Using the ADmonitor/Preference/Submonitor

The Admonitor , Admonitor Preference and Submonitor were born as an answer for an accurate high quality multi-channel music monitoring and reproduction system, with performances compatible with the highest currently available recording standard: DXD .

The individual products have been designed to conform and be compatible to all available musical multi-channel recording procedures (standard 5.1 to 10.2 through Dabringhaus 2+2+2 and Chesky 6 channel proposals)

Please note that we strongly emphasise the multi-channel musical reproduction aim of the system rather than the home theatre aspect… Home theatre systems are designed to mimic the cinema hall experience, film soundtrack mixes are optimised for halls, not domestic surroundings. Strong sound effects play a major role in films, opposed to music. Which helps explains the common rejection of home theatre solutions by music lovers and audiophiles . Our understanding is that music will seldom sound right on a typical home theatre optimised system, but films will always sound good on a multi-channel music optimised system.

The A/P/S system is compatible with many high quality amplifiers. Depending on room size between 25 and 250 Watts nominal power would be recommended, either tube or solid state . Care has to be taken for the quality rather than the quantity.

Usual care has to be taken for room acoustics (an excellent introduction can be found at www.wilsonaudio.com/technotes/roomacoustics.shtml). Please ask for advice form your dealer or the distributor if any acoustic treatment is necessary. Full optimisation of the listening room may require an acoutics expert, and possibly the use of digital "inverse function" digital room corrections.

We have gone for the no-compromise optimisation of the musical multi-channel experience, having accurately analysed the various available classical/acoustical multi-channel recording techniques . So our advice for setting up speaker systems is slightly different from the ITU-R BS.775-1 standard configuration.

In our experience it is most important to get right the front "stage" impression. Historically there have been quite a few important recordings commissioned in a 3 channel format , the most well known are the Decca "Decca Tree" and the Mercury "Living Stereo" recordings (the latter are available in the original 3 channel format on SACD), these recordings are a good way to judge the value of a 3 channel format.
We recommend to set up the front 3 channels with a 60° to 72° angle instead of the standard 30° The front left and front right speakers should be angled so that their axis cross roughly 0.5 to 1 meter in front of the central listener . The centre channel should be positioned in such a way as to be on the same virtual circle defined by the left front and right front speakers , if needed the centre channel should have delay applied, 2.94 ms for every meter of disparity (Where the centre channel is closer).

In the majority of multi-channel recordings conducted with classical music and pure acoustical music, the rear channels only carry "ambient" information such as hall acoustics (reverberation etc...) and public presence ( applause etc... ) , so it is very important that the rear positioned left and rear right speakers do not "dominate" the listening , creating a "giant headphone" effect , with resulting listening fatigue .
Along with the Recording Academy's Producers and Engineers Wing , we recommend to place the rear right and the rear left angled at 135° to 150° on the virtual circle (not the 110° of ITU-R), possibly in space and time , this might need the application of appropriate time delay on to the rear channels (too much delay being slightly better than too little) . Listening volume for the rear speakers should be set subjectively to create the right presence effect, too little being better than too much.

The virtual circle should optimally have a radius of 2 to 3 meters, but this parameter can be rather more flexible . The speakers should be ideally at the same height, as defined by the height of the Submonitor . If positioned higher, the centre channel and rear channels should be set up upside-down. One possible solution is to set the speakers up in "Pentagon" fashion , with a 72° angle in distance between all of them, the front speakers should be toed in to cross their axis 0.5 to 1 m in front of the central listener, the rear speakers should cross their axis 0.5 to 1 m behind the central listener.


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If possible, to limit early reflections, it would be ideal to have all speakers positioned at a minimum distance of one meter from the room walls, but this is very unlikely in domestic surroundings.

We recommend to use Admonitor ( Preference ) + Submonitor for front left and front right and Admonitors ( Preference ) for centre and rear channels . Using 2 Submonitors for left front and right front is ideal for correct low frequency decorrelation. Since there is no standard for bass management, it is possible to add later a specific infra-woofer for very low frequencies ( 5 to 75 Hz ) to this set-up , in addition of the two Submonitors, but not as substitution .

In case of use with large vision projection screens and/or rear vision projectors, it is possible to use 2 Admonitors/Preferences, one upside down over the screen and one upright under it .

Were there is a need to increase the number of playback channels, it is ideal to do it in view of optimising first the lateral perceptive quadrant, then the rear perceptive quadrant and last the height perception. But since the present standard is defined with 6 (5.1) channels , it is advisable to obtain the best results with this set up.
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In case of 2 channel reproduction , we still recommend the above optimisation: 120° to 144° between the 2 front channels and speakers angled in with crossed axis 0.5 to 1 m in front of the listener . Many homes do not allow for optimal multi-channel systems, due to size or logistics constrictions . It is much better to have a good 2 channel set-up than a bad multi-channel set up It is also eventually a good starting point with stereo first and adding the other channels later.

Due to the complexity of low frequency room interactions, for ideal optimisation purposes it is possible to interface the Admonitor and Admonitor Preference in different ways to the Submonitor :
- Using the upper modules with the internal crossover (high pass) of the Submonitor. Experimenting with the phase of the connection in some specific cases might be useful.
- Using the upper modules in "Bi-Wiring" fashion.
- Using the upper and lower modules in passive "Bi-Amping". Using one stereo power amp for each channel.
- Using the upper and lower modules in active "Bi-Amping", with a low level passive crossover (soon to be released). Also, using a stereo power amp is possible, for each channel .

For extensive information on room acoustics and electro-acoustic interface and correction, we suggest the following reading:
- A new approach to the design of control room acoustics , Robert Walker , BBC R&D dept., AES preprint 3543 , 94th AES Convention 1993 , Berlin.
- A controlled-reflection listening room for multi-channel sound , Robert Walker , BBC R&D dept., AES preprint , 104th Convention 1998 , Amsterdam.
- The loudspeaker-room interface, controlling excitation of room modes , R. Wilson , M. Capp , R. Stuart , AES , 23rd International Conference , 2003 Copenhagen.