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[dbemowsk]

Here is a theory I have for cleaning up the audio.  I may be totally wrong on this so all you pro audiophiles out there can correct me. 

I did some searching on noise canceling and found a site which shows a circuit schematic for a noise canceling headphone circuit.

(To read the whole article on this, go to http://gilmore2.chem.northwestern.edu/projects/noise_prj.htm)

The circuit is designed to have a microphone connected to J1 which picks up the outside noise.  It then uses that signal inverted to cancel out any of that noise that comes through the headphones.  J2 then allows you to insert your music or whatever you want to listen to on to the noise free signal. 

My theory is that I can use this to cancel out TV noise in the room by injecting the audio signal straight from the TV into J1.  Next, inject the pre-amped signal from an omnidirectional room mic into J2.  The omnidirectional room mic will pick up the TV sound as well as my voice commands.  This circuit should effectively do the following:
(voice commands with TV noise) - (TV noise) = voice commands
Thus the noise canceling properties of the circuit should strip off any signal put into J1 from anything put into J2 and output the difference of the two which should be a cleaned up signal with mostly just the voice commands.

I have not yet tried to build this circuit, but I plan to try it out.  When I do I can post my findings.

As mentioned, any corrections to my theory are welcome.

dbemowsk

[HA Dave]

... I did some searching on noise canceling and found a site which shows a circuit schematic for a noise canceling headphone circuit.
(To read the whole article on this, go to http://gilmore2.chem.northwestern.edu/projects/noise_prj.htm)

Great idea dbemowsk!

I always positioned my baby monitors/Microphones in a way... like turned to point into a corner. I then look in the direction of the mic (even though it is hidden) when I speak a command or command phrase. This (of course) causes my voice to need to reflect (bounce) off of a wall to be picked up by the microphone.

But the positioning of the mic also causes TV sounds to need to reflect or bounce around much more than my voice. I have always felt that those shorter sound waves are more difficult for the baby monitors circuit to process... and are lost due to my extreme lack of amplification.

I would think if you could use the two mics to pickup a directionally spoken... as well as a wide area set of sounds... and then remove the wide area sounds/noise. You could have really clear voice in even a noisy area. Please keep us posted on your progress.

[mkgriff]

I was wondering if a USB microphone would work just like the computer microphone?  That's what I'm using and it seems to give me good service.  Like Brian I am only using it in one room so it could be a wired microphone with no problem but I'm wanting to get the best set up for my application.

[HA Dave]

I was wondering if a USB microphone would work just like the computer microphone? 

I don't know... does the USB microphone utilize an autogain? That is what makes using a microphone (plugged in the microphone in jack) does...  and why that can't be used for a 24/7 setup. The autogain just keeps climbing the volume up.

[mkgriff]

I don't know, I had not noticed it doing that but then again I haven't checked.  I use a USB microphone on my office computer which runs DragonDictate, and the firecracker and BVC, it always works well.  How would I checked that?  It seems to work well, I've been using it for about three months now.  It is a directional microphone about 12 feet away from the TV then pointing away from it as well.  I can access the HA computer from the other room.  I've also attempted the baby monitor but with my disability and having to find somebody that can solder I'm pretty limited and I never got that project off the ground but if this microphone keeps working then I guess I'm good

[HA Dave]

I don't know, I had not noticed it doing that .........  It seems to work well, I've been using it for about three months now. 

I would think if you were going to have a problem... it would have shown up by now.

[mkgriff]

oh come on Dave, you know better than that, Murphy lives in my house!

[HA Dave]

oh come on Dave, you know better than that, Murphy lives in my house!

I can only judge by my own experiences... with so many different systems and setups... it really is hard to tell. But if it works for 3 months... your probability good.

[floyduww]

I am thinking about doing the baby monitor setup.  And was wondering if anyone has tried using 2 receivers one on the left and one on the right channel of the stereo plug.  Or if for this to work you have to wire both left and right to a single receiver, which limits me to just the one transmitter.

Thanks

[HA Dave]

And was wondering if anyone has tried using 2 receivers one on the left and one on the right channel of the stereo plug.  Or if for this to work you have to wire both left and right to a single receiver, which limits me to just the one transmitter.

I haven't heard or read of anyone trying a dual-receiver setup (using the stereo line in jack). But I use two transmitters... and switch them on and off using appliance modules. I've fully described my setup here. If you do decide to try the dual-setup.... please keep us posted on the results.

Intercoms are also an option.

[floyduww]

Yeah I had read about your 2 transmitter setup and the intercom setups.   What I was hopping to accomplish is be able to say commands in the room I am in without having it be premeditated or have to carry a remote or setup a Bluetooth proximity setup.

I will post my findings after I rebuild my AHP computer.   It died on me today, and my new one is being shipped tomorrow.

[HA Dave]

I will post my findings after I rebuild my AHP computer.   It died on me today,

Sorry about your loss.

I think your idea has real merit.

[Noam]

... What I was hopping to accomplish is be able to say commands in the room I am in without having it be premeditated or have to carry a remote or setup a Bluetooth proximity setup...

Once you get it working, you can call it "Star TreX10" ;-)

[HA Dave]

Once you get it working, you can call it "Star TreX10" ;-)

Using BVC really is a lot like living the Star Trek experience. I been using BVC for a few years now... and I really enjoy it.

As a child.... technology writtings foretold a future where we could talk to our computers and automation performed many of our everyday tasks. We would watch TV on wall sized screens, own Robots, and commute in flying cars.

I am still ticked.... about the lack of flying cars!

[Dan Lawrence]

Once you get it working, you can call it "Star TreX10" ;-)

Using BVC really is a lot like living the Star Trek experience. I been using BVC for a few years now... and I really enjoy it.

As a child.... technology writtings foretold a future where we could talk to our computers and automation performed many of our everyday tasks. We would watch TV on wall sized screens, own Robots, and commute in flying cars.

I am still ticked.... about the lack of flying cars!

Considering the number of nuts on the road now with ground based cars, I'm glad flying cars didn't come along.