That would be great!sadko4u wrote:You need to use special APO DR filters in LSP equalizer to match the REW settings.lilith wrote: And which slope factor to use in the LSP EQ then and what type of EQ (resonance?)?
Also, Since LSP equalizer provides APO-compatible filters, I'm currently working on this feature request sent to me as a feedback some time ago:
https://github.com/sadko4u/lsp-plugins/ ... #L196-L231
HOWTO: Quick Frequency Response Measurements Using JAPA and Faust
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Re: HOWTO: Quick Frequency Response Measurements Using JAPA and Faust
Re: HOWTO: Quick Frequency Response Measurements Using JAPA and Faust
Yeslilith wrote:Is it ok to choose the Generic EQ in REW?
I set up the first equalizer in the LSP parametric EQ as in your settings as an example. See below. The slope control does not affect the APO style of filter.lilith wrote:And which slope factor to use in the LSP EQ then and what type of EQ (resonance?)?
Settings:
Hope it helps!
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Re: HOWTO: Quick Frequency Response Measurements Using JAPA and Faust
Thanks! I thought it's not implemented yet. Wow... the difference between e.g. APO and RLC is quite huge. Is it because of different Q definitions?CrocoDuck wrote:Yeslilith wrote:Is it ok to choose the Generic EQ in REW?
I set up the first equalizer in the LSP parametric EQ as in your settings as an example. See below. The slope control does not affect the APO style of filter.lilith wrote:And which slope factor to use in the LSP EQ then and what type of EQ (resonance?)?
Settings:
Hope it helps!
- sadko4u
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Re: HOWTO: Quick Frequency Response Measurements Using JAPA and Faust
This is also because of a bit different filter design:lilith wrote: Thanks! I thought it's not implemented yet. Wow... the difference between e.g. APO and RLC is quite huge. Is it because of different Q definitions?
https://lsp-plug.in/?page=manuals§i ... r_x16_monoAPO - Digital biquad filters derived from canonic analog biquad prototypes digitalized through Bilinear transform. These are textbook filters which are implemented as in the EqualizerAPO software.
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Re: HOWTO: Quick Frequency Response Measurements Using JAPA and Faust
why not use one of the LSP convolvers?lilith wrote:Thanks! I thought it's not implemented yet. Wow... the difference between e.g. APO and RLC is quite huge. Is it because of different Q definitions?CrocoDuck wrote:Yeslilith wrote:Is it ok to choose the Generic EQ in REW?
I set up the first equalizer in the LSP parametric EQ as in your settings as an example. See below. The slope control does not affect the APO style of filter.lilith wrote:And which slope factor to use in the LSP EQ then and what type of EQ (resonance?)?
Settings:
Hope it helps!
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Re: HOWTO: Quick Frequency Response Measurements Using JAPA and Faust
How will this work and is there any advantage?Capoeira wrote:why not use one of the LSP convolvers?lilith wrote:Thanks! I thought it's not implemented yet. Wow... the difference between e.g. APO and RLC is quite huge. Is it because of different Q definitions?
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Re: HOWTO: Quick Frequency Response Measurements Using JAPA and Faust
@sadko4u: Just to make sure that it's correct, what I'm doing:
When saving the filter.req file from REW I have to choose the GENERIC filter type, right? When importing this into your EQ it automatically jumps to APO.
In here I have to choose PK, I guess (as written a page above from here):
https://i.imgur.com/wCQ17zN.png
When saving the filter.req file from REW I have to choose the GENERIC filter type, right? When importing this into your EQ it automatically jumps to APO.
In here I have to choose PK, I guess (as written a page above from here):
https://i.imgur.com/wCQ17zN.png
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Re: HOWTO: Quick Frequency Response Measurements Using JAPA and Faust
there is in option in REW to export the filter IR. it then can be simply put in a convolver in the audio chain.lilith wrote:How will this work and is there any advantage?Capoeira wrote:why not use one of the LSP convolvers?lilith wrote:
Thanks! I thought it's not implemented yet. Wow... the difference between e.g. APO and RLC is quite huge. Is it because of different Q definitions?
I actualy don't know which one is better. I just always did it like that. In theory with convolution you can have infinite filters, but REW is limited to 20 anyways
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Re: HOWTO: Quick Frequency Response Measurements Using JAPA and Faust
Ah, I found it. Hmmm... When using the EQ I know what I'm doing and I see which frequencies are filtered. When using the IR response it's more nebulous, but I will try this too. ~5 filters or less is enough in my case. Thanks for the tip.Capoeira wrote:there is in option in REW to export the filter IR. it then can be simply put in a convolver in the audio chain.lilith wrote:How will this work and is there any advantage?Capoeira wrote:
why not use one of the LSP convolvers?
I actualy don't know which one is better. I just always did it like that. In theory with convolution you can have infinite filters, but REW is limited to 20 anyways
- sadko4u
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Re: HOWTO: Quick Frequency Response Measurements Using JAPA and Faust
APO filters are the most matching filters for the REW file. Other filters are non-DSP-book designed, so their characteristics do not match REW ones. That's why automatically APO filters are selected when you import REW file.lilith wrote:@sadko4u: Just to make sure that it's correct, what I'm doing:
When saving the filter.req file from REW I have to choose the GENERIC filter type, right? When importing this into your EQ it automatically jumps to APO.
In here I have to choose PK, I guess (as written a page above from here):
https://i.imgur.com/wCQ17zN.png
Sorry for delay. I haven't monitored this topic.
Reference to textbook: https://shepazu.github.io/Audio-EQ-Cook ... kbook.htmlAPO - Digital biquad filters derived from canonic analog biquad prototypes digitalized through Bilinear transform. These are textbook filters which are implemented as in the EqualizerAPO software.
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Re: HOWTO: Quick Frequency Response Measurements Using JAPA and Faust
Thanks, it's working!sadko4u wrote:APO filters are the most matching filters for the REW file. Other filters are non-DSP-book designed, so their characteristics do not match REW ones. That's why automatically APO filters are selected when you import REW file.lilith wrote:@sadko4u: Just to make sure that it's correct, what I'm doing:
When saving the filter.req file from REW I have to choose the GENERIC filter type, right? When importing this into your EQ it automatically jumps to APO.
In here I have to choose PK, I guess (as written a page above from here):
https://i.imgur.com/wCQ17zN.png
Sorry for delay. I haven't monitored this topic.
Reference to textbook: https://shepazu.github.io/Audio-EQ-Cook ... kbook.htmlAPO - Digital biquad filters derived from canonic analog biquad prototypes digitalized through Bilinear transform. These are textbook filters which are implemented as in the EqualizerAPO software.
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Re: HOWTO: Quick Frequency Response Measurements Using JAPA and Faust
whats your opinion on the EQ vs convolver question?sadko4u wrote:APO filters are the most matching filters for the REW file. Other filters are non-DSP-book designed, so their characteristics do not match REW ones. That's why automatically APO filters are selected when you import REW file.lilith wrote:@sadko4u: Just to make sure that it's correct, what I'm doing:
When saving the filter.req file from REW I have to choose the GENERIC filter type, right? When importing this into your EQ it automatically jumps to APO.
In here I have to choose PK, I guess (as written a page above from here):
https://i.imgur.com/wCQ17zN.png
Sorry for delay. I haven't monitored this topic.
Reference to textbook: https://shepazu.github.io/Audio-EQ-Cook ... kbook.htmlAPO - Digital biquad filters derived from canonic analog biquad prototypes digitalized through Bilinear transform. These are textbook filters which are implemented as in the EqualizerAPO software.
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Re: HOWTO: Quick Frequency Response Measurements Using JAPA and Faust
According to the DSP theory, convolution is another way to present the frequency characteristics of the linear system.Capoeira wrote:whats your opinion on the EQ vs convolver question?
But parametrized filters have two huge advantages:
- parametrized filters can be simply edited by adjusting their parameters; to do the same thing with convolution, you need to add additional filter or pre-process the impulse response with this filter.
- if parametrized filters are IIR (infinite impulse response) filters, then they require much less CPU resources than convolution which works as a FIR (finite impulse response) filter.
The advantage of convolution is the following: if you have a linear system that does not need additional post-processing, then loading a single impulse response that represents this system is much easier than building chain of filters with custom parameters.
So these both are the different methods to do the same thing.
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Re: HOWTO: Quick Frequency Response Measurements Using JAPA and Faust
Maybe another thing: Boosting frequencies is not recommended and does not work in some cases. So, I like the flexibility of EQ filters.
Re: HOWTO: Quick Frequency Response Measurements Using JAPA and Faust
Sorry guys, I did not follow the forums too much in the last few months...
Do you mean using an Impulse Response to boost low frequency? Detailed low frequency filtering can be implemented with FIR filters only if they are pretty long. I reckon that's why it has a high chance of not working: if your impulse response is too short you loose low frequency detail.lilith wrote:Maybe another thing: Boosting frequencies is not recommended and does not work in some cases. So, I like the flexibility of EQ filters.