During simulations for a new speaker project I once again came upon the old problem of optimizing for low group delay/phase shift or optimizing for uniform directivity. I wanted to see for myself how audible the phase shift from typical speaker crossovers is (if at all), so I decided to create some impulse files in RePhase, which can easily be used with JRiver MC. Simply import the files into the JRiver convolver in its DSP studio and activate the convolution. For those of you who do not have JRMC, there's also a convolver plugin for foobar: https://www.foobar2000.org/components/view/foo_convolve I chose 2048 taps for most files, which seems to be plenty in this case. They all have a flat FR magnitude. I wish RePhase had the option to simulate (and correct) filter types other than Linkwitz-Riley, but for correcting a speaker's excess phase I'd recommend measuring the speakers, anyway. You can then use REW to export an excess phase version of the measurement, import it into RePhase and use the 'Filters Linearization' tab aswell as the 'Paragraphic Phase EQ' filters to linearize the excess phase response. I also went for a 44.1kHz sampling rate for the files since pretty much all of my music is 44.1kHz. I wanted to hear the effect with music, not specialized test signals. The names on the files should be self-explanatory: TEST_LP1_Q0707_1kHz: A file for testing if the convolution works. First order low pass at 1kHz with a Q of 0.707. 44_perfect_inv: This one simply inverts the impulse/swaps absolute phase. 8_inch_widebander_with_whizzer: This one has a phase shift like the one you'd see introduced by an 8" widebander with a whizzer cone. Based on a measurement of such a driver. 4_inch_widebander_with_whizzer: Same thing here, except a smaller 4" driver. The phase shift happens at a higher frequency here. LR12_2500_tweeter_inv: A 12dB/octave Linkwitz-Riley filter at 2500Hz. Many bookshelf speakers have a crossover similar to this. In this case wired with the tweeter inverted. As far as 'normal' speaker design goes, this is about the least amount of phase shift you'd encounter. LR12_2500_midrange_inv: Same thing, but with the midrange/midbass inverted instead. LR12_250_LR12_2500_tweeter_inv: An added 250Hz LR 12dB/oct filter, similar to many 3-way speakers. Tweeter and bass inverted, midrange in positive polarity. LR24_250_LR24_2500: Same crossover points, but using steeper 24dB/oct filters (to get less crossover lobing). 3_way_speaker: A real world 3-way speaker, based on a measurement. Similar to the LR12_250_LR24_2500 file. Tweeter and bass inverted, midrange in positive polarity. The tweeter may be slightly ahead of the midrange and the crossover may be slightly asymmetric to compensate. This is despite a small waveguide the speaker has. LR_48_80_LR12_2500_tweeter_inv: Similar to the above bookshelf, but with a sub crossed at 80Hz at 48dB/octave. It is quite easy to create them in RePhase, so feel free to experiment with other arragnements. I think it might be interesting to explore how different crossover frequencies affect the sound, i.e a LR12 filter at 2000Hz vs 2500Hz vs 3000Hz. These files can also be imported into REW to better visualize the effects they have. For example you can easily view the effects they have on the step response and compare group delay between different filters. In the next post I will do just that. I've already done experiments like this in the past, so I will say the results are not surprising to me, but I think everyone should really give this a try. Headphones will mask the differences less than speakers, but listening via speakers which are close to minimum phase works aswell. Otherwise it makes more sense to listen to a file which corrects the speaker's excess phase.