subject: Loudspeakers Active Or Passive? [print this page] Within the realms of professional audio, much is often said regarding the pros and cons of a PA system featuring active or a passive speakers. Avoiding the techno speak, here are the facts. For ease, we will refer to a loudspeaker box or loudspeaker enclosure containing one or more drivers as a speaker.
A passive speaker is the more traditional way of doing things. It has no internal amplifier and is connected to a power amplifier, located at a convenient and perhaps remote point within the venue, via traditional speaker cable. The speaker itself might contain a single driver e.g. a sub-woofer where the original audio signal has previously been split up into frequency bands so that the correct range of frequencies go to the correct driver(s). Alternatively the speaker might actually comprise of two or three drivers e.g. bass, mid, high featuring a passive crossover within the box which takes the entire audio signal and splits them up (as best it can) to each appropriate driver.
An active speaker is where the power amplifier for each driver is actually located inside the box as an all-in-one solution. In professional sound systems there will be two or three integral dedicated power amplifiers one for each size or type of driver. In this instance, there will also be an active (or electronic) crossover that acts in the same way as an external active crossover in a passive system, accurately routing the right frequencies to the right driver. Active speakers are connected to the mixing desk or audio source via screened signal cables.
A self powered portable PA system such as those from SoundPlus, dB Technologies and Mipro which have integral re-chargeable batteries can, to a degree, be referred to as an active speaker as they obviously have their own amplifier on board although some may say that, as they dont have dedicated amplifiers for each driver and rely on a passive crossover, they are not strictly active PA speakers and are merely self-powered!
In Part Two, we will look at the advantages and disadvantages of active speakers vs. passive speakers.
