TOPIC:

heheh.. You beat us to the race Peter!

We're about to add an online calculator to our Advanced plug-ins. It will simplify the process greatly when it comes to building some custom/cascaded filters in the Biquad mode.

Thanks again for sharing your work,

All attachments are lost in this theme (

I restored the attachments.

Whatever happened to the online calculator?

Help please

I have calculated the following parameters per attached spreadsheet

a0=1
a1=1.995203563661810
a2=-0.995211837027711
b0=1.002767239860590
b1=-1.995188529985050
b2=0.992459630843881

I inputted these for biquad1 .... biquad8
When I ask to process I get an error indicating values are missing

Thanks in advance

Bob

Add a comma to each coefficient except a2 and it should work.

Albert

Albert

I actually have

biquad1,
a0=1,
a1=1.995203563661810,
a2=-0.995211837027711,
b0=1.002767239860590,
b1=-1.995188529985050,
b2=0.992459630843881,
biquad2,
a0=1,
a1=1.995203563661810,
a2=-0.995211837027711,
b0=1.002767239860590,
b1=-1.995188529985050,
b2=0.992459630843881,

to biquad8 ( I end without a comma.

I do this in the output section

Thanks

Bob

Bob,

Your formatting is indeed incorrect.. See the help/front page of the plug-in (REW input format button) or user manual for more info, but basically the plug-in expects something like this:

biquad1,
b0=1.00255060195923,
b1=-1.99872541427612,
b2=0.996345996856689,
a1=1.99872541427612,
a2=-0.998896598815918,
biquad2,
b0=1.02530908584595,
b1=-1.97203516960144,
b2=0.963742733001709,
a1=1.97203516960144,
a2=-0.989051818847656,
...

FYI, using the spreadsheet from this forum there is a section in yellow that should say "paste to miniDSP plug-in". That's what you'd need to paste (i..e in the correct order and without the a0.

Hope this helps,

DevTeam

Thanks

I will do this.

Do I paste at the input or the output? Sorry for being dense.

Best

Bob

Thanks for all the help = Up and running

knuisje,

Thanks so much for posting your spreadsheet (in post #1118 ) that can calculate the MiniDSP Z-transform transfer function coefficients. I had developed a very complicated crossover using the Laplace Domain transfer functions, but obviously could not enter those coefficients... I would have been stuck... so thanks again!!!

One request, however, as you are missing two important filter functions: the FIRST order shelving high and low pass filters. Any chance that you could add these to the spreadsheet???

-Charlie

Charlie,

Those first-order filters can be programmed without using the advanced biquad capability. Just select a normal high/low-shelf and Q=1.

Cheers,

Dave.

Dave,

Thanks!!! I am still introducing myself to my MiniDSPs, so I was not aware I could do it that way... originally, I was planning on implementing everything via the biquad transfer function coefficient programming.

So, I guess I would still like to know how to do it with the biquads... any ideas?

-Charlie

Charlie,

Select the "Biquad Calculator" tab on your advanced plugin application and select PEQ, low(high)-shelf, Q=1, etc, etc, and hit the "calculate" button. It'll compute the required coefficients which you can then paste into the appropriate PEQ area of your plugin.

(This is on page 16 of the 2x4 user manual.)

Cheers,

Dave.

Hi Dave,

Again, thanks! Also a good way to get the coefficients.

But!!!! I am designing an Excel based active crossover modeler. I would like for it to display the transfer function coefficients, so I need to know how to calculate them, e.g. formulas, so that I can enter them in the spreadsheet. This is for DIY purposes only. I am planning to copy out all the other calcs from knuisje's spreadsheet, and so I am only missing these...

-Charlie