In the first part of this series we described the basic differences between Active and Passive Loudspeakers. From the feedback we received, the article was very helpful to some in cutting through the sometimes-complicated way in which we in the high-end audio world describe things.
In Part 2 we’ll go into more depth in our aim to help you decide which set-up is best for you.
Essentially, Active Loudspeakers have a built-in power amplifier which require a power source as well as an incoming signal to operate, whereas Passive Loudspeakers require an external power amplifier to operate.
You may already have a separate amplifier, so you just need to match that with suitable passive loudspeakers.
Your amplifier may have 4 channels, but you may only be using 2, so you can easily give your system set-up a big boost by simply adding 2 more passive loudspeakers by matching the impedance and power ratings.
Maintenance can be easier. If your amplifier breaks down, just swap that out without having to replace the loudspeakers. If a loudspeaker blows out then again, just replace that.
Tuning and optimising a passive set-up can be simpler as it can be done from one central mixing location.
Matching passive loudspeakers with the right amplifier can sometimes be challenging due the myriad of power rating and impedance options available. There are however instore audio experts that can assist here.
The more loudspeakers you run around a room (or house) then the more opportunity for signal loss there is. When the distance from a loudspeaker to an amplifier gets close to or exceeds 5m this can have a negative impact on the sound quality. This can be minimised somewhat by purchasing high quality loudspeaker cables which unfortunately can be quite expensive.
Since an active set-up is an all-in-one solution, all that you need to do is plug in your line level source sound and away you go.
The manufacturer of your active loudspeakers is an expert who has already perfectly tuned the in-cabinet amplifier to the loudspeaker. Perfect sound is achieved immediately as soon as you plug in.
No technical expertise is required to fully utilise an active system as they are extremely simple to set-up.
If you have a preference for a particular sound, active loudspeakers allow you to change the sound from the back of the loudspeaker cabinet without the need for an audio engineer.
It is not likely to blow-up your loudspeakers in an active configuration due to engineering design which has gone into them.
These loudspeakers are heavier to move around as the cabinets include all the necessary electronics for ease of use. This is not an issue in a home once set-up.
In the unlikely event that an amplifier breaks down then the entire loudspeaker needs to be sent away for repairs.
In traditional hi-fi audio systems, there is a source such as a turntable or CD player, an integrated amplifier (or possibly a preamplifier and a power amplifier) and pair of passive speakers. The signal path is pretty basic as shown in the following;
The loudspeaker crossover network which does not require a power source directs different range of sound frequencies to different speakers, low frequencies to the bass or sub-woofer and high frequencies to main speaker, the tweeter.
In the case of the sound source being a turntable, you also need a phono stage (not shown in the simple diagram above) to increase the output from your cartridge to what we term line level and the signal needs to be equalised before feeding into the preamplifier.
At this point the power amplifier takes over increasing the signal from the preamplifier and feeding loudspeakers after the sound frequencies are split up via the crossover network.
In a 2-way set-up the sound signal is directed to the tweeter and sub-woofer, in a 3-way set-up the signal is sent to treble, midrange and sub-woofer (bass) speakers.
In an active system the set-up is the same as with passive up until after the preamplifier as shown in the following;
The signal from the preamplifier is then fed into an active crossover network. This crossover network performs the same function as the crossover in a passive set-up it does so at a different line level, typically at 2v as opposed to the level at the speaker which can range from 15 to 35v.
Working at these lower signal levels means that the components can be optimised for precision operation rather than just the way they can handle power. The end result is a crossover filter network that is much more accurate in operation.
At this low line level each frequency band is then delivered to a dedicated power amplifier which is optimised for that particular frequency range delivering an end sound which more closely reproduces the original sound.
On the surface it appears that active loudspeakers have a range of advantages over passive loudspeakers. The crossover design gives the designer much greater control over the signal which is less prone to loss and distortion compared to passive.
In active the power amplification is integrated into the design which is optimised for the specific drive unit cabinet. Less cabling is also a huge advantage.
On the flip side, when comparing cost, it appears as if passive is a better bet however as in most things in life you need to be careful to compare apples with apples. A passive setup needs to include the cost of a power amplifier which is already included in an active set-up.
Everybody will have their reasons to prefer one type of loudspeaker set-up over another. It may be historically based, it may be room size and layout, it may be portability, it may be cost, or it may just get down to the purity and type of sound which can be achieved.
Whatever your circumstance, SGR Audio has a solution for you.
September 30, 2020
Active versus Passive, it's a big question. In this 1st part of our series, we help you decide on what sort of Loudspeaker suits you best.