Prices start at $425.00

SKU: ab-asc IsoThermal: Category:


Finally: You can get rid of the dreaded “rear wall bounce frequency suckout.” (and also increase your bass absorption below 250 Hz!)

We’ve added a new model to our TubeTrap line, brand new for 2015.  It’s an isothermal-class RC time constant bass trap combined with the adjustable treble diffusion of our regular TubeTrap. It delivers twice the bass absorption of an equivalent sized TubeTrap within the first octave, between 20 Hz and 55 Hz. That’s why the IsoThermal TubeTrap has two chrome dots along the rim instead of the traditional one dot: two dots means twice the power!

By eliminating the thermal component of acoustic pressure, The IsoThermal TubeTrap has an effectively 40% larger internal volume below 150 Hz, which doubles its absorbing power while retaining all of the other familiar sonic characteristics of the TubeTrap you know and love.


Because of the dynamic performance of the IsoThermal TubeTrap, it is at home in a variety of venues giving you extended low end absorption and increased efficiency. 

  • Home Theater
  • High End Listening Rooms
  • Recording Studios

The IsoThermal TubeTrap offers:

  • Extended bass absorption below 250 Hz
  • Treble diffusion (or absorption) above 250 Hz
  • Great for controlling the phase add/cancel effects of the rear wall bounce
  • Available in a variety of sizes, each with their own absorptive properties
  • 30 day, 100% satisfaction guarantee
  • Sturdy hand crafted construction

How It Works

We developed the IsoThermal TubeTrap to aggressively manage typical HiFi rear wall bounce phase-cancel effects.  What we got was a major performance boost across the entire bass spectrum.  And we did it without altering the fundamental voice of a TubeTrap.

Check out the absorption data for the new 16×4 Isothermal TubeTrap compared to a standard 16×4 TubeTrap.  Power is doubled in the sub-bass range, while the LF rolloff is extended by over half an octave!  The efficiency of the unit is a solid 40% greater all the way up through the “muddy” range of bass. 

We were even more impressed when third party theoretical calculations made in ESI’s NOVA software (a multi layered acoustic simulator used in advanced acoustic engineering) corroborated our data to an uncanny degree.

As with standard TubeTraps, larger diameter units reach to lower frequencies.  However, with the IsoThermal upgrade, the operating frequency of each size TubeTrap has come to match that of the next model size larger, approximately.  This means that if you previously used and loved the sonics of a 16″ TubeTrap, you can now replace your old tubes with new 13″ IsoThermal TubeTraps, with very similar voicing.  Better yet, if you always wished you had the space in your room and money in your wallet to fill your corners with deep-breathing 20″ TubeTraps, now you can simply upgrade your system with 16″ IsoThermal TubeTraps to manage that 35 Hz rumble.

What is the IsoThermal effect?  The short story begins with the statement that when you compress gas, it heats up, while when it expands, it cools down.  High pressure sounds entering the acoustic capacitor of a TubeTrap cause a rise in pressure, or compression.  When the air pressure inside the TubeTrap reaches that of the ambient air outside it, the capacitor is essentially “full.”  The air then cools off fairly rapidly due to thermal and hydraulic losses, and returns to low pressure, ready to be filled up again.

The frequency of this “filling-up” is proportional to – you guessed it – the frequency of the sound.  Therefore low frequency sounds “fill up” the capacitor much more quickly, due to the slowness with which they propagate through the media.  A larger capacitor (think of a 24″ TubeTrap) takes the longest to fill, and so reaches the lowest frequencies.

The conversion of the capacitive section of a TubeTrap into an isothermal vessel alters this behavior in a very beneficial way.  The low-pressure air inside the capacitor is prevented from rising in temperature upon being subjected to a high-pressure pulse.   Through this action, the effective size of the capacitor is increased by 40%, almost as though the IsoThermal TubeTrap is 40% larger than it appears!  (This comparison is not quite accurate, since other factors come into play regarding the resistance of the absorptive material among various TubeTrap models, but it is a good approximation).




Acoustic Sciences Corporation (ASC) provides acoustical products for ultra-high-performance, high-fidelity recording and audio rooms, auditoriums, churches, and a multitude of other venues including home listening rooms. Tireless research and experimentation with sound led ACS founder Art Noxon to essentially create the Room Acoustics Industry with the development of a patented sealed cylinder as a device for absorbing excess low-frequency sound energy, and has become an iconic fixture in high-end audio. The cylindrical columns seen frequently in the corners of music venues are referred to as Tube Traps. An ASC Tube Trap is unquestionably one of the most effective acoustical treatments available to the audiophile. No element has as much impact on the performance of an audio system than the room in which it is installed. In an “untreated” room, listeners find themselves raising the volume in an attempt to attain more clarity. A “trapped” room allows one to listen at a lower volume level while gaining in dynamic impact. With the room effectively removed from the equation, the sense of listening in the recorded space is greatly enhanced by eliminating the negative effects of standing sound waves and low-frequency reflections in the room. Simple in design, relatively simple in execution and simply indispensable for improving the acoustics of your listening room, ASC’s Tube Traps, installed by Overture, will have a profound, positive effect on your enjoyment of your fine recordings.