SubTrap 18/22 .


So, you bought a new sub and were trying to reach the musical blue sky…but you ended up with the subwoofer blues. You thought maybe deep bass was supposed to sound this way: drab, sluggish and boring. You keep the volume turned down and the crossover set low so your sub can “support” the bottom end without drowning out the music. But… you know you can do better. It’s time for a subwoofer stand!

Now you can “raise” your subwoofer to its full performance potential! The SubTrap is more than a simple vibration isolation stand. In addition to isolation, it absorbs excess bass (the BAD bass) and decouples your subwoofer from room modes. Once you hear the difference, you’ll never go back! Only from ASC.

Installation and integration could not be easier; just slip a SubTrap underneath your sub. You’ll instantly improve sonic detail, changing “fuzzy” playback into a richly detailed picture by lowering the running noise floor of the room in the all-important low bass range. You’ll hear musical bass lines you never knew existed!

Utilizing our patented Isothermal technology to boost the low bass performance, the ASC SubTrap should be the foundation of your acoustic control plan. From there, build your musical experience with rich harmonics and a lush, immersive soundstage.


  • Home Theater
  • Two-channel HiFi Listening
  • Home Studio
  • Professional Studio
  • Live sound

The resonant modes inherent to rooms often cause what we call “room boom,” a muddled blur of sound that can range from disorienting to painful. This also masks subtle sonic detail all the way through the treble range, and it happens even when the subwoofer is producing great bass and plenty of detail. The SubTrap reduces the running reverberant noise floor in the room, allowing this detail to reach you-the listener.

By raising the sub off the floor and putting a SubTrap under it, the subwoofer is effectively decoupled from the vertical room mode. This reduces the degree of energy storage in the room, allowing the playback volume of the subwoofer to be raised much higher than before without suffering painful room boom.

The SubTrap utilizes the same RC-time constant acoustic circuit as our famous TubeTraps to provide lower bass extension than competitor’s products of the same size. In terms of bass response, the SubTrap-18 is comparable to a TubeTrap Model-20 and the SubTrap-22 is comparable to a TubeTrap Model-24.

The outer surface of the SubTrap is composed of a flow-resistive membrane while the inside is an capacitive air cavity, and together they act as an acoustic high-pass circuit with a rolloff below 50 Hz. Thanks to the isothermal upgrade, the equivalent of heat sinks have been added to eliminate the thermal backpressure of compression, providing a 200% improvement in the deep bass and 130% in the upper/mid bass.


Easy setup: just place the SubTrap under your subwoofer, and that’s all there is to it. Sit back and enjoy!

Model Sizes & Compatibility

Model-18: 18″ x 18″x 18″ (fits most subwoofers using drivers 15″ and smaller)

recommended compatible subwoofers:

JL Audio Fathom f112

SVS SB-3000

Rythmik F12

Model-22: 22″ x 22″ x 22″ (fits larger subwoofers using drivers up to 18″)

recommended compatible subwoofers:

JL Audio Fathom f113v2

SVS SB16-Ultra

Rythmik F18

Since 2018, all SubTraps have utilized ASC’s patented Isothermal technology to boost low bass performance!

The Model-18 offers meaningful absorption as low as 30 Hz, and really shines in the “boom zone” between 60 and 80 Hz.  The tuned core promotes high efficiency in this range, making the lowest notes more audible.

The Model-22 extends as low as 20 Hz, matching the performance of most high-end subwoofers, while still offering tremendous absorption in the 40-80 Hz range.

To extend absorption to even lower frequencies requires construction-oriented constrained-layer-damping systems (see the ASC Iso-Wall system!)

  • Isothermal Performance Boost
  • Mounting information: Free standing
  • Feet: 1″ butyl rubber isolation-type
  • Stackable: Yes
  • Load Bearing Capacity: 250lbs
  • Fire Rating: Class 1 fire rated ASTM E-84
  • Finish Colors: Guilford FR 701 Series
  • Warranty: 1 year parts and labor

Dimensions: 18″x18″x18″ LWH
Weight: 30 lbs
Shipping Details: UPS Box

Dimensions: 22″x22″x22″ LWH
Weight: 40lbs
Shipping Details: UPS Box (oversize)

Standard Product Absorption Curve



Custom Fabric Colors

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

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


Order Cost Custom Fabric Cost    Total
$2,500.00 $250.00 $2,750.00
$218.00 $175.00 $393.00

NOTE: Some lighter-colored fabrics can incur additional sub-charges for hue matching.

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 1-4 weeks lead time based on availability.  Contact us for details and availability.

TubeTrap Endcaps

These are painted gloss black with texture lacquer.



The SubTrap is a recommended upgrade for subwoofer playback by Stereophile, Wide Screen Review, Home Theater, Home Theater Review, Secrets of Home Theater and High Fidelity and The Absolute Sound.

Stereophile Review

Widescreen SubTrap Review

Home Theater Magazine Review

Secrets of Home Theater Product Review

“My first and usual test piece was the opening 30 Hz organ note at the beginning of the movie 2001: A Space Odyssey. That note is supposed to sound like approaching thunder. In the past, when I listened for this note, it was distant alright, distant and THIN. With the SubTrap I have finally (after many years) heard this note the way it was meant to be heard… With other music the bass is tighter, cleaner, faster and deeper. Being a ‘bassaholic’ for many years I cannot express fully enough what a difference the SubTrap has made for me. When I get my Supercube II subwoofer, I’ll be getting a 18″ SubTrap for that one too. Thank you, thank you, thank you…”

– L Harvey (satisfied SubTrap owner)

“Without a SubTrap, the excellent rhythm & timing that I have gotten used to was diminished to some extent; the bass seemed just a tad slow on rock music. Also, there was a somewhat ‘plasticky’ and ‘thuddy’ coloration to the bass. What is more, I could not contain my surprise when, while spinning a piece for six percussionists and choir (Wolfgang Rihm, last part of Tutuguri), I heard a ‘brownish’ coloration from large snare drums, the sound of which did not have lots of bass output! (The somewhat thuddy sound upon subsequent entry of the heavy bass drums was the final nail in the coffin for me). Putting back the SubTrap under the subwoofer confirmed that the ‘brownish’ coloration of the snare drums had been no illusion; the pristine sound that I had been used to returned”

– A Moritz (satisfied SubTrap owner)

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