Sound Advice: Digital Mixer Features

Prentice TyndallIn my first blog article, Audio Mixers…Analog or Digital?, I discussed the differences between analog and digital audio mixers and how those differences would affect your choice in purchasing a new or replacement audio mixer.  In this article, as promised, I’ll mention a few of the features common to most digital audio mixers and how those features possibly leave their analog friends behind.

Presets

While this is, by far, the most common feature found on all digital mixers, it is worth mentioning, since I still talk with sound techs not familiar with this simple, yet powerful, feature.  For those that have never used a digital mixer, how would you like to have the ability to save all the settings on a particular channel, such as EQ, panning, aux volumes, group assignments, etc., as a preset that can be recalled later on any channel you wish?  How about storing the entire mix setup?  That is the idea of presets.  Presets open up a whole new way of mixing in the church environment.  As an example, you could create a channel preset for each of your lead vocalists and ensemble members.  The presets would include the settings tailored for each vocalist, and can be recalled onto any channel, as needed.  So, when Jane Doe, who’s channel settings are customized to her voice, is scheduled to sing lead on the big choir special for that Sunday, you simply call up her preset onto the channel for her mic and you are ready to go.  The EQ and dynamics settings for her voice are instantly recalled to fit her voice.

Until recently, not every channel parameter on a digital mixer could be saved within these presets or saved globally, primarily one common parameter: channel preamp gain.  Several digital mixers still have physical, non-digital preamp gain controls that are not saved within a channel’s preset.  The reason for this is simple:  Creating a variable preamplifier that is digitally controlled, and thus, saveable within the preset, would either significantly increase the cost of the mixer or seriously degrade the performance of the preamp.  So, most manufacturers chose to leave the gain adjustment as a traditional, physical, variable control.  But, fortunately, today technology has progressed where these channel gains can now be digitally controlled, and therefore, saved and recalled within the presets.

In addition to channel presets, digital mixers can also have many other types of presets, as well.  Since many sound techs have their own personalities and workflows, they like to set up the mixer to fit the way they mix.  All of these configurations and custom settings can usually be saved, as well.  Simply put, that means each sound tech that uses a particular digital mixer could set the mixer up as they prefer, simply recalling their own personal settings when they use the mixer.  Now, from an administrative point of view, this is probably not the best of ideas for most churches, but the features would certainly support this idea.  But, as long as the technicians are competent and familiar with the mixer, there is inherently nothing wrong with this idea.

Finally, the real power of presets can really shine through during a large production, such as a Christmas or Easter drama, or other large event.  The ability to pre-program mix presets, or scenes, that include fader volumes, mutes, aux settings, and processing, is a huge advantage over the typical analog mixer.  While quite a bit of work is required to get everything initially setup, primarily during tech rehearsals, it certainly takes the stress away from the sound tech during the actual performance or service, and will minimize technical errors during the event.  This feature is not just for large events, either.  Saving scenes for the sermon, the choir specials, the music worship with the band, and anything else would greatly simplify the changes needed between the different parts of a typical church service.  Note:  You may have used an analog mixer with scene capability.  Usually, scene memory on most analog mixers is limited to channel muting only.  On a digital mixer, scene functionality is not limited just to channel mutes.  All channel settings are usually saved within the scene memories, completely making scene memories a huge tool in your bag!

Routing

Another very underutilized feature that most digital mixers have is their tremendous flexibility in signal routing.  Many digital mixers have what’s generically known as a virtual patchbay that allows the sound tech to re-route inputs to different channels, and groups and auxes to different physical outputs.  There are many uses for this feature, but one of my favorites is when additional sources are added to a mixer during special events, such as a Christmas drama or music service that features new or additional musicians.  The routing feature allows the additional sources to be “plugged in” to any available input, but routed so they appear on the mixer in a logical order or numerical location.  Here’s an example scenario:

An electric guitarist, which is not normally part of the band, will be added to the audio mixer for today’s service.  The only available stage inputs in his area are inputs 18 and 19.  But, you really want him to be on the mixer’s channel 5 to be grouped along side of the other instruments.  So, you simply plug him into stage input 18, and on the digital mixer, route input 18 to channel 5.  Done.  Easy!

For a typical setup where their are multiple stage boxes distributed across a stage, this is normally the frustrating issue sounds techs encounter.  Some sound techs (guilty!) resort to physically switching the XLR connectors on the back of the mixer to remedy the issue.  But, this is not recommended due to the fragility of these connectors on the end of most snake fan-outs.  The routing feature of the digital mixer handles the issue, effortlessly.  So, now, save this alternate route as a preset for next time!

Integrated Audio Processing

On of my favorite features of the digital audio mixer, especially in a typical church sound application, is their integrated audio processing tools, such as equalization, dynamics, gating, delay, effects, and others, depending on make and model.  With a traditional analog console, a properly outfitted sound system would include a rack or two of outboard analog and digital processing equipment, such as a few audio compressors, a few channels of gating, a couple of parametric equalizers, several 31-band equalizers, and a couple of effects processors, just to get you started.  This setup, which is not commonly found in most small to medium churches simply because of the costs, can now be found included within the digital audio mixer.  And, even better, many digital mixers have enough audio processing to be utilized on every channel, if necessary.  Even analog setups with several racks of outboard gear can’t compare in numbers to what’s available in the typical, late model digital audio mixer.

Another popular trend in digital audio mixers is the implementation of analog modeled hardware as software plug-ins.  These plug-ins are designed to mimic the characteristics of popular outboard hardware, such as audio compressors, equalizers, effects units, and even guitar stomp boxes and amplifiers, and many other devices!  Plug-ins are common in the recording studio and have now migrated to live sound.  While, arguably, they are not the sonic equivalent of having the real outboard devices, they are certainly much more cost effective and obviously much more reliable.  And, the plug-ins usually allow several instances of the same device, up to several on each channel!  So, the advantages, here, outweigh the disadvantages, for most cases.

Remote Control

An awesome feature of many digital mixers is remote control via a tablet, smartphone, or computer.  If there is any feature that could sell itself, this has to be it.

How would you like to sit on the fifth row in the audience and completely control the sound?  Well, you can!
How about controlling the audio mixer that is installed in the rear of the sanctuary from the stage?  Well, you can!

How about… Well, you get the idea.  Many current generation digital audio mixers need only the addition of an inexpensive wireless router, such as used in a home wireless network, to open up wireless remote control to the mixer.  Many manufacturers, such as Mackie, Presonus, and Behringer, offer free apps for the iPad or iPhone.  Some offer additional apps for Android tablets and phones, and Windows and Mac computers.

Several manufactures are now making digital audio mixers that don’t even have a traditional control surface.  Presonus and Behringer come to mind.  For these new generation of audio mixers, a remotely connected device must be used to control the mix.  This saves on cost, especially if you were planning on using a remote device, anyway.

Networked Audio

P16 Personal Mixer
Behringer P16 Personal Mixer

Another popular trend is the ability to eliminate installing a traditional snake from the stage to the audio mixer.  With today’s digital mixers, a digital stage box can be used to send audio to the digital mixer via a single ethernet cable, as opposed to a bulky audio snake.  Using special audio networking protocols, this digitized audio signal from the stage box can also be delivered to personal monitor mixers and other digital mixers.  Since the audio has been converted to a digital signal, it simply makes since to keep the audio in the digital domain until we need to convert it back to analog, which is usually right before the power amplifiers and/or speakers.  This includes the distribution between the stage and mixer, the monitoring system, and any additional mixers that may be employed for recorded audio (such as for television and live web streaming).  Now, some protocols used to distribute audio are proprietary and only work with like-branded equipment, while a couple protocols are compatible across different brands of equipment.  Be careful when planning a system install relying on digital audio networking.  This is usually a very advanced task requiring professional guidance.

Other Features

Password Protection – Most digital mixers have some form of password protection that can be enabled to prevent unauthorized use of the mixer.  Many of them also offer tiered access, where users can be created with different levels of access.  For example, some users could log in and make simple volume changes, but may not have access to change equalizer settings or other advanced settings.  Those settings would only be accessible to “super users”.

Integrated Recording – Want to multitrack record a service for post-mixing?  That’s an easy task on many digital mixers.  Simply insert a flash drive or external hard drive to the USB port, enable the feature in the mixer’s settings, and record!  Some digital mixers also will operate as an audio interface when connected to a Mac or PC.  Now, you can use your favorite DAW (digital audio workstation) software to record, edit, and mix a church service for later web delivery, CD’s, or even audio for video.

Auxiliaries & Busses – Are you out of aux outputs on your current analog mixer?  Many digital mixers offer plenty of additional outputs not found on analog mixers near their price range.  There are also eight or more busses and matrices found on most digital mixers.  For the church environment, this is great news.  Now, you have enough auxes and groups to handle stage monitors, in-ear monitors, and plenty of other aux feeds.

Conclusion

Well, there you have it.  I’ve scratched the surface of some of the features that make digital mixers great for the typical church installation.  There are many other features that vary depending on brands, models, and price ranges.  But, the features I’ve mentioned here are my top reasons they are the ideal audio mixer for the typical church installation.  Are there disadvantages to digital mixers?  Sure there are.  But, most of the disadvantages are minor, in comparison.  Many complain about the learning curve required by some digital mixers, but, in my opinion, the advantages they offer are worth the time to learn.

In the next article, I will start discussing some practical tips on mixing live sound.  For starters, we will look at all of the different signals coming into our mixer and how to properly handle each one.  We will also talk about how to set the channel gains for these signals, a very important first-step in properly setting up a mix.  So, thanks for reading my articles.  Spread the word and get interested individuals to subscribe to this blog.

Prentice Tyndall

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