Von Schweikert Audio

Transcription

1 VR-S/1 HIGH-SPEED Subwoofer Instruction Manual Please read this manual thoroughly before using your new subwoofer. There are several different ways to connect the VR-S/1 and proper adjustment of your system can be found in this Manual. Thank you for purchasing the VR-S/1 engineered by, a leader in scientific loudspeaker technology. This active subwoofer system has been designed to combine an extremely high level of clarity with very deep bass (20 -3 db) at high output levels. Transient response speed and accuracy have been optimized by our use of space age technology and unique engineering not available at this price point from any other manufacturer. The transient response of many subwoofers often suffers because large woofer cones are typically too heavy to respond quickly to the input signal, blurring the sound. In addition, large diameter woofers are susceptible to cone flex, which further muddies the sound quality. Most subwoofers, when played without the main speaker, sound like a roar, without any pitch definition or timbre. It is often quite difficult to determine whether the bass sound was caused by a train going by or a kettle drum. EXTREME-DUTY DRIVER To eliminate transient speed problems and cone flex distortion (approaching 30% at low frequencies at high power output!), the VR-S/1 Extreme-Duty woofer utilizes a space age diaphragm made from carbon fiber reinforced ABS, an incredibly rigid and lightweight material specifically designed for low frequency clarity combined with massive "punch." The 10" cone has enough surface area to energize very large rooms, allowing high SPLs to be generated with extreme clarity, a combination of sonic factors not found in competing models. To handle high volume levels without distortion, we have employed a Low Distortion Motor System with an extremely long voice coil (2" peak-to-peak excursion), high temperature rated 2.5" diameter voice coil (can handle 1,000 watt peaks without burning), and double-spider suspension with Bias Control. One of our two major advances in technology relating to the extremely accurate speed and lack of transient blur is the Bias Control spider design. Since most subwoofer drive units employ only one spider to hold the voice coil in position in the magnetic gap, the cone tends to continue to vibrate long after the signal has stopped, since the cone mass cannot be easily damped with a loose suspension system. Our solution was to use two spiders, with one biased towards the outward cone travel motion, while the second spider is biased in the opposite direction. Since the two extra-heavy duty spiders are opposing each other, they mechanically "brake" the cone motion very quickly after the input signal has stopped. In fact, our subwoofer has 4 times less ringing than 1

2 conventional designs! When combined with our very thick and stiff edge surround and 15 lb magnet with a very high degree of magnetic damping, our Double Spider system with Bias Control is a major advancement in transient response clarity. If you are wondering whether these improvements actually contribute to an audible difference, we offer the fact that the VR-S/1 is the only subwoofer we have tested that is as fast and clean as a midrange driver! Imagine being able to hear each mallet strike in a kettledrum roll or the sound of fingerprints brushing the catgut strings of an upright bass. If you are an action movie fan, be prepared to experience window-rattling power! CABINET DESIGN Since the enormous pressures generated by our Extreme-Duty driver would distort an ordinary cabinet, causing serious resonances that would interfere with its clarity and output, we over-engineered the cabinet's rigidity. The maximum density resinfiberboard is twenty-five millimeters thick with heavy internal bracing, eliminating wall flex. Since the VR-S/1 had to be as small as possible without compromising the extreme engineering and sonic standards we envisioned, it was not possible to use any type of porting to augment the deep bass range since the cabinet is too small to use a port. Consequently, this is a sealed design, with no resonant signature. As small cabinets normally truncate the deepest bass frequencies, we have preprogrammed the amplifier with a correction circuit combined with electronic servo control that ensures powerful response down to 20 Hz (-3dB). DOWNWARD FIRING DRIVER To reduce the dips and peaks caused by standing waves, our design target specified a 360-degree radiation pattern. This was accomplished by firing the woofer at the floor, and the result is a more uniform bass-wave propagation. All enclosed rooms generate standing waves due to boundary reflections, and this causes severe dips and peaks of up to 18 db in the frequency response! By using a 360-degree dispersion pattern, the standing wave situation is broken up into smaller dips and peaks spread out over a wider range, greatly reducing the audible "room boom." Another advantage of firing the woofer downwards is the physical slot loading of the bass pressure. In theory, the woofer's diameter is not large enough to efficiently couple with the air in the room; however, using the slot loading technique (where the woofer's bass wave pressure is modified by the floor boundary 2" from the cone), the radiation resistance is more closely matched to the room. The result is louder, tighter bass response. To accomplish slot loading, we supply 2" spikes that elevate the cabinet. AMPLIFIER Most competing subwoofers use Class D switching amplifiers due to their low cost, light weight, and high efficiency. However, in side-by-side listening tests against Class A/AB High Current amplifiers, the Class D switching amps do not have the depth or heavy impact of the traditional High Current Class A/AB amps. For this reason, we have engineered a 300- watt Class A/AB High Current amplifier with 600 watts of peak power available. The huge transformer and large filter capacitors enable the bank of 2

3 high current transistors to put out enormous peaks without distortion (0.08% THD). Since the small sealed cabinet would not normally allow the woofer to respond at 20 Hz due to the high internal air pressure and subsequent high resonance frequency, we have engineered a feed-forward pre-programmed correction circuit into the input stage. However, since the overall output has to be monitored to ensure correct moment-tomoment transient response accuracy, we have designed an electronic monitoring circuit, which samples the back electromotive force generated by the woofers voice coil. With feedback correction, we have simplified the principle of servo control, ensuring an extremely high quality response to the most challenging input signal. The VR-S/1 will probably be the best sounding subwoofer you have ever heard! Naturally, all necessary controls and inputs/outputs are provided, as well as a removable IEC power cord, 117V/230V switch and 2" spikes to elevate AMPLIFIER CONTROLS Volume Level control potentiometer; Crossover Frequency control, calibrated from 50 Hz to 100 Hz. Phase Reversal switch, two position, 0- degree and 180- degree selection. Crossover Bypass switch. For adjustment information, see the SETUP section below. SUBWOOFER PLACEMENT The VR-S/1 Subwoofer has been designed to be placed almost anywhere in the room. When used in a two channel stereo system with small speakers, it is desirable to place the sub between the speakers, on the same plane, if possible. This will integrate the sound stage in a very coherent manner. However, since the bass waves will reflect from all of the room boundaries, there will be a series of peaks and dips in the bass response if the sub is placed in the wrong place. The smoothest bass response occurs when the subwoofer is placed against the wall or better yet, in the corner of the room. However, this does not automatically guarantee that the bass will be totally integrated with the main speakers unless they are also placed for the smoothest bass response. For this reason, placement experimentation is mandatory with both the sub and the mains. If you are happy with the linearity of the bass response you are obtaining with your main speaker system and do not hear problems with dips and peaks, then placing the sub in the room corner will most likely result in a good blend. If the main speakers are more than ten feet away from the sub and you hear a hole between the mains and the sub, try reversing the phase of the sub using the Phase Reversal Switch. Keep in mind that deep bass is largely non-directional at frequencies below 80 Hz, and that system integration will be facilitated with the BASS LEVEL, CROSSOVER FREQUENCY, and PHASE controls. For adjustment of these controls, please see the SETUP section below. It is recommended to keep the VR-S/1 at least 3 feet from conventional video monitors, as the magnet is not shielded. 3

4 MOUNTING IN EQUIPMENT CABINET Since the slot loading and downward firing techniques are designed for free space placement, they are not optimum when placing the VR-S/1 sub in an equipment cabinet. To achieve best performance in a cabinet, do not use the supplied metal spikes. Instead, place the VR-S/1 on its side, with the driver facing the opening in the cabinet door. To reduce the transmission of vibration that will cause a boomy coloration, use the supplied soft rubber feet. CONNECTING TO YOUR SYSTEM The VR-S/1 is unique in that is has been optimized for transparent two-channel music listening and extreme bass punch for explosions and special effects when watching action movies. There are two input sections, one for two-channel connection and the other for multi-channel processors used for movies. You can actually use both inputs at the same time, so you don't have to configure the subwoofer for the two different usages each time you change from music to movies. See below for details on High Level and Low Level input connections. BEFORE YOU BEGIN: Prior to making any connections to the VR-S/1, be certain to turn the VOLUME control all the way down (counterclockwise) on the subwoofer amplifier, and turn the main system off. MULTI-CHANNEL PROCESSOR HOOKUP FOR MOVIES: Connect a single RCA interconnect from the processor/decoder or multi-channel "receiver" to the Right Channel LINE IN input of the subwoofer amplifier. If your processor has a stereo output, run a stereo interconnect to the subwoofer amplifier inputs. Next, making sure that the VOLUME control on the subwoofer amp is turned down to "0," plug the subwoofer amp into an 120V/60Hz AC outlet. Refer to the SYSTEM INTEGRATION section of this manual. TWO CHANNEL SYSTEM, USING PREAMPLIFIER OUTPUTS: Using a high-quality stereo RCA cable, connect the Left and Right preamp-out or lineout jacks on your main preamplifier to the respective LINE-IN input jacks on the subwoofer amplifier. Then connect another stereo RCA interconnect cable to the OUTPUT RCA jacks on the subwoofer amplifier and run this to the main amplifier, completing the connection. Alternately, for a cleaner signal, run two pairs of RCA interconnects to both the subwoofer amp and the main amp. If you do not have two sets of RCA output jacks on the preamp, use a very high quality Y splitter. Finally, making sure that the VOLUME control on the subwoofer amp is turned down all the way, plug the subwoofer amp into an 120V/60Hz AC outlet. Refer to the SYSTEM INTEGRATION section of this manual. 4

5 TWO CHANNEL MUSIC SYSTEM, WITHOUT SUBWOOFER OUTPUT JACKS: If you do not have low-level (line-level or preamp-level) output jacks available, speaker wire can be run either from you main amplifier s speaker outputs, or, if the main speakers are closer to the sub, directly from your main speakers to the HI-LEVEL IN binding post inputs on the subwoofer amplifier. Connect the subwoofer amplifier parallel to your main speakers, i.e. positive to positive and negative to negative. Double-check connections at both the subwoofer and your main amplifier (and your main speakers if that s where the subwoofer is connected) before plugging in the subwoofer amplifier. Next, making sure that the VOLUME control on the subwoofer amp is turned down to "0," plug the subwoofer amp into an 120V/60Hz AC outlet. Refer to the SYSTEM INTEGRATION section of this manual. AUTOMATIC POWER-ON. Once the subwoofer amplifier is plugged in, it will switch on automatically when an audio signal is detected; the pilot light will change from red to green. After 15 minutes without an input signal, the subwoofer amplifier will automatically shut off again. The pilot light on the amplifier will change from green to red when the signal has not been sensed for 15 minutes. SETUP: INTEGRATING THE SUBWOOFER INTO YOUR SYSTEM VOLUME/BASS LEVEL CONTROL. If possible, use an SPL (Sound Pressure Level) meter and test tones or pink noise from a test disc or your decoder/receiver to match the output level of the subwoofer to that of your main speakers. If using pink noise or test tones without an SPL meter, be aware that the human ear is most sensitive in the upper midrange and least sensitive in the deep bass, so well integrated bass will not appear as loud as the midrange when using pink noise. Confirm the bass level by listening to a variety of recordings. Many first time subwoofer users tend to turn the volume level too high, in order to feel the music. However, this will degrade the sound from the main speakers since you will overpower the midrange with the bass volume level. If you hear any compromise in the midrange tone quality of the main speaker, you have turned up the subwoofer volume too high or you have set the crossover frequency too high, see below. LOW PASS SWITCH. If you wish to use the crossover built into your decoder or receiver and do not need a steep rolloff slope, flip the Low Pass switch to OFF (left position) on the subwoofer amplifier. This switch will disconnect the electronic crossover inside the subwoofer amplifier. However, if your decoder or preamp does not have an electronic crossover, use the one built into the subwoofer amplifier by turning the Low Pass switch to ON (right position). Note: you may want to use both the decoder crossover and the subwoofer crossover together if you need a very sharp cutoff, i.e. if you do not want midbass frequencies coming from the sub. 5

6 CROSSOVER FREQUENCY CONTROL. If possible, use an SPL meter and a test disc with a series of tones to determine the frequency at which your main speakers begin to roll off. This will give you an approximate setting for the LOW PASS CROSSOVER FREQUENCY control. If you do not have test equipment, refer to the main speakers specification sheet and set the subwoofer crossover frequency to the -3 db roll-off point of the main speaker. Alternately, you can try setting the frequency by ear, which may result in a perfect blend if you use several recordings to average out the result. Generally, setting the subwoofer crossover point too high will result in overlap and may thicken the midbass sound quality. Since the subwoofers crossover point is adjustable from 50 Hz to 100 Hz, you can expect to use the crossover control at 50 Hz with large speakers and Hz with small bookshelf sized speakers using 4-6" woofers. PHASE CONTROL SWITCH. This control synchronizes the subwoofer with your main speakers in the region of overlap. It is best to judge this setting from the listening position. Using pink noise or a recording rich in mid and upper bass (50 Hz to 100 Hz), listen to the subwoofer/main speakers combination and adjust the PHASE SWITCH to maximize the mid and upper bass output. The speakers will then all be in phase with each other, no matter where you set the switch. Normally, if the subwoofer is on the same plane with the main speakers, you will set the switch to 0 deg. (right position). If you hear a lack of midbass, flip the switch to 180 deg. (left position). TROUBLESHOOTING WARNING! Do not remove the amplifier from the woofer cabinet! The VR-S1 is not user serviceable except for the external fuse. REPLACE ONLY WITH THE CORRECT FUSE VALUE, as a larger fuse may cause amplifier damage. DO NOT REMOVE THE AMPLIFIER FROM THE CABINET, as hazardous energy levels exist inside the chassis, even when unplugged (the filter capacitors store energy).. If you experience a failure of the unit, please return it to your authorized dealer. Never attempt to service the unit! Death or personal injury may result. If a unit has suffered shipping damage, immediately notify the shipping company and equipment dealer. Please retain all packaging materials. NO OUTPUT: Turn the VOLUME control completely down (counterclockwise) and recheck all connections. Turn the VOLUME slowly clockwise until you reach the desired output level. Try using a different interconnect cable, as it could be defective/intermittent. 6

7 Turn the decoder or preamp volume control down, disconnect the subwoofer, unplug the subwoofer amplifier. Using a flat-head screwdriver, remove the fuse on the external bottom right hand corner of the subwoofer amplifier and inspect the fuse. If the fuse is blown, trace the subwoofer connections to make certain setup is correct. Replace fuse with original type and rating after reconnecting the system. Make certain the subwoofer output of your decoder/receiver is not defeated. HUM OR BUZZ: Ground loops in the AC line will occasionally inject a 60Hz hum into the subwoofer. The hum can be eliminated by installing a three-prong to two-prong cheater plug onto the AC cord, then reversing the polarity (accomplished by turning the plug "upside down." RF feedback through the subwoofer amplifier may cause distortion in the subwoofer or any other speakers in the system. Replace the LINE-IN connection with HI-LEVEL connections. See CONNECTING TO YOUR SYSTEM section above. SPECIFICATIONS Amplifier: High Current 600 watt peak (300 watts rms) custom amplifier with built-in electronic crossover (adjustable from 50 Hz to 100 Hz), Low Pass switch, Phase switch (0 deg-180 deg), volume control, stereo/mono RCA low level inputs/outputs and high level speaker-line inputs/outputs. Electronic Servo Control to monitor pre-programmed response (to extend the bass down to 20 Hz). Fuse: T5A type, 250V fuse.for 115V USA power, T3A 250V fuse for 230V European power. Line Voltage: 115/120 V or 220/230 (Europe), switchable on control panel of amplifier. Active Crossover: Low pass: adjustable, 50 Hz to 100 Hz, Linkwist- Riley slopes. Bass Loading: Sealed box, air suspension design with Q of 0.5. Subwoofer Driver: One- 10" Extreme-Duty vented motor woofer with carbon fiber/abs cone, 15 lb. vented magnet, 2.5" Hi-Temp voice coil, butyl rubber surround, 7

8 C-max double-spider with Bias Control, and Low Distortion Motor (voice coil/magnet/pole piece) with custom Theile/Small Parameters to enable use in very small enclosures. Due to the 2" excursion potential, dynamic range is immense. Frequency Response: 20 Hz to 100 Hz, +/- 3 db. Distortion: Less than 0.8%. Warranty: Ten years on woofer, one year on amplifier (from date of sale). Weight: 54 lbs (24.5 kgs). Dimensions: 11" H x 11" W x 14" D 28 x 28 x 35.5 cm (without spikes or amplifier fins). Supplied Accessories: 4-2" long spiked feet to elevate the cabinet; 4-rubber feet to isolate cabinet when mounting in an enclosed equipment cabinet/wall unit, and velvet dust cover. 8