Soundproof curtains are a great way to reduce noise in your home or office. But how effective are they really at blocking sound? In this article, we’ll look at the different factors that determine how much noise soundproof curtains can block, including:
- Material
- Number of layers
- Weight
- Overlaps and seals
- Installation method
Understanding these key factors will help you choose the right soundproof curtains for your needs and get the maximum noise reduction. Read on to learn how much noise you can expect soundproof curtains to block in different situations.
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How Soundproof Curtains Block Noise
Before we look at specific noise blocking capabilities, it helps to understand how soundproof curtains reduce noise in the first place.
Soundproof curtains act as a noise barrier by absorbing and blocking sound waves rather than allowing them to travel through the fabric. The materials used in soundproof curtains are densely woven and several layers thick in order to provide this noise blocking effect.
When sound hits the curtain, some of the energy is absorbed by the material itself. The remaining sound energy is reflected away rather than passing through to the other side. The more dense and heavy the curtain material, the greater the noise reduction.
In addition to absorbing and reflecting sound, soundproof curtains also help minimize noise leakage through gaps around the edges of the curtain. Overlapping curtain panels and weighted bottoms seal the gaps where sound could otherwise escape.
Together, these properties allow soundproof curtains to significantly decrease the amount of noise coming through your windows. But the exact amount of noise reduction depends on several factors.
Material
The material used to make soundproof curtains is one of the most important factors determining noise blocking capability. Not all fabrics are created equal when it comes to sound absorption and blocking.
Common materials used for soundproof curtains include:
- Velvet: Made of dense woven cotton or polyester, velvet is excellent at absorbing mid-to-high frequency sounds.
- Felt: Non-woven felt material effectively dampens sound vibrations across all frequencies.
- Denim: Like velvet, denim uses tightly woven fibers that reflect sound rather than letting it pass through.
- Flannel: Flannel’s napped fabric surface helps absorb acoustic energy, reducing echo and reverberation.
- Wool: The natural density of woven wool makes it effective at blocking sound transmission.
- Cotton: High thread count cotton can block some noise, but lower thread counts are less effective.
- Polyester: Lightweight polyester on its own doesn’t block much noise. But layered or woven tightly, polyester can absorb sound.
- Vinyl: Plastic vinyl materials reflect high and mid-range frequency sounds reasonably well.
The best material for sound blocking is heavyweight woven fabric, often 100% cotton, wool or velvet. The density and fiber thickness prevent noise from passing through. Felt and denim also perform very well.
Lighter fabrics like linen, silk or polyester chiffon are not as effective at reducing noise. Although taking some measures like quilting layers of lighter fabric can improve sound dampening.
Ultimately, the heavier and more layered the curtain material, the higher the sound reduction.
Number of Layers
In addition to using heavy, noise-blocking fabric, another way to improve the effectiveness of soundproof curtains is to use multiple layers. The more layers in a curtain panel, the more noise it can absorb and block.
Double layer soundproof curtains can reduce noise levels by 25-35 decibels. Triple layer curtains provide even more noise reduction at 35-45 dB. Here are the noise blocking capabilities of single vs multi-layered curtains:
Single layer
– Provides 15-25 dB of noise reduction
Double layer
– 25-35 dB noise reduction
Triple layer
– 35-45 dB noise reduction
The best results come from using two or three layers of 100% woven cotton, wool, or velvet, which provide density and air gaps between layers. Hanging a noise reducing blackout lining behind the main curtain also adds effective mass.
With each additional layer, sound waves have to pass through more material to penetrate the curtain, which dissipates more of the acoustic energy. The air space between layers also helps absorb sound.
Weight
The weight and thickness of the curtain material matters when it comes to blocking noise. Heavier, thicker fabrics absorb more sound energy than lighter materials, reducing the amount of noise coming through.
Here is how the weight of the fabric impacts noise reduction:
Lightweight (<400 gsm)
– Provides 15-20 dB noise reduction
Medium Weight (400-800 gsm)
– 20-30 dB noise reduction
Heavyweight (>800 gsm)
– 30-40+ dB noise reduction
gsm stands for grams per square meter, referring to the density of the material. A lightweight curtain is less than 400 gsm. Medium density is 400-800 gsm. Heavy density is over 800 gsm.
The best soundproof curtains use thicker, heavier fabric in the 800+ gsm range. With more mass per square meter, heavyweight curtains can block more noise across all frequencies. Lightweight curtains under 400gsm provide less noise protection.
A good rule of thumb is that increasing the weight and thickness of the curtain material by 100 gsm adds around 1 dB of sound blocking. So choose the heaviest curtains within your budget to maximize noise reduction.
Overlaps and Seals
Even the best soundproof curtains will be less effective if noise leaks through gaps around the edges. Proper installation is key.
Overlapping curtain panels and using weighted hems and edges prevents sound flanking around the sides of the curtain. Here are some features that help block noise leakage:
- Overlaps – Panels should overlap by at least 4 inches in the middle and at edges.
- Weighted hems – Bottom hems with rod pockets for curtain weights prevent sound going under.
- Velcro edges – Velcro strips seal gaps between curtain panels.
- Side seals – Vertical Velcro, magnets or overlap seals prevent flanking around the sides.
A good overlap for soundproof curtains is 4-6 inches between panels. This prevents light and noise leaking through gaps.
Bottom weighted hems are also essential, using pockets and metal weights to hold the panel down firmly. This blocks noise traveling under the curtain.
Finally, edge seals using Velcro, magnets, or extra overlap on the sides seals any remaining air gaps where sound can escape.
With all gaps sealed, you ensure the maximum amount of noise is blocked by the curtain material itself rather than leaking around it.
Installation Method
Properly installing soundproof curtains is just as important as using the right materials. Even heavy duty curtains will lose some effectiveness if not mounted correctly. Follow these best practices:
- Mount curtains high and wide – Cover the entire window or wall space from top to bottom.
- Use separate blackout linings – Hang a noise blocking liner behind the main curtain.
- Seal edges – Use adhesive velcro strips or wall mounting clips to seal edges.
- Create an air gap – Leave 1-3 inches between curtain and window.
Mounting curtains all the way from ceiling to floor provides full noise protection across the entire surface. Leaving even small gaps at the top or sides permits sound to flank.
Hanging a separate blackout lining behind your main curtain adds another noise blocking layer. The air gap and insulation between the two fabrics improves sound absorption.
Sealing the edges with velcro strips or special mounting clips prevents flanking while allowing the curtains to be opened easily.
Finally, leaving an air space between the window and curtains helps dissipate sound. An air gap of 1-3 inches is ideal to absorb noise before it hits the glass.
With full coverage mounting and proper edge sealing, you’ll get the maximum noise reduction from your soundproof curtains.
Noise Blocking Capability by Source
Now that we’ve looked at the key factors that determine effectiveness, how much noise can soundproof curtains block in real rooms?
The amount of noise reduction depends on the sound source, frequency, and intensity. Here are general guidelines for how much soundproof curtains can block from common noise sources:
Traffic and roads
– Reduce noise by 25-40 dB
– Best for blocking mid-low frequencies like engines
Neighbors and voices
– Block noise by 30-45 dB
– Effective at muffling speech and TV sounds
Trains and subways
– Reduce noise by 20-35 dB
– Help absorb rumbling low frequencies
Construction and tools
– Block noise by 15-30 dB
– Partial reduction of sudden impact noises
Bands and loud music
– Reduce noise by 20-35 dB
– Help absorb bass and mid-range frequencies
In general, the more noisy the source, the more reduction you’ll get by using heavy soundproof curtains. Loud noise like traffic and construction can be reduced by 35-40 dB. Quieter sounds like neighbors and TV are reduced by 30-45 dB.
The frequency of the sound also impacts blocking ability. Lower frequencies like car engines and music bass are harder to absorb. High pitches like voices are easier to muffle. The best curtains will block sounds across all frequencies.
No curtain can block all noise. But using the right heavy, multilayered curtains, you can expect a noise reduction of 25-45 dB in most situations, cutting apparent loudness in half or more.
Noise Blocking by Curtain STC Rating
STC (Sound Transmission Class) ratings are also used to identify the effectiveness of soundproof curtains. This rating measures how well a material prevents sound from passing through.
Higher STC ratings indicate better noise blocking:
STC 25 – Reduces noise by 25 dB
STC 30 – Reduces noise by 30 dB
STC 33 – Reduces noise by 33 dB
STC 35 – Reduces noise by 35 dB
STC 39 – Reduces noise by 39 dB
STC 42 – Reduces noise by 42 dB
STC 44 – Reduces noise by 44 dB
The best soundproof curtains have STC ratings of 35 or higher. This provides noise reduction of 35 dB or more across common frequencies. Around STC 42 is very heavyweight.
STC 25-35 offers moderate to good sound blocking, reducing apparent loudness by half or more. Under STC 25 is lightweight with limited effectiveness.
Ideally, look for an STC rating over 35 from acoustical testing data to ensure maximum noise blocking from your soundproof curtains.
Noise Reduction Comparison Table
Here is a table summarizing the typical noise reduction provided by different types and ratings of soundproof curtains:
| Curtain Type | Noise Reduction |
|---|---|
| Single Layer Lightweight | 15-25 dB |
| Double Layer Medium Weight | 25-35 dB |
| Triple Layer Heavy Weight | 35-45 dB |
| STC 25 Curtains | 25 dB |
| STC 35 Curtains | 35 dB |
| STC 42 Curtains | 42 dB |
As you can see, using multi-layered curtains with higher STC ratings provides the most effective noise blocking. With heavy STC 42 curtains, noise levels are cut almost in half.
How to Choose the Best Soundproof Curtains
Now that you know what makes an effective noise blocking curtain, here are some tips for choosing the right soundproof curtains for your needs:
- Look for heavyweight, layered fabrics like cotton, wool and velvet
- Aim for a minimum of 2-3 layers for the best noise reduction
- Make sure panels have overlapping edges and weighted hems
- Check the STC rating – higher than 35 is optimal
- Measure the full window or wall space and order curtains wide enough
- Install ceiling to floor with velcro edge seals for full coverage
- Leave an air gap between curtain and window for improved absorption
Prioritize thick, multilayered fabrics with an STC rating over 35 to ensure meaningful noise reduction. Also pay close attention to full coverage installation using overlaps and edge seals to prevent flanking gaps.
With the right heavy soundproof curtain and proper mounting, you can expect excellent noise blocking of 25-45 decibels in most environments. That’s like turning the volume down on loud noises coming through your windows and walls.
Conclusion
Soundproof curtains can reduce unwanted noise in your home, office, or other indoor spaces by 25-45 decibels on average. The exact amount of noise blocking depends on several factors:
- Material – Heavyweight woven fabrics block more noise.
- Layers – Using 2 or 3 layers improves sound absorption.
- Weight – Heavier fabrics over 800 gsm block more sound.
- Overlaps/Seals – Prevent flanking around curtain edges.
- Installation – Mounting floor to ceiling without gaps maximizes effectiveness.
With heavy, multilayer curtains installed properly, noise from common sources like traffic, neighbors and construction can be reduced by 35-45 dB. This makes rooms noticeably quieter and more peaceful.
When shopping for soundproof curtains, look at the material density, layers, STC rating, and weight to choose curtains that block the most noise. Follow best practices for sealing edges and mounting installation.
With the right soundproof curtains, you can enjoy a quiet, peaceful indoor space and block disturbing exterior noise.
