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Old 14th February 2015 | Show parent
  #165
Gear Nut
 
Bobecca are right Its not possible to measure a Sabin value on a reactive absorber that make any sense

The explanation is that a fully developed standing wave is 90 degrees phase difference between pressure and particle velocity and have switch to a reactive wave basically without energy Asking for a Sabin value on a Varitune module only shows that GS regulars dont understand that we have two different waves to keep track on in small room acoustic
The reactive wave and the active wave
To better understand the difference between the reactive nature of standing waves and the active nature of interference we can compare a bell and a loudspeaker. A finger placed on the bell will silence it but not the loudspeaker.

Concequences of chasing strong axiell modes with a Sabin toolbox (different kind of mambrane absorbers ) have developed a mantra on GS , You cant get enough of Sabin absorbers and dont expect magic in the frequency respons
Its like aiming on the piano player instead of tuning the piano

The Varitune family are reactive absorbers and the only modules on the market thats optimized for strong axielle modes This means you cant measure the effect in Sabin as its not energy problem . Instead we must look how even the reactive absorber distribute the mode ,deals with harmonics and fill the dips with a minimum of tuching the active wave = Robin Hood Effect
This is the exiting rock and roll part of small room acoustic

Some examples how the Varitunes works as effective phase shifters on the reactive wave
No DRC can achive the same
https://gearspace.com/board/10045400-post60.html
https://www.youtube.com/watch?v=GjdACNPLzzg
The attached photo show untreated ,sabin treated and how the Varitune effect surf on top without tuching the active wave

SMT AB
Attached Thumbnails
How to treat nulls 2-varitune-effect.jpg