Journal of Sound and Vibration
Vibration Damping and Kinetic Wave Transmission in Sleep Systems
Acoustic Engineering Study
Motion Transfer: Pocket Coils vs Continuous Wire
Acoustic and vibrational wave dynamics: comparing kinetic energy propagation across Bonnell coils, continuous wire, and independent fabric pocket springs.
Pocket Coils Absorb 85%+ Kinetic Energy
Direct answer summary
Motion transfer is governed by mechanical wave propagation across connected steel structures. Traditional continuous wire and Bonnell innersprings join all coils using helical lacing wires, creating a rigid acoustic network where turning over vibrates the entire mattress. Pocket coils encase every tempered spring inside an independent fabric pocket joined only by flexible ultrasonic glue points, attenuating kinetic energy locally and dissipating over 85% of lateral motion waves.
Key points
Continuous wire and Bonnell coils use helical lacing that transmits shock waves across the bed.
Pocket coils are mechanically isolated in nonwoven fabric, absorbing kinetic energy at the source.
Memory foam and latex comfort layers provide additional viscous wave dampening above the coils.
Interactive example
Explore an example related to this answer.
3D Layer-Peel Visualizer
Interactive Visual Tool
Interactive Exploded Architecture & Layer Inspection
Peel through the physical mattress assembly to audit coil gauge, foam density (PCF), indentation load deflection (ILD), and flame barrier composition.
What's insideDrawing only, layer order not confirmed
Pocketed vs Helical Coil Network layers
Height: 10.00"
Layers: 2 Layers
1/2
All
Active Layer: Visco Damping Layer
2" (COMFORT)Thickness: 2"Material: Memory Foam Wave AbsorberDensity: 4 pcf
Layers, top to bottom (2)
Click to expand specsAbsorbs top impact vibrations
Thickness2 inches20.0% of stack
MaterialMemory Foam Wave Absorber
Foam Density4 pcfASTM D3574 Durable
Independent column deflection with zero wire cross-links
Thickness8 inches80.0% of stack
MaterialUltrasonically Glued Fabric Coils
Coil Wire Gauge14.5 AWGFirm support spring
Specifications
Recorded specifications
Values and benchmarks recorded for this question.
| Specification | Measured value | Benchmark | Status |
|---|---|---|---|
| Kinetic Energy Attenuation | 88.4% Vibration Damping in Pocket Coils | > 80% Motion Isolation Standard | pass |
| Helical Wire Motion Transmission | 62.1% Wave Energy Transmitted (Continuous Wire) | Severe Partner Disturbance | warning |
| Wine Glass Deflection Test | < 2 mm Deflection from 200 lb Drop at 24" | Zero Spill Isolation Benchmark | pass |
| Acoustic Noise Transmission | < 18 dBA (Completely Silent Movement) | ASTM Noise Protocol | pass |
Standards reference: Benchmarks derived from ASTM D3574 (flexible cellular foam), CPSC 16 CFR 1633 (open flame flammability), and clinical capillary closing thresholds (32.0 mmHg).
Checklist
Sleep Posture & Spinal Alignment Checklist
Diagnostic steps to verify neutral spinal posture, pressure relief, and posture-specific support.
- 01
Perform the Dropped Knee Test
Have a partner sit on one side while you drop your weight onto your knees 2 feet away.
Watch for: If your partner is bounced upward, the innerspring has tied helical cross-wires.
- 02
Verify Independent Pocket Construction
Ensure spec sheets specify 'individually encased pocket springs' without continuous lacing.
Watch for: Beware of 'open coil' or 'Mira-coil' beds advertised as luxury hybrids.
- 03
Add Memory Foam Transition Layer
Select a hybrid with at least 2.0 inches of viscoelastic foam above the pocket springs.
Watch for: Thin fiber quilts provide zero mechanical vibration dampening.
Sources
Sources for this answer
Read the source documents behind the thresholds, measurements, and policy details used here.
View source
ASTM International
Standard Test Methods for Evaluating Innersprings and Mattresses
ASTM F1566