Equal Loudness Contours

Equal loudness contours are  a graphical representation of perceived loudness of different frequencies at different volume levels.

equal loudness contours

Does that confuse you? First of all, loudness and volume have different definitions in this context. Loudness is subjective, volume is the objective measurement of the amplitude of sound (a more technical term is sound pressure level). The gist is that we subjectively perceive certain frequencies to be louder, even at the same volume as other frequencies. For example, a 40hz sine wave is perceived as being much quieter than a 1khz sine wave, even if the same amount of volume is being measured. Conversely, if we want a 40hz sine wave to sound as loud as a 1khz sine wave, we will need to add about 10db of gain to the 40hz sine wave to perceive it as the same loudness.

This phenomenon is mainly caused by the fact that our ear canals resonate at a range of 2khz-5khz. Notice the dips in the graph at that range, representing the most sensitive range of our hearing.

How does understanding this concept help us as musicians? The most important lesson here is that loudness affects how we perceive tone.

When we are shaping the tone of the guitar on an amp, we should be doing it at a level that’s similar to when we’ll be performing. What may sound good at “bedroom level” may reveal a bunch of problems (like too much highs or bass) at “gigging level”.

Another quick tip I’ve learned is that if a sounds is too “harsh” to the ears, then the likely culprit is the 2khz-5khz range where our hearing is most sensitive. Grab the EQ and do a little bit of reduction in that range to take the harshness out of the sound without sacrificing volume.

If you’re interested in these types of acoustic phenomenon, you might want to take a look into the field of psychoacoustics. Hope this was helpful!


My Cure for G.A.S.

GAS is an acronym that stands for Gear Aquisition Syndrome. It’s a colloquialism that describes a guitarist/musician’s tendency to endlessly desire and acquire more gear. While most people use the term to comically describe their own obsessions with gear and their quest for the “perfect sound”, there is a serious down-side to this mindset that a specific piece of gear is the be-all of good sound.

I’ve been through many phases of lusting over the latest high-tech gear to improve my sound but I seemed to have calmed down in the recent years. I attribute this to the fact that after learning some audio-engineering concepts, I have a better understanding of what a piece of equipment does and how to use it to its fullest potential.

Technique over Tools

When you are constantly acquiring new tools , it’s a natural outcome to have less time to learn how to use each piece of equipment properly. Taken to the extreme, you can end up with a room full of gear that’s only seen a few weeks of use before being stored away. People will eventually get rid of their stash of gear only to repeat the cycle all over again.

What you need to do is purchase gear with a specific goal in mind, and learn how to use it until you begin to get the results you want out of it. For example, a guitarist may become obsessed with a certain model amp because their favorite musician uses it. They get the amp and plug in, only to find that they’re still missing the mark. This is because they don’t have the same experience and techniques as the artist they are trying to emulate. If you don’t get the results you’re after, don’t blame the gear. Blame your lack of skills.

You should be trying to learn everything about whatever piece of gear you’re using. What does it do? Who has used it? When and where should it be used? How does it work? These are all the questions you should be asking yourself. If you try and answer each of the questions in depth, you will be spending more time being concerned with maximizing your equipment instead of thinking what new piece of gear might fix your problem.

By understanding how to use each piece of equipment better, you will also be able to apply the same concepts to gear that you unfamiliar with. The different categories of tools, such as EQ, compression, chorus, flanger, etc. operate on the same principle and brands only slightly differ in character. I recommend, for guitarists, to study equalization as a starting point. It is by far the most useful concept to understand. Equalizers are ubiquitous in the audio world and all operate on the same principles. If you can master equalization, you will be able to get a decent sound out of almost any amplifier!

If you take the time to really understand your gear, I can guarantee you will find greater satisfaction with what you have! Who knows, maybe your golden sound is waiting somewhere in your closet to be rediscovered?

Understanding Effects: Distortion

I notice a lot of guitar players tend to be, through no fault of their own, groping in the dark when it comes to using effects pedals. I find that a big problem is that manuals only delve into quick-and-easy type settings that doesn’t explain much about what is actually happening to the sound. I’m going to try and demystify some of this so that you can learn how to get the exact sound you are going for.

To begin the series, I’d like to talk about a fundamental guitar effect, that’s become so ubiquitous that it comes built in to most amplifiers: distortion.

We all know the sound – a screaming guitar solo or a thunderous riff are products of distortion that have become the hallmark of the rock guitar sound. So what is happening to the sound that causes this change? To put it simply, it does exactly what it’s named – it “distorts” the actual sound waves that are coming from you guitar. Imagine a sine wave with its nice flowing curves when it’s visualized. Distortion occurs when this signal is boosted past the limit of the maximum volume. The wave literally hits a ceiling, visually chopping off the top/bottom curve to produce a flat part in the wave. This is what we hear as distortion. Different types of distortion are available, but they are generally categorized as saturation/overdrive (mildly distorted) and distortion (greatly distorted sound). When these deformities in the sound waves happen, they also create harmonics/overtones that we perceive as adding a richness to the sound.

The controls that we have over this effect are generally: level/volume, and the amount of distortion (sometimes there’s a bit of EQ as well). It’s easy to hear the difference each of those controls make, but there are some traps that you will want to watch out for. Distortion is a dynamics based effect, meaning it affects our perception of volume. If you’re switching between a clean and distorted sound, it’s important that the volume level transitions smoothly. This is more difficult than it sounds, because if a distorted signal and a clean signal were to have the same amount of energy, the distorted sound will be perceived as being louder. Secondly, when you’re using heavily distorted guitars against the drums, there can be a lot of overlapping high frequencies between the cymbals (and crowd noise, if you’re in a venue) and guitar sound. You can avoid this by using and equalizer to get the guitar to sit in an less occupied part of the frequency spectrum. Many distortion stomp boxes will have a built in tone control to deal with this issue.

Overdrive is a type of distortion that is often associated with driving the power amp to distort. This is distinct from (heavy) distortion which is done in the pre-amp stage. Power amp distortion is generally described as a “crunch” tone. Historically, this is how all early forms of distortion were achieved, before amps came with the effect built-in. That means if you want a vintage blues/rock type of sound, you should go for this type of distortion by cranking that tube amp up.

Now for a few tips and tricks. When it comes to distortion, I want to emphasize that less is more. Even heavily distorted genres like metal can benefit from this mindset. Dynamic range is lost as more distortion is used and eventually you will end up with little difference between the loud and soft parts of your playing. If we were to take this idea (less is more) to the extreme, we get to the territory of saturation. This is a type of distortion that is most often associated with analogue gear that is powered by tubes. By using an almost imperceptible amount of distortion that retains most of the original sound, you’re able to add a subtle layer of overtones to the signal.

Mixing Gypsy Jazz Guitar

There are so many great Gypsy Jazz records out there now that are well produced; Selmer #607 and Les Doigts de l’Homme are among my favourites. However, there are even more poorly mixed records out there.

I don’t blame the mix engineer. This is a small niche in the jazz world and requires an entirely different approach to mixing the guitars. If you haven’t listened to a ton of Django Reinhardt records and modern Gypsy Jazz artists, you can’t expect them to be aware of the different roles the guitars take in this genre. Having experienced mixing in this style myself, I’d like to offer some advice to those who might be less informed in this style and looking for some guidelines to follow.

Let’s talk about the instrument itself first. These guitars (Selmer/Macafferi design) tend to be voiced as a lead instrument rather than an accompaniment instrument. Tonally, it translates to having much more of a mid range bite rather than a deep low end and shimmering presence. One huge mistake I hear frequently is giving these guitars a shelf-EQ boost in the presence (>4khz) which results in a harsh and unpleasant attack.

When the guitar is not playing lead, it will be playing rhythm. This isn’t to be mistaken with sustained and open chords ringing behind a lead. The guitar actually replaces the drums as a percussion tool, since this style is usually performed without drums. A rhythm guitarist will generally play short chords with a heavy backbeat that imitates a snare drum. To that extent, applying EQ and compression in a similar approach to drums would yield better results than the traditional approach to mixing guitar accompaniment.

Now that we understand the roles of the guitars, I’d like to address the history of recording technology and this style. Django Reinhardt’s recordings are often considered the holy grail, but the tone on his records are a result of the technology available at the time, as much as his technique. Ribbon mics were the norm back then, and recording in mono around one microphone. The high frequencies were attenuated even further by the medium of vinyl records. There’s no reason to slavishly follow this approach (although some have achieved an uncanny resemblance to the original recordings). Now you have plenty of new technology to create a compelling modern sound, but it’s important to understand what the ears of the audience has been trained to expect.

Let’s get down to the practical part now. EQ and compression are the most commonly used mixing tools so let’s talk about those. For EQ, it seems fairly obvious now that you will likely have to cut the high frequencies instead of boosting them. Pay close attention to the pick attack of the players, as it is probably the most distracting part. Low frequencies can be extremely lacking in these guitars so sometimes a little boost in that range can help thicken up a sound. If the sound is otherwise pleasing, you can apply a high pass filter to make room for other bass instruments in the mix.

One component of the high frequencies is pick noise, which is especially problematic in this style.  Players tend to use a technique called rest-stroke picking that accentuates the attack. If an equalizer doesn’t quite cut it for dealing with this annoyance, a multi-band compression can be a handy tool. I’ve sometimes used vocal de-esser (essentially a narrow band compressor) to specifically weed out this problem area in a natural and subtle way.

A trend that’s becoming increasingly common is to compress the crap out of the rhythm guitars, to give it an extremely aggressive and punchy swing feel. The guitars are often played with very little sustain so a fast attack/release is recommended. If there is a doubled rhythm guitar, you can get a wider stereo mix by hard-panning the two, a common trick in rock mixes.

Finally, any mix should always be tested against a reference track. My recommended reference recordings are (if you haven’t guessed already) the Selmer #607 record series, and the Les Doigts de l’Homme records (particularly Mumbo Jumbo and Couers des Vivants). The Selmer #607 series is particularly interesting as Ghali Hadefi’s production style evolves over the course of the records.  It’s particularly interesting to hear the latest Selmer #607 record and its treatment of the high frequencies. To me, it borders on sounding unnatural but the result is very smooth on the ears. Les Doigts de l’Homme records have incredible arrangements that do a great deal to create an amazing mix but the rhythm guitars is where it particularly shines.

This ended up being a little long but I hope it helps you create a more compelling Gypsy Jazz mix!