 there is a small device named the MSGEQ7 Music Visualizer. It is based on the ATmega328p-au. It uses the Adafruit NeoPixel library which makes for some simple code. I have used this with two ALITOVE 5 volt WS2811 12mm 50 LED strings w/ 3-pin JST-SM connectors. It works pretty well, except it does not exactly change the LED colors with the frequency changes in the music. This could be operator error because I am not well versed in code. Hence I went back to analog and the X-Kit because I understand that billion year old technology.


   
ReplyQuote
Ron
 Ron
(@zander)
Father of a miniature Wookie
Joined: 3 years ago
Posts: 6906
 

@dennis-in-dayton Thanks, that looks useful for my project.

First computer 1959. Retired from my own computer company 2004.
Hardware - Expert in 1401, and 360, fairly knowledge in PC plus numerous MPU's and MCU's
Major Languages - Machine language, 360 Macro Assembler, Intel Assembler, PL/I and PL1, Pascal, Basic, C plus numerous job control and scripting languages.
Sure you can learn to be a programmer, it will take the same amount of time for me to learn to be a Doctor.


   
ReplyQuote