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C6713DSK _ Feedback ANC

Started by Wave Waves June 1, 2010

Hi Dears,


Is there anyone who may probably help me with Feedback ANC system project ;
I wanna Implement the Active Noise Control system with TMS320C6713 DSK and perhaps with one Error Microphone and one Anti-noise Loudespeaker with Feedback ANC algorithm ;
I have read so many IEEE papers and TI documents about that but I have some practical problems.


Best Regards.
wAVe
r...@ieee.org
Waves,

You will have two audio inputs,
The input you want to pass to the listener via the head phone.
The input of sound within the headphone.

You take the difference between the two inputs, invert the signal, add the
inverted signal to the desired signal.

signal propagation delays will be a problem to solve.
signal amplification levels will be a problem to solve.

R. Williams

---------- Original Message -----------
From: Wave Waves
To: r...@lewiscounty.com, c...
Sent: Mon, 31 May 2010 18:37:15 -0700 (PDT)
Subject: [c6x] C6713DSK _ Feedback ANC

>
> Hi Dears,
>
>
> Is there anyone who may probably help me with Feedback ANC system
> project ; I wanna Implement the Active Noise Control system with
> TMS320C6713 DSK and perhaps with one Error Microphone and one Anti-
> noise Loudespeaker with Feedback ANC algorithm ; I have read so many
> IEEE papers and TI documents about that but I have some practical problems.
>
>
> Best Regards.
> wAVe
> r...@ieee.org
>
------- End of Original Message -------

_____________________________________
Wave,

Please reply to the list, not to me.

Please do not clip prior posts.
I answer a lot of c6x posts and need the prior posts to help me remember what
has already been said.

an appropriate Fourier transform will exhibit the frequency and amplitude of
each received frequency found in a audio signal.

The software will have to determine which of the frequency(s) needs to be
canceled. My first two ideas would be every sound that is greater than 10db
over the average sound level, all continuous frequencies, everything over ~4khz.
The placement of speakers and microphones will have to be considered as sound
takes a while to travel.

in an uncontrolled environment, such as a room with people, etc it will not be a
perfect cancellation of unwanted noise due to sound propagation time and
reflections; plus noise canceling speaker and noise pickup microphone locations.

Also, as the frequency of the unwanted noise increases, the amount of time
available to produce the cancellation signal decreases. I'm not exactly sure
why.
Also, as the frequency of the unwanted noise increases, the audio signal
sampling rate has to increase to achieve an accurate picture of the received
sound. I.E. a sampling rate at least twice the highest frequency to be
cancelled.

R. Williams

---------- Original Message -----------
From: Wave Waves
To: Richard Williams
Sent: Mon, 31 May 2010 22:17:28 -0700 (PDT)
Subject: Re: [c6x] C6713DSK _ Feedback ANC

> Dear Williams,
>
> Thank you for helping.
> Actually we have so many problems practically and maybe theorically !
> For Start, we just want to cancel a 1-KHz sinwave ;
> For the first step , I created the two 1-KHz sinwave by MATLAB with 4-
> KHz sample rate and inverted signal. The superposition of these two
> signal in GoldWave software is quite zero. but practically when we
> play them two different channel of double loudspeaker of a PC, they
> can cancel eachother when they are exactly face to face and close !
> what if we want to cancel a real-life noise in the room ,not just in
> ear-cup ?! what should we do about volume?! we decrease the volume of
> the Anti-noise Loudspeaker via a potentiometer(variable resistor) or
> there is formula for that to do that from software?! Actually I
> have so many other inquires about NLMS in similink, that I will ask later.
>
>
> Yours Sincerely,
> wAVe
> r...@ieee.org
>
>
>
> --- On Tue, 6/1/10, Richard Williams wrote:
>
> From: Richard Williams
> Subject: Re: [c6x] C6713DSK _ Feedback ANC
> To: "Wave Waves" , c...
> Date: Tuesday, June 1, 2010, 4:37 AM
>
>
>
> Waves,
>
> You will have two audio inputs,
> The input you want to pass to the listener via the head phone.
> The input of sound within the headphone.
>
> You take the difference between the two inputs, invert the signal, add
> the inverted signal to the desired signal.
>
> signal propagation delays will be a problem to solve.
> signal amplification levels will be a problem to solve.
>
> R. Williams
>
> ---------- Original Message -----------
> From: Wave Waves
> To: r...@lewiscounty.com, c...
> Sent: Mon, 31 May 2010 18:37:15 -0700 (PDT)
> Subject: [c6x] C6713DSK _ Feedback ANC
>
> >
> > Hi Dears,
> >
> >
> > Is there anyone who may probably help me with Feedback ANC system
> > project ; I wanna Implement the Active Noise Control system with
> > TMS320C6713 DSK and perhaps with one Error Microphone and one Anti-
> > noise Loudespeaker with Feedback ANC algorithm ; I have read so many
> > IEEE papers and TI documents about that but I have some practical problems.
> >
> >
> > Best Regards.
> > wAVe
> > r...@ieee.org
> >
> ------- End of Original Message -------
------- End of Original Message -------

_____________________________________
Hi everyone,
Is there anyone else who have any more idea ?!
Thanks a lot.
--- On Tue, 6/1/10, Wave Waves wrote:

From: Wave Waves
Subject: Re: [c6x] C6713DSK _ Feedback ANC [1 Attachment]
To: c...
Date: Tuesday, June 1, 2010, 8:39 AM

 

[Attachment(s) from Wave Waves included below]

Dear Williams,
 
You're the best as always. Thanks a lot and a lot more ...
 Thank you for your considerations.
 
So here are my other questions :
Actually, I have two plan to make an ANC project with C6713DSK ;
The first plan is to stick to the simulink and build this project with RTW(real-time workshop);
The second plan is by ccs project only ;
 So, for first plan with simulink, Can you tell me that where should place my microphone and my loudspeaker in the wave_RLS.mdl (simulink file with NLMS algorithm ) that we made, in details ;
(please check the attachment)
 
As far as I concerned, this is true project and should perform truly but it didn't cancel the noise practically ;
 desired is signal (alarm or speech) plus noise ;
input is noise ;
output of NLMS is Anti-noise or noise ??!!!!!!!!! why ????!!!!
In feeback ANC systems ,Error is input microphone but this simulink file, it's just output of estimate of NLMS ;
so we plugged the input mirophone (6713 DSK ADC)to the input and desired (we do not want any signal (alarm or speech)  here,we wanna cancel everything i.e. everything is noise for us) ;
And we plugged the Loudspeaker to 6713 DSK DAC ;
 
But it didn't cancel the noise ;
BTW, we removed the random source noise by NLMS & RLS by simulink but all we couldn't do was creating the Anti-noise for Loudspeaker to cancel the noise ;
 
So please take a look at this simulink file and tell me your comments ;
 
> Yours Sincerely,
>      wAVe
> rafi3e@ieee. org
 
 
--- On Tue, 6/1/10, Richard Williams wrote:
From: Richard Williams
Subject: Re: [c6x] C6713DSK _ Feedback ANC
To: c6x@yahoogroups. com
Date: Tuesday, June 1, 2010, 5:56 AM
 

Wave,

Please reply to the list, not to me.

Please do not clip prior posts.
I answer a lot of c6x posts and need the prior posts to help me remember what
has already been said.

an appropriate Fourier transform will exhibit the frequency and amplitude of
each received frequency found in a audio signal.

The software will have to determine which of the frequency(s) needs to be
canceled. My first two ideas would be every sound that is greater than 10db
over the average sound level, all continuous frequencies, everything over ~4khz.

The placement of speakers and microphones will have to be considered as sound
takes a while to travel.

in an uncontrolled environment, such as a room with people, etc it will not be a
perfect cancellation of unwanted noise due to sound propagation time and
reflections; plus noise canceling speaker and noise pickup microphone locations.

Also, as the
frequency of the unwanted noise increases, the amount of time
available to produce the cancellation signal decreases. I'm not exactly sure
why.
Also, as the frequency of the unwanted noise increases, the audio signal
sampling rate has to increase to achieve an accurate picture of the received
sound. I.E. a sampling rate at least twice the highest frequency to be
cancelled.

R. Williams

---------- Original Message -----------
From: Wave Waves
To: Richard Williams
Sent: Mon, 31 May 2010 22:17:28 -0700 (PDT)
Subject: Re: [c6x] C6713DSK _ Feedback
ANC

> Dear Williams,
>  
> Thank you for helping.
> Actually we have so many problems practically and maybe theorically !
> For Start, we just want to cancel a 1-KHz sinwave ;
> For the first step , I created the two 1-KHz sinwave by MATLAB with 4-
> KHz sample rate and inverted signal. The superposition of these two
> signal in GoldWave software is quite zero. but practically when we
> play them two different channel of double loudspeaker of a PC, they
> can cancel eachother when they are exactly face to face and close !
> what if we want to cancel a real-life noise in the room ,not just in
> ear-cup ?! what should we do about volume?! we decrease the volume of
> the Anti-noise Loudspeaker via a potentiometer( variable resistor) or
> there is formula for that to do that from software?!   Actually I
> have so many other inquires about NLMS in
similink, that I will ask later.
>  
>  
> Yours Sincerely,
>      wAVe
> rafi3e@ieee. org
>  
>  
>
> --- On Tue, 6/1/10, Richard Williams wrote:
>
> From: Richard Williams
> Subject: Re: [c6x] C6713DSK _ Feedback ANC
> To: "Wave Waves" , c6x@yahoogroups. com
> Date: Tuesday, June 1, 2010, 4:37 AM
>
>  
>
> Waves,
>
> You will have two audio inputs,
> The input you want to pass to the listener via the head phone.
> The input of sound within the headphone.
>
> You take the difference between the two inputs, invert the signal, add
> the inverted signal to the desired signal.
>
> signal propagation delays will be a problem to solve.
> signal amplification levels will be a problem to solve.
>
> R. Williams
>
> ---------- Original Message -----------
> From: Wave Waves
> To: rkwill@lewiscounty. com, c6x@yahoogroups. com
> Sent: Mon, 31 May 2010 18:37:15 -0700 (PDT)
> Subject: [c6x] C6713DSK _ Feedback ANC
>
> >  
> > Hi Dears,
> >  
> >  
> > Is there anyone who may probably help me with Feedback ANC system
> > project ; I wanna Implement the Active Noise Control system with
> > TMS320C6713 DSK and perhaps with one Error Microphone and one
Anti-
> > noise Loudespeaker with Feedback ANC algorithm ; I have read so many
> > IEEE papers and TI documents about that but I have some practical problems.
> >  
> >  
> > Best Regards.
> > wAVe
> > rafi3e@ieee. org
> >  
> ------- End of Original Message -------
------- End of Original Message -------