Electronics World articles Popular Electronics articles QST articles Radio & TV News articles Radio-Craft articles Radio-Electronics articles Short Wave Craft articles Wireless World articles Google Search of RF Cafe website Sitemap Electronics Equations Mathematics Equations Equations physics Manufacturers & distributors LinkedIn Crosswords Engineering Humor Kirt's Cogitations RF Engineering Quizzes Notable Quotes Calculators Education Engineering Magazine Articles Engineering software RF Cafe Archives Magazine Sponsor RF Cafe Sponsor Links Saturday Evening Post NEETS EW Radar Handbook Microwave Museum About RF Cafe Aegis Power Systems Alliance Test Equipment Centric RF Empower RF ISOTEC Reactel RF Connector Technology San Francisco Circuits Anritsu Amplifier Solutions Anatech Electronics Axiom Test Equipment Conduct RF Copper Mountain Technologies Exodus Advanced Communications Innovative Power Products KR Filters LadyBug Technologies Rigol TotalTemp Technologies Werbel Microwave Windfreak Technologies Wireless Telecom Group Withwave Sponsorship Rates RF Cafe Software Resources Vintage Magazines RF Cafe Software WhoIs entry for RF Cafe.com Thank you for visiting RF Cafe!
PCB Directory (Manufacturers)

RF Cascade Workbook 2018 by RF Cafe

KR Electronics (RF Filters) - RF Cafe
Anritsu Test Equipment - RF Cafe

You Can Build These 16 Speaker Enclosures
March 1969 Radio-Electronics

March 1969 Radio-Electronics

March 1969 Radio-Electronics Cover - RF Cafe[Table of Contents]

Wax nostalgic about and learn from the history of early electronics. See articles from Radio-Electronics, published 1930-1988. All copyrights hereby acknowledged.

Philip Blattenberger with Kirt's Homemade Speaker - RF CafeBuilding speaker enclosures was a popular project for stereo enthusiasts in the 1969 time period when this article appeared in Radio−Electronics magazine. Lots of well-designed speakers were commercially available, but they tended to be expensive. High−end speaker enclosures typically had high−end speakers within, which contributed to the increased cost. I built a pair of wooden enclosures while in the USAF at Robins AFB, Georgia (click on thumbnail image). It had a very nice woodshop. The speaker cabinets had a very simple internal design; the removable front frame was the hardest part to build. Mine were made from pine. For my level of music appreciation, I found that a quality set of car speakers (Radio Shack p59, 40−1341) provided great sound for all but the deepest bass frequencies. An added advantage was that the crossover circuit was built in, so all I needed was to build a crossover to split the really low frequencies to 10" bass speakers that were purchased at Radio Shack (p58, 40−1331). The Radio Shack crossover circuits were too high (1 kHz) so I found an article showing how to build one that split at around 500 Hz; admittedly, it didn't work very well. The grille cloth also came from Radio Shack (p61, 40−1936).

You Can Build These 16 Speaker Enclosures

You Can Build These 16 Speaker Enclosures, March 1969 Radio-Electronics - RF Cafe

Fig. 1 - A doubly expandable, tuned-duct University system. Start with 12" model M12 wide-range speaker (1). Add 15" C15HC woofer to extend bass response (2), and a HF206 tweeter (3). Note boxing of 12" speaker and duct.

Fig. 2 - Another University system, similar to Fig. 1, starts with an 8" M8D wide-range speaker (1), using a duct. If a 12" M12 woofer is added (2), duct length is changed. The addition of MS tweeter (3) extends response of system.

Fig. 3 - A 2 speaker-2 way Altec-Lansing bass reflex system. Use a 15" 416A woofer, 811 treble horn with a 806A driver.

Fig. 4 - This infinite baffle Altec-Lansing system uses two 416A woofers. Use 511B treble horn with 802D driver.

by Abraham B. Cohen†

Despite the quantities of low-cost, assembled loud-speaker systems on the hi-fi market, do-it-yourself projects are still very popular. If you're planning such a project, your choice of a loudspeaker enclosure should take several factors into account: performance, cost, size, appearance and expandability.

The speaker system should be installed in the room where your family does most of its "living," and the space available in this room will influence your selection.

The table below and the following figures describe 16 enclosures whose construction information was supplied by six leading loudspeaker manufacturers. The enclosures selected vary in size and may be installed in room dividers, hung from walls, inserted in alcoves and placed on counters or desks. Larger enclosures, which are regaining some of their early popularity, may be built as floor furniture pieces.

To simplify construction, the manufacturer's original external design is not included. The builder can select the enclosure's exterior appearance to match room furniture. Several of the systems shown are expansible or include adapter boards. This permits either an 8-, 12- or 15-inch speaker, for example, to be installed without major changes in the enclosure.

Expansible systems minimize obsolescence, enabling you to increase the audio "fullness." of the system as your budget permits.

Optimum performance will be obtained only if the proper lumber is carefully assembled. Here are a few construction tips.

Plywood of 3/4-inch thickness should be heavily glued at all mating surfaces. When joints are clamped or screwed together, surplus glue should seep out along its entire length. Small glue blocks are often used to reinforce interior edges of the panels. Apply glue to surfaces between the blocks and panel, and secure the blocks to both panels with screws.

Bass-reflex and infinite-baffle enclosures must be especially rigid to avoid distortion and loss of bass response. Use at least four good-sized screws along each edge of the rear panel. At least 1 inch of sound-insulation material should be applied to all interior surfaces in any enclosure. Large panels may require diagonal cross-braces to minimize vibrations, and a cross-strut can be used between large surfaces.

Make sure the speaker mounting panel is very flat, especially where the speaker is mounted. If possible, make the front panel thicker than the others.

If wood screws are used to mount the speaker, drill small guide holes and drive the screw in carefully. A better method of speaker mounting is with machine bolts and T-nuts, which are pressed into a hole in the baffle board.

Avoid grille cloth material that is acoustically opaque, as this will ruin high-frequency response. The cloth should be loosely woven - at least 50% of its area should be open space. Tighten and secure the cloth to the back side of the panel. R-E

† From Hi-Fi Loudspeakers and Enclosures, by Abraham B. Cohen, Hayden Book Co., Inc., Copyright © 1956, 1968.

* Add cost of enclosure and for multiple-speaker systems, crossover networks. Manufacturers can provide crossovers and details.

 

 

Posted April 17, 2023

Innovative Power Products Couplers

About RF Cafe

Kirt Blattenberger - RF Cafe Webmaster

Copyright:
1996 - 2024

Webmaster:

Kirt Blattenberger,

BSEE | KB3UON

RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling 2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas and reference material while performing my work as an RF system and circuit design engineer. The World Wide Web (Internet) was largely an unknown entity at the time and bandwidth was a scarce commodity. Dial-up modems blazed along at 14.4 kbps while tying up your telephone line, and a nice lady's voice announced "You've Got Mail" when a new message arrived...

Copyright  1996 - 2026

All trademarks, copyrights, patents, and other rights of ownership to images and text used on the RF Cafe website are hereby acknowledged.

My Hobby Website: AirplanesAndRockets.com | My Daughter's Website: EquineKingdom

Crane Aerospace Electronics Microwave Solutions: Space Qualified Passive Products

Innovative Power Products Passive RF Products - RF Cafe

TotalTemp Technologies (Thermal Platforms) - RF Cafe