Room Correction Magic | AV Receivers and Processors: How AV Receivers and Processors Can Transform Your Home Theater

AV receivers and processors are crucial components of a home theatre, cinema or audio system! It obviously provides the necessary power and processing to deliver high-quality surround sound audio and great video. One of the key features of AV receivers and processors is room correction, which if used and setup correctly can dramatically improve the sound quality and immersive audio experience of your system.

Room correction is the process of measuring the acoustic characteristics of a room, its contents and how the speakers react in the room with the electronics connected. It adjusts the audio signal to compensate for any irregularities. Each room has its own unique acoustic properties, such as the size, shape, and materials used for walls, floors, and ceilings. These factors can have a significant impact on the sound quality of a system, leading to issues such as resonances, echoes, and reflections.

To correct these potential issues, AV receivers and processors use a variety of room correction technologies, such as Audyssey, Dirac, and Anthem Room Correction. These technologies work by using a microphone to measure the frequency response of the room and then applying digital signal processing (DSP) in attempt to correct any issues. Each technology has different levels of effectiveness and capabilities, not to mention ease or difficulty of use.

The first step in the room correction process is to take a measurement of the room using a calibrated microphone. This measurement captures the frequency response of the room, which is then compared to an intended target frequency response. The target response is a pre-defined curve that represents an ideal frequency response for a given system.

 

Once the measurement is taken, the DSP algorithms can adjust the audio signal to compensate for any irregularities in the frequency response. For example, if the measurement shows that there is too much bass in the room, the DSP can reduce the bass level to achieve a more balanced frequency response.

Room correction can also address issues such as time delays and phase issues, which can result from the positioning of speakers and other components in a room. By measuring the time delay and phase relationships between different speakers, the DSP can adjust the audio signal to ensure that all the components are working together in phase and time.

Whether you are a music lover, movie buff, or gamer, room correction can help you achieve the best possible sound quality from your system. So, if you want to take your audio system to the next level, be sure to invest in an AV receiver or processor with room correction technology.

Below is a list of just some of our products with their various room correction technologies:

• ARC Genesis – Anthem Room Correction
• Audyssey MultEQ/XT32
• Dirac Live
• Yamaha YPAO
• Trinnov Audio Optimizer
• RoomPerfect
• MCACC – Multi-Channel Acoustic Calibration System
• AccuEQ

A few of the Room Correction Technologies in a bit more detail:

ARC Genesis – Anthem Room Correction

The distinctive features of a room, such as its size, shape, construction, and furnishings, can create standing waves, resonances, and reflections that have a detrimental impact on the performance of an audio system. However, ARC Genesis, designed by Anthem engineers, employs exclusive algorithms to generate personalized correction curves that preserve the desirable acoustic qualities of loudspeakers while eliminating the negative effects of the room. These customized filters are then integrated into top-notch digital signal processing (DSP) technology that is incorporated into compatible audio devices.

Audyssey MultEQ/XT32

Audyssey Technologies Supported by MultEQ-X

• Setup – MultEQ-X measures the speaker system and calculates trims, delays, and suggested bass management settings based on the in-room acoustic response.
• MultEQ / MultEQ XT / MultEQ XT32– This technology automatically customizes your home theater system to overcome the acoustical problems specific to your room. An optimized audio system provides the most clear and balanced sound possible. It is the basis for the rest of Audyssey’s technologies.
• Dynamic EQ – As the volume is turned up or down, Audyssey Dynamic EQ maintains consistent bass response, tonal balance, and surround impression.
• Dynamic Volume – This technology controls volume levels to eliminate spikes and raise soft dialog for more enjoyable television and movie viewing.

Dirac Live

With its research-based acoustic processing algorithms, Dirac Live is a robust tool that enables you to optimize your speaker performance. By assessing your room and mitigating its impact on sound quality, Dirac Live and its multiple features make it possible to achieve speaker performance that would be unattainable otherwise.

Yamaha YPAO

Yamaha Parametric Acoustic Optimizer is a sound calibration technology developed by Yamaha that utilizes automatic acoustic optimization. Its primary function is to analyze and adjust the audio settings of a Yamaha audio system for optimal sound quality based on the acoustics of a given room. YPAO employs a microphone to measure the sound waves in the room and subsequently modifies parameters such as speaker distance, size, and volume levels to deliver an optimized listening experience. In essence, it ensures that the audio system is precisely tuned to the specific acoustic characteristics of the room to provide the best possible sound output.

RoomPerfect

RoomPerfect is an advanced room correction technology developed by Steinway Lyngdorf. It is specifically designed to optimize the audio performance of an audio system by minimizing the negative effects of a room’s acoustics. It utilizes sophisticated algorithms to analyze the acoustical properties of a room and generate a customized correction filter to compensate for any standing waves, resonances, and reflections that could affect the sound quality. Additionally, it corrects the frequency response of each speaker in the audio system, ensuring a seamless and coherent soundstage. The system also features an intuitive interface for easy configuration and customization of the correction filter. By precisely calibrating the audio system to the unique acoustics of the room, RoomPerfect provides listeners with a high-fidelity audio experience that accurately reflects the intended sound.

Some Tips and Tricks Taking Measurements for example with ARC Genesis:

Proper microphone positioning is essential for good results. Multiple microphone positions are required to prevent standing waves or boundaries from skewing results. To achieve the best results with ARC Genesis, follow these simple rules.

• ALWAYS point your microphone at the ceiling.
• ALWAYS place the 1st position at your primary listening location. The 1st position is critical because it is used to set the level of the overall system.
• ALWAYS place the mic height near ear level (if you sit when you listen, use the relative height of your ears when seated). The microphone, the listener’s ears, and the speaker’s acoustic center (or tweeter if in doubt) should be at approximately the same height. If the result sounds dull or bright, a new feature of ARC Genesis is the ability to boost and cut deep bass and high frequencies in the “Adjust ARC Settings> Adjust Targets” menu.
• WHENEVER POSSIBLE, make sure the primary listening position is a minimum of two to three feet (60 to 90 cm) from walls and other large hard surfaces. Please note:

We understand that the location of the primary listening position is often not flexible.

• For best results when listening, a listener’s ears should be away from any walls a minimum distance of two to three feet (60 to 90cm).
• If the 1st mic position falls within two to three feet (60 to 90cm) form a wall, high-backed furniture, or similar obstructions, it’s important to measure from a position as close to the listener’s head as possible. So place the first mic position just in front of where the listener’s head would be. In this case, always place the 2nd through 5th positions the recommended distance from each other, even if this results in them being less than two to three feet (60 to 90cm) away from a wall. The resulting pattern may look less like an X and more like a V or M, and that’s okay.
• WHENEVER POSSIBLE, place the 2nd through 5th positions two feet (60cm) from the 1st position. Up to three feet (90cm) is acceptable, but not usually necessary.
• WHENEVER POSSIBLE, place the 2nd through 5th positions symmetrically around the 1st position. Use an X pattern, with the 1st position in the center of the X, and each corner two feet (60cm) from the center.
• WHENEVER POSSIBLE, vary the mic height for the 2nd through 5th positions, with two measurements being 6 to 12-inches below the 1st position and the other two measurements 6 to 12-inches above the height of the 1st position. This method provides ARC with a more three-dimensional view of the room and its acoustic signature.

Other Considerations When Taking Measurements with ARC Genesis

A shorter distance between mic positions is advised only for systems where ARC is being used exclusively for low-frequency corrections (subwoofers or speakers with active woofer systems), where the room is already well treated, or where there’s only one primary listening position. In these cases, consider varying the distance between microphone positions by as little as one foot (30cm).

Don’t Make These Common Mistakes!

• NEVER measure all five positions at the same location—the differences in the acoustic response at the five measurement locations are what allows ARC to understand the acoustic signature of your room.
• NEVER place the 2nd through 5th positions at the four corners of the room—don’t do it! There doesn’t need to be much distance between microphone locations for ARC to understand a room’s acoustic signature. Long distances between measurement positions adversely impact your final room corrections.
• WHENEVER POSSIBLE, do not place the 2nd through 5th positions further than three feet (90cm) away from the 1st position—a symmetrical pattern of spots around the first location is more important than putting the microphone at each listening position throughout the room.

Dealing With Subwoofers That Have Built-in Equalization or Room Correction

We’ve often heard, “Equalization is available for my subwoofer. Should I use the sub’s built-in EQ when I am also using a receiver to correct the sub as part of a multi-channel system?” Since rooms and correction systems vary, the answer varies. If using MartinLogan or Paradigm subwoofers (with ARC or PBK built-in), results are often better with the subwoofer’s correction system is run before correcting the entire system. If the sub’s EQ is not ARC or PBK based, it is usually best to disable the subwoofer’s EQ before running ARC. When using ARC Genesis to correct the entire system with your Anthem receiver or preamp, if the resulting target curves and calculated curves in the room correction software resemble each other, there is typically no reason to use the sub’s EQ. If the two curves differ significantly through a wide range (meaning the room correction software was not able to make the subwoofer fully match the target curve), enable the sub’s EQ and rerun ARC to see if it helps.