Audio DSP

Hello Juergen, and welcome to the forum! Sorry that your local ADI support wasn't able to help you.

The ADAU1701 is easy to work with. SigmaStudio provides for active crossovers such as the Linkwitz-Riley, as well as IIR filters. There's also a FIR filter although you'll need to figure the tap coefficients with other software such as Matlab, and available memory limits their practical size to several hundred taps. The ADAU1701 can perform about 1000 instructions per sample at the usual 48KHz sample rate, enough for quite a bit of filtering and dynamic processing. If you need a higher sample rate, you can do about 500 instructions at 96KHz. As a point of reference, the simple crossover circuit below uses 124 instructions:

The 1701's analog input - output latency of about 1mS would limit woofer active feedback to a very low frequency. If that's acceptable, you could route the woofer feedback through the 1701's second analog input and process as necessary. I used current feedback from a speaker to measure its impedance -- this example at https://ez.analog.com/message/67877#67877 shows the range of processing that SigmaDSP can perform.

The best way to explore the range of algorithms available is to download SigmaStudio and try building a project. You can do this before obtaining hardware.

See https://ez.analog.com/message/121823#121823 for download instructions.

The -1701 mini eval board is quite suitable for developing analog in-out applications. You can go a long way with this before needing the larger -1401 board with its SPDIF I-O.

Best regards,

Bob

Dear Bob!

Thanks for the fast reply! Tomorow I will check your answer in detail and I think will come back to you with further questions.

Many Thanks - Juergen :-)

Dear Bob!

After checking your helpful information, I have of course a couple of questions. (background: we have only a very limited budget for this master project at the University of Applied Sciences Aschaffenburg / Germany)

A) EVAL-ADAU1401AEBZ (1701 Eva Board):

You mentioned this Eva Board for the 1701. The documentation refers to the 1401. This confuse me a little!

This EVA-Board is available under the AD University program for 500$ (normal price 699$). Do I need any additonal parts (USBi, PowerSupply, Target-Board-1701, ...) to fully work with the 1701 and the SigmaStudio Software?

B) Eva Mini Board 1701:

You mentioned an Eva Miniboard. I think you mean the EVAL-ADAU1701MINIZ Board? Available for students for 150$ (normal price 195$). Do I need any addional parts to fully work with 1701 and SigmaStudio. As I know this board has only one analog input & output

C) SigmaStudio Software:

For fully (free) filter and feedback programing of the 1701, do I need any other software (e.g. VisualDSP++), If yes, any further costs?

D) Performance for closed loop feedback:

You mentioned the I/O Latency of 1ms (f=1000 Hz). This is not so much, for controlling a woofer. Is there any other DSP platform with better performance/latency (e.g. SHARK) and comparable I/O-features (e.g. integrated AD/DA's) and SigmaStudio Support for rapid prototyping ( I like it!) ?

Regards and thanks in advance - Juergen

Hi Juergen,

The EVAL-ADAU1401AEB helps you develop projects for both the ADAU1401 and -1701 because these two chips are pin-compatible. The -1401 has only a wider (automotive) temperature range. This board features many switches & jumpers to configure the chip's MP pins for digital I/O, as well as on-board SPDIF support. All SigmaDSP eval boards come with a USBi and a power supply where needed (the smaller ones are USB bus powered). The target DSP on each board allows it it to run a SigmaDSP project for that chip.

The EVAL-ADAU1701MINIZ is much simpler, thus lacking support for digital I/O. With it you can access the -1701's two ADCs and two of its DACs via 1/8" stereo jacks. The other two DACs are routed through a small on-board Class-D amplifier. With a bit of careful soldering you can access those DACs directly as well. This board is bus-powered and includes a USBi. The chip's MP pins are hardwired as described in its user guide at: https://www.analog.com/static/imported-files/eval_boards/EVAL-ADAU1701MINIZ.pdf

After a bad experience with another manufacturer's product, I understand your concern that additional software might be needed to make it all work. Assuming the download described above is available in your country, this is the full SigmaStudio -- not some stripped-down version. You only need an eval board with its included items, and of course your PC. SigmaStudio's system requirements are moderate -- it runs on most Windows XP or newer machines with Microsoft .net installed (download this from Microsoft if needed, many PCs already have it). Be sure your PC has a USB 2.0 port -- the USBi won't work with 1.0, and hiccups annoyingly with 3.0. There's occasionally an issue with installing SigmaStudio on a networked computer, for which a workaround is available on this forum.

See https://ez.analog.com/message/7706#7706 for more info on the 1701's group delay. Since this latency is almost entirely from the ADC and DAC, you could use faster external ones (of course this complicates your engineering work). I'm unfamiliar with the SHARC DSPs, you could try the SigmaStudio for SHARC forum. SHARC development does need Cross Core Embedded Studio -- a licensed product -- in addition to the SigmaStudio for SHARC plugin.

Best regards,

Bob

Hi Bob!

Question to EVAL-ADAU1401AEB: Is my favorite target DSP 1701 included with the EVAL Board, or is this a extra position on the bill of material?

Regards - Juergen

Von: KJBob analogvm-admin@analog-vm.hosted.jivesoftware.com

Gesendet: Mittwoch, 20. November 2013 13:09

An: J. Zahn

Betreff: New message: "Audio DSP"

<http://ez.analog.com/index.jspa>; EngineerZone

Re: Audio DSP

created by Robert Blowsky <http://ez.analog.com/people/KJBob>; in SigmaDSP Processors and SigmaStudio Development Tool - View the full discussion <http://ez.analog.com/message/124077#124077>;

Hello Juergen,

Although the EVAL-ADAU1401AEB can be used to develop for the fully-compatible -1701, it has only a -1401 on-board.

The eval boards come ready to use, but with no additional loose parts for prototyping. Also ADI does not produce DSP cards specifically designed for building into a finished product (perhaps third parties do?). If after developing & testing your project you wish to lay out your own custom pcb, you'll need to obtain the needed components as available locally (is this what you meant by "bill of material" above?). Although ADI does not consider their eval boards as reference designs, some have used their schematics and BOMs as a starting point for their custom design.

Bob

Hi Bob,

Thanks for helping out with answering Juergen's questions!

Hi Juergen,

I was actually the one support you on the support email address, but due to many other projects, it has been difficult to be punctual in responding to questions.

If you'd like to try SigmaStudio, please download it and install it.

Just follow the steps in this FAQ to get the software:

http://ez.analog.com/docs/DOC-3470

Brett, Thanks for the proper link for the download instructions.

Juergen, by all means follow Brett's advice. You can have SigmaStudio plot the response of your filters even before obtaining hardware, as shown below:

Hi!

Thanks for the useful tipp using plots in SigmaStudio. Have you seen my other open task regarding problems to installing and running Sigma Studio 3.10.2 Beta in my DELL Laptop (W7/SP1/32bit/German)? The Installation process finish without error, but when I start SigmaStudion I got the following error and the app stopped:

Stopped working

Problemsignatur:

Problemereignisname: CLR20r3

Problemsignatur 01: sstudio.exe

Problemsignatur 02: 3.10.2.1278

Problemsignatur 03: 52772047

Problemsignatur 04: System.ServiceModel

Problemsignatur 05: 3.0.0.0

Problemsignatur 06: 5063ffbf

Problemsignatur 07: 1f94

Problemsignatur 08: 7e

Problemsignatur 09: IOIBMURHYNRXKW0ZXKYRVFN0BOYYUFOW

OS/Betriebsystemversion: 6.1.7601.2.1.0.256.48

Gebietsschema-ID: 1031

Regards - Juergen

Hello Juergen,

Sorry to hear you're having this issue with running SigmaStudio. It hasn't given me any sort of trouble like this. I see from your original post at

https://ez.analog.com/message/124075#124075

that Brett hasn't seen such an issue either, but he made the software team aware of it. Until we hear from them, about the only thing I would try is to uninstall the beta version, then install the stable 3.9 x86 release and see if that runs for you.

Bob

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