Interior lighting

One of the often ignored areas in an office is interior lighting. Most often, design considerations for interior lighting is often based either on functionality or aesthetics. However, poorly designed lighting can often cause health and safety issues in the office, resulting in errors, reduced productivity, and various health problems. I had a chance to work on a relatively simple project recently. It was a small office and the client had complained that the original down lighting was casting a harsh light on the work surface causing glare and other health related issues.

After discussion, I decided on a diffused light source in order to soften the interior. I surveyed the office, entered the dimensions into the lighting program, selected the appropriate luminaire and crunched some numbers. In the end, I settled on a large diffused pendant, with two 24 watt TC-TEL bulbs, giving an illumination level of 100 lux at the working plane with a gentle wash falling off the walls. Below are the illumination plot and lighting simulation :



Lighting measurements confirmed that the work plane was within the simulated output of 100 lux at working plane. The client was extremely pleased with the final result :
The diffused lighting eliminated the glare at the work surface and other health related issues.

Big Picture

Recently, on one of the listserves that I was on, a church sound operator was asking for opinions on the audio system that was put into the new hall which they had just moved in. This was an existing system from the old place and the bloke wanted to get a new pair of loudspeakers that had 'tighter' coverage in order to overcome the highly reverberant worship hall.

That kinda got me thinking a bit because, a while back, I wrote about priorities in this blog. I was describing how the loudspeakers should be the first priority, in view of other technical equipment purchases. I reckon I should now include acoustical treatment as a high priority in the mix of things.

Now, I need to explain that in certain cases where heritage and architectural issues are involved, it will almost be impossible to provide these spaces with the ideal acoustical treatment needed. In the case of cathedrals and churches with strong liturgical and traditional backgrounds, higher reverberation times are oft the preferred choice. However, in the case of more contemporary type worship services, where modern musical instruments such as synthesizers, electric guitars and drumsets are involved, a much lower reverberation time is required as the tempo of the music is much faster.

It is the latter that is more common in modern day buildings and I have been dealing with these type of spaces for over 90% of my projects in the last 15 years. Any good sound system designer will tell you that the audio system will only be one half of the entire sound equation. The other important factor is appropriate acoustical treatment. While there are audio systems that are designed to 'overcome' acoustical issues, none of those that I've heard sound as good as the conventional loudspeakers that can be installed in a space that is well treated.

Now, back to the original line of thought..... in the listserve, I tried to convince the bloke to consider acoustical treatment instead of spending more money on getting new loudspeakers, as the acoustical treatment would make a improvement for the sound in the hall. Unfortunately, the leadership felt that too much money had been spent on the decor and was not willing to invest any further in the short term. Instead, getting a technical solution was deemed to be a 'better' solution for them. The reason why another set of loudspeakers would not solve the problem lies in the fact that all two- or three-way, small format type loudspeakers are fairly wide in coverage despite their marketing claims.

A real loudspeaker system solution would entail using a multiple line driver design with adjustable directionality to direct the sound into the audience area. More drivers, usually equal more money....hence, on the logical end, spending the money you would normally spend on a pair or regular two way boxes for acoustical works, will yield much more satisfactory results in the end.