Von Schweikert VR-4-JR Mk2 Brochure

Von Schweikert Audio

World Class Reference Speaker Systems for Music and Film

VR-4jr Mk II

he VR-4jr Mark II is a two-piece speaker system
utilizing the world’s finest cabinet design: a time-

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aligned, decoupled sat/sub for incredible tweeter,
midrange, and woofer transparency, as well as
unparalleled soundstage reproduction. Clarity is
enhanced with custom-made Low-Distortion drivers with
the best available Transparency Factor. The engineering
target was to design a highly accurate, laboratory-grade
system with the ability to be used as a professional
reference monitor. Studios using VR-series include
Sheffield Labs, Musical Fidelity Sound Labs, A&M
Records (Herb Alpert), and Walt Disney Studios (Alan
Menken, winner of 7 academy awards). Many recording
engineers brought these speakers home, including Robert
Harley, now editor of TAS, and Herb Alpert, creating an
audiophile demand. A reference monitor must have wide
bandwidth, low distortion/coloration, with convincing
three dimensional depth and realistic sound staging. The
VR-4jr is highly optimized for this use and is highly
musical as well. Imaging and depth are state-of-the-art
due to our proprietary Ambience Retrieval System
Global Axis Integration Network.
Virtual Reality design emphasizing four dimensions of
sound reproduction:

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1. Amplitude: A speaker system used for reference
monitoring must meet a +/- 1dB tolerance level;

2. Phase: Consistent phase between drive units

and slow rotation is desired; no out-of-phase
drivers;

3. Time: The drive units must be time coherent in

the ear’s sensitive 3ms range;

4. Space: The speaker design must replicate a

palpable three-dimensional sound stage with

The elegant book-matched wood veneer two-piece
stacking cabinet is built to the highest level of
professional build quality and includes a new
bracing/damping system that enables incredible
transparency and the total elimination of coloration. The
cabinet walls are 1” thick and internally lined with thick
acoustic felt. Twin shielded 7" poly-laminate mica­cellulose woofers reproduce the bottom octaves with
authority and clarity, using a modified triple-chambered
transmission-line to achieve response flat to 23Hz (-6dB
@ 20Hz). Our hybrid bass loading system utilizes a
specially damped 3" wide vent, front-mounted to allow
close placement to a wall in small rooms without boom
or coloration. Unquestionably the most impressive and
compact 23Hz bass system available!

We have developed a shielded 7" composite cone
midrange driver with incredibly flat frequency response
and low distortion. The cone is fabricated from carbon
and mica impregnated cellulose acetate pulp using a
ceramic liquid binder, with a surface coating of polymer
to damp the stored energy waves. This high tech
composite cone has a remarkable Young’s Modulus
(ratio of stiffness to weight), allowing incredible
transient speed up to 6,000 cycles per second without
distortion of timbre or phase. This new midrange driver
has greater clarity and dynamic range than our reference
electrostatic speakers!

Our tweeter is possibly one of the world’s finest drivers,
with the highest level of clarity and detail combined with
a very smooth, lush sound quality due to the Low
Distortion Motor design. The diaphragm is composed of
silk with three layers of proprietary polymer applied to
the surface. This enables the tweeter to reproduce
stunning detail without added harshness or "buzz" that
untreated fabric produces. Magnetic shielding makes
this tweeter perfect for music or film reproduction.

In order to duplicate the depth and air space of the
concert hall, we have developed a dipolar rear
mid/tweeter and ambience derivation circuit, complete
with Dimension Control for effects level. This completes
a 360-degree spatial image with virtual realism!

depth.

Von Schweikert Audio

World Class Reference Speaker Systems for Music and Film

Specifications

System Type: Dynamic-driver four-way system
using a triple-chambered transmission line and two­piece stacking enclosure system to eliminate
resonance and ensure image focus.

Woofer Tuning: The triple-chambered
transmission line is a hybrid design composed of
three separate chambers coupled to the room by a
tuned vent at 25 Hz. The chamber filling is
acoustic foam and Dacron. The 3"-wide damped
vent tube extends bass response without the "one
note bass" problem found in other ported systems.
Dynamic range is incredible due to the large
amount of low frequency air movement.

Cabinet and Bracing: A one-inch thick front baffle
provides exceptional vibration control and image
solidity, while one-inch MDF fiberboard
interlocking braces provide exceptional rigidity and
freedom from boxy colorations. The internal
damping consists of thick acoustic felt lining and
Dacron stuffing to eliminate cavity resonances.
Large carpet spikes are provided.

Size: Midrange/Tweeter (12.5"h x 8"w x 20"d).
Woofer (25.25"h x 8"w x 20"d). System (38.5"h x
8"w x 20"d).

Weight: Woofer module: 52 lbs. M/T module: 26
lbs. System: 78 lbs. each (up to 128 lbs. each with
lead shot).

Driver Complement: 2-7" mica-cellulose poly­laminate woofers, 1-7” carbon mica-cellulose poly­laminate midrange driver, 1-1” poly-tri-laminate
silk-dome tweeter, 1-1” rear firing ambience
mid/tweeter with fabric dome and transmission-line
loading. All drivers use our proprietary Advanced
Motor System with low distortion design.

Crossover: Acoustic fourth order, at 200 Hz and

2.2 kHz, optimized for flat off-axis response and
phase consistency over a wide Global Axis. Very
high quality parts are used, including film-foil
capacitors and custom air-core inductors that can

handle up to 1500 watts before saturation, with
computer-optimized internal wire.

Binding Posts: Double sets of five-way rhodium
posts enabling bi-wiring. Single wire can be used
with optional Data Link connector.

Ambience Driver: 1” treated fabric dome with
Wave Guide and transmission-line rear wave
loading. Ambience circuit uses Dimensional
Control (effects level) to compensate for room
acoustics and soundstage depth. Provides a Global
Axis polar response pattern to simulate live musical
reproduction.

Frequency Response: 23-20 kHz, +/- 2 dB, 20 Hz­25 kHz –6 dB, (+/- 1dB at midband).

Impedance: 6 ohms avg. (4 ohms 20 Hz-150 Hz; 8
ohms 150 Hz-20 kHz).

Recommended Power: 20 watts up to 300 watts
music power.

Sensitivity: 89 dB @ 1w/1m using 2.83 v (91.5 dB
in room with boundary reinforcement).

Warranty: Ten years Parts and Labor, excluding
burned voice coils due to amp clipping.
Transferable to second owner.

Finishes: Available in four book-matched wood
veneer finishes including African Hazelwood, Dark
Red Cherry, Light Maple, and Black Ash. A satin­gloss polyester resin clear-coat protects the fine
wood surfaces.

Von Schweikert Audio

930 Armorlite Drive

San Marcos, CA 92069 USA

[phone] Fax [phone]

Website:

www.vonschweikert.com