Podcast Mixers (As General Audio Production Tools)

The release of the Rodecaster Pro marked a pivotal moment in audio production. It is a small audio mixer with integrated vocal processing, two ways to integrate cell phone audio or web meeting audio, multiple headphone outputs and big pads for triggering pre-loaded sounds. Broadcast mixers designed for radio stations have always been expensive and often complicated to install. There were very few affordable devices with that kind of capability, designed specifically for creating a radio show or podcast. Since the Rodecaster Pro was released, several similar devices have been produced by other companies, each with strong and weak points, but all offering similar design and operation. The Zoom Livetrak L8  and L12, Podtrak P4  and P8, and Tascam Mixcast 4 are clearly all targeting the same market.

General purpose audio mixers can be configured to do most things required in radio or podcast production, but some functions remain complicated, and usually require additional equipment. Applying compression, de-essing, and other processing to microphones, integrating phone calls or internet chats, providing multiple headphone feeds, triggering pre-produced audio clips, and feeding audio to and from a computer, are all handy tools, and used to be difficult to configure. But podcast mixers simplify many of these functions, which can be useful for more than just recording a show in real time.

A certain style of podcast has become a cliché: a host, a sidekick, a guest or two (either in-studio or remote) some perky theme music, and a sponsor spot. The program sounds like it’s done in real time, as though live on the radio, and features relatively unstructured participant interactions, rather than a strict Q & A between a host and a guest. Podcast mixers make this style of production easy, with multiple microphone inputs and headphone outputs, integrated cell phone and internet audio inputs, sound pads for triggering recorded sounds, and both internal recording and a feed to a computer.

To be blunt, we’re not huge fans of this style of program, and at first, thought devices designed to create that kind of production wouldn’t be that interesting to us. Of course this style of show has its place, and there are good programs made this way, both radio shows and podcasts, but they can sometimes feel half-baked and haphazard. We generally encourage more intensive editing — finding ways to tell the story more effectively, perhaps changing the order of comments to enhance clarity or drama, possibly inserting narration written after the fact to move the story along and add background, maybe adding music or ambience to underline the dialog.

If you produce in a nonlinear way, you may have written off these podcast-oriented mixers, which are clearly intended to make a real-time production flow more efficiently. But these mixers can be very helpful in many ways, so you might consider getting one, even if you don’t have a wisecracking sidekick, or a panel of pundits, or need to insert a funny sound effect or theme song in real time.

At about $600 USD, the Rodecaster Pro represents a significant investment, but it remains one of the most fully-featured of all the options, with large volume faders that make mixing smoother, extensive sound shaping capabilities, and both Bluetooth and TRRS phone inputs on dedicated input channels.

The Tascam Mixcast 4 is the newest model at press time, and has the same list price as the Rodecaster Pro, but generally sells for about $550. Its capabilities are very similar to the Rodecaster’s, with nice volume faders, a slick touchscreen interface, dedicated bluetooth and TRRS hard-wired phone inputs, and flexible voice processing. One notable innovation is the display of names of the sounds assigned to the eight sound pads, so you don’t need to memorize which sound is where, or use a clunky paper overlay.

Zoom offers a wide range of devices, and we’re especially fond of the usefulness-per-dollar of the smallest, most affordable option: the Podtrak P4, which sells for about $220. It has no volume faders, only input gain knobs, very limited voice processing, a minimal screen, and only four sound pads, but it’s small, can run on batteries, and can handle four XLR mics, four headphones, and provide a useful interface with telephones and web chats.

The Zoom PodTrak P8, at $550, offers six XLR inputs, short volume faders, a much better display than the P4, and slightly better voice processing. But in that price range, both the Rodecaster and the Tascam Mixcast 4 outperform the P8, so unless you need all six XLR inputs, either the Tascam or Rode would be a better choice.

The Zoom LiveTrak series inhabits a space in-between the podcast workstation and a more conventional mixer. They offer many of the same functions, with multiple mic inputs and headphone outputs, cellphone and web chat interfacing, and sound pads, but the input channels are more flexible, with XLR/quarter-inch combo inputs. stereo panning, and more extensive plug-in processing. The LiveTraks are worth looking at if you’re integrating musical content, or other inputs that need more flexibility than mono XLR-only inputs with voice-focused processors. The Livetrak L8 sells for about $380, and has six XLR/quarter-inch combo inputs, plus dedicated cellphone and USB channels. At $650, the LiveTrak L12 is the most expensive of this style mixer, but it offers eight XLR/quarter-inch combo inputs, which is likely more than you’d need for most podcasts, but could be very handy if you were including some simple musical performances, or audience mics, or other more complex scenarios.

Here are some strengths of podcast production boxes:

Stand-Alone Operation 

Any of these devices can operate without a computer, recording directly to internal SD, or Micro SD, cards. This can be very convenient for recording outside of a studio environment, like in a conference room, or even if you want to track your voice alone in a closet. Although these boxes are replete with multiple inputs, you can also just use them like a field recorder to record a mic or two.

The Rodecaster Pro and Tascam Mixcast 4 do not operate on batteries, but the Zoom versions can operate on AA batteries, or with a USB-C power bank. While most of them are a little too bulky to use regularly as portable field recorders, being able to run the Zooms on batteries opens up even more possibilities for recording locations. Tracking narration in a closet might be easier without worrying about finding an electrical outlet. You could record in a car. Background ambience would likely be distracting, but you could record outside, or on-the-scene at events. Though a conventional field recorder might seem a more logical choice for this purpose, it’s rare for those recorders to offer a chain of vocal processing that can give the voices you record a professional sheen, quickly and easily.

USB Interface

While these mixers can be self-contained production workstations, they also can serve as USB interfaces that connect microphones to your computer. Even if you don’t need telephone recording capabilities, or sound pads, or multiple microphone inputs, you probably do need a USB interface. There are cheaper and simpler USB interfaces, such as the Focusrite 2i2, or the Audient evo4, but it’s very convenient to have an interface that can record a backup copy of whatever you’re sending to the computer on its own memory card. That may be overkill for some circumstances, but for an interview that would be impossible to repeat, or that is needed right away, having a backup copy can occasionally save the day. And as mentioned above, these mixers can add voice-enhancing processing that’s not generally available on standard USB interfaces.

Note: not all models work as true multitrack USB interfaces that can feed each input as a discrete track in your computer editing program.

• The Podtrack P4 and P8 can only send the mixed stereo output to a computer in real time. They DO make true multitrack recordings, with each input recorded to a separate file, but they only save those files to their internal memory cards. Those individual files can be transferred to your computer for detailed editing and mixing, but you can’t record a multitrack session on your computer in real time with the Zoom Podtrack models.
• The Rodecaster Pro, Zoom LiveTrak series and Tascam Mixcast 4 can stream individual tracks over USB to a multitrack session on a computer workstation.
• The Tascam even ships with a proprietary multitrack editing program for your computer.

Microphone Input Channels Designed for Voice Recording

The XLR mic inputs on these devices have enough gain to use popular dynamic mics, and feature spoken-word-oriented processing that enhances warmth, presence and clarity, often via helpful presets. Most have basic settings for EQ, compression, de-essing and more, that don’t require intimate knowledge of how to tweak the parameters. Most of these devices will also allow you to get “under the hood” and make fine adjustments if you desire. Unsurprisingly, the larger, more expensive units give you more sophisticated options, but even the tiny PodTrak P4 offers a low-cut filter and a limiter on each mic channel. Trying a few presets can be a quick and easy way to get a good vocal sound, without additional outboard gear, or wrangling plug-ins in your digital editor. It’s a nice change of pace to have a device designed to record spoken word, rather than singing, or musical instruments.

Multiple Headphone Outputs

All of these mixers feature at least four separate headphone outputs, each with its own volume control. Even if you’re not recording a panel discussion, this feature can be handy for listening with someone else while mixing. When working alone, it can be useful to have more than one set of headphones connected, for the sake of comparison. Using multiple types of headphones, perhaps one set that’s open-back and another that’s closed-back, one set of inexpensive earbuds, just like using multiple sets of speakers, can help when mixing by comparing the way things sound in different playback environments. Different headphones will require different amounts of amplification, and all these mixers offer separate volume controls for each headphone output. It’s great to not have to spend the money, or use up space, for a separate headphone amplifier. This isn’t a replacement for a dedicated monitor controller or high resolution headphone amplifier, but it’s better than unplugging and re-plugging in a single output jack.

Telephone Integration

We’ve published articles documenting the difficulty of recording telephone calls. It has always been a complicated process to get clean audio from a telephone call, and it’s even more complex to get more than one microphone routed back to the phone, so the caller can hear more than one person talking to them. Configuring phone audio connections often requires expensive and complicated external devices, and dizzying “mix-minus” routing on a mixer. These podcast mixers will ONLY interface with cell phones — none of them offer interfacing with landlines — but as analog phones become less and less common, cell phone connections are more practical anyway. Many of these mixers allow wireless connection of a cell phone via Bluetooth, or by a TRRS cable. The cable always sounds better, but may require an adapter when using many phones, iPhones in particular. Bluetooth is easier, but tends to have noticeably lower audio quality. The Zoom mixers require an optional Zoom BTA-2 Bluetooth adapter to connect to a cellphone wirelessly, but again, we encourage you to use a hard wire when you can, because the audio quality is better.

The “mix-minus” routing is handled automatically, so callers can hear any sources routed through the mixer, and will not hear an echo of their own voices. This one function can make these devices worth purchasing: even if it’s a simple phone conversation between two people, it’s a relief to be able to get a clear, noise-free recording, quickly and easily. The Podtrak P4 serves that role in our studio at Echoes: an easy telephone interface, or backup recorder of web chats. We never use the additional microphone inputs or sound pads, and find it totally worth the $220-ish.

We generally prefer the interviewee be recorded on a good microphone, rather than using the constricted sound coming over a cell phone, but sometimes a phone connection is the most practical option. Audio producers often utilize a “tape sync” or “double-ender” to get good quality audio, even if the interviewer and interviewee cannot be in the same room at the same time. The conversation takes place over the phone, while an audio engineer records the interviewee (on site) into a stand-alone recorder using a good microphone. Or perhaps, especially in the event of difficult situations like a pandemic, interviewees record themselves. That resulting audio is sent to the producer and synchronized in a computer editing system. Even when recordings are made locally, the phone audio can be a lifesaving backup in the event of a technological failure. This happens more than you might expect, especially if interviewees are doing everything themselves: recorders malfunction, or sometimes people just forget to hit “record.” Microphones or cables could be defective, or picking up interference. Audio files can get lost or corrupted.  So it’s a safe practice to make your own copy in case of disaster. It’s also handy to have a recording of your questions on a good microphone, along with your interviewee’s answers, in-sync, which makes it much easier to line up the audio file they send you.

Cell phone audio will always be lower-quality than a good mic straight into a recorder, but it still can be useful in several ways.  Here’s a brief clip of audio from the PodTrak P4, with me on a Shure SM-7B microphone, setting-up a session over the phone where the interviewee was recording himself. We didn’t end up needing the cellphone audio, but it was reassuring to have the backup, and ultimately made syncing all the files easier. 

Web Meeting Recording

In recent years, more and more interviews are conducted remotely over a computer-based conferencing application, such as Zoom, Skype, Google Chat, Microsoft Teams, etc. Ideally, one can make a high-quality recording on site, rather than relying on the reduced-quality audio that comes over the Internet. That can be achieved through a tape sync, as described above, or by using certain web-based applications, such as Riverside, Ringr, Zencastr, and others. Those programs record audio locally, and automatically send those audio files to the producer.

However, even when making a high-quality recording locally, it’s ALWAYS a good idea to record the real-time conversation, just in case! Tinny telephone audio, or gurgle-y web chats are not ideal, but they’re better than nothing. Most web conferencing applications have a way to record the conversation, but as mentioned above, in the real world, things sometimes go wrong! It’s not uncommon for a local recording to fail for any of several reasons, so having your own recording of the web chat can sometimes save the day! Even if you don’t need that audio for your final production, it might be helpful to use for transcription or for doing a rough edit before you receive the high-quality recording.

Live Event Mixing

Before the pandemic shut down live events, onstage storytelling events were very popular, and hopefully will be again! While these devices are not designed for live audio, and lack some features that can be helpful in live events, such as aux feeds for monitor mixes, they still could work quite well in a typical storytelling event. The multiple mic inputs can be used for an emcee or host, with a separate mic, or mics, for people telling stories. Theme music and pre-produced audio segments can be loaded into internal memory, and triggered by the hardware sound pads. The microphone channels on these mixers are generally mono only (although the Zoom L-series mixers can pan any of the channels to the left or right.) This is usually fine for live productions. Pre-produced audio triggered by the sound pads can play back in stereo if desired, and the hardware cell phone input, which uses a mini TRRS jack, can handle stereo sound, either from a phone, or from any external playback device, with some simple adapter cables. All these mixers have a USB playback channel too, which can play stereo audio from your laptop, perhaps from a DJ software program. Connect some speakers to the audio out, and you have a simple PA system, with easier-to-use voice processing capabilities built-in than many live mixers provide.

Even better, these devices can record your event, each input to its own channel, so you can readjust the levels if you want to make a podcast or radio program out of it. As mentioned above, you can record to internal memory, or to a computer. (Remember: the PodTrak series can only send the mixed audio to your computer, but the others can send multitrack audio into a recording program, such as Pro Tools, REAPER, Audition, Hindenburg, Logic, etc.)

Radio or Live Audio Streaming

As mentioned above, most of the input channels on these devices are mono (except for the Zoom L-series) so they’re not ideal for connecting turntables or CD players, but the USB or TRRS inputs can feed audio from your computer, or an external device. XLR microphone inputs provide convenient voice processing for a host and guests if desired. If the TRRS channel is not being used for audio playback, it could be used to route a phone call to the mix. If the USB channel is not occupied playing back audio, it can be used to patch in a web-based chat.

Instead of connecting the outputs to speakers for a live event, they could be connected to a transmitter, like any radio production board would be, or the USB output from the mixer can be routed to an internet streaming service on your computer. These devices are not as fully featured as a typical broadcast mixer, but they’re smaller and less expensive, and can be enough for simple productions.

In Conclusion

Although these devices are targeted toward podcasters, making conversational programs with multiple guests, they can also be useful tools for many other tasks. If you simply need a way to record a phone call, or a web chat, one of these boxes can make that very easy. If you have desk space, and can afford them, the larger mixers offer more options, larger faders, better preamps, and most important, larger screens and buttons that make operation easier, but even the small and affordable PodTrak P4 does a remarkably good job of recording phone calls and microphones. It’s always good to have some extra options, just in case unexpected circumstances arise.

They often do.

All Transom “Tools” column reviews are independent reviews of equipment we buy ourselves. When you purchase items by clicking the affiliate links on this page, Transom receives a paid commission from either Amazon or B&H.

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