UNDERLAYMENT COMPARISON
Eclipse II vs. Eco Ultimate Silencer™

Both products by Foam Products Corporation · Continental House #606 · Floor Renovation
Product A — Eclipse II: Field tested by CENSEO AV+Acoustics on May 7, 2026 (Test #26035-01).
Product B — Eco Ultimate Silencer™: Candidate underlayment under evaluation. No field test conducted.

Acoustic Ratings (Lab)

Table 1: Lab Acoustic Ratings
Rating Eclipse II Eco Ultimate Silencer™
IIC 72 73 ▲
STC 66 73 ▲
ΔIIC not published 22 ▲

The Eco Ultimate publishes a ΔIIC of 22 — the improvement the underlayment contributes to any assembly, independent of concrete thickness or ceiling type. Eclipse II does not publish this figure, making direct comparison harder. ΔIIC 22 is a strong result for a product this thin.

Eco Ultimate Silencer™ — IIC by Assembly

Table 2: Eco Ultimate Silencer — IIC by Assembly
Assembly IIC
Laminate/Engineered on 8″ concrete + ceiling73
Laminate/Engineered on 6″ concrete + ceiling70
Hardwood on 6″ concrete + ceiling58
Laminate/Engineered on 6″ concrete, no ceiling52

Specification Comparison

Table 3: Side-by-Side Specification Comparison
Attribute Eclipse II Eco Ultimate Silencer™
Thickness0.070″1.9 mm (≈ 0.075″)
MaterialClosed cell EVA foamPU foam + recycled rubber granules ▲
Densitynot listed25 lb/cu ft ▲
Compression resistancenot listed20 psi (ASTM D3676) ▲
Compression setnot listed<4% (ASTM D3674) ▲
Moisture barrierYesYes (upgraded film, 7 lb rated)
GreenGuard GoldYes · UL 2818Yes · UL 2818
AntimicrobialYesYes
Radiant heatYesYes
Installation methodsFloating onlyFloating · Glue · Nail ▲
Recycled contentNoYes (LEED MR 4.1/4.2) ▲
R-Valuenot listed0.17
WarrantyLifetimeLifetime
Made in USAYesYes
Manufacturer linkfoamproducts.com ↗

Cost Comparison

Table 4: Retail Pricing (100 sq. ft. roll)
Item Eclipse II Eco Ultimate Silencer™
Price per roll (100 sq. ft.)~$30~$53 ▲
Price per sq. ft.~$0.30~$0.53 ▲
Premium for Eco Ultimate+$0.23/sq. ft. (+77%)
Example: 500 sq. ft.~$150~$265
Example: 800 sq. ft.~$240~$424

Retail single-roll pricing. Eclipse II from JNS Flooring & Supplies; Eco Ultimate Silencer from The Home Depot (model ECOULTIMATEGREEN100). Prices vary by supplier and volume — confirm current pricing before ordering.

Assessment

At nearly identical thickness (0.070″ vs. 0.075″), the Eco Ultimate Silencer outperforms Eclipse II on every published acoustic metric — IIC 73 vs. 72, STC 73 vs. 66, and a published ΔIIC of 22 that Eclipse II cannot match because it does not publish the figure.

The material difference matters: recycled rubber granules in the Eco Ultimate handle low-frequency impact energy more effectively than closed-cell EVA foam, particularly in the 100–315 Hz range where thin foam underlayments typically perform weakest.

No field test has yet been conducted with the Eco Ultimate Silencer. Worth confirming projected field performance with CENSEO's Jeanette Hesedahl before specifying.

Understanding ΔIIC

IIC (Impact Insulation Class) measures how well a complete floor/ceiling assembly blocks impact sound — footsteps, dropped objects, etc. Higher is better. It is always a lab measurement of the whole stack: concrete slab + underlayment + flooring + ceiling below.

The problem: IIC is assembly-specific. Eclipse II's IIC 72 was measured in one particular lab setup — a specific slab thickness with a specific ceiling. Put it in a different building with different concrete and a different ceiling, and the number will be different. You cannot directly compare two products' IIC ratings unless they were tested in the same assembly.

ΔIIC (Delta IIC) solves that. It measures how much the underlayment alone contributes, by testing the same assembly with and without the underlayment and taking the difference. The result is portable — it represents the underlayment's improvement regardless of what assembly it is used in.

Eco Ultimate's ΔIIC 22 means: whatever your bare floor/ceiling assembly scores on its own, add the Eco Ultimate and it should improve by approximately 22 points.

Table 5: ΔIIC Practical Example
Scenario Eclipse II Eco Ultimate Silencer™
Published ΔIICnot published22
Bare assembly baseline (hypothetical)4242
Estimated field IIC with underlaymentunknown~64
HOA threshold (new installation)FIIC 62FIIC 62

Eclipse II publishes IIC 72 but no ΔIIC. Without that figure, it is not possible to predict how it will perform in Continental House's specific assembly. The CENSEO pretest returned AIIC 51 in the field — well below the lab IIC of 72, which is typical, but still a significant gap.

Because Eco Ultimate publishes ΔIIC 22, its contribution to any given assembly can be estimated in advance — making it easier to project whether the HOA's FIIC 62 threshold will be met before committing to installation.