Before the H5 and H6, the XLR preamps were quite bad and would produce noticeable hiss. Thus, I could never recommend connecting XLR microphones directly to the H4 or H4n.
But Zoom now uses a drastically improved, newer generation of preamps in all their recorders and interfaces since the H6’s release in late 2013. These are good enough to provide enough gain for most dynamic microphones and with very little hiss.
And that’s why the Zoom H6 is so great for podcasters! You can connect up to four XLR microphones directly to the H6. Each mic can have its own phantom power, pad, gain, compressor or limiter, and low-cut filter. That means you could even mix condenser mics with dynamic mics, since you can turn on phantom power for only the condensers.
You can use these mics in a studio or even for remote-location interviews with your Zoom H6 packed in a bag and an XLR cable connected to your hand-held mic. That's what I did for my interview videos at the 2015 NAB Show and New Media Expo.
If four inputs aren’t enough for your needs, you can purchase the EXH-6 Dual XLR/TRS Combo capsule to add two more XLR or TRS inputs! These, too, can have their own pad, gain, compressor or limiter, and low-cut filter. However, the EXH-6 does not provide phantom power, so you won’t be able to connect most condenser mics to the additional inputs.
Each of these inputs are actually combo inputs. They can accept a balanced XLR input, which is ideal for microphones, but they can also accept mono 1/4” balance TRS or unbalanced TS input, which is ideal for instruments and other devices.
To activate any of these inputs for recording, press the corresponding track button on the front of the H6 and it will light up to indicate it will be used for recording. The L and R buttons will be for the EXH-6’s additional XLR inputs, if you attach it.
The H6 will record each input separately into a project folder that’s created whenever you start a new recording. For example, if you connect and activate mics on tracks 1, 2, and 3, then you’ll get three mono audio files that contain only the audio from their corresponding inputs.
You can also make the H6 combine the tracks into left and right channels for separate stereo files. This would send track 1 to the left and track 2 to the right of one stereo file, tracks 3 and 4 to the left and right of their own stereo file, and the attached additional XLR tracks to the left and right of their stereo file. But you’ll still have separate stereo files, so you don’t have to worry about tracks 1 and 3 mixing into the same left channel of the same stereo file.
To switch between separate mono files or linked stereo channels, simultaneously press track buttons 1 and 2, or 3 and 4, or L and R. You can record in any combination of stereo and mono like this. But for most podcasting needs, you probably want the XLR inputs to be their own mono files.
Look at the display to see how your tracks will be recorded. When two tracks are in stereo link, you’ll see a single volume meter, one collection of effects icons, and the track numbers combined with a slash, such as “1/2.” When the tracks are mono, you’ll see them have their own volume meters and effects icons, and the numbers will be separated from each other.
Plus, when the tracks are in stereo link, you’ll hear the audio in your left or right headphones connected to the H6’s output. But when the tracks are in mono mode, you’ll hear the audio in both ears unless you change the pan for any channel.
The -20 dB pad switch for each input is more intended for recording loud sources, such as instruments or singing. For podcasting, I recommend you switch them to 0. Then, use the gain knob to find the right level for recording.
Ideally, spoken word should average between -12 and -6 on the track volume meter. If the audio goes all the way to the top, the light above that track button will blink, indicating clipping, which results in distortion. An occasional and half-second clip won’t completely ruin your audio, but it’s best to avoid any clipping. That’s where the Compressor or Limiter settings can help prevent that.
If audio clips for a longer time, the distortion will be noticeable and unrepairable.
These XLR inputs are not locking, so ensure your cables are safely out of the way from being yanked. Also ensure there’s enough slack in the line that the cables won’t be slowly unplugged from tension.