active two-way speaker with 1701: help for loudspeaker management and protection

the channels used will be only 1 and 2

Hello Angelz,

I just want to mention that the posts on the forum should be in English. We are trying to keep it consistent.

I put your text into a translator and the first part is clear but the second part does not translate well.

" For now I have created this structure but I accept advice on what to do to make everything sound better and I told you. I often read in advertisements that signature filters are used but how do they dry out and above all really serve? I accept advice, thank you! "

I do not know what signature filters are and what "dry out" means? I think you are talking about adaptive FIR filters?

One thing to mention before I talk about speaker protection. You will need to add some DC block filters at the very input of your project. The ADC does have a DC offset like all ADCs do. Then it will get boosted by your EQ and that is not good.

I have attached an example project that uses peak limiters on the outputs to prevent the DACs from clipping.

This is a basic way to keep the DSP from sending out a clipped signal. However, there are many higher levels of protection that can be done. The first basic way is to know what level going out of the DAC will clip the external amplifier. Then the limiter in the DSP can be set to limit just before that level. Then there is yet another way and that is to know how much power the speaker can handle or at what level does the driver bottom out? Those sorts of things. Then again, set the limiter to prevent that from happening.

Then the really good speaker protection algorithms will make an attempt to track the voice coil temperature and adjust the limiter (or volume control) to lower the output so that the speaker will not overheat and be damaged. This gets very complicated very quickly and a high level of knowledge of the speaker parameters are needed. Then you can even go further! Some amplifiers have I/V feedback (current and voltage) so that the performance of the driver can be measured in the DSP and protect the speaker that way.

Most of the approaches in the last paragraph are difficult to do using the ADAU1701 and difficult for the average DSP user to understand how to design these systems.

My suggestion is to figure out how much power the speakers can handle and understand what level out of the DSP will produce that level at the speaker and set the limiters appropriately.

The limiter in the example project is a peak limiter which reacts to limit the peak with zero attack time. It is often good to have an RMS limiter/compressor before the final output limiter that you can set to gradually start the limiting in a more pleasant sounding way. The RMS limiter will have an attack time so the final limiter is still needed to ensure no peaks get by.

Dave T

6445.ADAU1701 Crossover 2-way with 2-band Limiting.dspproj

HI! I translated the text :) I meant the FIR filters, for example RCF uses them in its speakers as a sound revolution, but to tell the truth the new models sound better at low volume but have little power!

What I would like to do is use a custom b&c woofer that has a power of 700 watts, the amplifier has 750w per channel with 1% thd, for the driver I have 80w of power, but it is very efficient, and using them with a limiter traditional dbx even hitting a lot are not breaking them :D
but there the parameters are standard, attack, relase, mantein, db ratio, like 50:1 etc, with sigmastudio instead there are infinite possibilities :D

Here are the amplifier data:

Gain 32 dB (x40 voltage gain)

Input sensitivity @ 8Ω 1.12 V / 3.2 dBu

Max input level 4.36 V / 15 dBu

Input impedance 10 kohm balanced

Thank you :)