Mixer resistor values

[helpful55]

In addition to inside I run my pc audio music stream to a sound system in my shop. I like to be able to just move one of the shops stereo system speakers outside when I am working there with a longer wire. The problem is that some of the music has mixing where the vocals or part of the music is not the best with one channel. So I am making a passive mixer for the shop setup. I would like to find an appropriate resistor value that won’t attenuate the signal any more than I have to. If this circuit does cause some input mixing that is not really a problem as I can disconnect the mixer when it is not needed so I won’t be diminishing my stereo effect in the house when I listen there. I have seen 10K recommended, but that was for general audio equipment and I don’t know if a pc output would need similar, I wouldn’t want to harm my pc sound circuits. What would anyone recommend for resistor values for this mixer? I can experiment if there is a range I should try, I would just like to have a good starting point if so. And since I am obviously driving two stereo systems (the main one will probably still be on, I don’t want to be flipping a switch back and forth) should I be using some type of impedance adjustment for that part of this? Thanks for any help.

 

[Sunnysky]

mixing not the best? or amplifier distortion? or bad speaker?
No idea what you have for speakers, cable or amp or output signal quality.

 

[Gryd3]

In addition to inside I run my pc audio music stream to a sound system in my shop. I like to be able to just move one of the shops stereo system speakers outside when I am working there with a longer wire. The problem is that some of the music has mixing where the vocals or part of the music is not the best with one channel. So I am making a passive mixer for the shop setup. I would like to find an appropriate resistor value that won’t attenuate the signal any more than I have to. If this circuit does cause some input mixing that is not really a problem as I can disconnect the mixer when it is not needed so I won’t be diminishing my stereo effect in the house when I listen there. I have seen 10K recommended, but that was for general audio equipment and I don’t know if a pc output would need similar, I wouldn’t want to harm my pc sound circuits. What would anyone recommend for resistor values for this mixer? I can experiment if there is a range I should try, I would just like to have a good starting point if so. And since I am obviously driving two stereo systems (the main one will probably still be on, I don’t want to be flipping a switch back and forth) should I be using some type of impedance adjustment for that part of this? Thanks for any help.

Any problem simply setting up a secondary sound output on the computer?
Problem with passive is that the signal WILL attenuate, by a noticeable amount

 

[helpful55]

Any problem simply setting up a secondary sound output on the computer?
Problem with passive is that the signal WILL attenuate, by a noticeable amount

Yes that sounds like the way to go so I don’t have to modify my normal sound output system at all. I have a USB sound device that I got set up and it seems to be working fine. I will run it’s output to the shop and if I think it is deficient I will go to a better USB device. Do you think that I could just directly connect the stereo outputs on this device without ruining it or should I still use a mixing resistors? I can use low resistance resistors because for the shop sound I would like the channels mixed as well as possible anyway. I have tried it with 1K resistors and the drop was not too bad. I have a pretty decent wattage sound system it is on and if I would have to I can go bigger. I can turn it up the volume, but I am never into that if possible I'd rather keep my input level up. An experiment is not really a big deal if I fry it as it’s an inexpensive device. Hadn’t got back to this earlier as I had been real busy with other projects in the summer. Thanks for your help.

 

[Gryd3]

Yes that sounds like the way to go so I don’t have to modify my normal sound output system at all. I have a USB sound device that I got set up and it seems to be working fine. I will run it’s output to the shop and if I think it is deficient I will go to a better USB device. Do you think that I could just directly connect the stereo outputs on this device without ruining it or should I still use a mixing resistors? I can use low resistance resistors because for the shop sound I would like the channels mixed as well as possible anyway. I have tried it with 1K resistors and the drop was not too bad. I have a pretty decent wattage sound system it is on and if I would have to I can go bigger. I can turn it up the volume, but I am never into that if possible I'd rather keep my input level up. An experiment is not really a big deal if I fry it as it’s an inexpensive device. Hadn’t got back to this earlier as I had been real busy with other projects in the summer. Thanks for your help.

Not a problem.
1K is a decent value to work with, go for it.
You may also be able to find a setting in the sound properties of you computer to actually set the output as 'Mono' for a select device. Some music players also have a 'DSP' section allowing you to customise things like Down-mixing Stereo to Mono and other effects.
So you could continue to do this in software, or build your Stereo to Mono passive Mixer.

I do apologise actually about my earlier reply. Your desire wasn't to simply output two different media streams, but to down-mix to Mono when you decide to play audio outside with a single speaker.
In this case, I would suggest your original approach of a passive mixer to mix your Left/Right into a single Mono Channel, or see if you can run the outdoor stereo in 'Bridge mode' or Mono.
(As long as your indoor stereo is connected to the audio-out of the PC *before* your resistor mixer, you will still get stereo in the house although you may get a slight mono mix in the house. This effect will be more pronounced with smaller value resistors. A second audio device either built-in or USB will avoid this)

 

[helpful55]

Not a problem.
1K is a decent value to work with, go for it.
You may also be able to find a setting in the sound properties of you computer to actually set the output as 'Mono' for a select device. Some music players also have a 'DSP' section allowing you to customise things like Down-mixing Stereo to Mono and other effects.
So you could continue to do this in software, or build your Stereo to Mono passive Mixer.

I do apologise actually about my earlier reply. Your desire wasn't to simply output two different media streams, but to down-mix to Mono when you decide to play audio outside with a single speaker.
In this case, I would suggest your original approach of a passive mixer to mix your Left/Right into a single Mono Channel, or see if you can run the outdoor stereo in 'Bridge mode' or Mono.
(As long as your indoor stereo is connected to the audio-out of the PC *before* your resistor mixer, you will still get stereo in the house although you may get a slight mono mix in the house. This effect will be more pronounced with smaller value resistors. A second audio device either built-in or USB will avoid this)

Ok I got the circuit set up and it does what I want. This is great now, both channels from my one outside speaker with adjustable inside volume and no degradation of my house stereo sound. My settings don’t have a mono setting. I guess windows is too smart and maybe it recognizes the speakers as stereo! What I am calling a sound system is just a simple Logitech Z623 pc speaker system so no settings on it either. I had to do a little wiring anyway as I also inserted a pot in the channel that is for the inside speaker I need to lower once I raise the total volume for outside use. The 1K resistors do some reduction but a pretty small amount, I barely have to raise the volume. I get kind of crazy on things that aren’t quite right and although this setup can make plenty of noise to annoy neighbors I may get a hair and build a low power active mixer. Like I say not needed though.

I was having my usual “setting” problems with windows and plugging into a front case usb allowed the audio, but the rear mobo jacks wouldn’t so I got a “potentially” better usb device and same problem. I have been through some of these windows sound settings before and it has been a pain. I ultimately found that I had to set the stereo mix in recording for listening to that device then it worked off the rear port. I hope I don’t run into the no stereo mix difficulty like I did one time. That is a pain and I think required a downgrade in driver to get that, although I have done some of the updates and they haven’t deleted it so I don’t know. Thanks for all of your help. On to my other always ongoing problems/projects.