What's the use of an audio processor? Meeting room/stage must know dry goods.

To build a professional sound system, many people have heard of the "audio processor", but they don't understand its positioning. Many novices have two extremes when configuring equipment: either they think the processor is dispensable and directly connect the mixer to the power amplifier; Either blindly buy at a high price, and when you buy it back, you will only turn it on, and the internal functions will never be used.

The mixer is responsible for mixing and audio processor, and it is the "housekeeper and goalkeeper" of the whole sound system. Regardless of the fixed sound in the conference room, small performance stage and multifunctional banquet hall, if we understand its core functions, we can avoid common problems such as howling, broken sound, unbalanced volume and burned speakers.

First, popular positioning: the signal hub between the mixer and the power amplifier.
Simple sequence of signal flow direction: sound source → mixer → [audio processor] → power amplifier → speaker.

Mixer: mix multi-channel sounds, adjust the voice size, and preliminarily adjust the high and low voices.
Audio processor: accurately control the overall output audio, protect the speakers, and optimize the sound field. In a word: the mixer tube "Who makes the noise and how loud it is"; The processor is in charge of "what standard sound is sent to the speaker".

Second, the core function of the audio processor, combined with the scene to explain
1. Frequency division (most important, required for multi-unit speakers)
Professional speakers are divided into bass, midrange and treble units. If the full-band signal is directly sent to the speaker, the high-pitched unit bears the low-frequency signal and is easily burned. The processor has a built-in frequency divider, which can divide the frequency bands: low-frequency signals are given to the bass unit, and medium-high frequencies are given to the treble unit. Application: professional stage speakers, multi-channel banquet hall audio passive integrated household speakers generally do not need to use frequency division function.

2. Limiting protection (speaker life-saving function)
Most speakers are damaged, not because of poor equipment quality, but because of instantaneous loud volume impact. The limiting function will set the upper volume limit. No matter how high the front mixer is pushed, the output signal will not exceed the set threshold. Put an end to the impact of sudden roar and background music sonic boom, and greatly reduce the risk of horn burning. Meeting rooms and stage performances are recommended to be opened for a long time.

3. Equalizing EQ: correcting acoustic defects of the site.
Room structure, wall, glass, tables and chairs will all affect the sound quality: low-frequency roar in empty rooms; Narrow conference rooms are prone to harsh resonance. The mixer EQ adjusts the sound of one-way people; The processor EQ adjusts the overall timbre of the whole set of speakers. It can eliminate the harsh resonance frequency band generated in space, reduce the echo and make the sound cleaner.

4. Feedback suppression (automatic howling prevention)
Howling means that the sound of the speaker is transmitted back to the microphone to form a sound cycle. Ordinary mixer can only be relieved by reducing the volume and attenuating the high notes. The high-end audio processor has its own feedback suppression module, which automatically captures the howling frequency and weakens it. Advantages: You don't need to depress the treble greatly, and the voice is still clear, which is very suitable for the scene where multiple microphones are used at the same time in the conference room.

5. Delay adjustment, to solve the sound synchronization.
In large venues, multiple sets of speakers are scattered. The distance of the audience is different, and the sound will be heard in tandem, and the hierarchy will be chaotic. The audio processor can set a sound delay for each output, so that the sound of all speakers can reach the audience area synchronously. Common in hotel banquet halls and large venues.

6. Signal matrix allocation
A processor has multiple inputs and multiple outputs, which can flexibly distribute signals: for example, one channel of mixer signals are respectively transmitted to the main amplifier, the return speaker and the background music partition. There is no need to add multiple signal lines, which simplifies the whole set of wiring.

Third, the meeting room VS the stage, the use of demand distinction
[Meeting room/multi-function hall]
Core requirements: feedback suppression, EQ space correction and output limiting.

Key points of use:

1. Often, multiple gooseneck microphones are turned on at the same time, giving priority to automatic anti-howling;
2. Lock the parameters after debugging to prevent the staff from misadjustment;
3. Set a reasonable amplitude limiter to prevent newcomers from pushing up the volume at will to damage the sound.

[Outdoor/Indoor Stage Performance]
Core requirements: frequency division, amplitude limiting, channel delay and independent channel EQ.

Key points of use:

1. For professional active/passive speakers, the crossover point must be set correctly;
2. Debug the sound field before the performance and save the preset;
3. Adjust the parameters of the return speaker and the main amplifier separately.

Fourth, high-frequency misunderstanding, many engineers will not take the initiative to tell you.

Myth 1: With a mixer, you don't need an audio processor. The mixer has no precise amplitude limiting, multi-channel frequency division, sound field delay and professional feedback suppression. Small KTV and simple background music system can be dispensed with; Professional conferences, stage systems, and processors are just needed equipment.

Myth 2: The processor parameters are adjusted at one time, and the acoustic effect will change without changing the venue, the number of microphones and the seasonal environment forever. If the parameters are not rechecked for a long time, there will still be howling and poor sound quality.

Myth 3: The more expensive the processor, the better the sound quality. First, match the usage scenario. Small conference rooms buy large performance processors, and a large number of functions are idle, which is a waste; It is easy to buy the wrong one just by looking at the price and not at the number of channels and functional modules.

Myth 4: The mixer built-in effector can be used instead of the audio processor mixer effector to process single-channel signals; The audio processor acts on the output bus to control all the speakers, and the two cannot replace each other.

5. Which scenes can be used without audio processor?

1, home K song set, simple Bluetooth audio;
2. Background music of small stores (played directly by a pair of active speakers);
3. A simple small room with only one or two microphones and less than 30 square meters.

Six, novice simple debugging ideas (general reference)
1, first set up a complete set of lines, all equipment normal noise;
2, set the output limiter, and do a good job in the basic protection of speakers;
3. Turn on feedback suppression, slowly increase the volume and find the critical howling point;
4. Use EQ to eliminate spatial roaring and harsh frequency bands;
5 Multi-speaker system, adjust frequency division and delay in turn;
6. After debugging the parameters, save the preset configuration.

The audio processor is the "shield+tuning master" of the whole sound system. It will not directly transform ordinary cheap speakers into high-end equipment, but it can give full play to the original performance of speakers, avoid use accidents and optimize the acoustic defects brought by the venue. The sound system wants to be stable, pleasant to listen to and durable, and the reasonable configuration and debugging of the processor are indispensable.