Converting stereo audio input to mono

Discussion in 'Analog & Mixed-Signal Design' started by adhith, May 30, 2017.

  1. adhith

    Thread Starter Member

    May 29, 2017
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    hello everyone
    I'm planning to build a mono sub woofer amplifier with TDA 2030A IC. Since the IC is a single channel amplifier, I need to somehow combine the stereo input to mono. Could a two resistor mixer solve the problem??. I dont have any idea to select the values for the resistors. Could anyone suggest me a circuit with the resistor values??
     
  2. R!f@@

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    Apr 2, 2009
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    Google Summing Amplifier.
    You will find plenty.
    Find one, post it and we can discuss it
     
  3. shteii01

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    Feb 19, 2010
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    Are you not going to use crossover to separate low frequencies for sub from the regular frequencies that will go to the speakers?
     
  4. dante_clericuzzio

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    Mar 28, 2016
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    I think i tried this kind of circuit before and its very simple just combine the wire input combine all input and ground all ground...and it works nothing wrong
     
  5. adhith

    Thread Starter Member

    May 29, 2017
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    What about the gain of the input signal, it would be doubled right?? could it become a problem??

    yes, I'm using a three way crossover before it. The input what I'm talking about is the sub woofer output from the crossover. I have already posted about it in my previous thread & that's why i haven't mentioned here.
     
    Last edited by a moderator: Jun 2, 2017
  6. dante_clericuzzio

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    Mar 28, 2016
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    I do not believe so and there is a mini transformer you can use to reduce noise if necessary...and for the record i found that the TDA2030 sound is not so loud not sure why...If you use the TEA2025 or LM386 is much louder...but that was my personal experience perhaps you have a better circuit arrangement
     
  7. Dodgydave

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    Jun 22, 2012
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    Yes all you need is two resistors any value 10K to 75K, from the left and right inputs to your Tda2030 input, if you want a better circuit diagram download the datasheet.
     
  8. adhith

    Thread Starter Member

    May 29, 2017
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    Thank you dante_clericuzzio for your help. I know that TDA2030 have a lower sound capabilitiy, since it is specially designed for low frequency applications I thought of using it to get some advantage for the sub woofer. For mid range speakers I'm planning to use LA4440.
     
  9. Dodgydave

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    Jun 22, 2012
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    The Tda2030 is a 20W amplifier or 35W if bridged, how loud do you need it???
     
  10. R!f@@

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    IMHO TDA2030 is crap.
    LM3886 is far better.
     
  11. adhith

    Thread Starter Member

    May 29, 2017
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    I have made a LA4440 audio amplifier before and it was able to deliver a good loudness. from the datasheet it was seen that ii could be around 50dB. I believe TDA2030 is of 30dB loudness and it is a problem. The thing was I couldn't get much resources for audio amplifier between 10 & 20w for sub woofer. could you give any other suggestions for the same?? Also I would like to know that using LA4440 is a good option or not??

    I'm planning to have an output of about 10-20w with a 12v supply but, LM3886 needs a minimum supply of 20v & is above 20w specifications right??
     
    Last edited by a moderator: Jun 2, 2017
  12. Dodgydave

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    Last edited: Jun 2, 2017
    R!f@@ likes this.
  13. dante_clericuzzio

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    Mar 28, 2016
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    experiment before...

     
  14. adhith

    Thread Starter Member

    May 29, 2017
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    Thank you Dodgydave for your help. Haven't heard about TDA1562 before, it seems like a good option. Actually I'm working on a DIY portable Bluetooth speaker project where size,power input is limited. I'm thinking of using a two way active crossover and 2 amplifiers(1 stereo & 1mono) to drive 2 speaker & a sub woofer. A part from the speakers it consist of LED strip vu meter. I have made a 2 channel speaker with vu meter in my last project. So now I'm thinking of having crossovers & much more advance VU meter on my next project. Could you have a look on my previous project to get a picture of what I'm trying to do.
    https://www.instructables.com/id/LIGHT-BOX-a-Portable-Speaker-With-Vu-Meter/
    so the PCB could only have limited size & current input cant be more than 4A with 12v supply

    LM836 is a 1w amplifier with good loudness right?? Now I'm having a doubt that is the power output or the loudness of an amplifier the most important ?? which one contributes more to the sound quality??
     
    Last edited by a moderator: Jun 2, 2017
  15. R!f@@

    AAC Fanatic!

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    LM386 is tiny bugger.
    It cannot drive a Sub.

    Power contributes a lot to "loudness"
    Power without distortion.

    Sound quality depends on a lot of things.
    The component you use.
    The Design.
    The PSU.
    The Quality of the Source.
    The Speaker
     
    adhith likes this.
  16. dante_clericuzzio

    Member

    Mar 28, 2016
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    I believe design...some people think that the chip (IC) is the most important probably it's true...but after some experiment that i made before i come to understand that different design produce different quality...and some simple design with the right component can also produce quite decent sound..despite using simple speakers.

    Many people would recommend this ICs and that ICs but I like to know them by experiment that's how i think a good design based on either experience people or expert who has done good amp before is very good reference to refer.

    Even the way you connect the components to one another especially the ground wire and also how close the component to one another can also contribute to significant sound quality...so i guess to be good in amplifier design ....R & D is very important....and of course who has done a good one before is worth to refer to.
     
  17. adhith

    Thread Starter Member

    May 29, 2017
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    1
    I totally agree with your opinion that design is one among the important things for amplifiers. Few months back I dismantled one of my creative desk speakers and found that it uses TEA2025B amplifier,but when i made a TEA2025B amp on my breadboard by referring the datasheet the quality was not good.But a better quality was achieved when i made the PCB version.

    So friends
    what should I search for to get the datasheet. Is there any specific name for these kind of circuits??

    Thank you for the info R!f@@
     
    Last edited by a moderator: Jun 2, 2017
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