What can do more than anything to improve your room & speakers? FIR filters maybe?

[Feanor]

What the heck is a FIR filter? For relatively simple explanation (of the kind I need), see THIS link.

Or you could ask Google AI as I did and got this answer ...

FIR (Finite Impulse Response) filters are digital tools used to achieve highly precise audio correction for both speakers and the rooms they are in. Unlike traditional IIR (Infinite Impulse Response) filters, FIR filters can manipulate frequency response and phase response independently.

Speaker Improvement

• Phase Correction: Speakers naturally introduce phase shifts, especially at crossover points where different drivers (like a woofer and tweeter) meet. FIR filters can "flatten" this phase, ensuring all frequencies arrive at your ear at the same time to prevent transient smearing.
• Linear-Phase Crossovers: They allow for steep crossover slopes that do not introduce the phase distortion common in analog or IIR designs, resulting in more natural sound reproduction.
• Driver Alignment: Manufacturers use FIR filters to match the magnitude and phase of different speaker models, making it easier to tune them together in complex setups.

Room Improvement

• Room Mode Mitigation: They are used in advanced Digital Room Correction (DRC) systems to address "room modes" (boomy bass or dead spots caused by room shape) with high precision.
• Boundary Correction: FIR filters can compensate for acoustic anomalies caused by a speaker’s proximity to walls or other boundaries.
• Complex EQ: Because they can create very detailed frequency curves, a single FIR filter can replace a complex chain of multiple parametric EQ filters to correct a room's specific acoustic profile.

So how do you construct a FIR filter? The freeware program, REW, is one one which is consider highly accurate and precise but has a steep learning curve. Recently I discovered a much simpler tool, also free, that will produce excellent FIR filters, at least in my limited experience: that is Gsonic. The is an excellent thread on Gsonic, started by the developer, at ASR.

The other question is how FIR filters to be applied. The the answer is that numerous computer players and stand-alone streamers are able to apply FIR filters.

I have used Gsonic to build FIRs and am currently using Equalizer APO to apply them on my Win 11 PC.

 

[Feanor]

Hello!!! Anybody? Anyone?

Is nobody using DSP room correction, (so called) in their main stereo systems? Surely a few are useing DIRAC or similar DSP in their home theatre systems, but what about the former?

Above I said that using an FIR convolution filter in my system was a very big improvement, probably the biggest overall improvement in my system in many years. Unless my ears are failing me terribly, I'm hearing imaging and soundstage improvements, and also big bass improvements (likely due to better subwoofer integration). BUT I'd like others to share their own experiences ... if any.

I suspect results will vary. Those with finely tuned listening room should probably find the least improvement. Also, those using full-range planars, (electrostatics), might fine less improvement because such speakers ought to have fewer phase, impulse, and time domain shortcomings than dynamic driver systems

 

[Bones13]

Back in my small room, I did make a convolution filter for Roon, using REW. This was after I figured out that I could not eliminate a 40hz boom with room treatment. It made some difference, not relevatory. It also did not affect vinyl playback.

There certainly a squad over at Audiophile Style who use room correction systems, big and small. As well as a gentleman who makes custom filters. So it is done.

I get the feeling that many here, including myself, (sub)consciously object to inserting both a ADC and the following DAC into the analog output stream. Many also use high end vinyl, and don’t want their pure analog subjected to this treatment.

I would find it hard to stomach having a high end DAC, and or Vinyl, being dependent on the unknown DAC chip at the end of the room correction device. I’m not saying that it would sound bad, and I will consider a Roon convolution filter again when my system changes are complete this fall. (LOL on “complete”) But in general, in my 2.0 main system, I have no plans to insert a room correction device between pre-amp and amp(s). In the TV room, I did use the microphone to set the 5.1 Sony AV receiver, with its built in correction software.

 

[Feanor]

Back in my small room, I did make a convolution filter for Roon, using REW. This was after I figured out that I could not eliminate a 40hz boom with room treatment. It made some difference, not relevatory. It also did not affect vinyl playback.

There certainly a squad over at Audiophile Style who use room correction systems, big and small. As well as a gentleman who makes custom filters. So it is done.

I get the feeling that many here, including myself, (sub)consciously object to inserting both a ADC and the following DAC into the analog output stream. Many also use high end vinyl, and don’t want their pure analog subjected to this treatment.

I would find it hard to stomach having a high end DAC, and or Vinyl, being dependent on the unknown DAC chip at the end of the room correction device. I’m not saying that it would sound bad, and I will consider a Roon convolution filter again when my system changes are complete this fall. (LOL on “complete”) But in general, in my 2.0 main system, I have no plans to insert a room correction device between pre-amp and amp(s). In the TV room, I did use the microphone to set the 5.1 Sony AV receiver, with its built in correction software.

I guess FiR convolution does have its limitation when it comes to extreme peaks & troughs; to be expected.

I can understand instinctive reservations about inserting ADC-DAC into an analog stream. I don't listen to LPs anymore but given quality converters, I doubt I'd worry about. Similarly a FIR-filtered stream to one's DAC isn't going to be "bit perfect" by definition. Nevertheless, the better the DAC the less to worry about.

 

[nicoff]

To the OP: If you follow the science, DSP and FIR filters can do far more to improve speaker/room interaction than cables, power conditioners, fiber, switches, streamers, DACs, or the latest gimmick. If you trust only your ears, then only you can decide what matters.