Glass houses

Here's a short list of things to consider if planning to use a conservatory as a music room.

First is that the acoustics will be a matter of geometry as much as material. Sloping roofs can have odd effects on soundfields, more especially if the conservatory is large enough to have a double-pitched roof . Non-parallel surfaces do effectively disperse standing-wave patterns but the resultant soundfield is actually very complicated. Instead of the typical regular standing wave patterns of rectangular rooms, a frequency sweep in such a space would, if you could see it, produce something akin to a changing moire pattern. Everest's Master Handbook of Acoustics illustrates this well. This is not to say such shapes cannot work well - it's rather that, because the outcome is so dependant on geometry and context, it can actually be easier to 'sort' a rectilinear space with particular acoustic issues than to treat the apparently chaotic behaviour of a space with non-parallel boundaries if it fails to meet some expectation.

The second issue usually raised by people with music in mind is the direct consequence(s) of all that glass. For the primary issues see the 'glass and glazing' link (left) - it's an ill-founded myth that glass sounds 'bright', but when the music room is to be mostly glass there are other matters to consider. Compared to the rest of building enclosure glazing systems are lacking both rigidity and mass. As a result, a conservatory as an enclosure will be far more 'transparent' to sound. The likely consequences are that i) as a music room it would be a potential source of annoyance to your neighbours, and ii) a 'thinner' sound may result because the flexible structure acts to some degree as a diaphragm absorber in the bass spectrum - although this could be construed to be an advantage. All very subjective this.

However for long term use the primary concern for audio use is probably the environment. Even in the UK, conservatories do get hot; they also get pretty cold, due to radiative loss to the night sky, and such daily temperature and humidity swings is unlikely to audio equipment any good, especially loudspeakers. Speaker drivers - particularly their suspensions - are fragile and subject to hysteresis effects that vary with temperature. More permanently, timber cabinets and veneered finishes are soon damaged by sunlight (bleaching) and temperature/ humidity swings (leading to dimensional changes). Consider the siting of your expensive equipment carefully before having it baked, bleached warped and frozen by turns!

Any comments.?

© the twisted pair 2004