ASC Tube Traps Are The Real Deal

[Michael TubeTrap]

Originally Posted by chessman

Dan ... I do not have the waterfall graphs to prove it, but by ear I am sure that the decay times have really evened out. The sudden "lock" into realistic sounding is what has me so jazzed about these tube traps. I think the first order harmonics of the bass notes were muddying up the mid-range, which is why 11's are working when theory says 24's. The subs are not on for music, which is another reason I am getting away with the 11's. Getting 24's would be wretched excess ... like that has ever stopped me.

Randy, you might be surprised at what your waterfall graphs shows you, or rather doesn't show you. TubeTraps were first invented based on sound science, but because the company took off so quickly, it took founder Art Noxon a while before he could do a lot of testing and experimentation. Being both an engineer and a physicist, his test results were puzzling. His invention clearly improved the playback in listening rooms, everyone agreed, A/B comparisons left no doubt. Yet, most tests showed very little change in the room's acoustics. For instance, the typical improvement in frequency response was usually a dB or two, not enough to account for the dramatic improvement listeners heard. It was almost as if this scientist's invention worked by magic! Wouldn't that have been ironic.

What we have since learned is this: most traditional acoustics are based on steady-state tones, in a room that is "fully pressurized". A musical note is made of an attack transient (and release), a sustain, then a decay. Testing is typically based on the sustain phase, or the decay of a note (such as RT60). No traditional room acoustics test deals with the attack transient/release, before the room is fully charged up with sound pressure.

The one standardized test that Art found that seemed to correlate with his invention's improvements was a test for articulation, from the speech pathology world. It is the basis for our Music Articulation or MATT test. This is a series of rapid tones, with silence between. It allows you to hear what your room does to the attack and release phase of musical-length notes.

If you listen on headphones, you hear a series of pulses with silence between, sweeping through bass and midrange frequencies. Headphones don't have acoustics issues. Listen to your sound system, and you'll hear where your room slurs together those same pulses. Your room may only slur part of the test range, and part may play well. For TubeTrap owners that report their music now sounds so much better, they can remove the Tubes from the room, run the test, and hear where slurring occurs. They can put the Tubes back in, run the test again, and hear how the slurring has been reduced or eliminated.

You can find the MATT test on the Stereophile Test CD2, or download it for free from our website here. We offer a service where we'll take your recorded test and analyze it, provide you a printout, etc, but the greatest value we have found is by having people just listen, for free.

Michael Adams