Incredible Surround
FAQ
What is Incredible Surround?
Incredible Surround is the newest patented sound-improvement from Philips. This feature gives the acoustic impression of a very wide stereo effect even if the speakers are located relatively close together.

Why do I need Incredible Surround?
In many Audio and Video sets the distance between the loudspeakers is too short to have a GOOD STEREO effect, as the effect of Stereo-Sound is depending on the distance of the two speakers placed apart from each other. Incredible Surround increases the virtual distance between the loudspeakers: the perceived sound gives an impression of a wider stereo image.

What is Spatial Stereo?
Spatial Stereo is a stereo widening system developed app. 20 years ago to solve the problems as described above. Spatial Stereo can be called the predecessor of Incredible Surround.

What is the difference between Spatial Stereo and Incredible Surround?
The Spatial Stereo effect suffers from coloration of the sound and more or less seemed like an Echo-function. The effect of widening the stereo-base is not as impressive as the one of Incredible Surround. Spatial Stereo uses a non-frequency dependent cross-talk between the Left and Right channels, giving a phasey sound impression. While Incredible Surround uses frequency dependent cross-talk filters, based on investigations of the human perception of stereo sound.

What is the difference between Incredible Surround and Dolby-Prologic Surround?
Dolby Prologic is a cheaper version of Cinema-Sound for normal living rooms. A Dolby Prologic System decodes an encoded music signal into 4 channels (left/right/center/surround), which can be played back through 3,4 or 5 speakers. Incredible Surround is intended to improve the stereo-sound-impression, and does only need two loudspeakers and only a normal stereo signal. However it works fine with Dolby encoded signals as well.

Is Incredible Surround only a feature for Audio-Equipment?
Incredible Surround is suitable for all sound reproduction apparatus, like television-sets, multi-media monitors and of course Audio-Equipment as 3M-and portable sets. Incredible Surround is only available from Philips!

What is adjustable (parameterizable) Incredible Surround?
Some listeners have the idea that the effect of Incredible Surround is overdone, and want to adjust/reduce the effect of IS. Therefore the effect is made adjustable (parameterizable) in a very simple way with only one knob. The effect can be adjusted between 0% (normal stereo) and 100% (full Incredible Surround). Depending on the set, where Incredible Surround is built in, the feature can be adjusted in different steps (1 - 2 - 3).

When listening to Incredible Surround you have the impression that the high frequencies are enhanced, why?
Incredible Surround is tuned in such a way that - while listening on the axis between the loudspeaker- the timbre or sound color, is the same as without Incredible Surround. While if one deviates from the listening axis in a lateral way the color might change, however with normal stereo, the stereo effect decreases too.

Why is the performance of Incredible Surround different in Audio & TV-sets?
Basically, there is only one Incredible Surround circuit (either paramerizable or fixed). However, in order to optimize the sound for various sets, local developers might adjust the sound for a particular set, to optimize the performance of Incredible Surround for this particular set. As you can imagine, different sets like Tvs, Hifi-Components or CD-RCRs have different demands on the sound output.

Why does Incredible Surround sound differently when the loudspeakers are place apart?
The system is designed for set-ups with closely positioned loudspeakers. For wide separated loudspeakers, the effect can be decreased in sets with adjustable Incredible Surround, or even switched off, since the effect is not necessary in such set-ups (See Answers 1 and 2!).