It’s not what you do
As Pete Thomas points out, “it’s not the approach you use but how good you are at implementing it that makes the difference between good and less good speakers”. Anyone can stuff a pair of drivers and a crossover in a box and it will produce sound, but as we all know that is only the beginning. When it comes to loudspeakers, the elephant in the room is, er, the room. Building a speaker that measures well in an anechoic chamber is very different to coming up with a speaker that works in rooms with widely varying dimensions and acoustic characteristics. One of the big reasons why small two-ways are very popular is that they don’t produce a lot of low frequency energy, and thus are less likely to excite the room modes that can muddy the most transparent of midranges. It’s also the reason why the best sounding rooms at hi-fi shows tend to have smaller speakers in them: bass is an all encompassing beast that takes a lot of taming if the walls are made of cardboard.
As well as interfacing with the room acoustically, loudspeakers interact with the floor beneath them. For a long time, the accepted wisdom has been to have spikes on the speaker’s undersides that effectively nail them down. This allows them to sink certain frequencies into the floor and minimises vibration at low frequencies, which means that more energy is transmitted into the floor and thence into the source and amplification. There is another school of thought that isolation is a good thing for loudspeakers: you can see it in the way Bowers & Wilkins decouples its tweeter pods with highly compliant mountings and other brands use similarly soft gaskets to stop driver chassis from exciting the surrounding cabinet. Townshend Audio makes damped spring supports that attempt to isolate the whole speaker from the floor which seem to be highly beneficial. It is clearly time that the spiking ethos was re-evaluated.
Choice and place
So there you have it: a riddle, wrapped in a mystery, inside an enigma*. Loudspeaker design is a series of choices with very little in the way of an absolute sound agreed upon. The state of the art has come a long way, however, and you can get some pretty remarkable speakers for less than the price of a family outing to Legoland. Distortion levels are constantly dropping and fit and finish improving at an impressive rate; all you have to do is find a pair that works in your system, your room, and with your music,. Often the key to that lies in placement and set-up as much as actual hardware. An hour or so finding the best place for your speakers will reward you with years of top flight entertainment.
*(Churchill’s description of what to expect of Russia at the beginning of the second world war)