Audio question

[ivconic]

Ok..i have interesting question to ask here.
I was thinking to make some 2 channel metal detector and to put separate audio outputs to both channels. Ok...that is not so hard to do.
But....how to use only one speaker!?
I dont want to use 2 speakers, i want to use only one speaker with 2 audio outputs at the same time!
How?
Any suggestions?

[Qiaozhi]

Ok..i have interesting question to ask here.
I was thinking to make some 2 channel metal detector and to put separate audio outputs to both channels. Ok...that is not so hard to do.
But....how to use only one speaker!?
I dont want to use 2 speakers, i want to use only one speaker with 2 audio outputs at the same time!
How?
Any suggestions?

Probably the easiest solution would be to use an audio IC (such as an LM386) and mix the inputs together using a resistor network.

[ApBerg]

Use 2 opto ?

Regards.

Ap

[Rov]

ivconic,try use a simple TDA 8 pin ic for stereo,for each input ,each channel into a small twin cone 3 1/2 inch cheap speaker ,with simple crossover if you wish,for freq. or without?output 1 channel each cone.Maybe?

[simonbaker]

Ok..i have interesting question to ask here.
I was thinking to make some 2 channel metal detector and to put separate audio outputs to both channels. Ok...that is not so hard to do.
But....how to use only one speaker!?
I dont want to use 2 speakers, i want to use only one speaker with 2 audio outputs at the same time!
How?
Any suggestions?

I'm interested same thing -- maybe using Kurtie TGS layout as starting point and changing notch channels to other use.

I want to use two different tones and mix into speaker. I think mixing is not hard as Q says -- more interesting problem is getting two separate tones off of 4024 without interfering with each other. Probably not hard for expert, but interesting for me.

-SB

[simonbaker]

multiple audio tones

Maybe something like this. Resistors adjusted so each channel alone makes half-max volume in speaker. Actually should feed into op amp summer -- this circuit probably not sum well.

[ivconic]

Probably the easiest solution would be to use an audio IC (such as an LM386) and mix the inputs together using a resistor network.

Not good! Easy and dirty! I want something more advanced...

[ivconic]

Use 2 opto ?

Regards.

Ap

Eh....that is the same as Qiaozhi suggested. Ok..not same but simillar...

[ivconic]

ivconic,try use a simple TDA 8 pin ic for stereo,for each input ,each channel into a small twin cone 3 1/2 inch cheap speaker ,with simple crossover if you wish,for freq. or without?output 1 channel each cone.Maybe?

Not good.

[ivconic]

Maybe something like this. Resistors adjusted so each channel alone makes half-max volume in speaker. Actually should feed into op amp summer -- this circuit probably not sum well.

Nice. But not what i wanted. I was interested more in using 4046.
I am not doing that at Tesoro. I plan to do that on Classic 3.
Almost everything i need is already projected at CL3. Just need small mods.

[ivconic]

To all. I was hoping to hear suggestion like....(de)multiplexer!
First thing came to my mind is 4025.
But i am not sure about signal levels there! Must be checked.
Any experiences?

[homefire]

I'm Confused.

Why can't you just Isolate the two audio sources with diodes and go right to the speaker?

[ivconic]

I'm Confused.

Why can't you just Isolate the two audio sources with diodes and go right to the speaker?

Theoretically it can work. In practice i am affraid i can face some unwanted sideffects.

[ivconic]

To all. I was hoping to hear suggestion like....(de)multiplexer!
First thing came to my mind is 4025.
But i am not sure about signal levels there! Must be checked.
Any experiences?

Oooh! More i think about this - looks more as a bad idea to me!

[simonbaker]

Nice. But not what i wanted. I was interested more in using 4046.
I am not doing that at Tesoro. I plan to do that on Classic 3.
Almost everything i need is already projected at CL3. Just need small mods.

I think more description needed because just guessing game here ...

-SB