Integration of ADAU1466 and ADAU1777 for Feed Forward Active Noise Cancellation ANC
Hello,
After several hours of searching through these forums for solutions for implementing a feed forward ANC system I have come to a few conclusions.
1. ANC Algorithm can be implemented using SigmaStudio given appropriate device-library compatibility.(ADAU1466 supports this) Here
2. ADAU1466 latency is not suitable for ANC Here
3. The ADAU1777 is a relatively low-cost option for low latency application of certain DSP functions (IIR filtering) Here
4. ADAU1777 cannot execute FxLMS but has 2 banks for IIR Filter Coefficients and can be updated by an external processor Here
Given this info, My questions are as follows.
1. Can these two devices be integrated together such that ADAU1777 serves as low latency filter throughput for Anti-Noise signal and ADAU1466 runs the ANC algorithm?
2. Can they be connected as discussed Here and Here ?
I am a Electrical Engineering Student and Valencia College working on my Senior Design project.
Here is a Block Diagram of my team's design.
The system will cancel noise as it passes through a rigid barrier (door, wall, ceiling) via a tactile transducer (bass shaker) which will drive the barrier with anti-noise. The device is intended to be equipped with path selection circuitry to enable operation in either direction depending on user input.
Any help or advice would be greatly appreciated.
Thank You,
John Waters
Audio Signal Processors
anc
Integrated/Special Purpose A/D Converters
SigmaDSP Audio Processors
active noise control
adau1777
Audio CODECs
adau1466
anc projects
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Hi Jason,
I'm hoping someone on here can also point me in the right direction for the same reason. I'm looking at a DSP that can output ideal voice, Analog devices is one that came up in my search but it seems none of the DSPs in the Tree Tool Box of Signma Studio have both NS (Noise Suppression) and AEC (Acoustic Echo Cancellation), trial or not.
Is this really the case, none of the DSP's support both algorithms at the same time?
Hello expresspotato,
The ADAU1452 and ADAU1462/1463/1466/1467 all support AEC and Noise Reduction at the same time. Both AEC and Noise Reduction are licensed algorithms. We do have trial versions available under Tools > Manage Downloadable Add-Ins.
Documentation for AEC is at Acoustic Echo Cancellation [Analog Devices Wiki] and NR at Noise Reduction (Standard) [Analog Devices Wiki].
I would also point you to the SHARC line of processors, for which we have a more sophisticated AEC/NR/BF toolkit available: Audio Signal Processing Solutions | Analog Devices. SHARC processors are powerful, but have several layers of complexity beyond SigmaDSP; not as straightforward for beginners to integrate into products.
Regards,
Joshua
Hi John,
The converters in the ADAU1777 and ADAU1787 are optimized for low latency. The analog-to-analog latency of ADAU1787 is 5 us, low enough for ANC headphone applications.
The serial ports on these parts are compatible with other SigmaDSP processors, including ADAU1466. There will be some added latency beyond 5 us due to the additional signal routing through the serial ports. I can find information on exactly how much latency would be added, if needed.
Since this is for a senior project, I should mention that the ADAU1777 and ADAU1787 are only available in WLCSP packages; extremely difficult to solder by hand. Take a look at the lead pattern and spacing in the datasheet. Your best bet would be to use an eval board rather than attempt a custom PCB.
Best regards,
Joshua
Thank you for the prompt reply. Noise Removal -> Noise Reduction is missing for me in SigmaSudio 4.6 for the ADAU1467 even after installing and restarting SigmaStudio. AEC is there though and strangely it's there for the ADAU167x, but I believe it's a different algorithm entirely for that series.
Hello, the residual echo suppressor and noise reduction blocks for ADAU1467 are easy to miss if you don't know where to find them.
Both these components work in the frequency domain, so they are accessed from the block schematic.
There are a number of considerations when integrating AEC and Noise Reduction into a project, not least of which is the bandwidth; usually we do processing at 16 kSPS (wideband) and use a further QMF filter to split the lower 4 kHz and upper 4 kHz of content for more efficient processing.
So I'd highly recommend starting from one of the example projects. They are available from the Wiki pages I linked to earlier.
Regards,
Joshua
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