MSGEQ7 alternatives?

Hello everybody

I was wondering if there's an alternative for the MSGEQ7 chip, because it seems like it is not widely available anymore (at least here in Germany). Several years ago I found and bought a lot of those ready-to-use MSGEQ7 breakout boards from amazon and ebay - but today they are either super-expensive, take months to be delivered or are simply sold-out.

Yes, I still have a bunch of single MSGEQ7 chips and I could wire them myself - but the breakout boards were really convenient and saved a lot of time.

So... is there maybe another chip(set) that I could use to analyze audio signals in different fequency bands?

It's a unique chip and I don't think there's anything similar.

The usual alternative is to do it in software with FFT/FHT.

Arduino is not powerful enough to perform a decent FFT, at least not if you want some decent inclusion of the lower frequencies at near real time.

Alternative is to build the band filters yourself (by using some resistors I believe).

Those fully assembled boards are not really that expensive: a good MSGEQ7 will cost about 8 USD, components ~2-3 USD. Some even have free shipping atm.

I went for the "cheap" route first, got 2 fakes, then the "more expensive", got another 2 fakes, finally got a full board for ~16 USD. Spent a multitude of that 16 USD now, and a lot of time...

Alternative is to build the band filters yourself (by using some resistors I believe).

It’s not that easy… Op-amps, resistors, and capacitors.

Typically, you make an active bandpass filter from a high-pass and low-pass filter, so that’s two op-amps (and associated components) per band. Although, you would use a low-pass for the lowest band and a high-pass for the highest band. So you could do 7-bands with 12 op-amps. (Quad op-amps are common so you don’t need 12 ICs.)

Then if you want to sort-of “simulate” the MSGEQ7 and put-out DC, you could add peak detector to each band (one more op-amp per band).

Or, there are specialized “switched capacitor filters” chips. (That’s what the MSGEQ7 uses internally).

…It doesn’t get much easier than the MSGEQ7!

Basically the MSGEQ7 is seven switched capacitor 2nd order filters. You can get these in a separate chips and build the equivalent if you want. Although I don’t know of anyone doing this, it should be quite simple.

Search for the chips on line.

This one is quite elaborate (see Step 3):