HVAC In Line Muffler

Interior Noise-Reducing Mufflers

ASC designs and manufactures in-line mufflers, noise-reducing outlet diffusers, duct baffle inserts, and material-handling mufflers to help reduce noise in the recording industries and manufacturing industries.

Professional Recording In-Line Mufflers

Recording studios and rooms with quiet requirements, particularly in hot climates, need dampened HVAC supply and return ducting. ASC designs and manufactures in-line mufflers, noise-reducing outlet diffusers, and duct baffle inserts.

Most residential and commercial HVAC equipment creates too much noise for use in recording studios. We build specialty mufflers that combine built-in bass traps with standard treble range absorbing panels. Our solutions not only deliver air into rooms silently but also reduce the acoustic crosstalk between rooms through the HVAC ducts.

Additional information


HVAC Silencer, Material Silencer

ASC builds in-line mufflers to quiet the HVAC ducts in recording studios and hanging baffle air diffusers for quieting the air inlet and outlets of studio rooms.  We also manufacture plug-and-play duct baffle inserts which can be installed into nearly any ductwork.

One oft-neglected issue regarding HVAC systems in recording studios is air movement. The last thing a ribbon mic needs is to be blown around by uncontrolled air drafts. Air entering into a studio room needs to be diffused and redirected into a desirable and controlled air circulation pattern. The problem with standard mechanical diffusers is that they make a lot of air turbulence and noise. Our sound absorbing hanging baffle air diffusers effectively deliver quiet air into a room. And they are used for noise control on air return vents as well.

Our engineers design the muffler within the imposed constraints and to achieve the desired noise reduction, and the crew at the ASC factory hand builds each muffler one at a time. In-line mufflers for studio work usually combine streamlined straight duct inserts for the treble range and an “inside out” TubeTrap to absorb the bass range. Our mufflers use the most acoustically efficient sound absorbing materials available. Unlike acoustical foam products that degrade into dust after a few years of service, our fiberglass products are fiber sealed and built to last a lifetime.  Our mantra is: there can be no chance for fiberglass particles to enter the room, even with our absorbers exposed to heavy air turbulence.

Mufflers are designed and built to your specifications, and are available as a custom designed item available direct through ASC. To quiet down existing studios we need a sound level reading and a recording of the noise in the room due to HVAC ducting. We analyze the noise and determine what the muffler or baffle needs to do to deliver the kind of sound dampening needed in the room.

All HVAC Mufflers are custom engineered to required specifications of  each project.   These are not an ‘off-the-shelf’ type products.

Average Pricing varies between $1000 – $2000 per custom designed & built muffler.

Custom Fabric Colors

Any product using our Guilford Stock Fabrics can have one of our 70+ custom fabrics ordered.

Custom Fabric Pricing is 10% additional, minimum $175/order.

  • If your selection is 499.00, the total cost for custom fabric is 499.00+50.00=549.00

Custom fabric does not impact shipping costs or product weight.

We carry many custom colors in our factory, but this is not guaranteed.  Orders requesting custom fabric will require 1-2 weeks lead time based on availability.  Contact us for details and availability.

TubeTrap Endcaps

These are painted gloss black with texture lacquer.



TubeTraps (all variations)


  • Standard TubeTraps products are built taller than the nominal listed height by 1/2″ to 3/4″
  • Maximum available single height for any full-round product is 48 1/2″
  • Custom Sizes under 4′ available


  • All of our TubeTrap products are also ~3/8″ oversize in diameter.

Custom Sizes

These are built within 1/8″ tolerance.

  • A 13 x 3ft TubeTrap will have a diameter of 13 3/8″ and a length of approximately 36 5/8″
  • A 16 x 46″ Custom made TubeTrap, which will have a diameter of 16 3/8″ and a length of 46″ +/- 1/8″

This includes but is not limited to:

  • TubeTraps
  • IsoThermal TubeTraps
  • Quarter Rounds
  • Half Rounds
  • TowerTraps (all variants)
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