Years ago appeared a new kind of speakers called active speakers, with their own electronics inside. These speakers, because of their direct ultra low impedance empowering and digital signal processing tightly coupled to drivers, offers an increased development potential with regard to audio quality.
They also offer the advantage of possible wireless interface.
However active speakers are not well accepted by all audio consumers for at least these reasons:
- Active speakers are incompatible with a regular stereo amplifier.
- Audio systems components should traditionally remain separate.
- Acousticians must remain in their field and are not considered quite legitimate in electronic systems.
How can one address these points and beyond?
An active or passive speaker in a single product
The speaker comprises only the enclosure, a connector, drivers connected to the connector and a memory component also connected to the connector.
The memory component stores at least settings for configuring a digital crossover module.
The speakers can be marketed with a passive crossover module (optional) for traditional use with a stereo amplifier.
The user can as well replace its stereo amplifier and passive crossover modules by a pair of generic active crossover modules comprising: a wireless interface, digital crossovers and digital "amplifers".
Notice that this generic active crossover module contains the same electronics of an active speaker. The only difference is that crossover parameters are now discovered when connecting the module to the speaker.
Competive advantage against active speakers
- The product is highly credible and of great technical cohésion because purely from acoustic technologies.
- The product is legitimate under the traditional model of speaker (enclosure with passive crossover) as it may be plugged to a regular stereo amplifier.
- To follow technology improvements, consumer can upgrade its electronic without changing speakers.
Competitive advantage against passive speaker
- The product offers the possibility while still in the field of traditional speaker to assert a scalable crossover.
- The product can be wireless (Home integration).
- The sound can be much better because of the following points:
- The removal of passive crossover allows much better electric damping of speakers for better bass and transient response.
- The removal of passive crossover also eliminates non linearities from ferromagnetic inductor cores, electrolitical capacitors, as well as the possible protection devices.
- The use of FIR crossover allows fine setting of time alignment as well as amplitude and phase response driver by driver. The result is a much better frequency response in a wider area of the radiation pattern.
- The use of a driver model (this involves an other set of parameters) allows to compensate magnetic and mechanical non-linearity of the driver and its acoustic load.
- The use of a driver model also allows a more accurate management of power handling. In this regard it is possible to act independently on motion and thermal aspects.
Strategic opportunities
- Allows for a speaker manufacturer the total or partial convergence of active and passive speaker ranges.
- Allows speaker manufacturers, to refocus on their core business, which is acoustics not mastery of active nor passive crossover technologies.
- Allows a revival of speakers market on the basis of a new type of product reconciling tradion and modernity.
- Allows a market recovery of audio electronics by creating a new type of component dedicated to accurate powering of drivers.
- Allows any manufacturer of passive speakers to create products benefiting digital active speaker performance without having to acquire digital technology nor to create partnerships.
- Allows for the active speaker manufacturers, the interchangeability of electronics, thus offering more freedom in managing the possiblel partnerships.
Communicating on the concept
What kind of message could be delivered to consumers to justify new investments?
It may be interesting to elaborate on the analogies between this kind of speaker and music instruments.
This speaker does not put any electronic component onto music path.
It is neither an active nor a passive speaker, it is purely an acoustic speaker.
The coupling standard
The real issue here is the definition of an open coupling standard shared by the largest number of brands. Ideally the standardization process should be the widest possible cooperation between acoustics and electronics players.
From this openness will depend the audio market dynamism and fluency. Typically this could be similar to the micro four third system standard created in collaboration between Olympus, Panasonic and Kodak in the field of digital photography.
In case of co-existence of divergent standards, one can nevertheless assume that either on the speaker's side or on the electronic's side, the same product could be available following different variants corresponding to different standards. One may also consider the existence of a product conversions kits to another standard.
Standard Perimeter
The standard should be as flexible as possible in order not to be a constraint in speaker design. For example it should be possible to locate the electronic module:
- Behind the speaker,
- Suspended under the speaker, between base parts,
- Under the speaker, the speaker laid on electronic module (for small speakers).
The standard should not cover more than the following points:
- A form factor range of the electronic module,
- Mechanical interface (how the electronic module is tied to the speaker),
- Electrical interface (pins dedicated to speakers + pins dedicated to memory),
- Data interface (defining how electronic module reads and parses information stored in the memory).
About the author
I hold a master of applied physics (optional signal processing) and a postgraduate degree in electronics.
I made my first experiments in the audio field in the course of the 80s. First with a negative output impedance amplifier to increase electric damping of drivers. I also worked on the mechanical compensation (linear and nonlinear based on analog circuitry) of a bass driver loaded by a reduced volume.
More recently in the early 2000s, I began to think about ways a speaker driver engine could be fitted with a power DAC. I also developed different (unrelated) non-switching class AB amplifiers topologies. One was the subject of a patent in 2010 and another is still nicely operational in my living room.
My professional career is taking place in IT.
