I've said in an earlier post that many audio systems that I've heard are not properly calibrated and optimised. What does this really mean? Is it just about improper selection and matching of equipment? Is there really a level of 'acceptance' or 'standard' ? Is it due to poor understanding or a lack of knowledge of how audio systems work? Incompetence? Poor design?
Based on my experiences, it's a little or all of the above. I don't want to focus on what the causes may be at this point, but rather, I'd prefer to look into the design process that leads to a successfully installed system.
I was in Singapore for a few days to commission technical systems that I've designed for a refurbished community centre. Basically, this tail-end job ensures that the system specifications are installed properly and meet the prescribed design standard. In order to get to this point in time, a whole slew of process would have taken place. So, bear with me as I describe this process.....
Designing an audio system is not a task that is done in isolation - many times, I've met sales people who have come up with 'designs', complete with fancy graphic simulations and predicted sound pressure levels, even before a building plan is finalised. This is pure salesmanship.... designed to impressed with lots of meaningless data and fancy charts.
The design process begins by talking to the client and listening to their thoughts on music, programming and operational issues. We may visit different venues to evaluate various systems that are installed, and discussed preferences in terms of audio quality and perceptions.
On another front, discussions with the architect or interior designer will be happening in order to get an idea of the space and its finishes. This may also be the time to specify acoustical finishes for the floors, walls, ceiling and stage. This is often overlooked in many projects, but a sound system never works in isolation. It is always installed in a particular environment - it could be a very live sounding space or a dead space when indoors, or, a system may have to cover large areas if it is outdoors.
Once I have firmed up the client's needs and nail the space requirements, various audio system options are presented as possible solutions depending on programming and budget. Loudspeaker simulations are a good starting point for a consultant to study the effects of the audio systems and how it could possibly perform in a particular space. Like any other computer program, careful entry of data is crucial and a sound knowledge of the program's limitations is very important to successful use of these type of programs. Many times, these simulations are used to impress possible clients by unscrupulous sales people, who churn out colourful charts with meaningless data.
Once the system concepts have been firmed up, a specification is drawn up and sent for tender or quotations. Once that is sorted out, usually with the appointment of a contractor, site supervision is the other important issue during installation; equipment positions will need to be confirmed and checked, ensuring proper wiring runs and high quality of connection termination will ensure the system will be free from physical hums, crackle and pops.
One of the most important steps after the physical system is installed is its calibration and optimisation. It is not simply tinkering with the master program equaliser and making it sound OK at the mix position as is often seen and done. This process involves checking each and every component in the audio system to ensure that it is in phase, in time and balanced with each other. Issues such as coverage and summation are addressed by using various instruments to confirm and check the results of the installation. Besides using test gear, ultimately, lots of listening tests are conducted to using music which I am extremely familiar with. Voice tests using microphones are also conducted.
Usually, after the final calibration and listening tests is completed for a system that is designed properly, there is little need for drastic adjustments to the master EQ. In this type of system, any adjustment on the master or channel strip EQ should be consistent across the entire listening area. All the settings should be password protected and copies of the settings made as backup for future reference.
In many cases, I'll usually pop in after a couple of months to have a final listen and confirm that the sound quality of the system is as last left it. Sometimes, it is necessary for some final tweaking as there may be changes to the space or feedback from the users based on their preferences.
In conclusion, it's important to get an experienced system designer as this may mean it's going to be the last system you'll ever put into the space.
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