BEHRINGER Tech Talk #03: Subgroups and DCAs
The X32 features 8 DCA Groups which help make mixing easier by giving you the ability to control the volume of a group of channels with a single fader. This Tech Talk will explain how DCAs work, why they are different from Subgroups, and how you can use the two together for an easier mixing experience on the X32.
DCA Defined – DCA is an acronym that stands for “digitally-controlled amplifier”. Some manufacturers still refer to these groups as VCAs, which is a term from the analog days referring to “voltage-controlled amplifier”. DCA or VCA, the concept is still the same. They both allow you to use a single fader as a remote control to control the volume of multiple channels simultaneously, while maintaining their proportionate levels.
Before DCA/VCAs, or on smaller format consoles, “subgroups” are provided for the same general purpose. The difference is that rather than acting as a remote control, subgroups actually SUM the audio coming into it, just like your main Mix Bus does. Because the individual channels in the subgroup are summed together, group processing such as EQ or compression could be applied across the group and the resulting signal can be metered. This is not possible with DCA/VCA groups, because the audio is never actually being added together (until it gets to its’ destination such as your main mix bus). This also means that 2 buses/groups are required for each group if working in stereo, (one each for left and right). A huge benefit of DCAs is that you are not wasting 2 mix buses for such control.
So on a console like the X32 where I have DCAs and the ability to use Subgroups, how do I know when to use which?
Case 1 - I only need to control the volume of multiple channels simultaneously, such as all of the mics on a drum kit. All EQ and Dynamics processing is taking place in the individual channel strips and no group processing is needed.
Use a DCA - You can assign as many channels as needed to a single fader while maintaining a stereo image. Also, the 16 mix buses on the X32 remain free for other uses.
Case 2 - You are still creating a drum group, but this time you want to apply a EQ across all of the drums to brighten or darken them a bit OR you need to send all of the drums to a pair of channels on the P16 Personal Monitoring system.
Use a Subgroup - Utilize a pair of buses to create a stereo subgroup. You will need to be sure that the subgroup is assigned to your Main LR mix, and that the individual channels are not. Otherwise, the pre EQ and post EQ signals would mix together, which would probably not be desirable.
Case 3 - Lets say that in addition to the stereo drum group from the previous case, we have created a stereo group for all background vocals. We also have 6 DCAs setup for other instruments, and would like to control the subgroups for drums and background vocals on the remaining 2 DCA faders. This would allow for total control of the mix on the 8 DCA faders, even when using subgroups.
Solution - Assign Subgroups to DCA - You can do this by viewing all 16 buses on the input faders (using the BUS MASTERS layer). This allows you to easily assign mix buses to DCAs just as you would do for input channels. You can assign both mix buses for each subgroup (left and right) to a single DCA.
Note that DCA groups can contain both individual channels and subgroups simulataniously. Remember that when using mix buses in subgroup mode, the channel sends to those buses are "post fader". This means if you have channels assigned to a DCA and you change the level of the DCA, the level of the signal going to a subgroup, (or any post-fader mix bus), would also be affected. If this is not desired, such as when applying processing such as parallel compression, I would suggest using the "pre-fader" option rather than "subgroup" when sending channels to a bus, (as these sends would NOT be affected by the DCA).
By properly utilizing the DCA groups on the X32, you can make the most out of the 16 buses for other needs such as monitor mixes or FX sends. If you have any further questions on this topic, feel free to ask us here.
Senior Specialist, Product Support
I'm not a member of the specialist team, just a member. But maybe I can help. Be assured that those on this forum (especially the Behringer specialists) will correct anything that say that would be misleading.
First of all, you can't send subgroups or mixbusses to other mixbusses. These can only be sent to matrixes. If what you are planning on doing is to mix a number of drum channels to a stereo pair subgroup, then mix that with other inputs to various monitor feeds, then matrixes are the only way to go. Unfortunately since subgroups are always in pairs (L & R), you would have to link 2 matrixes in order to keep the stereo signal. But there are only 6 matrixes, so they would be used up rather quickly.
Monitor mixes are usually mono in nature (except for IEM applications). So there is probably no need to use the stereo subgroup. Instead send those drum channels to a mixbus. Make another mixbus of say the vocals, and maybe another mixbus of say guitars, etc. then send each of those mixbusses to a matrix for each of the monitor feeds (max 6).
Hope that helps
Joe Sanborn just posted a webinar announcement (Thursday 12:00pm PST) on the first thread of this section, that will be explaining mixbusses, etc. Joe and John do an excellent job in these webinars in explaining various topics using both visually, audibly and Q&A. Each one I've attended, I've learned a ton.
right the moment I postet my question I had exactly the same solution (by using matrixes). It's great to be confirmed by your quick answer (thanks a lot for that).
Seems even an absolute amateur, who only "learned" mixing via video-platforms and forums, can handle an X32 an get really good results. (another) big compliment to all the brains of Behringer!
Also thanks to Paul for the hint with the webinar!
Thank you Paul for the kind words on the Webinars, I hope you can both make it on Thursday. One correction on the time, this Thursday's Webinar is actually scheduled for 10AM PST.
Thomas: While Paul is correct that you cannot send mix buses directly to other mix buses, there is a workaround IF you have a pair of extra input or AUX channels available. Select a channel/aux and press the VIEW button near the CONFIG/PREAMP section of the channel strip, which brings you to the "config" page for that channel. Here, you can use the 3rd rotary encoder to select the source for this channel. As you scroll through the options, you will notice that you can choose any of the 16 buses as a source for a channel. Select the bus that contains your drum group for the source. This creates a virtual patch from the output of the selected mix bus to the input of the channel. With the signal now on an input channel, you can send it to another mix bus for a monitor mix.
*NOTE: By default, all input channels are assigned to the STEREO BUS. You will want to make sure that the channels you are using for this are not going to the stereo bus along with your drum group.
Hope it helps!
Senior Specialist, Product Support
Thanks John for replying. I'm going to try and make it. But my wife and I are currently vacationing in the Smokey Mountains and the internet is iffy at best.
Regarding your suggestion for rerouting alternative, my first reaction was Wow, unbelievable. I had not clued in that you could convert a mixbus to a channel input that way.
Thanks John for the great workaround with re-routing the bus back to intput/aux and send them (stereo bus deactivated for these input channels) to the monitor mix. I will use it that way.
It's absolutely fascinating how versatile this mixer is.
I will follow your webinar afterwards by watching on youtube ASAP (unfortunatelly will be in office at live-time).
Please keep up with your great work close to your customers. I'm getting a bigger fan of yours with every day.
Also a big THANK YOU to Paul, who helped also a lot with his posts. Enjoy your vacation, hope to hear from you again.
Thomas /Germany, Thuringia
Glad to be of help. And good news - I'll be able to attend the webinar tomorrow. We have moved from the cabin to a condo (still in the Smokeys) with dependable internet. And my wife has given me permission to take the hour for the webinar. All is good!!
Here's a nifty use for DCAs "coupled with" groups: http://www.youtube.com/watch?v=MMMmR1u0CFk
Originally Posted by John DiNicola
any idea when this webinar will be available on youtube?
Thanks for any replies.
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