The most frequent question that I have been asked from my customers over the past few years is “how do I know that what I process sounds right”? I have also seen many sound engineers in various pro-audio newsgroups asking questions “how does this plugin sound” or “how does this EQ or compressor sound”?
I am afraid that what they are asking really is “hey you out there that I don’t know where you’re coming from or if your ears or monitoring setup is better than mine, can you tell me if this unit or plugin is the right one for me”? How do these people asking these questions know that the person who answers them is actually more knowledgeable than they are or his ears and acoustic environment is better than theirs? I am mostly referring to “newbies” who haven’t established a good relationship with anyone yet and they are just shooting questions hoping that they’ll receive the right answer. This is something that isn’t easy to answer and personally I would not approve any equipment purchasing unless they have passed the critical listening test that I put them through.
I would like to take this opportunity to try to shed some light in these areas hoping that at the end of this article everyone will know what to listen for and try it on their own instead of asking someone else. I have borrowed some terms from the audiophile industry as well as the pro audio one to describe things better.
Quality Equipment – Setup Properly
In order to do critical evaluations when listening to new equipment you’ll need a good sounding room with the speakers positioned at the correct location. The second is the easiest and least expensive item on the list that follows. Putting your speakers in the right location can make a huge difference in their performance. Best of all it is free. All you need to do is some experimentation to find the right location. You’ll also need reference quality power amp, reference quality full range monitors (preferably time aligned) and a great quality DAC (Digital to Analog Converter). You can check some of the links at the end of this article in case you need to do some searching for this equipment.
In the following sections I will try to describe the frequency areas that our ears are capable of hearing and I will try to keep them as simple as possible so you can have a better understanding.
First allow me to introduce the bass. Welcome to the most misunderstood area of the frequency spectrum. Most projects that I receive for mastering have problems in this area. Most of the people that I talk to think that the more bass there is the better their recording will sound. What counts here is the quality of the bass and not the quantity. Personally I’d rather hear less bass in a recording instead of poorly engineered bass.
The bass should be reproduced with pitch definition without having an earthshaking effect like when NASA is launching the Space Shuttle. You should be able to hear the notes precisely and also the instrument’s dynamic envelope. Slow, boomy, muddy, thick, fat and loose bass should be avoided. It should be quick, clean, tight and precise. The amount of bass as mentioned above is also important. Too much bass gives you a heavy, boomy feeling. Too little bass will sound thin with no depth and powerless. During reproduction it should be reproduced with extension (how low the bass goes) and depth. The speed of the bass is also essential. A fast accurate bass will reproduce a kick drum’s envelope (attack and decay) precisely.
Midrange – the source of musical energy
Second is the midrange. This is the area where the human ear is most sensitive and where most of the musical energy is. This frequency area is a good one to test your monitors. If your monitors have peaks or dips in the midrange they will sound very unnatural. Poor midrange performance will sound coloured, chesty, boxy, thick and peaky. It should sound sweet, smooth, and velvety. Male speaking voice or a male vocalist is a good place to start testing coloration in this area. Clarity, transparency and detail should be present in this area.
Treble – warm, rich, full, sweet, smooth, soft, silky & gentle!!
Third is the treble. Does the treble sound too forward? Is it bright, grainy, brittle, edgy, aggressive, metallic or sterile? Well, if you found that the treble falls within any of the above descriptions then you’ll need to try to look for one that it will sound warm, rich and full, sweet, smooth, soft, silky and gentle. If the treble area is under-emphasized you’ll find that is lacking detail. It won’t sound airy, open and extended. It will sound close rather than open and it will be missing a sense of space. It should be balanced with the rest of the frequencies and it shouldn’t be sitting on top or under them.
Another important area that needs your attention is the soundstage. Width and depth are the physical properties of the soundstage. A soundstage lacking these dimensions is called narrow and flat. Some speakers over-emphasize the soundstage giving you the feeling of a bigger space and some shorten the depth and width of it. Sometimes the soundstage will sound great at low levels but when the volume is turned up it collapses. A bad listening room with poor speaker placement will destroy the soundstage.
Now that you are a bit more familiar with the frequency areas and soundstage let’s take a step towards processing evaluation.
Evaluating processing results by ear is essential especially if you don’t have the right equipment to further analyse the sound.
Our hearing mechanism is very complicated and sensitive and even the most sophisticated equipment on the market cannot measure up to our ears’ accuracy. No matter what the specifications of your processing equipment are, your ears should always be the final judge. The human ear along with the brain are the most superior pieces of equipment that you’ll find in the most expensive and technologically advanced studio.
Your processor(s) may have the best signal to noise ratio and distortion characteristics but still doesn’t tell you how good it sounds. Knowing what sounds good and what doesn’t is easy. All of us in the industry should be able to tell the difference between a good and a bad sounding unit. However the ability to recognize and pinpoint subtle differences while processing are skills that you’ll have to learn. The best way to do this is practise. The more you practise the better listener you’ll become. Paying attention to detail when processing you’ll be able to distinguish how certain processes will affect the music and you’ll be able to decide which processor to use and at the end you’ll know why.
Many processors will introduce artefacts when you pass the signal through them such as grainy treble, boomy bass, and coloration to the midrange, soundstage etc. Make sure that when the processor is engaged it is going to give you better results than when it is in bypass mode. Use the bypass switches often enough for comparison so you know how it affects your music. Always go back to source-processor-source. Don’t just use only source-processor.
Listen to the tonal balance of the music. How well balanced are the bass, midrange and treble? Is the bass too heavy, boomy or too light and lean? If there’s too much treble then it’s bright. First evaluate if there’s a problem in the frequency spectrum and then you will know how to choose the right tool to take care of the problem. Almost every processor adds or takes away something when it is engaged.
If you are examining a complete mix instead of an individual instrument, listen to how well the instruments are balanced in the mix. Is the soundstage lacking something? Check if the instruments are forward or backward. It’s kind of like someone screaming in your face angry or someone else talking relaxed in the background.
Trust your ears
Critical listening requires you not to be biased. That means that the reputation of the manufacturer of the processor, the price tag of the unit, how many good reviews it has received raving on how good its sonic quality is, should be absolutely forgotten. Just clear your mind and listen to what your ears are telling you.
Listen to one thing at a time. Don’t listen to many processes at once. For instance if you are examining a unit which has both compression and EQ processors in it, evaluate each process separately. Once you are satisfied with the results of the first processor then move on to the next one.
Level matching within 0.1dB accuracy is another extremely important area. That is to match the levels of the processing unit with the levels of the original source so you can hear how the sound is affected. Slight level difference between the source and the processing unit can lead you to the wrong conclusion. The ear’s sensitivity to treble and bass increases disproportionately with volume which means that you’ll hear more bass and treble when the music is loud.
Check your music library and try to find recordings which contain wide dynamic range and frequency balance. They’ll reveal much easier any artefacts when they are passed through the processing unit.
I hope that you have learned some things by reading this article. If you have any questions or comments please feel free to e-mail me at firstname.lastname@example.org . Below I have included some links to manufacturers that I have great respect for their products. This is just something to guide you through but please take my advice and evaluate for yourselves the equipment in your own environment and with your own ears. Thanks for taking the time to read this and I wish you all the best with your decisions.