LinFIR – DSP Software for FIR/IIR Filter Design and Speaker Correction

[Arnwald]

A couple of years ago I started coding a small tool for my own DIY loudspeaker projects. I wanted an easier way to design FIR filters for crossovers and corrections without constantly switching between REW, rePhase, VituixCAD, etc.

One thing led to another, and the project grew far beyond its DIY beginnings. The result is LinFIR, a full application that now includes:
– Integrated measurement with sweeps
– Automatic FIR-based magnitude and phase correction
– Causality transform (linear phase, minimum phase, or anything in between)
– IIR + FIR EQ and crossover design, with real-time visualization of frequency, impulse, step, and group delay
– Detailed report export to track all applied filters, delays, and gains
– FIR filter export to audio DSP formats

What started as a personal experiment has become a proper software project. I’ve decided to make it available as a paid product (not freeware), built by someone who’s been through the same DIY frustrations and wanted a more streamlined workflow.

I’m sharing this here because ASR has many measurement-oriented people who might provide constructive feedback. Curious to hear your thoughts!



https://linfir.demaudio.com

 

[eddantes]

Looks interesting. But you might move this into the dealer forum. Additionally, you should post some videos of the usecases and how this product satisfies them. I'd watch.

 

[Arnwald]

Looks interesting. But you might move this into the dealer forum. Additionally, you should post some videos of the usecases and how this product satisfies them. I'd watch.

Thanks for your interest! I initially thought this section was the most appropriate, I just hadn’t noticed the dealer forum.

Videos are planned and I’ll post them later. In the meantime, anyone curious can download and try the software.

 

[ErVikingo]

How would I apply the resulting filters? MiniDSP box or do i have to add a computer to my chain?

 

[Ciobi69]

Does it do automatic eq with the fiir filters ? It should be an Easyer way instead of using multiple programs right ?

 

[somebodyelse]

Given the name I thought it might support linux, but it doesn't - just MacOS (intel and ARM) and Windows x86_64.

 

[Keith_W]

I’m sharing this here because ASR has many measurement-oriented people who might provide constructive feedback. Curious to hear your thoughts!

Very nice. I am happy to test drive it for you and give you some feedback. But it looks as if I have to shell out some money for a license for it. If you are happy to give me a 2 week trial, i'll try it and let you know. I don't intend to use it long term, since I already use something else.

 

[ShadowBoxer]

Also, FYI, the purchase page doesn't appear to have any place to enter the "early adopter" discount code that is mentioned.

For those following along the Home (single activation) version price listed on the web page is ~$173 USD (non-discounted).

 

[jtwrace]

@Arnwald have you had @mitchco look at this?

Digital Room Calibration Services, Convolver, Headphone Filtersets

We provide digital room calibration for stereo and multichannel. Software provider of audio convolver, plugin host, and headphone filtersets.

accuratesound.ca

He did this on my system:

'My Audiolense Experience (JBL M2)'

Oct 5, 2021

In 2019, I purchased Audiolense XO to try. Long story short, I couldn't get it to work due to an odd error I kept getting. Fast forward to 7 months ago when I interviewed Mitch on my podcast here. The more we talked, the more I wanted to try Audiolense. After the podcast Mitch asked me if I was going to try it and I explained my previous issue. He mentioned to me that anomaly was just solved a month prior.

For the next few months I had to decide on how I wanted to handle the MCH DAC and Roon Core setup. I built a W10 NUCi7 connected directly to a Motu UltraLite Mk5.

@mitchco...

• jtwrace
• Replies: 12
• Forum: General Audio Discussions

• 

 

[Arnwald]

How would I apply the resulting filters? MiniDSP box or do i have to add a computer to my chain?

LinFIR is dedicated to filter creation only. You can use any system you like to apply the FIR or IIR filters.
FIR filters can be exported in several formats to match your hardware.
For now, you’ll need to manually enter the IIR filters into your DSP interface, since there’s no universal standard for exchanging those.

Given the name I thought it might support linux, but it doesn't - just MacOS (intel and ARM) and Windows x86_64.

I have a compiled version for Linux, but I need to test it before putting it online. ;-)

Very nice. I am happy to test drive it for you and give you some feedback. But it looks as if I have to shell out some money for a license for it. If you are happy to give me a 2 week trial, i'll try it and let you know. I don't intend to use it long term, since I already use something else.

You can already test it, you just can't export projects, reports and filters.

Also, FYI, the purchase page doesn't appear to have any place to enter the "early adopter" discount code that is mentioned.

For those following along the Home (single activation) version price listed on the web page is ~$173 USD (non-discounted).

This should be fixed now.

@Arnwald have you had @mitchco look at this?

Digital Room Calibration Services, Convolver, Headphone Filtersets

We provide digital room calibration for stereo and multichannel. Software provider of audio convolver, plugin host, and headphone filtersets.

accuratesound.ca

He did this on my system:

'My Audiolense Experience (JBL M2)'

Oct 5, 2021

In 2019, I purchased Audiolense XO to try. Long story short, I couldn't get it to work due to an odd error I kept getting. Fast forward to 7 months ago when I interviewed Mitch on my podcast here. The more we talked, the more I wanted to try Audiolense. After the podcast Mitch asked me if I was going to try it and I explained my previous issue. He mentioned to me that anomaly was just solved a month prior.

For the next few months I had to decide on how I wanted to handle the MCH DAC and Roon Core setup. I built a W10 NUCi7 connected directly to a Motu UltraLite Mk5.

@mitchco...

• jtwrace
• Replies: 12
• Forum: General Audio Discussions

• 

I haven’t shown it to Mitch yet, but I’ve often seen his name come up in discussions about room correction.
LinFIR is a bit different though, it’s mainly focused on filter design and visualization, rather than calibration services or convolution playback. It’s primarily intended to shape the response of speakers based on anechoic measurements (though it definitely works for room correction too).
Would be interesting to get his take on it at some point!

 

[JSmith]

dealer forum

It's been renamed actually;

Audio Industry Forum

If you are a member of the audio/video industry and want to post information about your products (announcements, getting product feedback, etc.) this is the forum for you. Note: you must be a forum donor to create new threads in this forum

www.audiosciencereview.com

But agree about being moved.

I’ve decided to make it available as a paid product

Please see below;

'Rules for Audio Dealers, Manufacturers, Members with Commercial Interest. This includes any Guest Contributors/Reviewer with Commercial endorsement'

Dec 6, 2020

Audio Science Review Rules for Dealers, Manufacturers, Reviewers and Members of Industry.

• We encourage participation from members of industry in the forum. So please feel welcome here.
  
  
• We expect you to post with highest levels of professionalism. You are representing an industry and it is important that this be done with utmost politeness and respect for the membership. Be especially careful when you post about your competitors.
  
  
• The above is subject to proper participation in the forum, not just to come and sell things. If you have nothing to...

• amirm
• Replies: 0
• Forum: Forum Suggestions and Announcements

• 

JSmith

 

[Arnwald]

Does it do automatic eq with the fiir filters ? It should be an Easyer way instead of using multiple programs right ?

Yes! You just select a target curve and frequency range, and LinFIR automatically generates the FIR filter to match your target, as long as you have enough taps to cover the low end.
You can also use the Auto IIR EQ to quickly flatten the response before fine-tuning it with the FIR correction.

Here’s a short demo video showing it in action:

 

[Arnwald]

It's been renamed actually;

Audio Industry Forum

If you are a member of the audio/video industry and want to post information about your products (announcements, getting product feedback, etc.) this is the forum for you. Note: you must be a forum donor to create new threads in this forum

www.audiosciencereview.com

But agree about being moved.

Please see below;

'Rules for Audio Dealers, Manufacturers, Members with Commercial Interest. This includes any Guest Contributors/Reviewer with Commercial endorsement'

Dec 6, 2020

Audio Science Review Rules for Dealers, Manufacturers, Reviewers and Members of Industry.

• We encourage participation from members of industry in the forum. So please feel welcome here.
  
  
• We expect you to post with highest levels of professionalism. You are representing an industry and it is important that this be done with utmost politeness and respect for the membership. Be especially careful when you post about your competitors.
  
  
• The above is subject to proper participation in the forum, not just to come and sell things. If you have nothing to...

• amirm
• Replies: 0
• Forum: Forum Suggestions and Announcements

• 

JSmith

No problem if the thread needs to be moved.
Sorry if I posted in the wrong section, I thought this was the most relevant place to show a technical demo of the software.

 

[JSmith]

the software

Looks interesting, a helpful idea and kudos to you for asking for feedback from ASR.


JSmith

 

[RickS]

No problem if the thread needs to be moved.
Sorry if I posted in the wrong section, I thought this was the most relevant place to show a technical demo of the software.

Per ASR rules for commercial activity, your account needs to be reviewed by Amir as well. Please read the posted rules and feel free to contact Amir or I via direct message. It is usually a simple process most of the time.

 

[Arnwald]

Per ASR rules for commercial activity, your account needs to be reviewed by Amir as well. Please read the posted rules and feel free to to contact Amir or I via direct message. It is usually a simple process most of the time.

Thanks for the clarification. I’ll make sure to review the rules and reach out to Amir. No problem at all, now I understand the process.

 

[ShadowBoxer]

You can already test it, you just can't export projects, reports and filters.

I would suggest you clearly spell out the "read only" nature of the trial-demo. You can't really test the effectiveness of a filter if you can't create the filter (file). I realize other demos also take the read-only approach (as long as it's clear upfront).

 

[jtwrace]

LinFIR is dedicated to filter creation only. You can use any system you like to apply the FIR or IIR filters.
FIR filters can be exported in several formats to match your hardware.
For now, you’ll need to manually enter the IIR filters into your DSP interface, since there’s no universal standard for exchanging those.

I have a compiled version for Linux, but I need to test it before putting it online. ;-)

You can already test it, you just can't export projects, reports and filters.

This should be fixed now.

View attachment 479494


I haven’t shown it to Mitch yet, but I’ve often seen his name come up in discussions about room correction.
LinFIR is a bit different though, it’s mainly focused on filter design and visualization, rather than calibration services or convolution playback. It’s primarily intended to shape the response of speakers based on anechoic measurements (though it definitely works for room correction too).
Would be interesting to get his take on it at some point!

@mitchco is far more than a calibration service. He's pretty much the master of Audiolens for the consumer while Bernt is the developer https://juicehifi.com/

 

[ShadowBoxer]

Audiolens: The demo even lets you create 90 seconds of corrected music.

 

[jtwrace]

Audiolens: The demo even lets you create 90 seconds of corrected music.

Actually more, if you email Bernt, he will even provide a temp code so it works as normal to really try it. He's a heck of a nice guy.