Active loudspeakers are built in a way which gives you sharper sound quality for much less than normal speakers.
They have one big difference over normal passive stereo speakers. In simple terms: they have an amplifier inside them. Actually, they usually have two amplifiers, one for each driver unit (speaker cone).
How does this work, and what are the benefits (especially for classical music)?
First, let's have a look at the signal path in a conventional system...
The signal is started by the source being read. A laser reading a CD surface, or a computer audio file being read by a hard disc head. This produces a very small current and voltage signal, which then goes through a control stage usually called a pre-amplifier.
Next, the signal travels along a wire to the power amplifier. This hugely boosts the voltage, and gives the signal enough power to drive loudspeaker cones.
But after the signal leaves the power amplifier, it's usually split by a device called a crossover into high-frequency signals and low-frequency signals. These then go to two different speakers cones: the tweeter (smaller, high frequency), and the woofer (bigger, low frequency). Still with me?
The crossover device has to match the frequencies it sends to the woofer and tweeter very precisely. It's really important that the crossover gets this matching right, otherwise the music sounds bad!
So the crossover has to be pretty good quality, with components which can handle high voltages. This means $$$!
But there's a better way to do things, which is where active loudspeakers come in...
An active speaker deals with the problem by changing the order in which the signal travels through the components of the chain. Like before, the signal leaves the preamplifier with a low voltage.
But now, instead of going into a power amplifier, it goes straight into a crossover! So it splits the frequencies while the signal is still low-voltage.
This means that the crossover can be very high quality without being hugely expensive. Definitely a good thing!
After leaving the crossover, both high and low frequencies go to different power amplifiers optimized specially for that frequency. THEN they go either the tweeter or the woofer.
Let's have a look at the advantages...
The end result?
Active loudspeakers have several characteristics which make them sound as good as normal speakers costing three to five times as much.
The disadvantages are bulk and weight, since the cabinet has to fit two amplifiers as well as the speaker cones. Each speaker cabinet also needs a separate electric plug.
They get pretty warm as well, and need a fair amount of space around them for ventilation and to achieve their best sound.
You'd definitely want to take these delightful traits into account when thinking about your listening room design!
But I think these sacrifices, and the basic fact that you can get better quality sound for a much lower price, means that active loudspeakers are the perfect speakers for classical music aficionados!
Have less space? See our guide to the best bookshelf speakers...