Meridian DSP8000 User Manual page 12

1
Technical History
Being able to deliver bass from an enclosure an eighth of the size is a useful ability:
it makes possible loudspeakers that are physically the right size: on a human scale.
That means that they will fit into a room more easily, and take up less space.
Stereo imaging is also significantly improved: the more like a point source your
loudspeakers sound, the better the soundstage – especially in surround.
The Digital Dimension
Digital media like CD and DVD made it possible to take the next step and keep the
signal in pristine digital form as long as possible – with many benefits. There are
no long analogue cables carrying signals to the loudspeakers, for example, with the
possibility of induced hum and noise: a slim cable carrying digital audio data is all
that's required. Full level is supplied to the loudspeakers, removing issues with noise
at low levels.
The final step is the addition of Digital Signal Processing (DSP) to the digital
loudspeaker. Meridian uses DSP in loudspeakers to provide the crossover, allowing
the digital to analogue converter (DAC) to be placed even later in the chain. A
separate DAC is used for each band, maximising dynamic range – currently up to
10 dB – for better intermodulation performance and lower background noise.
This, however, is only the beginning. Now you can design "impossible" crossovers,
with linear phase, steep slopes, and time delay compensation; and even "apodising"
filters, which can actually clean up some recording problems, especially in early digital
recordings.
Volume control in a Meridian DSP Loudspeaker uses a precision combination of
analogue and digital techniques, giving the best of both worlds. And "balance"
doesn't just mean changing the relative levels of the loudspeakers. Instead, it's more
a "Where am I sitting?" control, using both level and time delay to make the sound
exactly right in the listening position you choose. Our processors can also provide
decoding using Trifield and Ambisonic technologies, which recreate a solid image
of the original environment in your listening room – producing an incredibly lifelike
surround-sound experience.
DSP technology also provides additional features, such as tone controls. Loudness
controls can be implemented more naturally than ever before, along with dynamic
bass extension in smaller loudspeakers, where low frequencies are boosted more at
low levels. The system computes voice coil temperature, cone movement, frequency
and level to provide bass and thermal protection. Allowance can be made for different
locations, such as being placed near a wall.