Why Room EQ?
1. MathAudio Room EQ applies a state-of-the-art multipoint correction algorithm
The frequency response of your room is very different in every point of the room. "Good" equalization in one point can worsen the sound in the neighboring point. Single-point equalization is not reliable and cannot be used in a professional room correction system. On the other hand, the multipoint equalization is not simple: both the volume and the phase of the testing signal are very different in different points of the room. Simple averaging is not applicable. MathAudio Room EQ applies a state-of-the-art multipoint correction algorithm which ensures the best possible improvement in every point of the listening area.
2. MathAudio Room EQ doesn't add pre-echo to the sound
Pre-echo (pre-ringing, pre-reverberation) is a kind of distortion which is present in the sound of a lot of modern digital room correction systems. MathAudio Room EQ is free of this problem (see the impulse response plots below).
We live in the world where pre-echo is absent. A guitar string doesn't sound before you touch it. Analog electronic circuits also don't create pre-echo. Pre-echo came to our life together with digital processors. For example, you can hear pre-echo in MP3 recordings. Of course, it is not a problem of digital processors, it is a drawback of the mathematical algorithms that are used to process the sound. It is possible to make a digital room correction system which doesn't add any amount of pre-echo to the sound. MathAudio Room EQ is such system.
If you want to check the presence/absence of pre-echo in the sound of any room correction system, you can use the following simple method. Download this audio file which contains a Kronecker delta function. Process it in your DAW by means of the room correction plug-in and save it as a WAV file. Open the WAV file in a wave editor (e.g. Wavosaur) and "stretch" the waveform along both horizontal and vertical axes to see "pre-reverberation" and "post-reverberation" which is added to the sound by the room correction system. Post-reverberation is necessary to compensate for the room resonances created by the natural post-reverberation of your room. Pre-reverberation is an unnatural digital artifact which distorts the sound in your room. Thus you can visually compare the amount of pre-reverberation in different room correction systems.
3. MathAudio Room EQ doesn't overcompensate your room
The result of the digital room correction is heavily dependent on the correctly chosen amount of the correction. Both undercompensation and overcompensation should be avoided. Unfortunately, automatic room correction systems are not as smart as they pretend to be. In particular, they try to "make everything flat". However, the "dead flat" frequency response is often not the best one. As a result, the automatically chosen amount of room correction is often far from the optimum one.
The vertical slider of MathAudio Room EQ allows you to manually choose the optimum amount of the room correction in real-time mode and thus to avoid the overcompensation of your room. Rooms with traditional acoustic treatment usually need a smaller amount of digital correction than conventional rooms.
4. MathAudio Room EQ doesn't use any kind of resampling
The performance of all types of digital equalizers depends on the sample rate. It is impossible to make a digital filter which could work the same way if we would change the sample rate of the audio signal. Modern room correction systems must support a lot of standard sample rates. There is a simple method to solve this problem: resampling. Resampling is a method of transformation of the audio signal which allows the developer to use a single digital filter for all sample rates. For example, the sample rate of the original sound (e.g. 96 kHz) can be resampled to the sample rate of the filter (e.g. 48 kHz) and then resampled once again to the sample rate of the output signal (96 kHz). The downside of this method is that the resampling adds some distortion to the sound.
MathAudio Room EQ doesn't use any kind of resamping in its filters. It natively supports the following standard sample rates: 44056 Hz, 44100 Hz, 47250 Hz, 48000 Hz, 50000 Hz, 50400 Hz, 88200 Hz, 96000 Hz, 176400 Hz, 192000 Hz, 352800 Hz, 384000 Hz.