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   Von Schweikert Audio 

930 Armorlite Drive,  San Marcos, CA 92069 

Ph (760)410-1650                Fax (760)410-1655 

                               E-mail:

[email protected]

                 World Class Reference Speaker Systems for Music and Film

 

  ~  Website:

www.vonschweikert.com

 

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power. In these cases, it will be necessary to move either the speaker position or the 
listening position in order to optimize the response. By playing a recording with a 
repeating bass line, try walking around the room until you find the places where there is 
apparent bass. It will be necessary, in some cases, to reposition the speakers in order to 
allow the room to boost the bass by using the natural ‘gain’ of the boundary reflections. 
Simply move the speakers closer to the rear wall or side-wall in small increments until 
the bass sounds right. 
 

LEAD TRAP 

 
The VR-4jr has a special compartment at the bottom of the cabinet, hidden by the 
removable bottom plinth. This compartment was designed to be filled with lead shot in 
order to damp spurious cabinet resonances.  Bass and lower midrange frequencies will 
be tightened when the Lead Trap is filled, as the movement of the damping particles 
adsorbs vibration.  We have found that two 25 lb bags of lead shot from a gun or 
sporting goods store is sufficient to fill the cavities in both speakers (the lead will not 
completely fill the chamber, it takes around 180 lbs to fill both chambers, but that may 
be excessive).  

 

Place the VR-4jr upside down on a soft surface, such as a towel, and remove the 
bottom plinth. 

 

Poor approximately 25-50 lbs of lead into the opening. Shake the speaker until 
the lead settles. 

 

Replace the door and plinth and you're done. Note that the midbass/lower 
midrange frequency bands are now cleaner and tighter. 

 

ANCILLARY EQUIPMENT 

 

The VR Series is far more transparent than any other competing design, including 
electrostatics. (If you don’t believe this, put any electrostatic next to a VR and use a 
transparent switching device such as a copper knife switch to directly compare the sound 
of the VR to the electrostatic. Make sure that you use the same channel, since the 
electronics may have a large difference in sound between the channels, and the same 
brand of cable. It may be necessary to use a metal film resistor to equalize the sensitivity 
of the louder speaker in order to make a fair test.)  Since the VR design is quite 
transparent, lacking audible coloration and distortion, it is necessary to use only the 
finest sounding equipment available to drive the VR-4's. This does not mean you must 
purchase the most expensive gear, just 

good sounding

 electronics, especially in the front 

end. Many digital products have limited depth and excess treble brightness caused by 
overemphasis of harmonic structure. The VRs will enable you to easily hear the 
differences even between digital cables, which theoretically, should have no sound at 
all. Any sonic qualities you attribute to the VRs are actually coming from the chain 
preceding the speakers. When using neutral driving equipment, the VRs will be found to 
have virtually no sound of their own! 
 

Summary of Contents for VR-4jr

Page 1: ...speaker system designed by Von Schweikert Audio The Virtual Reality design was perfected over a 23 year period after several years of research at California Institute of Technology and consists of Acoustic Inverse Replication and is driven by the Global Axis Integration Network Please visit our website at www vonschweikert com for further technical information T When set up correctly the VR 4jr sy...

Page 2: ...hieve world class sound IMPORTANT NOTE Please read the following instructions regarding setup as imaging and bass response must be optimized to your particular room Since there exists no standard listening room dimensions or reflective absorptive standards each setup will be different A thorough break in 250 hours must be conducted in order to realize the full benefits of the VR s transparency and...

Page 3: ...cult to hear distortion when quilts are used Adjust the volume in advance Note that it may take several months or longer to break the speakers in if only quiet music is played at background levels Classical music played quietly does not contain enough bass or dynamics in most cases to do a proper job so we suggest using a CD player on repeat using a loud rock album or break in CD as the source Ple...

Page 4: ...e same distance from the rear wall and side wall as this distance will result in too much boost at this wavelength Stagger this distance by 40 70 Do not toe the speakers in at first place them parallel to the side walls In general the sound stage will be constrained to the distance between the speakers so if you have the VRs only six feet apart you will hear a small sound stage Since there will be...

Page 5: ...ices on the wall to ameliorate the wall reflections that may cause tonal imbalances or imaging confusion See your dealer FLOORING If you have a hardwood floor especially without carpeting there is the possibility that vibration and resonance will be transferred to the floor which will then act as a passive radiator The floor resonance will sound like extra midbass is being added to the sound and w...

Page 6: ...er and Sub posts located on the Sub cabinet and then connect the Data Link If you connect the main cable to the woofer and then use a jumper upwards to the M T by wire by jumper plates and by Data Link you will be able to hear a slight loss of clarity since there will now be two to four connections in the signal path instead of just one to the high resolution tweeter Also make sure that you make a...

Page 7: ... try using this method of wiring One channel will drive the woofer module while the other channel of the same amplifier will drive the upper M T s This wiring may sound much better than simply switching the amp to the mono block bridged mode HORIZONTAL BI AMPING If two different stereo amps are available one amp can drive the woofers and the other amp perhaps of lower power can drive the M T s Thi...

Page 8: ...l simulate this huge soundfield with its involving depth and dimension However correct placement is required to achieve the best possible sound quality Amazingly moving the speaker only a few inches can make the difference between good sound and great sound due to the reflective properties of your room Note that this fact is true with any speaker system PINK NOISE TEST TO FIND FOCAL POINT OF ARRAY...

Page 9: ...oving the speakers while you sit in the listening position giving orders Toe in is often critical with only 1 movements being very apparent When you have found the correct spacing and listening distance you will immediately know it since the image lock in is very obvious The pink noise will become a very strong ball of sound just floating in between the speakers Keep moving the speakers until you ...

Page 10: ...ass reflex cabinets but not the VR design the trapped rear wave of sealed enclosures results in low efficiency while the compressed air load results in sluggish transient attack For this reason transmission line loading has much appeal and makes more engineering sense since both deep bass and fast transient response resulting in tight sound are optimized at the same time Bass reflex systems howeve...

Page 11: ... will be mathematically additive and will cause a peak in the response at this frequency However if the path length is such that the reflected wave is out of phase with the main wave there will be a cancellation in the frequency response Researchers have found that the dips and peaks in the response can be very powerful with 18dB variances across the bass range Note that this effect occurs with AN...

Page 12: ...into the enclosure instead of leaving it in the vent tube proper BASS RESPONSE TUNING FOR TUBE AMPLIFIERS Since tube amplifiers have air and liquidity in the mid and treble ranges many audiophiles use them However the saturation back EMF and transient response delays of all output transformers will cause sluggish bass response which can be heard when using any speaker that has response below 50Hz ...

Page 13: ...soft surface such as a towel and remove the bottom plinth Poor approximately 25 50 lbs of lead into the opening Shake the speaker until the lead settles Replace the door and plinth and you re done Note that the midbass lower midrange frequency bands are now cleaner and tighter ANCILLARY EQUIPMENT The VR Series is far more transparent than any other competing design including electrostatics If you ...

Page 14: ...akers since they are the apparent source of all sound Some of the causes of brightness are 1 Powerline Noise Can be ameliorated with a proper line conditioner 2 Cable Resonance Too many brands of different cables which interact improperly Switch interconnects including the digital cable to a different brand 3 Digital Noise Use a powerline filter on DAC only Many times the harshness is created by d...

Page 15: ...eally bright you may feel that there is more treble than bass Try substituting different electronics or cables and recheck your room placement ROOM ACOUSTICS Many books have been written about room acoustics and there is not enough space in this manual to give detailed information on how to do it right However the general rule is to use 50 absorptive 50 reflective ratios when covering the room s s...

Page 16: ...led and shielded for video use Cabinet Design Isolated dual stacking cabinetry utilizing triple chambered transmission line loading with front vent on bass module and sealed for the midrange tweeter module Damping System Resonance trap in woofer module provided for addition of lead shot 25 to 40 lbs of shot can be added to stabilize the sound Crossover Type Global Axis Integration Network for accu...

Page 17: ...60 410 1655 E mail albertvonn aol com World Class Reference Speaker Systems for Music and Film Website www vonschweikert com 17 Weight Midrange Tweeter 26 lbs each Woofer 52 lbs each System 78 lbs each Warranty Ten Years excluding abuse or burnt voice coils due to amplifier clipping ...

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