Why SoundID is not enough ?
SoundID Reference is a wonderful software and you NEED to use it if you want the most accurate room as possible
...... but ......
Calibration can only shape magnitude/phase at one point and is very useful, anyway it cannot change the time-spatial physics of sound in rooms: reverberation, reflections, interference geometry, directivity, or spatial variability.
Those require physical absorption, diffusion, geometry, and/or source/receiver relocation backed by standards and literature (ISO 3382 metrics; Sabine/Eyring) and decades of AES research on SBIR, modes, and multi-sub strategies
What is impossible to do only with SoundID Reference
A software calibration like Sonarworks SoundID Reference (essentially EQ + optional phase linearization at one or a few points) cannot do the following things that only a physical room treatment/geometry can:
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Shorten reverberation/decay (EDT, T20, T30, RT60). Decay times are set by room volume and total absorption area (Sabine/Eyring). EQ does not add absorption, so it cannot reduce RT or late energy; adding absorbers/diffusers can.
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Remove or redirect early reflections (and the comb-filtering and image blur they cause). Early reflections are time-delayed copies of the direct sound from specific boundaries; EQ can’t change their arrival times or directions. Only absorber/diffuser placement and geometry fix that.
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Fix speaker-boundary interference (SBIR) and deep cancellation nulls. Nulls from path-length differences (speaker/ear vs. nearby boundaries) are interference problems; boosting with EQ just feeds the cancellation. Solutions are physical: move speakers/listener, add targeted treatment/soffit mounting, or change boundaries.
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Reduce seat-to-seat variability in the lows (room modes). Single-point calibration can “flatten” one spot but doesn’t fix the spatial variation. Physical strategies—bass trapping and/or multiple subwoofers at optimized positions—are required to make the response consistent across an area so EQ can work broadly.
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Change loudspeaker directivity and the room’s reflected sound field. Off-axis energy (which drives the room’s reflections/sound-power response) is a property of the loudspeaker and room boundaries. EQ of the on-axis signal cannot repair poor directivity or the spectral content of reflections; treatment can shape the reflected field.
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Improve objective clarity metrics by rebalancing early vs. late energy (e.g., C50/C80, D50). These ISO 3382 parameters depend on the time-integrated energy in reflections/reverberation; EQ at the source does not change that ratio in the room. Treatment and geometry change it.
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Eliminate flutter echo or specular “slap” between parallel surfaces. This is a geometric, multi-bounce phenomenon; it requires absorption, diffusion, or non-parallel surfaces—not EQ.
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Globally reduce low-frequency decay (modal ringing) across the room. At a single mic position, EQ can reduce a minimum-phase modal peak and its local decay signature, but it does not increase modal damping or shorten decay room-wide. That needs added absorption/volume changes.
