64 Band Stereo Spectrum Analyzer

[Grumpy_Mike]

@b707

MSGEQ7 has external clock input, which allows you to shift the base frequency of the channels. Using several chips with different clocks, you can get n*7 bands,

Well not quite because the switch capacitor filters it has are only second order filters so an attempt to get more frequencies from this chip doesn't result in a higher resolution in the spectrum but just more bands that are almost identical.

Note that the FFT produces evenly spaced bins which is not the same as perceptional spaced bins. This is because the ears response to frequency is logarithmic.

So normally several of the FFT bins are averaged to produce a lesser number of bins but ones that look more like what you here.

Personally I believe your initial requirements are way way too optimistic for such a low power processor.

[b707]

Thank for your answer, but I am not OP

[Grumpy_Mike]

@b707

but I am not OP

I know, but I wanted to point out to the OP that using that chip doesn't approach the sort of resolution that he stated he wanted,

[pasquada]

Hello @PerryBebbington thank you so much for interjecting in an attempt to mediate the flagging of unsuitable and unhelpful comments made toward this topic.

Re your multiple flags to the moderators: aarg is trying his best to help you, but you clearly do not find his style of help suitable to your style of learning.

I will attempt to curb my enthusiastic use of Flagging unhelpful comments in future.
I do not agree aarg was attempting to be helpful.
Correct, his approach was unsatisfactory.
If you were to compare his approach to previous responses from @TomGeorge or MrMark responses aarg manner of inquiry was of passive aggressive nature, challenging, condescending, inappropriate and unhelpful.

There is nothing wrong in this, different helpers have different styles of helping and different leaners have different styles of learning, sometimes the two don't match.

Of course there is nothing wrong with voicing my concern and disdain regarding his approach. And thank you for the enlightenment of the complexity between ‘Teacher and Student’ however this setting isn’t a classroom and I am not paying for tuition.

I suggest you thank aarg for his efforts but move on to someone whose help is a closer match to your learning requirements.

Thank you for your suggestion but I do not feel aarg warrants that kind of reward.

Please in future flag only one post to the moderators and think first whether it really needs our involvement, in this case I think not.

Again with passive aggressive tones. I’ll reiterate that I will try to refrain from excessive use of ‘flagging’ comments I believe are unhelpful toward the headlining topic.

aarg , thank you for your contribution but I suggest your help isn't what pasquada needs, so maybe time to give your excellent help to someone else.

Wow defensive much? and if that wasn’t a sly condescending passive aggressive dig toward me at the end of your comment … incredible!

I guess the maturity of point scoring is of the upmost importance and priority on this forum - in contrast to actual quality of knowledge based sharing and establishing friendships.

From this experience I don’t think I’ll be asking anymore questions in this particular forum as it is obviously a small community that feels threatened with newcomers wanting to learn. I’m amazed this type of behaviour still occurs in this day and age on the internet.

Thank you for your time.

[westfw]

@pasquada

You are asking what level my software and hardware comprehension is at? I think your questioning is irrelevant to my initial inquiry and very unhelpful.

For instance, see GitHub - connornishijima/SensoryBridge: OSHW Advanced LED Audio Visualizer based around a hacky Discrete Fourier Transform where the author switched from an FFT-based approach to 64 parallel instances of the Goertzel algorithm.
Which might be an interesting thought, or might be gibberish.

[pasquada]

Hey @westfw

Thank so much for that link.
That looks like an awesome little module and would be a perfect add on to the main board as a manual controller perhaps?

Lots to read digest and process

[DVDdoug]

pasquada,

I'd recommend starting-out with something simpler first... Maybe a VU meter. Then you can use the same audio-input setup and the same processor but "expand" your project with different software and different output-circuitry.

Or, maybe start-out with something super-simple like my World's Simplest Lighting Effect.

That was just made as an example to get people started but I made a very-similar real-life effect that uses a pair of floodlights, and there are some variations such as toggling between the lights, etc. (It is simple and "boring" and it's not intended to be the only lighting effect.)

That "Simplest" effect has automatic calibration (or "automatic sensitivity adjustment", and you might want to copy that concept.

Using 2 - 16x32 LED Matrixes...

...To be used for eye candy and a visual cue for my audience at gigs.
Customisable code to cater for more bands with larger LED matrixes.

It might be kind-of "small" with pre-made matrices. You could make your own and space-out the LEDs, but soldering hundreds of LEDs isn't "fun".

You could use long addressable LED strips and space those out for a "stage size" effect.

...I made a "giant 8-foot VU meter" which is just a regular stereo VU meter with 24 LEDs spaced about 4-inches apart on each side.(1)

Or, maybe you just write a computer application and plug-in a large-screen TV display or a projector.

You probably don't NEED 64 frequency bands... YOU might appreciate it but the audience doesn't care how many bands you have and they are going to get bored with ANY single effect after a couple of minutes.

(1) My "VU Meter" has several random variations that switch automatically... It has the usual bar-graph mode, there is a "dot" mode and a "dots" mode, it reverses so it goes "down" with louder sounds and it inverts so louder turns-off more LEDs. And it's more than a meter effect. There are 6 other flashing/sequencing effects and they all have variations. It also self-calibrates to the average loudness, so it's useless as a "meter" but it makes a good effect.

It stays in my living room connected to my stereo.

It just uses red LEDs and that seems a bit "outdated" sand I'm "thinking about" a version with RGB LED strips and then I can have "unlimited" color variations. And I can make an option where all of the LEDs are constantly on, so for example the meter effect could be green with silence the LEDs turning red with the sound (or any other random color-changing combinations).