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 (this kind I need), see THIS link.

Or you could ask Google AI as I did and got this answer ...iple parametric EQ filters to correct a room's specific acoustic profile.

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.