3Com CP-1 manual

Panorama Am bience Reverb Surr oun d CP-1 Digital A ud io Environment Processor Owne r' s Manual[...]

Unpac king and Inspection After unpacking the CP-1, save all pac king m aterials in case you ever need to ship the uni t. Thoroughly ins pect the CP-1 and packing materials for signs of da mage. Report any s hipment damage to the carr ier at once ; report equipment malfunction to your dealer . Precautions This equipment generates and uses radio fre[...]

Safety Suggestions Read Instructions Read all safety and operating instruc- tions before operating the unit. Retain Instructions Keep the safety and operating instruc- tions for future reference. Heed Warnings Adhere to all warnings on the unit and in the operating instructions. Follow Instructions Follow operating and use instructions. Heat Keep t[...]

Table of Contents CP-1 Digital Audio Environment Processor 1 Controls and Indicators Introduc tion 1 The Front Panel 2 The Rear Panel 3 The Remote Control 4 2 Connect i on and Calibration Installation 7 Connect i on s to Other Equipment 7 Setting t he Main Input and Outpu t Levels 9 Calibrati on of t he Panorama Program 11 3 Speaker Set-Up a nd Con[...]

Page 1 CP-1 Digital Audio Enviro nment Processor Introduction Controls and Indicators 1 All of the programs in the Lexicon CP-1 Digital Audio Environment Processor have a common goal: to draw you, the listener, more deeply into a musical performance or a film. For music the CP-1 uses unique digital processing to re-create either the original record[...]

Page 2 Lexicon The Front Panel Source The SOURCE buttons select one of two identical stereo pairs of audio inputs. Ordinarily Input I will be connected to the main outputs of your stereo preamp and the second input will be a spare. In video installations, Input I will be connected to the main audio outputs of your TV receiver, VCR or audio/video co[...]

Page 3 CP-1 Digital Audio Enviro nment Processor The Rear Panel Rea r and Si de Outputs Stereo outputs for rear and side power amplifiers, with level adjusting knobs. The procedure for balancing these outputs (as well as the center channel and subwoofer) with the main pair begins on page 9. Main outputs, with level adjustment. Level-setting of thes[...]

Page 4 Lexicon The Remote Control The Prog ram s The REVERB programs, like AMBIENCE, simulate rooms of three sizes with the aid of side and rear channels. These programs have fewer specific initial reflections than AMBIENCE but richer and smoother reverberant decay. REVERB is especially good for simulating large, highly reverberant spaces. Reverb T[...]

Page 5 CP-1 Digital Audio Enviro nment Processor Surround Controls and Indicators * The first push of either of this pair of buttons displays the current value for five seconds; another push during that time increases or decreases the displayed value. Holding the button down for 1 second engages auto-repeat. SYSTEM MUTE turns off all outputs and li[...]

Page 6 Lexicon Controls and Indicators[...]

Page 7 CP-1 Digital Audio Enviro nment Processor 2 Connection and Calibration Installation • Make sure the remote control receiver, located on the right side of the front panel, is unobstructed. The remote control must be in line of sight to this receiver for proper operation. The CP-1 may be placed in a glass- doored cabinet but smoked glass wil[...]

Page 8 Lexicon Connection and Calibration VCR or CASSETTE DECK AUDIO OUT I II TAPE OUT/IN REAR MAIN SIDE SIDE AMPS CP-1 INPUTS VCR, TV, VIDEO CONTROL CENTER REAR AMPS CENTER AMP SUBWOOFER AMP CENTER SUB WOOFER INTEGRATED AMP, PREAMP or RECEIVER TAPE IN TAPE OUT Connect i ng the CP-1 in a Tape Monitor Loop Connect the main outputs of your audio prea[...]

Page 9 CP-1 Digital Audio Enviro nment Processor Connection and Calibration Push the INPUT I button on the front panel. Push the MONITOR SOURCE and TAPE PRE buttons. Turn the INPUT LEVEL knob all the way down (counterclockwise). The CP-1 has its own volume and balance controls, which you will be using in place of the ones on your existing preamp or[...]

Page 10 Lexicon Connection and Calibration The output level potentiomenters (the small knobs above the output con- nectors on the CP-1 rear panel) allow you to balance the sound levels of all the channels in your system relative to each other. The most important thing to keep in mind when calibrating the system is to keep these potentiometers set a[...]

Page 11 CP-1 Digital Audio Enviro nment Processor Connection and Calibration PANORAMA works by canceling the sound going from each speaker to the opposite ear. The effectiveness of the program is highly dependent on the geometry of your front loudspeakers, the room and your listening position. The correct timing of the canceling signal varies with [...]

Page 12 Lexicon Connection and Calibration go on to step 6; otherwise, perform step 5. 5. Push PARAM twice so the display reads: SPEAKER ANGLE. If the sweet spot from step 2 (LEFT ONLY) is to the left of the sweet spot from step 4 (Right ONLY), push PARAM UP once. If the the step 2 sweet spot is to the right of the step 4 sweet spot, push PARAM DOW[...]

Page 13 CP-1 Digital Audio Enviro nment Processor Speaker Set-Up and Configuration Configuration Speake r Configurations 3 Press the PARAM UP or DOWN buttons until the contrast of the display is at a maximum as seen from your listening chair. Then push PARAM to enter the Configuration menu. Consulting the Speaker Configuration Chart, push PARAM UP [...]

Lexicon Page 14 Speaker Set-Up and Configuration Notes on Amplifiers How much power do you need? That depends on a number of variables — How efficient are your speakers? How big is the room? How loud do you play the system? Generally, the demands on the side and rear channels are higher for film sound than for music. The center channel is actuall[...]

Page 15 CP-1 Digital Audio Enviro nment Processor Speaker Set-Up and Configuration If your center channel speaker is smaller than the left and right fronts, increasing BASS BLEND will remove low bass from the center and increase it in the left and right speakers. The center channel is so important that if it is not possible to have an extra center [...]

Lexicon Page 16 1 Center Phantom Button IN Good 9 Center Phantom Button IN Best Better Center Phantom Button IN 5 If your main interest is music, you will most likely begin with two high- quality main speakers (Configuration 1). Here the Panorama program alone will add substantial enhancement in spatial impression, image size, image depth and freed[...]

Page 17 CP-1 Digital Audio Enviro nment Processor Subwoofer Connections The Subwoofer Output is a monaural signal created by summing the left, right and center outputs, then filtering out frequencies above 100 Hz at a rate of 12 dB per octave. Connecting a subwoofer to the CP-1 rear-panel Subwoofer Output, adds bass energy without removing any from[...]

Lexicon Page 18 Speaker Set-Up and Configuration[...]

Page 19 CP-1 Digital Audio Enviro nment Processor To Load, Modify and Store Programs 4 Using the Programs The CP-1 contains four basic programs: Panorama, Ambience, Reverb and Surround. Each program has three variations which occupy one row on the remote control. Pushing one of the buttons numbered 1 through 12 during normal opera- tion will load t[...]

Page 20 Lexicon Panorama The Programs: Panorama The location of the front speakers and the listening position are crucial to Panorama’s effectiveness and for best results your system and the CP-1 together should be set up and calibrated according to the procedure on page 10. The strength of the Panorama effect drops off as you move away from the [...]

Page 21 CP-1 Digital Audio Enviro nment Processor The Programs: Panorama The procedures for naming a new version of the program (SET PROGRAM NAME) and storing it in one of the User registers (MEMORIZE PROGRAM) are described on page 29. Set Program Name/ Memorize Program The use of the CALIBRATE mode is described in the setup instructions beginning [...]

Page 22 Lexicon Ambience The Programs: Ambience Ambience generates the appropriate early reflections for stereo simulation of one of six different halls — one rectangular hall and one fan-shaped hall in small, medium and large sizes — and sends the reflections to the side and rear speakers. For systems with only two loudspeakers, Ambience also [...]

Page 23 CP-1 Digital Audio Enviro nment Processor The Programs: Ambience ROLLOFF mimics the absorption of the air in the hall and its initial value is therefore more pronounced (the rolloff begins at a lower frequency) the larger the space. Rolloff PANORAMA EFFECT adjusts the strength of the signal used to expand the stereo image outward from the f[...]

Page 24 Lexicon Reverb The Programs: Reverb The Reverberation program differs from Ambience in that it does not simulate the early reflections of specific halls, but emphasizes rich, smooth reverberant decay in small, medium or large spaces. It works well for simulating a space with a long reverberation times relative to its size, such as a reverbe[...]

Page 25 CP-1 Digital Audio Enviro nment Processor The Programs: Reverb MID RT (Midrange Reverberation Time) is the time required for midrange sounds to decay 60 dB in level. Your choice of small, medium or large synthesized space determines both the initial value and the available range of MID RT. Mid RT BASS RT, the low-frequency reverb time, depe[...]

Page 26 Lexicon Surround The Programs: Surround Treble Mono Logic Program Paramete rs Effect Level The term Dolby Stereo refers to both movies and equipment used exclusively for theatrical presentation. When one of these movies is transferred to commercial video media, the special audio encoding of the Dolby Motion Picture matrix is retained in the[...]

Page 27 CP-1 Digital Audio Enviro nment Processor The Programs: Surround REAR ROLLOFF controls the treble attenuation and should be adjusted on music for maximum airiness and spatial realism without causing specific instruments to seem to come from behind you. Stereo Logic’s REAR ROLLOFF parameter contains an AUTOMATIC mode. In this mode the rear[...]

Page 28 Lexicon Program Parameters cont 'd The Programs: Surround Auto Azimuth/ Balance The AUTO AZIMUTH/BAL parameter should be set to ON for films, OFF for music. When it is on, special digital circuits continually monitor the dialog and adjust both the relative level and time offset of the two channels to keep the dialog properly centered. [...]

Page 29 CP-1 Digital Audio Enviro nment Processor To Rename and Store a Register Storing a Register Nam ing a Register Using the Programs Res t oring Original Settings 2. Push program # to select a position 1.Push Param to SET PROGRAM NAME 3.Push UP/DOWN to select a character See also TEST MODE, page 17. USER banks store automatically. 1. Push PARA[...]

Page 30 Lexicon Using the Programs[...]

Page 31 CP-1 Digital Audio Enviro nment Processor 5 Troubleshooting Troubleshooting If you encounter a problem, please review the items in the following checklist. Also be sure to thoroughly check all other connected components such as speakers, receiver/amplifier/preamp, VCR, TV, CD player, etc. Problem Possible Cause and So lutio n Input level me[...]

Lexicon Page 32 Troubleshooting Problem Possible Cause and So lutio n Muffled sound in L&R channels When no center channel is used, the rear-panel phantom button must be pushed IN. Center channel sound muffled The center channel amp may be connected to the subwoofer jack on the CP-1 rear panel. Reconnect to Center Output jack. Hum Finding and e[...]

Page 33 CP-1 Digital Audio Enviro nment Processor Troubleshooting Problem Po ssible Cause and Solution Restoring defaults If severe power surges or sags cause problems with CP-1 memory storage, or you simply want to start with a clean slate in the User registers, you can restore factory presets into the User registers with the following procedure. [...]

Lexicon Page 34 Troubleshooting[...]

Page 35 CP-1 Digital Audio Enviro nment Processor Lateral Sound For decades the study of concert-hall acoustics relied on certain basic measurements to characterize halls, the main one being the time it takes a sound to drop in level (decay) by 60 decibels. This is called the reverberation time or RT 60 and is approximately the same as the time it [...]

Lexicon Page 36 } Side sound must be within this angle. Theory and Design Understanding the importance of lateral reflections enabled more accurate evaluation of architectural acoustics. The best halls were usually found to have high lateral energy for obvious architectural reasons, such as a long narrow shape with high ceilings. Fan-shaped halls, [...]

Page 37 CP-1 Digital Audio Enviro nment Processor Theory and Design sides. Both methods depend on having the added sound come from a different direction than the original music, and each method has some advantages. With either method of generating SI there is an additional choice the CP-1 allows the user to make: the sideways energy cues of the ori[...]

Lexicon Page 38 the left speaker. The main problem with a first-order device is that the subtracting signal is also heard by the opposite ear. In our example, the canceling signal from the right loudspeaker will diffract around the head to the left ear, interfering with the left-speaker sound and producing a “comb filter” which colors the sound[...]

Page 39 CP-1 Digital Audio Enviro nment Processor signal that is canceling it are eliminated. This works extremely well when the room is well damped and the listener’s head is correctly positioned. The first order devices described earlier required the listener to sit on the center line between the loudspeakers, and to arrange the angle between t[...]

Lexicon Page 40 In a well-damped room with loudspeakers mounted on stands away from the walls, the Panorama effect can be very exciting, giving the closest possible approximation to the actual hall used for the recording. With true binaural recordings (made with a modern dummy head with accurate external ears and proper equalization) the playback c[...]

Page 41 CP-1 Digital Audio Enviro nment Processor Panorama greatly increases low frequency width and should only be used with true binaural recordings, which have very little out-of-phase low frequency energy. A few compatible binaural recordings are becoming available, in which the low frequency width has been increased to match the requirements o[...]

Lexicon Page 42 B A Theory and Design The best way to generate spatial im- pression (SI) is with appropriate sig- nals from loudspeakers at the side. Reverb, Ambience and the Surround programs can all be used to generate these signals. be the sound that comes from the sides. Early research with quadraphonics involved extensive experimentation with [...]

Page 43 CP-1 Digital Audio Enviro nment Processor Theory and Design Reverb is very good for simulating a large reverberant space. Th e Reverb Program music. If you have no side loudspeakers, both Ambience and Reverb contain versions of the Panorama program that will simulate them within a narrow area between the speakers. Choosing one of the speake[...]

Lexicon Page 44 The Su rround Programs Theory and Design enhanced film viewing. Mono Logic is a stereo conversion program for monaural film sound tracks. A quick look through any video rental selection will prove the usefulness of such a program; the vast majority of titles are mono. The problem of mono-to-stereo conversion is an old one. One time-[...]

Page 45 CP-1 Digital Audio Enviro nment Processor room simulator has outputs for left, right, side and rear surround speakers. The monaural input sound from the film is unchanged in the center speaker, so that all the dialog and music that the director expected to come from the screen still does, with no modification or reverb. Partly because of th[...]

Lexicon Page 46 Simple logic decoders turn down the left and right speakers during dialog. This seriously affects music and ef- fects. speakers, effects are smeared and often unconvincing . Pro Logic Decoding A Pro Logic decoder, like the professional Dolby Stereo cinema processor, both enhances the dialog in the center and removes it from the left[...]

Page 47 CP-1 Digital Audio Enviro nment Processor Pro Logic decoders remove dialog from the left and right channels, while maintaining stereo as much as possible. Pro Logic requires phase accuracy. Common azimuth errors cause ghost dialog in all channels unless the azi- muth error is corrected. Theory and Design is even more important in a home dec[...]

Lexicon Page 48 result is superior steering. An added benefit is that the CP-1 is the only Pro Logic decoder which needs no front panel input balance control; the user need not bother with this adjustment. You can check the quality of the balance and azimuth in a tape or disc if you wish by turning the Auto Azimuth/Balance parameter off and observi[...]

Page 49 CP-1 Digital Audio Enviro nment Processor Theory and Design sounds appear in the front left and right speakers (and the side left and right speakers, if present). The Rear Noise Chip parameter is preset to OFF, meaning that the high- frequency sound in the rear channels is set solely by the Rear Rolloff parameter. (The Rear Noise Chip shoul[...]

Lexicon Page 50 Theory and Design sound does not. Occasional extra wide sound effects can seem peculiar at first for being so much wider than the screen but when the mix is good the emotional impact of the wide sound can be very great. The disparity between the size of the video screen and the size of the sound is usually easy to accept, and the ad[...]

Page 51 CP-1 Digital Audio Enviro nment Processor 1. Schroeder, M.R., Gottlob, D. and Siebrasse, K.F.,"Comparative Study of European Concert Halls: Correlation of Subjective Preference with Geo- metric and Acoustic Parameters", J. Acoust. Soc. Am., vol. 56, pp. 1195-1204 (1974). 2. Barron, M., and A.H. Marshall, "Spatial Impression D[...]

Lexicon Page 52 Theory and Design[...]

Page 53 CP-1 Digital Audio Enviro nment Processor 7 Specifications Patents are pending on the CP-1 Unprocessed channels: 10 Hz - 100 kHz, +1, -3dB* Processed channels: 10 Hz - 16 kHz, +1, -3dB* *Ref. 1 kHz Frequenc y Response: Front: Less than .05%, 1 kHz, max level Sides: Less than .05%, 1 kHz, max level Center: Less than .05%, 1 kHz, max level Re[...]

06/00 | Lexicon Part #070-06619 | Rev 3.0 Printed in the United States of America 3 Oak Park Bedford, MA 01730 USA Telephone 781-280-0300 FAX 781-280-0490 www.lexicon.com[...]