"Can you turn up the Warmth?"
It seems like every piece of studio equipment these days is promising to add "warmth" or to "fatten" your tracks. Log on to any online recording forum and you'll quickly realize that this is a hot topic - particulary with manufacturers trying to sell new gear and less experienced engineers trying to improve the sound of their tracks. The more experienced engineers seem to find either frustration or humor (or both) in this never-ending quest for warmth by the masses... The word has become so overused that it has almost become meaningless.
Don't fall for marketing hype!
If you believe that there is a magic box of some kind that will suddenly make everything you touch turn to warm and full sounding gold records, you are being foolish. If you actually believe that something will sound full, fat, and warm just because it has a tube in it, you are being naive. Some manufacturers have realized just how naive and technically clueless many people are and if they tell you it is warm because it has tubes in it, the masses will blindly believe them. NEWS FLASH - wiring a tube up so that it glows a little and putting it in a piece of gear doesn't mean anything. Unless it is done right, you might as well just have a plain old fashioned light bulb instead, as sometimes, the tube does nothing more than look cool and give them something to talk about in their marketing literature.
So, when someone talks about warmth, what are they really talking about. This must mean using tube mics, preamps loaded with tubes and transformers, using the best converters, and using analog gear during mixing instead of working in the box. Ideally, you'll have a 2" tape machine of course. Right? Not necessarily. Before you start maxing out your credit cards...
Let me tell a little story to make a point...
I recently worked on a project for a band called "Barry Betts and The Cheaters". The album was tracked and mixed at Jarico Studios in Rockford, IL., and referred to me for mastering. I know these guys well. I know their recording system in detail, know how they like to work, what they normally work on, and what their "sound" is. I know that they consistently turn out one great sounding mix after another. Even so, I was a bit surprised when I listened to the tracks from their latest project. It sounded "classic" and "modern" at the same time; clean, warm, and full, with great clarity, no noise, and great dynamics. Honestly, it sounded like an album tracked in a vintage studio, but with better clarity and no noise. While everything Jarico Studios does seems to turn out great, this project in particular had a nice tone and warmth with it that was beyond what I was used to hearing on most "modern" projects.
I questioned Head Engineer, Matt Zilm, on his approach to this project. He acknowledged that a significant factor was the musicians themselves: "These guys have a ton of studio experience and they really knew what they wanted the individual tracks to sound like, so the "vintage" sound happened very naturally." He also noted that their instruments and amps "lent themselves very well to getting that vintage sound.". When recording the band, Matt spent a great deal of time selecting the proper microphones and getting the right mic placement in order to get the sound that they were after right from the start. When it came time to mix, there was very little EQ needed on the tracks, and what EQ was done, was mostly subtractive. The results of this careful attention to detail up front, and conservative mixing are obvious.
Now, you might be assuming that Jarico Studios tracked this project through an impressive array of tube mics, running through racks of vintage preamps, and through the best quality converters available. You might also assume that the project was mixed, or at least processed, in the analog realm with tube compressors and EQ. You might even assume that they tracked, or at least mixed, to a nice analog tape machine. But, none of these things are true. This album was tracked through "stock" preamps, with "stock" converters. Not a single tube mic or preamp was used, and the album was mixed "in-the-box". Sure, the equipment they used was good quality professional equipment, but the "warmth" came from talented musicians and engineers, good arrangements, and good decision making.
"Sources" of Warmth
While I've indirectly hit on a number of key ways to get warmth, I want to list some of them here, with brief comments for easy reference.
Start at the source: If your instruments and amps sound thin, harsh, and weak to begin with, can you realistically expect them to sound full and warm later?
Room Acoustics: If your tracking room has a "cold" sound or a nasty flutter echo, this will make it more difficult to achieve warmth. A good mix of broadband absorption and diffusion will help you get a better sound to start with.
Mic Selection: Tube, FET, and Ribbon mics have a great reputation for adding warmth, darkness or other pleasing colorations. However, don't overlook your "normal" condensor and dynamic mics. Matching the right mic to the task is key. Keep in mind that sometimes a dynamic mic, with their slower transient response than condensors, can also contribute a degree of extra warmth.
Mic Placement: An inch can make a big difference - don't just put up a mic, take some time to move it around to find the most pleasing spot. On acoustic instruments, you can sometimes get a warmer tone by backing off the mic to get more of the "wood" sound. On vocals you can sometimes get a warmer and "bigger" sound by moving closer to maximize the proximity effect. Of course, this all depends on the source, the mic, and the room. Experiment and let your ears be the judge.
Tubes: No list would be complete without tubes. A properly designed tube circuit adds warmth in the form of added harmonic content. Mics, preamps, compressors, EQs, and direct boxes are all great ways to add warmth. Try upgrading your guitar amp to a tube amp.
Transformers: Oh I love the sound of a good transformer. There are many types of transformer circuits that lend themselves to different sounds, but all of the quality designs have a pleasing impact. If you are looking for a warm, "vintage" sound, try using a quality mic preamp based on any of the great designs of the 70's.
Converters: In the digital world, your sound is only as good as your converters. A poor set of converters is often described as being cold and harsh. A good set of converters will overcome this. Additionally, some converters have features that allow you to mimic the sound of tape compression.
Digital Levels: Recording with conservative levels - leaving plenty of headroom for transients - can lead to a better sounding mix. The same goes for when mixing... make sure you aren't clipping anywhere in the signal path, including busses, aux sends, and plugins. Keeping your signal clean from start to finish will prevent a build up of unpleasant and harsh sounding digital distortion.
Tape: This one is obvious right? Properly maintaining, calibrating, and using a tape machine is not for everyone, and the expense of tape is a concern also, but if you have the cash and some motivation, you can utilize tape in your system. No need to throw out your DAW - just run your mix from your DAW to the tape machine during mixdown.
EQ: Warmth can come from gently rolling off the high end of a track, boosting the low mids/lows, or a bit of both. Use with caution though - there is sometimes a fine line between warm and full sounding vs dull and muddy!
Compression: While I may get some disagreements, I personally feel that compression and limiting can add warmth to a track. Harsh spikes are reduced and the track can gain a little more "body". This includes compression done in-the-box with plug-ins. Don't overdo it though - good dynamics are critical for a sucessful mix.
Reverb/Effects: Choosing the right reverb (or other effect) can make a big difference. Experiment and try different settings. If you are a relative novice, I suggest you refer to a preset of a "Warm Room" or a "Dark Plate" as a starting point to help you in learning how to change the settings of reverb to create the sound you are after. Don't forget - a classic trick is to process the reverb with compression or EQ to further alter (and possibly warm up) the sound. The same principals apply to other effects as well.
"Warming" Processors: There are a variety of plugins and hardware units that are specifically designed to bring warmth to your mix. Be careful about thinking of these as a magic box that will solve all of your problems, but with a little experimenting, you'll find they can be very effective. A good example of a hardware unit is the Empirical Labs Fatso Jr. In the software domain, there are a number of good tape saturation emulation plugins. Most of these, when used properly and when employing good techniques, can lead to warmer, more rich sounding mixes.
Consistency: I believe that using some common processing between tracks can (in many cases) help "glue" the tracks together and create a warmth and tone that can not be easily captured otherwise. One popular technique is using the same or similar preamps for the majority of your "core" tracks, while feeling free to use something "special" on the key tracks. For example, using your primary preamps for most of the band, but running the lead guitar through something else, MAY help "gel" the sound of the band, while letting the lead guitar cut through and stand out a bit more in the mix. When working with limited hardware resources, some people find it very effective to take a plugin that has a definite impact on color or warmth, and implementing it on every track in the mix. This could be a compressor, EQ, or some other plugin. I have had mixed results with this depending on the source material and the plug-ins used, but I do know that this can be an effective technique for creating your own "virtual vintage console", which can add warmth and fullness to your mix.
I could continue to list more ways to create "warmth" in your mixes, but the ideas and suggestions mentioned so far should be sufficient to take even the most novice of engineers to the next level in creating mixes that have a more richness and warmth to them. Pick a couple of these items, experiment, adapt them to your own style, and master them and you too will find that you can improve your mixes - and while more gear may help, the most important thing is how you use it!