Over the years, Altec, and
Altec Lansing, produced a large number of technical letters for use by
consultants and contractors. We have many of them available now online
to help you.
We now have a large assortment of Altec Techincal
Letters for your use and enjoyment.
If they help you, let us know, and, as always, your donations are both needed and willingly accepted (just use the PayPal DONATE button on the main page).
CLICK ON THE LINKS BELOW TO DOWNLOAD
THE LITERATURE YOU ARE
= Amplifiers In Parallel - Instructions for constructing a
circuit using an Altec 15067 Autotransfomer that makes it possible to
parallel the outputs of two power amplifier. May 16, 1960.
= Zone Volume Control - Instructions for building a zone
volume control for distributed, 70-volt speaker systems. May 16, 1960.
= Area Covered By A Horn Beam
- Subtitled "A Problem In Geometrical Projection", this Technical
is an excellent resource for those wishing to get in on the basics of
the behavior of multicellular and sectoral horns.
= Loss Due To Speaker Lines - Excellent instructions
for calculating the size of wire needed for a specific application.
TL-121 = Protection For High Frequency Driver Units - Dr. John K. Hilliard's expertise in making applications of Altec Lansing products interesting, understandable, and practical show here. Includes information on AL passive crossovers and protecting HF drivers from static discharge.
= Line Voltage Compensation
- Another Hilliard-influenced Tech Letter for those who have problems
with varying power sources for their sound system equipment.
= Acoustical Tube Delay System
- One of the finest men to ever work for Altec, Ed Seeley worked for
ERPI, and came along with George Carrington, Alvis Ward, etc., when the
formed the All Technical Service Company in 1936, and stayed with Altec
until his retirement. Mr. Seeley wrote this interesting article on
pre-digital delay problems and a practical solution to them! Mr. Seeley
died not too long ago of Alzheimer's disease - a sad thing to happen to
such a great mind!
= Objective Technical Specification for the Altec M50 Solid State
Condenser Microphone System
= Advertising Sales Brochures
- VERY INTERESTING! A neat set of examples of Altec's sales literature
in the mid-1960's.
= Sound Coverage: Degrees vs Distance - Still
accurate and up-to-date, this TL from Don Davis shows how to calculate
coverage for a ceiling-mounted distributed loudspeaker system. EVERY
SOUND SYSTEM DESIGNER & INSTALLER SHOULD READ THIS ONE!
= Amplifier Comparison Tests -
A VERY GOOD primer on how to test power amplifiers for output
= Altec "TRUTH BOX" Transformer Demonstration Board -
Even today, those who saw the Altec "Truth Box" in operation vividly
remember it's ability to demonstrate how cheaply built most "other"
transformers were. Someone ought to build one and test TODAY'S
transformers - it might be quite surprising to hear the results...
TL-162 = Sound Coverage: Degrees vs Distance - Still accurate and up-to-date, this TL from Don Davis shows how to calculate coverage for a ceiling-mounted distributed loudspeaker system. EVERY SOUND SYSTEM DESIGNER & INSTALLER SHOULD READ THIS ONE!TL-166 = Decibels - Don Davis is at it again: training Altec Engineering Sound Contractors and acoustical consultants how to understand the behavior of sound and help them design and install better systems!
= Directivity Of Loudspeakers And Microphones - Written by
our friend and colleague, Don Davis, this is one of the BEST articles
ever written on the subject. Includes a reprint of the now famous paper
on the subject by Hopkins and Stryker.
= Altec 9473A Limiter Amplifier -
Specifications for this early two-channel limiter. Interesting!
= Amplifier Impedance Effects On The Transfer Characteristic Of Filters
And Equalizers -
Altec's Director of Engineering, Jim Noble, shows how to make certain
that the input impedance to Altec amplifiers is not altered by external
filters or equalizers. Interesting!
TL-196 = Calculating And Using Critical Distance - Here's Don Davis again with a TL that, coupled with TL #'s 181, 182, & 183, makes for excellent reading. It would do the modern generation of system designers and installers to read it!
= Calculating The Maximum Electrical Power Required -
Again Don Davis shows us methods now forgotten by modern system
designers (until something blows up). How often have we seen systems
shut down when the A/C power breakers tripped because the designer or
installer forgot (if he ever knew) the principles laid out here?
= New Ways To Look At Potential Acoustic Gain -
As we get into the second generation of sound system designers and
installers who have never heard of PAG/NAG, it would do them well to
read this! Thanks Don!
= Finding A Realistic EAD -
Don't know what EAD is? Well, it's not surprising! Read here to find
out as Don Davis - again - makes it clear how to design sound systems
that work BEFORE they are installed!
TL-201-A = Useful Directivity Data For Reverberant Sound Fields - Altec's Chief Engineer in Acoustics, Bob Beavers, gives valuable directivity information on famous Altec horns, including the 811B, 511B, 311's, and multicellular models. If you use these horns, this will interest and hep you!
TL-202 = Modification of Altec 1591A Compressor For Use As A Line Amplifier In Altec Acousta-Voicing NetworkTL-203 = Measurement of Nominal Sensitivity Ratings For Horn-Driver Combinations Commonly Used In Acousta-Voicing
= High Frequency Driver Protection Capacitor For Biamplified Sound
Systems - Written by Paul Spranger, this is another excellent
article for those who design or install professional sound systems.
TL-206 = 1588B Gain And Overload Characteristics
TL-207 = Useful Directivity Data For Reverberant Sound Fields - Altec's Chief Engineer in Acoustics, Bob Beavers, gives valuable directivity information on famous Altec horns, including the 811B, 511B, 311's, and multicellular models. If you use these horns, this will interest and hep you!
= A More Accurate Way Of Calculating Critical Distance -
Here's Don Davis again - pushing the envelope in an MUST READ Technical
= Architectural Uses Of The Critical Distance Concept -
More from Don. Another essential paper for all sound system designers,
users, and operators! Published February, 1972.
= Calculating Percentages, Pages 1 & 2 -
EXCELLENT materials on how to conduct your sound contracting business
in a more business-like manner. Pages 1 & 2.
= Calculating Percentages, Pages 3 & 4 -
EXCELLENT materials on how to conduct your sound contracting business
in a more business-like manner. Pages 3 & 4.
TL-210 = Calculating Percentages, Pages 5 & 6 - EXCELLENT materials on how to conduct your sound contracting business in a more business-like manner. Pages 5 & 6.
TL-210 = Calculating Percentages, Pages 7 & 8 - EXCELLENT materials on how to conduct your sound contracting business in a more business-like manner. Pages 7 & 8.TL-211 = Notes On Loudspeaker Directivity - One of the most ignored and misunderstood concepts in the sound system design world today is that of loudspeaker directivity. In this TL, Don Davis again shows why he is so well able to communicate these important concepts in an understandable manner. DON'T MISS READING THIS ONE!
= Useful Equations For The Sound Contractor - A basic primer
on the equations that every sound system designer USED to know how to
use when designing a system. If every acoustical consultant, system
designer, and sound contractor would learn and use them again, the
quality of the systems being designed and installed would improve
= Using The General Radio 1564 Analyzer To Measure THD
TL-214 = Time Delay Calculations - Any sound contractor who has tried to set a digitally delayed loudspeaker systems needs to read this!
TL-217 = Using Altec Line Transformers and Autotransformers With European 100-volt Speaker Distribution Systems
= Acoustic Attenuation With Increasing Distance - Here's a
great TL by Don Davis that will help ANY sound system designer,
installer, or user! It's amazing how much has been forgotten...
= Improving The 1605A NOALA For Operation Under Adverse Noise Conditions
- Altec's Bob Bird, a true genius in electronic design and application,
developed the first properly operating automatic level control for
paging systems called NOALA -
"Noise-Operated-Automatic-Level-Adjustment". The NOALA worked so well
that many are still in operation all over the world. Only the advent of
digitally-controlled sound processing e equipment made it possible to
improve upon his design.
= Measurement Of Nominal Sensitivity Ratings For Horn-Driver
Combinations Commonly Used In Monitor And Playback Systems -
Similar to TL #203, which deals with the larger AL horns, this is an
interesting data on the smaller Altec horns.
TL-232A = Equalization Techniques And Practices - Our long-time friend Ted Uzzle wrote this sterling paper on the proper use of equalizers in live sound reinforcement systems. A MUST READ!
TL-236 = Control Of Radio Frequency Interference In Sound Systems - Paul Spranger wrote these instructions for controlling RFI in sound systems - another MUST READ for system installers!
TL-237 = Directivity Response Of Single Direct-Radiator Loudspeakers In Enclosures - Clifford Henrickson authored this exceptional paper on a incredibly misunderstood topic.
= Applications For The Altec Lansing MANTARAY® Constant Directivity
Horns - Our friend Chris Foreman wrote this helpful
and practical paper on how to use the BEST constant directivity horns
ever designed or built to date - the Altec MANTARAY's!
TL-255 = Coverage Of Altec Lansing Loudspeakers - Ted Uzzle's expertise in making the complex understandable and usable is easily seen in this, the FIRST application of modern computer-assisted loudspeaker coverage and system design techniques. Still a valuable tool for understanding how loudspeakers work, it is a valuable addition to the knowledge of sound system designers everywhere. June, 1981.
TL-257A = Sound Distribution On A Plane Normal To A Loudspeaker Axis - Rex Sinclair authored this paper on designing distributed loudspeaker systems. Very nicely done!
TL-258B = Uniformity Of Coverage In Distributed Sound Systems - Rex Sinclair again enlightens us on this important and often misunderstood topic.
TL-262 = Coverage Of Multiple MANTARAY® Horns - Our friends Mark Ureda and Ted Uzzle teamed up to write a paper whose concepts are still not understood by most modern acoustical consultants, sound system designers, and sound contractors - how to cover large areas with multiple horns while minimizing phase interference, and maintaining apparent apex. Another MUST READ!
TL-263 = Modifying The Altec 2204 Power Amplifier For 16-ohm or 70.7-volt Operation - Again, Ted Uzzle's years of cinema work shine through as he describes how to get the most out of a wonderful amplifier, the Altec 2204.
TL-264A = Using Thiele-Small Parameters - Rex Sinclair wrote this outstanding paper on how to use Thiele-Small parameters to design loudspeaker systems. Every loudspeaker designer should read this one!
= Articulation Loss In Consonants For Distributed Sound Systems
- Rex Sinclair's expertise with distributed sound systems shows up
in this often ignored design topic.
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The Sound of Experience
© Altec Corporation
Copyright © 2002 by Todd W. White.
A SPECIAL THANKS TO ANDY ANDERSON OF AUDIO-TECH IN ATLANTA FOR MANY OF THE SCANS WE HAVE HERE!<>Altec, Altec Lansing, Lansing, Duplex, Voice of the Theatre, and Voice of the Theatre are registered trademarks of Altec Lansing Technologies Corporation.
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construction. Last updated on: September 15, 2005