This is a special case of wireless audio transmission.
If one were to implement wireless sub-woofer for 20Hz to 250Hz band, by digitising a line level signal then what would be the requirements for
1) The minimum ADC bit resolution
2) The minimum DAC bit resolution, would 16 bit PWM via digital GPIO of micro controller work?
3) Minimum sampling frequency
3) Max end to end delay that can be tolerated
The wireless system should not be different from wired in terms of quality.
Thanks,
WA
If one were to implement wireless sub-woofer for 20Hz to 250Hz band, by digitising a line level signal then what would be the requirements for
1) The minimum ADC bit resolution
2) The minimum DAC bit resolution, would 16 bit PWM via digital GPIO of micro controller work?
3) Minimum sampling frequency
3) Max end to end delay that can be tolerated
The wireless system should not be different from wired in terms of quality.
Thanks,
WA
Last edited:
Hi,
This is a tough question. Your last statement "The wireless system should not be different from wired in terms of quality" means you can't take any shortcuts in the audio chain so if it was me and since it would be a custom project, I'd target the full range application in hope to use it more places. Also what is the saying, "shoot for the sun and you end up on the moon"?
You needs my vary but I'd shoot for:
1. ADC effective number of bits (ENOB) 17 or more.
2. DAC - I would not use GPIO from a controller, I'd stick with I2S lines to an audio DAC. In my opinion the PWM from GPIO would be too hard to get correct to sound proper. At the end of the day I would think, I could have done better if I used an audio DAC but that is just me. If you are using a microcontroller I think ST Micro has some that do I2S buses.
3. 44.1kHz
4. Is this going to be used to watch video? Also it may not be easy to delay the frequencies above 250Hz unless you have an active set up so I'd shoot for lowest latency possible. This would also cover you for video application.
CharlieLaub has a project you might be interested in. Maybe has some hints for you there
A bash-script-based streaming audio system client controller for gstreamer
Good luck!
This is a tough question. Your last statement "The wireless system should not be different from wired in terms of quality" means you can't take any shortcuts in the audio chain so if it was me and since it would be a custom project, I'd target the full range application in hope to use it more places. Also what is the saying, "shoot for the sun and you end up on the moon"?
You needs my vary but I'd shoot for:
1. ADC effective number of bits (ENOB) 17 or more.
2. DAC - I would not use GPIO from a controller, I'd stick with I2S lines to an audio DAC. In my opinion the PWM from GPIO would be too hard to get correct to sound proper. At the end of the day I would think, I could have done better if I used an audio DAC but that is just me. If you are using a microcontroller I think ST Micro has some that do I2S buses.
3. 44.1kHz
4. Is this going to be used to watch video? Also it may not be easy to delay the frequencies above 250Hz unless you have an active set up so I'd shoot for lowest latency possible. This would also cover you for video application.
CharlieLaub has a project you might be interested in. Maybe has some hints for you there
A bash-script-based streaming audio system client controller for gstreamer
Good luck!
Yes, its for live TV application.
Seems complicated to do a custom digital implementation.
So, there are atleast 2 other tangible options I see
1) FM radio. This is analogue and noise could be an issue since bass has some silent passages.
2) Bluetooth audio. I am doubtful of the end to end delay.
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