Is there a sigma family with built-in eq features (more than 4 bands)?

Hello Andrew,

All of our SigmaDSP products use SigmaStudio programming environment where you can build almost anything you can think to do. If you want to have the audio come in and go through 15 bands of filters you can do it provided there are enough memory and instruction resources available. This differs from part to part and it will depend on sampling rate etc.

Here is an example using one of our smallest SigmsDSP parts, the ADAU1701. I dropped in a double precision stereo filter and grew it to the maximum of 15 sections and then added a volume control on the output. This compiled and fit into the DSP.

So then I doubled it:

So with the above program with 15 filter sections for four channels, here is the compiler usage report:

################## Summary ########################
(Note: Estimates are based on a 48 kHz sample rate)
Number of instructions used (out of a possible 1024 ) = 634
Data RAM used (out of a possible 2048 ) = 381
Parameter RAM used (out of a possible 1024 ) = 153

As you see, there is still a fair amount of system resources available!

So how much EQ do you need and what type?

The questions to answer are going to be more about the hardware requirements so you can choose the parts to use.

Dave T

Thank you very much Mr. David
It's very helpful for me.

Hello Andrew,

One other comment I would like to add.

In our larger Sigma300 and Sigma200 products we also have a "High Order Shelving Table Interpolator" that can implement a graphic style EQ with many bands. It also has an external control version that allows you to use the AUXADC inputs connected to an external pot to control the gain of each band. I am not certain what you are looking for but there are many solutions for you depending on your needs and system design.

Dave T