Dipping my toe in - FV-1 crossover/signal correction; which offering is the best place to start?

[knucklehead]

Looking at the Binaural Stereo or the Dev PCB as foundation for a DSP-driven crossover and curve/signal correction - line level in. Am I looking in the right direction?

I expect there is a learning curve to successful programming and implementation, but I've built a few analog kits so by appearance I feel like I'm up to assembling either of the two mentioned above. We'll see about the EEPROM side of things . . . .

TYIA

 

[Digital Larry]

What do you mean by curve/signal correction?

 

[knucklehead]

What do you mean by curve/signal correction?

Meaning I am adjusting for/to 'flat' in a bi-amp system and need to be able to correct for two very different drivers at two radically different power levels. This is central to a powered wedge I built.

FWIW I am using a MiniDSP at present - it isn't failing me, but it's a costly option that is merely working. There is no under-the-hood with it - I am hoping that if I can program or acquire EEPROM options that are better suited to my specific application.

 

[CR0SSBL4DE]

If you just want to implement filters for an soeaker system, should be ok. Keep in mind the IC limitations, the first 3 I can think of are:
- You only have 2 outputs, so the limit is a two way speaker, or HPF for stereo signal.
- Not enough processing power for coeficient calculation, just filter implementation.
- Also, frequency response. Not sure how it behaves at clock speeds higher than 32768Hz, but according to the datasheet, at that frequency the DAC/ADC HF cutoff is -3dB at 15kHz (not clear but probably means -6dB after the 2 conversions)

 

[CR0SSBL4DE]

Meaning I am adjusting for/to 'flat' in a bi-amp system and need to be able to correct for two very different drivers at two radically different power levels. This is central to a powered wedge I built.

FWIW I am using a MiniDSP at present - it isn't failing me, but it's a costly option that is merely working. There is no under-the-hood with it - I am hoping that if I can program or acquire EEPROM options that are better suited to my specific application.

I don't think a DIY solution would be better than the miniDSP. It has a 400MHz floating point Sharc DSP.

Maybe you can get something to work with a ADAU1701 or similar DSP, but it wont be better than the miniDSP

 

[Digital Larry]

If you want to look at an existing FV-1 crossover/EQ program, search for "Active Crossover" on this page. https://www.spinsemi.com/programs.php

 

[knucklehead]

If you just want to implement filters for an soeaker system, should be ok. Keep in mind the IC limitations, the first 3 I can think of are:
- You only have 2 outputs, so the limit is a two way speaker, or HPF for stereo signal.
- Not enough processing power for coeficient calculation, just filter implementation.
- Also, frequency response. Not sure how it behaves at clock speeds higher than 32768Hz, but according to the datasheet, at that frequency the DAC/ADC HF cutoff is -3dB at 15kHz (not clear but probably means -6dB after the 2 conversions)

Thanks for the input - if I've read support docs correctly it suggested to me that there are programs I can cycle through that can give me malleability. If that ISN'T the case then stereo output is too severe a limitation. I need only high and low outputs in the end for bi-amping so stereo will suffice, and if optional programs I can dial/call up will give me 3 or 4 presets I am golden. I'll only ever need implementation I believe - volume per channel, EQ and crossover at any given moment - is there dynamic processing I'll need that I'm not considering? The wedge is meant for guitar and bass, so as such anything beyond 15kHz is theoretically beyond task, and the high frequency side of the speaker system reflects this in its capacity to do only 12kHz. I believe I am okay with this limitation.

There is nothing wrong technically w the MiniDSP - utilizing it results in disposing of the enclosure, hard-soldering to their board, and reliance on their programming environment and solutions. Their solutions are robust but in order to eek out a few niggly bits requires screwing with their code and programming - if I need to go that far to reach an ideal solution I would prefer to blow/burn my own EEPROMS. I should likely be careful what I wish for here, though.

 

[knucklehead]

If you want to look at an existing FV-1 crossover program, search for "Active Crossover" on this page. https://www.spinsemi.com/programs.php

Thanks for the link - a bit of informative homework and points of contact. I appreciate it!

 

[knucklehead]

I don't think a DIY solution would be better than the miniDSP. It has a 400MHz floating point Sharc DSP.

Maybe you can get something to work with a ADAU1701 or similar DSP, but it wont be better than the miniDSP

I'll rabbit hole the ADAU1701/similar stuff - this is likely a better solution than utterly rolling my own.

Thanks!

 

[phi1]

Some reference info - handwriting fv-1 code is a whole learning curve. You can also use SpinCad (by digital Larry) to generate code from blocks, but the code he linked from the spinsemi site is probably a better starting point for this specific project.

A single eeprom chip can hold up to 8 programs (see the pedalpcb arachnid / spatialist reverb for example).

The fv-1 does come preloaded with 8 programs (usable without eeprom chip), but they are not eq/crossover.

to have “presets” available, you or someone would have to hand-modify the parameters of that code that Larry linked, and load (up to) 8 versions onto and eeprom chip.

I use the dev pcb for flashing the code from my pcb, but it’s not stereo out. Looks like the binaura is out of stock, not sure when it’ll be back, I’m not aware of any other stereo fv-1 pcbs on here, but you could design your own pcb or use the fv-1 dip converter pcb from here and build on stripboard.