How to use the mixer grouping and matrix output? Practical configuration of small and medium-sized conference rooms and multi-function halls

Many government and enterprise conference rooms and multi-function halls are equipped with digital mixers, conference microphones, wireless microphones and computer audio sources hand in hand. During the meeting, more than a dozen pushers pulled back and forth, which made the operation cumbersome, and it was easy to roll over on the spot when the hand slipped and pushed by mistake.

Grouping GROUP and MATRIX matrix is the core ability of digital mixer. But in reality, the two extremes are very common: many projects directly put all the signals into the main LR, and the grouping and matrix functions are idle all the year round, and the equipment performance is wasted; There are also debuggers who blindly pile up buses, and the routing is complicated. The operation and maintenance that took over later can't understand it. When something goes wrong, it is silent and crosstalk.

Especially in the multi-function hall where meetings, performances and activities are integrated in one, a system should be adapted to various usage scenarios. Using grouping+matrix well can simplify complex mixing, and at the same time realize multiple sets of independent mixing, such as main amplification, sound supplement, recording and broadcasting, remote video conference and monitoring.

Today, I won't talk about obscure textbook theory, but talk about the essential difference between grouping and matrix. I attach a configuration scheme that 50,200 people can directly copy the landing, and make the high-frequency pit stepping point clear at one time.

First, understand the core: grouping Group VS Matrix matrix
Many people still can't tell the difference between grouping and matrix when they arrive at the scene. A popular understanding is:

The marshalling tube is "input packaging" and the matrix tube is "output distribution"

Group/Sub‑Group
Grouping is the first summary and mixing of the original input channels, and the same type of microphones and sound sources are packaged into a bus.

Signal source: original input channels such as microphone and player.
Signal flow direction: marshalling bus can be sent to the main LR main amplifier or directly output physically.
Support independent EQ, Qualcomm, compression: the whole group is unified to do timbre processing.
Independent grouping fader: Push a fader, and the volume of all channels in this group will change synchronously.
Distinguish DCA/VCA： DCA only controls the fader action in linkage, without audio signal, and can't add effect; Group is a real audio bus, which can mount EQ and compress. Group is preferred for conference projects.

The most classic usage of conference room: throw all hand-in-hand gooseneck microphones into the same group. By adjusting this fader, the volume of all conference microphones will rise and fall synchronously, and there is no need to adjust the channels one by one.

Matrix (matrix)
The matrix belongs to the secondary mixing bus. Matrix can't directly pick up microphone input, but can only receive bus signals that have been mixed: main LR, each Group grouping and AUX auxiliary output. Simply put: the original signals are grouped and packaged, and the mixed signals are mixed by matrix, and then mixed again and distributed for output.

Each matrix bus has independent EQ, delay, compression, amplitude limiting and physical output interfaces. With the same set of input sound source, multiple sets of non-interference remixes can be generated through the matrix and supplied to different devices and speakers.

What can a matrix do?

Independent output of the sound box in the venue, with delay EQ.
Signal output of conference recording and live broadcast
Video conference host pickup input
Backstage lounge partition broadcast
Independent monitoring of mixed output

Two, small and medium-sized government and enterprise meeting room | 5080 standard configuration
Scene: Hand in hand with some 24-way wireless microphones and computer audio sources in the conference unit; Give priority to with video consultation, internal meeting, occasionally small report.

Grouping Group planning (direct copying)
Group 1 | Conference Microphone Group: Gooseneck Hand in Hand (Chairman+Delegate Unit)

The marshalling bus turns on Qualcomm 80‑100Hz to filter out the low-frequency noise of air conditioner and ground;
Compression can be started moderately, and the volume fluctuation caused by simultaneous opening of multiple microphones can be suppressed;
Open the main extension of Main L‑R.
Use income: the overall volume of the microphone is high/low during the meeting, and only the Group1 fader is operated; All microphones need to be muted, and mute sounds should be grouped directly, instead of being muted channel by channel.

Group 2 | Wireless microphone group: wireless handheld and wireless collar group 3 | Music sound source group: computer, player and background music.

Engineering details: Do not keep CH01 and CH02 for channel naming, and change it to "Hand in Hand Chairman" and "Wireless Handheld 1" for quick identification by subsequent operation and maintenance personnel.

Matrix matrix programming
The main amplifier of this scene still uses the Main L‑R output of the mixer to drive the main speaker; The matrix does not do main amplification, but only signal splitting.

Matrix 1 | Video conference output, docking video conference host signal source: Group1 conference microphone+Group2 wireless microphone. It is forbidden to mix with Group3 background music.

This is the high-frequency rollover point of the project: if the background music is sent to the far end of the video, when the music is played locally, the far-end venue will receive music, which will induce echo and howling. Matrix1 has an independent level, which can adjust the volume of the live main amplifier without affecting the output size of the remote video.

Matrix 2 | recording and broadcasting output, signal source of docking recording and broadcasting host: Group1+Group2 voice, which can be mixed with a small amount of background music as required. Don't overdecorate EQ in recording and broadcasting matrix, and keep the original clarity of human voice.

The advantages of this routing
On-site sound reinforcement, video conference and recording and broadcasting are independent of each other;
Adjusting the volume of on-site speakers will not cause sonic boom in the far-end venue;
Conference microphones can be muted by one-button grouping to cope with the intermission.
Three, multi-function hall | 100200 people, meeting/performance/KTV three in one.
Venue requirements: Roundtable meetings, cultural performances and KTV activities are mixed; Configure the main amplifier, side supplement sound, stage feedback, and run video conference and recording and broadcasting at the same time.

Grouping Group planning
Group1: conference gooseneck microphone group
Group2: wireless vocal microphone group (host, performance handheld)
Group3: musical instrument input group (performance scene enabled)
Group4: accompaniment music sound source group
All marshalling can be sent to Main L‑R main expansion as required. Scene switching is very convenient: the Group3 instrument is closed in the meeting; KTV mode directly mutes the microphone group of Group1 conference.

Matrix matrix programming
Matrix 1 | side complementary sound output is taken from Main L‑R main signal; The matrix bus is equipped with independent EQ and time delay, and the volume and time delay of side compensation can be adjusted independently without changing the main amplification parameters.

Matrix 2 | stage echo output

Tip: AUX； can also be used in small venues; When the echo mix is consistent with the main amplifier, the matrix configuration efficiency is higher.

Matrix 3 | Video conference host only takes voice of Group1+Group2, and isolates accompaniment music of Group4 to avoid the problem of far-end echo.

Matrix 4 | The ratio of vocals to accompaniment can be adjusted freely and output to recording and broadcasting equipment independently.

Make good use of scene snapshots (necessary for digital mixer)
Save 3 sets of scene presets:

Meeting mode
: Enable conference microphone grouping, and matrices 3 and 4 will take effect;
Literary performance mode
: Enable microphone, musical instrument and accompaniment grouping, and mute conference microphone grouping;
KTV mode
: Turn off the conference microphone grouping and raise the music grouping level.
Switch snapshots, grouping, matrix routing, EQ and delay are all automatically loaded, and there is no need to re-debug on site.

Fourth, debugging high-frequency trampling, 90% of the projects have been encountered.
The marshalling forgot to open the feed into the Main L‑R.
The channel is assigned to the Group, but the Mains switch is not turned on, the marshalling signal cannot enter the main amplifier, the microphone is silent, and the novice is the number one fault.
Send the output of Main‑LR directly to the video conference host.
The main output contains background music, and the far end receives music, and AEC triggers the echo howling crazily. Video conference matrix, only pick up microphone grouping.
Double superposition of signals causes clipping distortion.
Microphone channels are grouped in Pan, and the channels themselves are sent directly to Main L‑R. The signal is superimposed at full level and the voice is distorted.
Correct way: the channel signal is assigned to the marshalling, which sends it to the main amplifier, and the channel is no longer sent directly to the Main‑LR.

Multiplex main spread EQ to matrix output.
Sound supplement, recording and video conference have different requirements for timbre, so the matrix must use its own bus independent EQ.
The number of analog mixer matrices is limited. Don't pile up functions.
The analog station has few matrix channels, giving priority to video conference+recording and broadcasting, and switching to AUX output for supplementary sound.
5. What site really needs a marshalling matrix?
Recommended configuration:

More than 3 microphones, with wireless microphone, video conference and recording and broadcasting requirements;
Multi-function hall, multi-mode switching of meetings and performances;
Multiple independent outputs are needed: sound supplement, recording and broadcasting, and video host.
Small conference room (12 microphones, only the main speaker): the income of marshalling matrix is very low, so there is no need to blindly pursue multi-bus digital mixer.

Grouping Group tube input, similar signal packaging unified control; Matrix tube output, realize multi-channel independent signal distribution.

Do government and enterprise projects, don't blindly pursue the more buses, the better. The routing is clear and convenient for operation and maintenance, which is far more important than the bus number on the parameter panel.

Remember an engineering formula:

Similar inputs are grouped, and multiple sets of outputs are used to find the matrix; Video conference only takes human voice, so don't mix it with background music.