Why are loudspeaker cabinets made out of wood?
Wood? That's about as traditional a material as you can get. Surely there must be something better by now - carbon fiber or some kind of composite plastic perhaps?
Let's look at the job the cabinet has to do...
Firstly it has to contain all of the components of the speaker - the drive units, the crossover, the wiring and connector. That's easy, you could do that with any sufficiently rigid material.
But the main function of the cabinet is to contain the sound radiated by the rear of the bass drive unit. If this is not contained, it will leak round to the front and cancel out the low frequencies. Significantly less bass would be the result.
So if the sound radiated from the rear of the drive unit must be contained, the cabinet therefore really ought to be soundproof, oughtn't it?
Yes, as close to totally soundproof as possible. But there is a problem with weight.
To provide soundproofing requires mass - there is no alternative to that. And speakers in the main are heavy enough as it is. So manufacturers don't want to burden themselves with even greater transportation costs.
So inevitably the panels of the cabinet will vibrate and allow quite a bit of sound through.
Now ask yourself, even if the drive units are the best that money can buy, what is the sound quality radiated by the panels of the cabinet likely to be?
That's right. Damned awful. The best option is to make the panels out of a lossy material that dissipates energy as it flexes. That way, even though the cabinet will still vibrate, what vibration there is will be minimized.
Now let's think of a material that can dissipate energy as it flexes...
You guessed it... wood! It turns out that wood, in the form of particle board, really is very suitable indeed to make loudspeaker cabinets from. Perhaps one day there will be better materials available at an affordable price. But right now, wood is king.