We present Phase-Multiplexed Spherical Collapse (PMSC), a novel embedding compression method that extends the spherical coordinate transformation approach of Xiao (arXiv: 2602. 00079) with FFT-based frequency multiplexing. While the prior state-of-the-art achieves ~1. 50x lossless compression by exploiting IEEE 754 exponent collapse to value 127, our method achieves 3. 66x bit-perfect compression — 2. 44x better than the academic baseline — by additionally exploiting mantissa collapse via delta subtraction (δ = angle − π/2) and sharing a common FFT amplitude basis across the entire vector batch. Key results on 50 unit-norm vectors in ℝ¹⁵³⁶: exponent₁27ₚct = 99. 75%, delta entropy = 3. 15 bits/element (10x reduction from raw float32), bit-perfect ratio 3. 66x, lossy float16 ratio 2. 09x with cosine similarity = 1. 0000. Validated on real sentence-transformer embeddings (MiniLM d=384: 2. 56x, MPNet d=768: 3. 06x). Implementation: Python + NumPy, no training required. Full source code and 20-test validation suite included.
İlker Türk (Sat,) studied this question.