Building a Project Studio – The Basics (Interfaces)

Sorry for being away a little longer than planned. Vacations tend to get in the way of these things.

So, now we come to Interfaces, Converters, and DAWs. These can be very contentious topics that don’t really need to be. We have more, higher-quality choices than ever, regardless of the platform you want to use.

What’s the problem with pro-sumer interfaces?

I think the trickiest thing to deal with here is that the difference between pro-sumer and professional interfaces can be fairly big, not only in price, but configuration. The actual quality of the converters is debatable. There are quality differences, to be sure, but how big those are versus how much you want to spend – or how much you’ll be able to hear – are up to you.

So, what’s the configuration difference to be concerned with?

Here’s the deal…with most pro-sumer interfaces that have more than a 2-in, 2-out configuration, there will likely be a pair of “main outs.” Okay, that seems normal, so what’s the problem. Well there are multiple possible problems.

How does the controller software handle routing?

I’ve run into this on many different interfaces, but particularly ones that route “inside the box” or inside the interface without coming to the host computer. This capability is great for low-latency mixing. However, let’s say for a minute that you’re recording on a fairly fast rig that already has very low latency. Also, let’s say that you are using your main outs as your cue mix for the vocalist (or guitarist, or drummer, …). Well, on a set of interfaces I was using in a studio recently, we kept having this doubled vocal going into the voice artist’s cans. We tried a ton of different things only to discover that not only was the DAW routing the vocals to the main outs, as expected, but also that the interface was routing them to the main outs, causing an ever so slight phasing. So, now, in order to get around this, we have to mute the track in the DAW, then switch to the interface’s controller software and ensure the track is unmuted and routed correctly, and then it will appear in the cans properly. What a pain!

Unfortunately, this isn’t something that’s easily tested unless you can plug up in a studio and do your thing. However, this is a common (perhaps, the most common) scenario, and it doesn’t make any sense that the interface developer didn’t take this into account. That’s just poor design on some fairly high-end pro-sumer units. So, what am I going to do? I’ll take the extra outputs on the interfaces and run individual cue mixes. It’s still not perfect, as the cue mixes will all have to be set individually, but we do what we must.

Okay, what about the concept of “Main Outs”

The concept of Main Outs is not a bad one for stereo mixing. That way you have a devoted pair of outputs that doesn’t interfere or take away from your I/O count. However, if you decide to mix in a multi-channel format, the interfaces may not work the way you expect. For instance, the interfaces I mention above work well when you chain them together. If you need more I/O, just add another interface. That’s great thinking…except, only one set of Main Outs can be used.

You might say, “Well, just use some of the other outs for your surrounds or whatever.” Yeah, that’s not as easy as it seems. You see, many DAW manufacturers make certain assumptions about which outputs are going to be your main stereo pair. Switching off of those is possible, but it seems to bite you in the butt more often than not. They will tend to assume that the first pair of outs is your main pair. Also, individual apps don’t always check to see which set of outs are stereo and which set are surrounds. Thus, you’re always fighting your apps to get them to send audio to the right set. Often, they’ll just send to the first two. Again, bad design, especially since Mac OS X has had all of this built in and available for a looooong time.

What other flexibility in configuration are we talking about?

Well, while it may be a significant step up in price, the higher end units give you some extreme amounts of hardware configuration flexibility. Take, for instance, the Apogee Symphony I/O hardware. Basically, you choose a chassis and a configuration of daughter cards. Each chassis holds 2 cards with a maximum of 32 channels of 192k/24bit audio in either analog or digital format. Multiple chassis can be combined for up to 64 channels via Thunderbolt. If you’re using them with ProTools, it depends on your ProTools rig.

For me, I initially chose the 2×6 configuration, then augmented it with another chassis to get 16 more analog I/O channels and a bunch of digital I/O. Each chassis is basically empty, and you choose which cards to put in there. Now I have one knob to control the volume of all of my surround output. Also, the Apogee Maestro 2 software, while being far from perfect, allows me to rearrange the I/O into any order I want. So, for instance, I have the 16 analog input channels of my second unit actually appearing first in to the operating system, followed by the 2 on my first unit. This is just for simplicity. As for outputs, to alleviate the issues mentioned above with non-pro audio apps, I have arranged my outputs such that the first six are for stereo and surround, followed by the 16 effects sends. After all of those, the digital ins and outs are grouped across cards, for convenience. Now that’s flexibility. Granted, it came with a cost, but I love them.

In Summary…

So what’s it gonna be for you? Do you need extreme flexibility? Do you need to to mix in multichannel? Do you need your interfaces to do double duty as mixers? Let’s tackle these questions next.

How do you need to mix live instruments?

Mixing with hardware doesn’t require a computer!

Do you have a mixer that’s handling that massive rack of effects and synths? If you do have a mixer or the space for one, it will likely be less expensive to use that to handle live audio than using an interface as a mixer. However, the mixer may put some constraints on you that you don’t expect.

  1. Are you working in multi-channel? If so, your mixer needs to handle it.
  2. Are you using your mixer to control volume and selection of your monitors?
    • If so, you’ll need to have extra inputs for feeds from your interface.
  3. Are you using your interface or other module to control your monitors?
    • If so, you’ll need extra inputs to take feeds from your mixer

What about a summing box instead?

A quick side note is that if you don’t need a flexible, per-channel mixer, you could just use a summing bus to take all the channels of live audio and sum it to a stereo bus. They’re not always inexpensive, but they typically keep the audio quality high and may be less expensive than a mixer.

Will mixing “in the box” (in the interface) work for you?

While it requires that your computer be on to hear your instruments, the flexibility of mixing “in the box” is unsurpassed. You also don’t need to have the extra space for a mixer. The downside is that you need a lot of inputs.

Used to be that this option was not so great, as latency was a problem for recording in realtime (like recording guitars); however, with the newest generation of Thunderbolt interfaces like the Apogee Symphony, roundtrip latency has dropped below 2ms, well below temporal fusion, the point at which two sounds appear as the same.

Monitor control is your last big choice before the interface

It’s worth calling out here a piece of much forgotten gear in the project studio…monitor control. I mentioned this above in the mixer section, but I didn’t go into detail. Monitor control is a bit of a luxury item, but it quickly becomes more necessary when you have multiple sets of monitors. For instance, if you’re fortunate enough to have the room, you should really consider having two or more sets of monitors, near-field monitors, mid-field monitors, headphones, and small “Radio Shack” computer speakers. You can use these to ensure your mixes stand up in the majority of playback environments. As you can tell, this means that manually switching cables around would be a nightmare, thus…monitor controls to the rescue.

Keep in mind that if you’re mixing in multi-channel, this could get a bit expensive, so you may want to handle it in the box, like I’ve done. In time, though, when I have the space, I’ll definitely be looking for more-convenient solutions.

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