What is room correction? 

This is a question asked by many of our web site visitors. Here we try to answer it without going too much into technical details.

Your Listening Room

It is the greatest limiting factor in home audio.

It is a measurable fact that acoustic room interactions contribute 30-40 percent to the quality of the sound that actually reaches your ears, regardless of how good your system is.

A unique room signature is stamped on everything you listen to. So when it comes to your listening room, you'd better be loving it.

Reality Check

Regardless of how good your gear is, once the signal leaves your speakers and is converted into the acoustical energy of music, your control over it is completely relinquished.

Your well processed signal is left entirely to the mercurial vices of a room; vices that are determined by a variable combination of room dimensions, room construction, interior surface properties, system layout, and speaker behavior.

So before popping in your next CD, take a moment to really analyze your listening room. Focus upon its construction and the composition of the materials making it up. From the perspective of a sound wave, your room is thus revealed for what it truly is: a collection of haphazardly strewn absorbing, reflecting, and diffusing materials.

What the room does to your music is more than enough to seriously undermine the value of your investment and to drastically impinge upon the quality of your listening experiences.

What is Room Correction

Room Correction is a process that consists of two steps:
1) Full spectrum room response measurements and
2) custom correction.

Full spectrum room response measurement

The first step towards correcting the room-speaker response of your room is to measure how the system and room together reproduce a series of test signals.

Required are aTact Room-Correction preamplifier and a supplied microphone. The microphone is placed in the desired listening position and calibration begins with a series of test pulses carefully selected to properly cover the entire audible spectrum.

TheTact proprietary measurement technique is a result of many years of research and development in the field of wave propagation.

The pulses are emitted in succession from each independent channel in the system.

To ensure accurate full spectrum measurement, the microphone combined with theTact preamplifier collects room-loudspeaker response information for a few seconds.

This long room-loudspeaker response observation window combined with high speed signal processing is crucial for precise and high-resolution room correction.

Custom correction

Analysis

Once the full spectrum room-speaker impulse response is measured, the room correction system sets itself to the task of analysis. It first needs to determine the differences, in both the time and frequency domain, between the original test signals and the measured ones.

The difference is calculated usingTact proprietary signal processing algorithms. The algorithms are based on a multi rate processing technique and have been developed over many years of research and development. They are continuously refined through extensive testing with experts worldwide.

The calculated difference is later used to derive the user defined room correction filters.

One of the features of room correction that differentiates it from parametric equalizers and parametric equalizer based “room correction systems” is that localized problems are not singled out and that uniformly shaped filters are not employed. Room correction entails in essence just one filter that with high resolution covers the entire range of audible sound.

The correction filter will perfectly match the room-speaker response with a resolution less than 1 Hz.

If you were going to compare just the resolution parameter to parametric equalizers and parametric equalizer based “room correction system”, you would need to have a parametric equalizer with more that 4,000 (four thousand) filters per channel. 

Correction

After the system has acquired all the necessary data, you are ready to move to the final stage: customized correction. In this stage you, the user, tell the system how you want your room to sound.

The real power of theTact room correction system lies in this: it allows you to create a room response of your choice. Each room correction is designed around a user selected, or designed, target curve.

By selecting a target curve you are defining how the room behaves at low frequencies, midrange and high frequencies. You can decide exactly how you want your base to roll off and precisely how you want your midrange and high frequencies to behave.

The room correction system will measure your room response, will compute it to a target curve, and will produce filters for each channel in your system.

Room correction filters are calculated based on the measured room-loudspeaker response and they are natural extension of the actual room measurement.

When the music source is played, the signal will go through the correction filter and will combine with the loudspeaker and room response to produce a total response that is equivalent to the target curve.

It is safe to say that the true room correction concept lies in the scope and versatility of the target curve.

No other technology is capable of synergistically harnessing the entire frequency spectrum and the time domain and no other technology is capable of giving listeners such control over their listening environment.

Tact is the leader in digital room correction technology and digital amplification.

Was this document helpful?
Please send you comments and suggestions toTact support team at:

support@tactaudio.com