SoundproofUSA vs. Indow inserts: Acoustic Performance & Feature Comparison

Indow Windows utilizes lightweight, friction-fit acrylic inserts designed primarily for thermal efficiency and minor high-frequency noise dampening. SoundproofUSA / CitiQuiet builds heavy-gauge, laminated secondary glass windows engineered specifically to block high-decibel, low-frequency sound like highway traffic, sirens, and diesel engines.

While acrylic inserts reduce some high-pitched noise (like speech or birds), acrylic lacks the mass required to stop low-frequency rumbling from heavy traffic. SoundproofUSA’s laminated secondary glass provides the necessary density and air gap to reduce traffic noise by up to 95%.

Mass and Material Physics (Why Material Density Matters)

• The Physics of Sound: Mass stops sound waves. Laminated glass is significantly denser than acrylic.

• Low-Frequency Resonance: Lightweight acrylic can act as a sound membrane, flexing and resonating when hit by heavy traffic rumble. Laminated acoustic glass absorbs and deadens these frequencies.

• Access to Fresh Air: Indow inserts need to be completely removed to open your window for fresh air. CitiQuiet windows open easily to allow access to fresh air

Understanding STC Ratings:

• • STC 30–35: Standard double-pane window (Speech audible).

  • STC 38–42: Indow Acrylic Insert added (Reduces light sound, drafts).

  • STC 48–54+: SoundproofUSA Laminated Window added (Blocks 75%–95% of extreme noise).

• The Logarithmic Decibel Scale: Explain that an STC gain from 40 to 50 represents a 50% reduction in perceived loudness.

• Acrylic Inserts: Prone to static attraction, scratching during cleaning, and UV degradation over long-term exposure.

• Secondary Glass Windows: Cleans like standard architectural glass, scratch-proof, and permanently durable.

• When Indow Windows Might Be Enough:

  • Budget is the single most important factor.

  • Landlord restrictions prohibit permanent frame installation.

• When SoundproofUSA / CitiQuiet  Is Required:

  • Living near a highway, bus route, train line, or airport.

  • Light sleepers or work-from-home professionals needing studio-level quiet.

  • Property owners seeking a permanent architectural upgrade that increases property value.