In this post, we're going to explore analogue warmth - what it is, and how to inject it into your recordings and mixes. Warmth in the context of audio production, is a hot topic. With the popularity of almost all digital signal paths, it has become much cheaper to record, mix and master your music. However many musicians, producers and engineers feel that there is sometimes an elusive sound quality missing from modern digital production methods.

In modern times, three common techniques in music recording and production have all but dissapeared since domestic and DIY audio production has proliferated. These are namely, the use of multi-track tape machines, large format analogue consoles and large recording studio spaces. These changes have definitely changed the character of audio in modern productions.

Defining warmth in recordings and mixes

Analogue warmth is subjective and difficult to describe in words and everyone’s interpretation is slightly different. However there are a few statements which appear to be commonly accepted as characterizing warmth within a mix or recording.

• A gelling of instruments, yet without compromising their own defined space in both tone and stereo image.
• A lack of harshness and rounded quality.
• A punchy and smooth sounding lower mid range.
• Not excessively bright and the brightness that is present is smooth.
• A punchy low frequency range.

To me personally, warmth can be a number of things. I can recall analogue tape recordings from the 1970′s which I would define as being warm. I can also produce something I define as warm with simple attenuation of high frequencies. In some instances a very rounded sound with a strong lower mid presence can sound warm to the ear. With this in mind I would like to suggest some pointers on how to create warmer sounding mixes and recordings.

What equipment and techniques can we use to enhance warmth?

All live-music recording starts with setting up microphones - experiment with different mic positioning or mic choices in order to get less bright recordings, although take care not to box yourself into a corner, Double-mic instruments with secondary ribbon or dynamic mics in addition to your usual choices. A common source of warmth can be certain audio transformers which can reduce harshness in the upper registers and provide additional body in the lower mid range. There is a wide selection of vintage and retro styled mic pre-amps that utilize audio transformers at the input stage. Audio transformers are usually used at the inputs and outputs of equipment and can be found in many outboard equipment types such as equalizers and compressors as well as microphones. They are often overlooked in the quest for warmth.

One of the most powerful tools which is overlooked for generation of warmth is equalization. You have the power to sculpt and adjust sounds as is required. Do not be afraid to experiment with rolling off high frequencies to reduce harshness, presence and brittleness in a mix. You can also employ EQ on effects returns to soften them and make them gel better with the source. Compression has the ability to smooth transients in recordings and fast attack times with 1dB or so of gain reduction can work wonders in smoothing out abrasive, harsh and aggressive transients in a mix. Analogue tape applied a natural form of compression when overloaded gently. It is a technique that can be used to good effect. Very gentle group or master bus compression can also provide a sense of “wholeness”.

In addition to these essential tools, in software form there is an emulation of virtually every piece of classic analogue studio equipment ever built. Often these software emulations rely on some kind of valve/tube saturation. In my experience valves do not add warmth as such but they can give a perception of thickening a sound as harmonics are added. Some emulations are better than others and I suggest keeping an open mind and downloading some demos and spending some quality listening time with them. Try and discern which ones seem to add that special something in terms of tone.

By experimenting with these techniques and equipment choices you should be able to start adding some warmth to your mixes. As always when experimenting in audio production take some time to rest your ears over night and double check that you have not laid the processing on too thick.