Search found 186 matches

by Rocko
Sun Nov 15, 2020 8:29 am
Forum: DSP
Topic: EQ Biquads limitation, direct Forms and representation
Replies: 3
Views: 18191

Re: EQ Biquads limitation, direct Forms and representation

Appreciated.

Can someone explain why in 'fixed point' one needs to limit the coefficients of the denominator?
While (I believe) that in floating point this is not needed?
by Rocko
Thu Nov 12, 2020 8:04 am
Forum: DSP
Topic: EQ Biquads limitation, direct Forms and representation
Replies: 3
Views: 18191

EQ Biquads limitation, direct Forms and representation

Hi,

Many EQ's and filters use 2p2z (two pole two zero) IIR filters, just like in Flowstone's stock modules.
With the FS implementation I do not see any limitation on the maximum/minimum values of the coefficients.
However, I know that some DSP manufacturers limit their coefficients to (example ...
by Rocko
Thu Jul 16, 2020 6:40 am
Forum: DSP
Topic: HPF overshooting - surprising artifact
Replies: 10
Views: 39448

Re: HPF overshooting - surprising artifact

Martin hi - thanks for the clear explanation. It is much appreciated.

For "inside FS" - yes I saw that recombining the LF and HF parts had eliminated the phenomena.
I also understand that for FS this is not an issue due to increased dynamic range for processing ("can go over 1.000").

But this ...
by Rocko
Tue Jul 14, 2020 1:02 pm
Forum: DSP
Topic: HPF overshooting - surprising artifact
Replies: 10
Views: 39448

Re: HPF overshooting - surprising artifact

According to the answers brought to us by Juha_tp (on other forum) - this phenomena is expected and is easily seen with square waves.

Let's assume this is true - so what is the remedy ? I mean if I use a digital domain cross-over with an HPF for the "tweeters" - do I need to add a limiter or ...
by Rocko
Sun Jul 12, 2020 7:30 am
Forum: DSP
Topic: HPF overshooting - surprising artifact
Replies: 10
Views: 39448

Re: HPF overshooting - surprising artifact

Hi,

For getting a LR4 (Linkwitz-Riley order 4) cross-over, one needs to use a Q factor of 0.5.
LR4 is the most common cross-over design, to the best of my knowledge. It is implemented in a zillion hifi-speakers, in analog (cross over of home speakers).

so, my surprise is that it is not straight ...
by Rocko
Thu Jul 09, 2020 11:06 am
Forum: DSP
Topic: HPF overshooting - surprising artifact
Replies: 10
Views: 39448

Re: HPF overshooting - surprising artifact

This is a generic phenomena which will occur on any implementation, not related to schematic or specific flowstone implementation.

However I have added a simple example of a 12dB (2nd order) HPF with known Biquads (tested) set for:
Cutoff = 1KHz
Q = 0.5
Sample_Rate = 48000

and a frequency response ...
by Rocko
Thu Jul 09, 2020 8:28 am
Forum: DSP
Topic: HPF overshooting - surprising artifact
Replies: 10
Views: 39448

HPF overshooting - surprising artifact

Hi all,

I'm playing around with a digital cross-over design when I noticed that the HPF adds unwanted energy to the signal, making it go over 0dbFS.

I've designed a very simple LPF and HPF pair of filters to cut the frequency zones into two parts: LF and HF.
I've tested the HPF by injecting a ...
by Rocko
Tue Nov 19, 2019 11:28 am
Forum: DSP
Topic: SQRT optimization
Replies: 14
Views: 46580

SQRT optimization

Hey there,

I got to a point in which I need to use a function:
Y = sqrt(x)
in which X is limited between [1:0].

Can this be optimized, by avoiding sqrt and instead using taylor/maclaurin approximations?
I guess those would reach 3rd order (to reach satsifactory precision) and some ...
by Rocko
Wed Sep 25, 2019 1:28 pm
Forum: General
Topic: Embed DLL in EXE product
Replies: 4
Views: 11153

Re: Embed DLL in EXE product

Thanks Trogluddite and Tulamide - appreciated.
I'm looking into this...
by Rocko
Tue Sep 24, 2019 8:11 pm
Forum: General
Topic: Embed DLL in EXE product
Replies: 4
Views: 11153

Embed DLL in EXE product

Using Flowstone 3.0.8.1 I had built a schematic which loads a DLL file (written in C), from a specific location, and runs it.
The DLL is loaded by RUBY within the schematic, as explained in the user guide.

Within flowstone it runs as expected, but when I export it as EXE, there is no sound and it ...