Theatre Design & Technology - Summer 1983 - 33

NEW PRODUCTS
structure·born sound is provided by an ingeni·
ous two·point pendulum suspension 0 the reo
verb unit.
Contact: AKG Acoustics, Inc., 77 Selleck
St" Samford, CT 06902.

32

flec ions are available as reflections only or
mixed with reverb: initial delay or the reverb
signal is switchable to 0, + 30ms and
60ms; two discrete reflections for each
channel may be adjusted in 6ms steps from
6ms to 60ms; bandwidth reflections: 12kHz.
The photograph shows he BX·25ED (reverb
and delay) with remote con rol unit.
For complete details contac AKG Acous·
tics, Inc., 77 Selleck Street, Stamford, CT
06902.

Summagraphics Announces Com puterAided Design/Drafting Systems for
Architects

AKG Announces a Portable
Reverberation Unit
The new BX·15E is a portable two·channel
reverberation unit from AKG Acoustics, Inc.
The unit is designed to provide both the quality
and operating features required In studio ap·
plications, and is based on the patented and
extremely successful Torsional Transmission
Line principle.
Independent decay·time adjustment, high·
and low·frequency equalization and re er·
berallon/dry signal mixing are provided for
each of the two electronically and acoustically
separate channels. Decay·time is adjusted
silently through he use of motional feedback.
Reverberation/dry signal mixing enables reo
verberation 0 be added to dry signal withou
the need for a "reverb return" mixing section
in the mixing desk.
The unit may be rack mounted in the con·
trol room or used as a portable system. Its
unique two·point suspension makes it imper·
vious to acoustic feedback and mechanical
vibration. There is no need to "Iock·down"
the system for transport, nor any need for ad·
justments after transport.
The BX·15E Reverberation Unit is a tor·
sional spring system with a high degree of dif·
fusion in the transmission line. This results In
a highly natural reverberation quality.
The torsion elements consist of several
parts with micro and macroscopic variations
of the line parameters. Controlled damping
and supporting elements are placed at sta IS·
Ically determined distances along the spring
system.
Additional elec ronic damping utilizing mo·
tlonal feedback. perml s he variation of the
decay time. A fl e·position sWitch provides
optional decay· Ime selec ion of 1.5,2.0. 2.5.
3.0 or 3.5 seconds.
The BX·15E provides a genuine two·
channel design. Either channel can be used
and controlled separately. (Reverbera Ion
channel separation > 35 dB).
The reverb spring unit IS enclosed In an In·
sulated steel box within a thlck·walled, foam·
lined. wooden case. There IS no danger of
acoustical feedback even If the BX·15E IS
placed In close vicinity of monitoring loud·
speakers. Full insulation against vibration and

Editors: A. Folke & T. H. Wells

AKG BX-25E Reverb/Delay
The new BX·25E is a studio and transpor .
able two·channel reverberation from AKG
Acoustics. Inc. Replacing the BX·20E, the
BX·25E continues to provide both the quali y
and opera Ing features required in studio ap·
pllcations. The BX·25E IS based on the pa .
en ed and extremely successful Tortional
Transmission Line prinCiple.
The TIL·SYSTEM has been improved by
extending the overall length of the spring by
about 25% over the BX·20E yet at the same
time reducing the overall size of the BX·25E
dramatically by about one·third. Independent
decay·time adjustment (via remote control),
high· and low· frequency equalization external
input/output level adjustments and dry/reverb
signal mixing are prOVided for each of the two
electronically and acoustically separate chan·
nels. Decay·time is adjusted silently through
the use of motional feedback.
In addition to the shelving type frequency
equalization, AKG has incorporated a high·cut
filter at the input/reverb drive amplifier. This
enables he selection of a bright. more ago
gressive sound or a more mellow na ural reo
verberatlon sound. Plug· In PC boards are
used for the elec ronlcs within he control
module. This module may be removed from
he main hOUSing and opera ed remotely via
an optional extension cable up to 30 fee away
rom the reverb section.
The eXCiting news IS the new M·250 Dig·
I[al Delay module that may be added to a BX·
25E at any later time or ordered within the
BX·25E. As a complete uni (reverb and de·
lay), the BX·25E Incorporates all the reverb
features menlloned above plus digital delay.
The new digital delay module prOVides:
remote mix control between reverb signal and
reverb plus IndiVidual reflections: IndiVidual·
Iy adjustable level for each of the discrete reo
flectlons In 2dB steps from original level down
to 20dB below the original level, discrete reo

Theatre De;ign & Teehnolog~ UStTT Summer t983

The Summadraft CADID architectural
series. said to be compatible with standard ar·
chitectural practices, is designed to increase
working drawing productivity without the need
for lengthy manpower commitments to com·
puter system learning cycles.
The new Summagraphics brochure is il·
lustrated with photos of actual building plans
and detail drawings produced by systems in
use in archi ects' offices. and drawing call·
outs describe certain tedious and/or complex
drafting tasks hat are made easy through ap·
plication of Summadraft systems. Sof ware
includes a comprehensive library of standard
graphic and construc ion details. developed
by architects and catalogued to conform to
the CSI numbering system. Symbol library
codes are compatible with. and are reference
to "Sweet's Catalogue" listings.
For a complimentary copy of the new
Summadraft Architectural Series brochure,
contact Summagraphics Corporation, 35
Brentwood Avenue, Fairfield, CT 06430: (203)
384·1344.

48 Volt Phantom Power Supply for
All Microphones From Crown
The Crown PH·4 system supplies 48 vol s
o D.C. phantom power 'or all types of micro·
phones. The PH-4 system conSists of a mas·
er unl (PH-4) with connections for up 0 four
microphones. plus slave units (PH·4S), eac
of which adds capability for another four mi'
crophones. The slaves are dalsy·chalned.
A master PH-4 unit will supply up to 100
milliamps. enough to power up 0 about
twelve condenser microphones, or up to
about twenty Crown PZM models. All types of
microphones can be powered from a PH·4
system In any combination so long as the 100
milliamp limit IS observed
Table of Contents for the Digital Edition of Theatre Design & Technology - Summer 1983
