Wood and finishes, tools and veneers are basic to any serious speaker builder. We had never seen Craftsman Wood Ser vice Co.'s catalog before it arrived a few days ago. Its 156 pages list a whole lot more for the woodworker than I had any idea was available. If you aim to build cabinetry yourself anytime soon I can't imagine you will want to get along without having this catalog handy for whatever you need. Tell them Speaker Builder magazine sent you. Craftsman Wood Service Company, 1735 W. Cortland Ct., Addison IL 60101.
If you have a new speaker system but no test gear yet, you may want to know about a good source of test gear for either short term rental--or to own. Rag Enterprises at 21418 Parthenis St., Canoga Park, CA 91305 (P.O. Box H, Eatontown NJ 07724 if you're in the East) offer new, used, reconditioned and rental test gear.
They will rent with a purchase option as well. So if you're dying to know how your speakers are performing in your living room, you might consider renting appropriate gear for a month just to see how your system is doing. This list of prices and terms is available on request.
Hardly anyone seems to stock more speakers-some seem orphans but no matter--than McGee Radio & Electronics, 1901 McGee St., Kansas City, MO. (816) 842-5092. They have a lot of other gear for sale too, of course. But I am sure that no one seriously interested in speakers and speaker building should be without their catalog. The bargains in all sorts of name-brands are genuine and well worth watching for. Tell them SB sent you.
Trusonic Speakers announce a series of auto speaker systems that include a three-way 120W unit with a five year warranty and a voice coil weighing 40 ounces. Kit systems for cars range from suggested retail of $90 to $ 150 per kit. The kits are said to be complete with grilles, crossovers, wire and even have removable jumpers in case the user prefers to bi-amp in his car. See your audio dealer.
A new 12 gauge sound cable from DB Systems, DBP-8 Speaker Wire, minimizes loss of power and damping factor, and does not affect the frequency response of loudspeakers. Such considerations are especially important to systems utilizing 4 ohm speakers or runs of more than 20 feet. The heavy gauge wire is otherwise conventional dual conductor copper, with leads at both ends pre-tinned and cut to 16 gauge to easily fit any type of connector. As a convenience, solderless banana plugs are separately packaged for this purpose. DBP-8 Speaker Wire comes in 3, 6, and 9 meter lengths, which translates to 10, 20 and 30 ft.
We're often asked where to find not only drivers, grille cloth, fiberglass and such other esoteric ingredients the avid speaker builder seeks but also where to find reliable information on speaker building. The Speakerlab people ( P.O. Box 15780, Dept. SB, Seattle, WA 98115) have about as comprehensive an offering of goodies as anyone around. They don't sell fiberglass-but they are remarkably cooperative in helping the builder with what he needs. Say you want to build a couple of large corner horns. Speakerlab will sell you anything from the complete kit, or drivers and a set of plans-or the plans alone if that's all you need. Their catalog tells you a lot about speakers and how they work-and how to put one together. It also, of course, showcases the Speakerlab line of offerings but if offers more basic data at modest prices than we have seen elsewhere.
Another great source of basic information, about theory most especially, is the interesting series of occasional papers published and distributed by KEF Electronics, Ltd. KEF are a British firm but unlike many British firms they are lively, imaginative, and extraordinarily innovative-even more so than the majority of US speaker manufacturers. Their publication, Keftopics is chock full of in formation about the basic rules governing the behavior of drivers in various sorts of enclosure. You will be glad, I am sure, that you asked to be put on their mailing list for these interesting publications. Send your request to: KEF Electronics, Ltd., c/o Intratec, Dept. E, P.O. Box 17414, Dulles International Airport, Washington, D.C. 20041.
Great America Companies, 2504 Freedom Drive, San Antonio, TX 78217, are manufacturing the first of a series of plastic cone drivers (the first made in the USA), an 8" woofer (8D12J1) which sports a 12 oz. ceramic magnet and a 1", four layer voice coil. The specs on the unit sup plied by the manufacturer show a response variation of approximately + 7dB to - 10dB over the 20Hz to 400Hz range. They argue that a plastic cone is superior to one made of paper (as most are) since it is not subject to humidity and temperature changes and does not deteriorate with age. Plastic cones have been viewed as a possible answer to the ideal cone design characteristic of stiff ness which has not often been completely achieved in driver design. Great America says their driver is suitable for vented boxes or transmission lines in either two way or three-way configuration. SRC Audio ( 3238 Towerwood Dr., Dallas, TX 75234) will, among others, stock the new driver. Great America have data sheets on request.
Gladstone Electronics offer Canadian speaker builders and audio buffs an excellent range of speaker kits and supplies including such names as Philips, Speakerkits, Peerless, JBL, KEF, Celestion and Decca. Indeed they stock a line of Philips kits that I have not seen readily available in the USA. Gladstone is willing, of course, to sell to customers south of the border. A card to 1736 Avenue Road, Toronto, Ont. Canada will put you on their list. They take MasterCharge, via telephone if you like, at 1 (416) 787-1448, but they are closed on Mondays. An interesting and different offering of supplies.
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Ultra definition is the name under which Hartley Products are marketing a 10 gauge wire for connecting speakers to their power amplifiers. They have a nice pamphlet on the subject with a series of spike and square wave oscillograms illustrating their reasons for considering their new speaker wire superior. Copies of the brochure, as well as information on their famous drivers are available by writing to 620 Island road, Dept. SB, Ramsey NJ 07446.
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ADs:
KEF
Now you can "build the best in confidence,'' as two of KEF's best-selling speaker systems-the Model 104aB and Cantata-are now available in kit form, enabling you to easily assemble a high quality speaker system at a considerable savings. And, because they are kit versions of two of our best-selling speaker systems, you can actually audition the units at your KEF dealer before buying and assembling. KEF speaker systems are designed and built using a Total System Design Concept, where by each part is developed to compliment all others in the system so as to achieve the targeted performance. The KEF Cantata kit consists of a bass unit, midrange unit, tweeter and an Acoustic Butterworth filter, and builds into an acoustic suspension loudspeaker system with a power handling capability of 100 watts. The KEF Model 104aB kit consists of a bass-midrange unit, tweeter, Acoustic Butterworth filter section, plus an acoustic bass radiator to increase the bass response from such a modest-sized enclosure. The kit makes up into a bass reflex system with a power handling capability of 150 watts. Both the kits include fuse units to protect the drive units, and con tour controls to adjust the final acoustic output to suit the listening room.
Loudspeaker kit building has now been raised to a new level of ease and reproduction quality. For more details and the name of your nearest KEF dealer where you can hear just how good our KEF-KITS are before your purchase, write to us at the address below. Individual drive units and crossover networks are also available for your special custom requirements.
KEF Electronics, Ltd., c/o Intratec Department E , P.O. Box 17414, Dulles International Airport, Washington, DC 20041.In Canada: Smyth Sound Equipment - Ltd.. Quebec.
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Professional, Inexpensive tests for your audio system's performance without instruments... CBS Laboratories' STR Professional Test Recordings
For over ten years, the original series of these high-precision test records set a standard for the audio industry. Now the new series sets an even higher standard. It's been revised, recut and expand ed.
The new series consists of eight records for professionals and one for non-professional audiophiles.
Each record contains a complete series of easy-to-use tests to help you rapidly and accurately evaluate components and systems.
Even one of these records can eliminate the need for costly, additional equipment. Each will find productive use and save you hours in the laboratory, on the production line and in field testing.
Take a look what this essential testing series contains: SEVEN STEPS TO BETTER LISTENING--For only $6.98, you can improve your system with CBS Laboratories' "Seven Steps to Better Listening." This high-precision test record enables you to make sure that your equipment functions properly...to tune your system to your ears and your room acoustics. Included is a detailed 16-page booklet by Audio's Edward Tatnall Canby explaining how to use the record to improve the performance of your system. With the record you can perform the following "ears alone" tests: left-right identification, phasing, loudspeaker balance, tone control setting, alternate phasing, buzz and rattle elimination, lateral tracking, and vertical tracking.
STR 100 STEREOPHONIC FREQUENCY TEST RECORD. Designed for the evaluation of pickups and systems. Provides a constant amplitude characteristic below 500Hz and a constant velocity characteristic above 500Hz. Tests include: Sweep Frequency-with the sweep rate synchronized for use with a graphic level recorder; Spot Frequency-with voice announcements; Channel Separation; Wavelength Loss and Stylus Wear-to pinpoint oversize or worn-out styli, and excessive pickup tracking force; Compliance; Phasing; Vertical and Lateral Tracking: Tone Arm Resonance-to check system performance at low and subaudible frequencies and thus reveal undamped resonance which may cause equipment overloading.
STR 112 SQUARE WAVE, TRACKING AND INTERMODULATION TEST RECORD. Enables detailed study of tracking capabilities of stereophonic phonograph pickups. The square wave modulation allows a rapid appraisal of stylus-tip mass, damping, and tracking. Low frequency compliance and tracking are determined by means of 300Hz bands of progressively increasing amplitude. Intermodulation distortion measurements are made possible by graduated 200Hz intermodulation test bands. The STR 112 has been cut with vertical angle approximately 15°, which is representative of current recording practice.
STR 120 WIDE RANGE PICKUP RESPONSE TEST RECORD. Makes possible the measurement of pickup response at frequencies far beyond the audible range, where elusive distortion elements can cause audible distortion. The low-frequency range includes glide-tones at twice normal level for the detection and elimination of arm resonance, loudspeaker cone and cabinet rattles. Other tests include: silent grooves for measuring rumble and surface noise characteristics; and standard level bands at 0dB for overall system S/N measurements. This record is suitable for use with a graphic level recorder to provide permanent, visible records for precise evaluation.
STR 130 RIAA FREQUENCY RESPONSE TEST RECORD. Provides RIAA frequency characteristics for the calibration of professional recording equipment and for testing the response of professional and consumer record reproduction equipment. This record is suitable for use with a graphic level recorder to provide permanent, visible records for precise evaluation. Spot frequency bands for use without automatic equipment are included.
STR 140 RIAA PINK NOISE ACOUSTICAL TEST RECORD. Designed for acoustical testing of systems and loudspeakers and for psychoacoustic tests on reproduction equipment.
With the STR 140 it becomes possible to test loudspeakers in the room in which they will be used. Spot frequency tones with voice announcements facilitate the testing procedure. Continuous glide-tones in 1/3-octave bands cover the frequency range from 30 to 15,000Hz and are synchronized with a graphic level recorder.
STR 151 BROADCAST TEST RECORD. Developed especially to meet the needs of broadcast engineers, audiophiles, and other professionals seeking a convenient signal source for the testing and adjustment of all audio equipment. Tests include: phonograph pickup response and separation, speed accuracy at 33 1/3 and 45 rpm, wow and flutter, rumble and hum detection, ballistic test of V. U. meters and many others.
STR 170 318 MICROSECOND FREQUENCY RESPONSE TEST RECORD. Provides pickup designers and recording studios with a high-level, easily-equalized signal for frequency response and channel separation measurements. The STR 170 employs a 318 microsecond characteristic corresponding to the "test" or "flat" mode common to most disc recording equipment. Constant amplitude recording is employed in the region below 500Hz with constant velocity recording in the region above. The transition is smooth, in contrast with the STR 100 which employs a sharp breakpoint at 500Hz. The record is suitable for use with a graphic level recorder to provide permanent, visible records for precise evaluation.
SQT 1100 QUADRAPHONIC TEST RECORD. Designed for calibration, verification, and adjustment of SQ decoding equipment. The record provides test bands for pickup measurements, for adjustment of decoder electronics and for channel identification and balance. Each band is described in terms of recorded characteristics and its intended use.
SQ is a Trademark of CBS Inc. Quantities are limited. Be sure to order enough for many years of use. Send me the following test records:
_ copies (STR 101) Seven Steps to Better Listening at $6.98 ea.
(STR 100) Stereophonic Frequency at $10. ea.
(STR 112) Sq. Wave, Tracking and Intermodulation $15. ea.
(STR 120) Wide Range Pickup Response at $15 ea.
(STR 130) RIAA Frequency Response at $15 ea.
(STR 140) RIAA Pink Noise Acoustical at $15 ea.
(STR 151) Broadcast Test at $15 ea.
(STR 170) 318 Microsecond Frequency Response $15 ea.
(SQT 1100) Quadraphonic Test at $15 ea.
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Time Delay Devices For Ambience Speakers
Any type of time delay will work with the ambience speakers as long as it has reasonable fidelity and a delay time of 15 to 30 milliseconds.
Tape delays are usually much too long and should not be used. Make sure the particular device is capable of operating as a pure delay with no recirculation or echoes. Desirable but not essential features are:
1. Two separate, independent left and right channels.
2. Variable delay of 10 to 100ms.
3. Superior audio quality (response to 10kHz or over, low noise and distortion.) If you choose a single channel delay, it will probably accept left and right inputs and delay the difference signal. If it is a mono in, mono out, device, (such as the Delta Lab) you should use a difference signal matrix. The Williamson Super Quadpod (Audio Amateur, p. 14) should work well for this (see also Audio Amateur 1/71 for an earlier version.) You might try no delay at all.
Surprisingly good results can be obtained using a rear channel output from a quadraphonic matrix or the Quadpods.
ASSORTED DELAY DEVICES Delta Lab DL-1 Professional, Digital Mono $1200.00 Delta Lab Research. Inc., 25 Drum Hill Rd., Chelmsford MA 01824 (617)459-2346.
Advent Sound Space Digital $595.00 Advent Corp., 195 Albany St.. Cambridge MA 02139 (617) 661-9500. Southwest Technical Products 2AS-A Analog, 2ch, kit $250.00 Southwest Technical Products Corp., 219 W. Rhapsody, Dept. SB, San Antonio TX 78216.
Preis Homebrew TAA 4/75 Acoustical, 2ch, pts approx. $100.00
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SEAS PROFESSIONAL SOUND
CABINET KITS. If you prefer not to build your own boxes, SEAS CABINET KITS are available for all loudspeaker kits.
Cabinet kits for 223, 253, 403 and 603 are supplied as ready cut chip-wood boards, with a brown lacquered ash-veneer finish. The front baffle has a dark brown finish. Everything the home constructor will need is included in the cabinet kits, such as damping material, cloth, glue, and front grille. They are designed for ease of construction and require no special tool for assembly.
A detailed building instruction is enclosed. The SEAS cabinet kits are acoustically optimized to each loud speaker kit. This is an easy way of building professional loudspeaker cabinets to a reasonable price.
Kit 223 is a three-way system at a reasonable price, designed for use in a 20 - 25 liters closed cabinet. The 5 cm tweeter is viscously damped by magnetic oil in the airgap. This ensures a smooth frequency response and a low distortion level at high frequencies.
Kit 253 is designed for bass reflex cabinets. The 1" dome-tweeter has a vacuum formed, high loss plastic diaphragm, with a shape optimized for the high frequency range.
Kit 403 is a 3-way system with a 10" woofer, a 4.5" midrange unit and a 1" dome tweeter. In a 40 liters, ported cabinet this system delivers smooth and effortless reproduction of the entire audible sound spectrum.
Kit 603 is a 3-way system, built for a 60 liters bass-reflex cabinet.
High efficiency and excellent reproduction of transient characterizes this system.
Contact Your Nearest Distributor
THE SPEAKER WORKS
P.O. Box 303 Canaan, NH 03741
SONIKIT
1173 65th Street Oakland, CA 94608 C.C.S.
DISTRIBUTING
5070 E. 22nd Street Tucson, AZ 85711
DISCO 47
This is a loudspeaker kit designed to reproduce high sound levels with little distortion. DISCO-47 is a 4-way system, consisting of 7 units. Two 12" woofers, two 6" midrange units, two 4" tweeters and a horn loaded supertweeter. The system is designed for use in a bass reflex cabinet of about 100 liters internal volume. This secures a very good transient performance, especially in the low frequency area. The system has a power handling capacity of 160W and the almost unbelievable low operating power of 0.4W. The system is equipped with an automatic protection device for the midrange and treble units. At high power levels the protection circuit will be engaged and the warning lights marked «tweeter protection» and «midrange protection» will light up.
Empty cabinets for DISCO-47 are available. They are supplied in black veneer finish. Damping material, cloth, front grille and cabinet stands are included.
SEAS FABRIKKER A.S has many years of experience in designing loudspeaker kits. Much effort has been made in making the kits easy to assemble, without special tools or equipment.
The use of push-on connectors eliminates the need for soldering.
All necessary material as screws, gaskets, DIN-cable, bass reflex tube and rear chamber are included. Also a metal badge for mounting on the front. For Kit 403, 603 and Disco-47, a decoration ring for mounting in the bass-reflex port is enclosed.
The specifications for every kit are included as the last page in the extensive instruction leaflet that comes with all kits.
This page can be glued on to the back of your cabinet to give the finished product a professional look.
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Our Speakerlab Thirties are the culmination of our acoustic technology and speaker building experience - in collaboration with one of the world's top acoustic designers, Mila Nestorovic. A speaker with better transient response in a smaller enclosure than any system we have ever off ered. They're our Stradivarius. Because our ears receive most information about a musical sound in its very first instant, a speaker's ability to react instantly to an impulse (called transient response) is extremely important. Our Thirties image so well that the speakers themselves actually seem to disappear. The pluck of a guitar string or the snap of a snare drum appear instantly in the Thirties field of sound. Because they use the patented Nestorovic Woofer System, Thirties achieve almost a full octave of extra low bass. Through a unique phase-control network and incredibly high flux density 8" and 10" woofers, you get amazingly tight bass transient response. The result is tremendous bass from a relatively small enclosure. Handling up to 350 watts/channel, Thirties are simply unlike any speaker system you have previously heard. Experience the Thirties: handcrafted, technically precise instruments.
And Thirties are just one of ten different speaker designs fro Speakerlab. We also ha ve a wide range of speaker parts available. Send for our free catalog - it'll tel you more about us, our kits and our famous patented Nestorovic Woofer System , Wave Aperture Drivers , Polylam Cones and Subwoofer Drive Systems.
Speakerlab --- Dept. 101, 735 N. Northlake Way , Seattle, Washington 98103
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GET IT TOGETHER ... SEAS SPEAKER KITS use finest Scandinavian drivers in computer optimized three-way designs, from $59 00. For literature and information on SEAS Speaker Kits, raw drivers, and crossover networks, send $1.00 (refundable upon purchase) to: THE SPEAKER WORKS Box 303 Canaan. N.H. 03741 Dealer Inquiries Invited (603-523-7389) with a Speaker Kit
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AT LAST, the dream driver to do most of the work in your dream speaker system. Its the Jordan 50mm Module, a miniature speaker from England, with 1.3 gms moving mass that delivers the most satisfying transient "tracing" speed over the range of 150 Hz to 22 kHz, as good as the best electrostatic headphones. No super tweeter required. No mid and upper crossover points required, utterly phase coherent. The usual crossover points, parts and extra drivers are There are Ted Jordan designed push-pull woofers too, using twin Bextrene drivers of 5", 6 1 /2" and 8" with 3 db points of 30, 27, 23 Hz, for the most amazing articulation and sonic accuracy yet, to come in such size and cost packages. Also semi-kit and build them-from-scratch packages available.
An interesting pack of literature awaits you, when you send us your name and address plus $1 to help defray costs. Crossover designs and parts. Mylar caps, NP Electrolytic caps with 110V 125VAC rating and 10% tolerance, air and iron core inductors etc.
TA basic module "Unbox" cylindrical enclosures now becoming available with anechoic interiors for zero coloration.
6796 Arbutus St., Arvada, CO 80004, 303-420-7356. Transcendental Audio Innovative Components & Designs in High -End Audio E. J. JORDAN • POLYDAX(Audax) • DALESFORD • DECCA • EMINENCE
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