If you have a digital mixer, you may be wondering, what is the best use of a matrix?
An audio matrix should be used anytime you need to create a slight variation of your main mix, like setting a crossover for your mains and subs.
An audio crossover is basically an EQ filter that enables you to split up an audio signal into two or more frequency ranges.
In other words, with a crossover in place, you can send only the low frequencies to your subs and everything else to your mains.
Modern powered speakers and amps will often have built-in crossovers. For example, on the JBL SRX828SP, you can use the little display on the back to program a crossover at 60Hz, 80Hz, 100Hz or even connect it to your network to select a custom crossover setting.
If your speakers don't have this capability, or you simply want to program it all from your mixer, an audio matrix is a great solution.
Although these are instructions for the Behringer X32, if your digital mixer supports matrix mixes, this should also translate to your mixer.
Step 1: Assign at least three matrix mixes to their respective outputs.
You will need to use at least three matrix mixes: Main L, Main R and Subwoofer. If desired, you can use four matrix mixes for a Sub L and Sub R.
On the X32, navigate to the routing screen and select the out 1-16 tab.
Find the output you are currently using for Main L (most likely Output 15). Set the 'Output Signal' to Matrix 1. Then, find the output you are using for Main R (most likely Output 16). Set the 'Output Signal to Matrix 2.
Finally, find the output you are using for your sub and assign the 'Output Signal' to Matrix 3.
Note: If you are currently using the same output as your mains for the sub, you will need to use an open output and connect your sub accordingly.
Step 2: Link Matrix 1 & 2
Matrix 1 & 2 will be used for Main L and Main R, so they need to be linked as a stereo pair. To do this, select Matrix 1, navigate to the HOME screen and push in the knob labeled 'Link'.
Step 3: Route the main mix to the matrix mixes.
Navigate to the HOME screen. Press the ‘SELECT’ button above the MAIN mix fader. Navigate to the ‘sends’ tab and bring the level up for 1, 2 & 3 (Matrix 1, 2 & 3) to 0dB.
Step 4: Bring the matrix faders up to 0dB.
Press the ‘MATRIX 1-6’ button and bring up the faders for Matrix 1, 2 & 3 to 0dB. Also, you will want to make sure all three are not muted.
Step 5: Apply a low cut filter to Matrix 1 & 2.
Matrix 1 & 2 are for the main speakers, so you'll need to cut out the frequencies that go to the subwoofers. To do this, select Matrix 1 and navigate to the EQ screen. Activate EQ by pushing the button labeled 'Equalizer'. Select your 'Low' EQ filter and change the mode to 'Low Cut'. Set the frequency to 100Hz.
Step 6: Apply a high cut filter to Matrix 3.
Matrix 3 is for the sub(s), so you'll need to cut out the frequencies that go to your mains. To do this, select Matrix 3 and navigate to the EQ screen. Activate EQ by pushing the button labeled 'Equalizer'. Select the 'High' EQ filter and change the mode to 'High Cut'. Set the frequency to 100Hz.
100Hz may or may not be the right frequency placement for your speakers. But, it will most likely be somewhere between 80-120Hz.
If you can't find crossover documentation for your speakers, experiment between the 80-120Hz range to find what sounds best.
There are several other good uses for matrix mixes. Check out your options in this post:
When to Use an Audio Matrix (and How To Set It Up on the X32)
I will be doing this tomorrow, actually.. We actually have flown subs (10-15"?), but have supplemented those with 2-18" JBL's.. Will the flown subs need to have their own L-R Matrix channels?
It all depends how you want to split up the frequency ranges. You could send everything 80Hz and below to the 18" subs and then 80-120Hz to your smaller subs. In this case, each set of subs would need their own matrix mix (but they do not have to be stereo). Only the mains need to be in stereo.
Or, you could send the same crossover to all of your subs. I'd experiment both ways to find what sounds the best. 🙂
Do you have a breakdown on this for any other digital mixers. We are running a QSC 22 channel. I will be looking in to it on my end.
Sorry, George. Only have a breakdown for the X32 at this time.
i just acquired an MGP 32X yamaha mixer but finding it a little difficult to synchronize it with my DXA PA. Can i get some assistance here
Hey Sipou - Wish I could help, but I am not familiar with the MGP 32X. Hope you are able to get it worked out!
Maybe this is a stupid question,
but what's the difference between EQing a separate main and sub matrix mix vs doing that same EQ just on the outputs for the mains and sub sans matrix?
Thanks!
Hey Ryan - great question! As long as you set the Sub Matrix to PRE EQ, this should work just fine. Actually, you have me rethinking that maybe this would actually be a better solution since it would free up two matrix mixes.
About to setup x32 crossover to split signal to tops and subs. Question: Does your technique in this article all sends on fader so we can set individual fader levels going to subs for bass, kik, and synth and exclude all other channels by leaving sends on fader faders off? Would this require setting up a mix bus and routing it to the sub matrix (3 in your instructions above)?
Hey Ken - If you are wanting this type of control, there is probably no reason to even set up the Matrix. You can just run everything you want to go to the sub through a bus, and then EQ that specific bus for your sub.
The matrix setup is for those who want a simpler setup where everything just runs to the main mix and then you split up the frequency spectrum into two pieces for your subs/mains.
Hey Kade,
Recently discovered this site and have found it as a great resource!
As an alternative to using Matrix mixes or busses, I've found routing the subs through the M/C output is a better fit to achieve this. Assuming you aren't using the M/C for a center speaker/array or anything else.
Utilizing the M/C for the subs will free up a matrix or bus. This method also gives you straightforward control of what you send to the sub, the same way you send something to the mains. Simply select the desired channel and use the Mono Bus button and knob located directly above the Stereo Bus button and knob. You can add your low cut on the Main LR and your high cut to the M/C.
*Make sure you select "M/C depends on Main L/R" from the setup -> config screen so that your sub volume follows your main volume.
This is genius, Daniel. Thanks for the tip!