Audio and Loudspeakers

bulletin boards and forums

Parts Express Tech Talk Forum
Madisound Audio Discussion Forum Forums
The Subwoofer DIY Page Discussion Forum
AudioCircle - Forum Index
AudioCircle - Index
Audio Area - AVS Forum
HomeTheaterShack Forums
Home theater forum with resident experts to discuss home theater systems and design. Discuss all aspects of audio, video and high definition.
HTGuide Forum
We are, your home theater forum and audio video community. We have a large audio video discussion forum with over 5000 members.
Audio Round Table Forums
Audio advice and discussions with audiophiles and professionals. Free discussion forums, open to all and frequented by industry experts. Ask questions and get advice on stereos, speakers, hi-end amplifiers, pre-amps, home theater, tube hi-fi, turntables, vinyl, tweaks, music, films, video, DVDs and more.
Audio Asylum Forums
Audio recommendations from audiophiles and free forums. Ask questions and get advice on stereos, speakers, hi-end amplifiers, pre-amps, home theater, tube hi-fi, turntables, vinyl, tweaks, music, films, video, DVDs and more. A personal Audio Advisor with tons of stereo equipment reviews. A special place for music lovers.
Audiokarma Audio Stereo Discussion Forums is a discussion forum about home audio and stereo, vintage television, DIY audio, speakers, stereo, and more ...

Vendors and Suppliers

Electronic Parts

Prototyping Supplies

Small PC Prototype Board - MCM
Order Small PC Prototype Board - 21-113 online from MCM Electronics. Manufactured by distributed by mcm. MCM order number 21-4590.
Small IC Prototype Board - MCM
Order Small IC Prototype Board - 21-110 online from MCM Electronics. Manufactured by distributed by mcm. MCM order number 21-4575.
IC Experiementers Board - MCM
Order IC Experiementers Board 1 3/4'' x 1 3/4'' x 3/32'' - 21-114 online from MCM Electronics. Manufactured by distributed by mcm. MCM order number 21-4595.
3 X 5 dual-row IC board - MCM
Order PC 22-0504 3 1/8 X 5 1/1 - 22-0504 online from MCM Electronics. Manufactured by gc electronics. MCM order number 21-3950.
Prototype Board @ MCM
Order Small PC Prototype Board - 21-113 online from MCM Electronics. Manufactured by distributed by mcm. MCM order number 21-4590.
UNI-BOARD Proto Boards
Circuit Specialists - Data Acquisition - Industrial Computers - Test Equipment - Components & Supplies, Digital Multimeters, Electronic School Kits, Resistors, Capacitors, Transistors. In business over 32 years.
Prototyping Boards at Futurlec


Sealed Rotary Switches - Page 1
7 Position Rotary Switch - shorting
71A30 switch datasheet
8-Pos Rot SW 2-Pole 2-Tier Shorting
1 POLE 11 POS ROTARY SW gold pl
Switch, rotary. DP6T shorting contacts.


Par-Metal - enclosures
Front Panel Express - Custom Front Panels with free Front Panel Designer - Home
Front Panel Express custom mills front panels and enclosures for electronic equipment based on customers design. Cost-effective high precision machining of single units and production runs. Our free CAD software allows you to design your prototype in a fast and convenient way.
Lansing Instrument Enclosures Home Page
Lansing specializes in the design and production of small and rack-mounted electronic instrument enclosures. We deliver quickly, take pride in quality, and provide strong technical support.
Chassis case THL Audio
Chassis Shop | Diy HiFi Supply
Goldpoint Project Boxes
Goldpoint Project Boxes
modu enclosures (Italy)

Amplifier Modules

Panson Audio Laboratories
TechDIY - chipamps and supplies
ColdAmp Electronics, S.L. is a spanish company that designs, develops and sells audio amplifiers and switching power supplies worldwide for the professional customer and the "Do it yourself" (DIY) enthusiast.
Hypex Electronics B.V.
Class D Audio
We manufacture Class D Audio amplifiers, power supplies and other state of the art equipment.
DIY Chip Amplifier Kits, Gainclone PCB's, Components and Information using the LM3886 National Semiconductor Opamps
AudioSector - chip amps
DIY Chip Amplifier Kits, Gainclones PCB's, Components and Information using the LM3875 LM4780 National Semiconductor Opamps
2x LM4780 at Audiosector
DIY Chip Amplifier Kits, Gainclones PCB's, Components and Information using the LM3875 LM4780 National Semiconductor Opamps
41Hz Audio:Sounds Good to Me!
Switch mode amplifiers in kit form for DIY:ers. Kits for DIY and small OEMs, based on Tripath chips.
James Audio: parallel TDA7293
O Audio - 500W BASH® Subwoofer Amplifiers

Marchand Electronics
MCM Electronics: Computer Parts, Batteries, Cable & Wiring, & more
Electronics, batteries, test equipment, and more all at MCM. MCM offers a wide variety of electronic and computer related parts.
Apex Jr.Home Page
Circuit Specialists (Web-Tronics)
Action Electronics
Action Electronics- Your Complete Source For Parts, Equipment and Supplies- Online Store
Ocean State Electronics
All Electronics Corp
Newark InOne
Digi-Key Corporation
Mouser Electronics
Michael Percy Audio
LC Audio Technology
Parts ConneXion
Smith&Larsen Audio (home of the woofer tester)
Welcome to the homesite of the Woofer Tester
NHT drivers and electronics surplus sale
NHT driver surplus sale.
Antek transformers
Modular PIC hardware,single board computers(SBC) and solutions
Heatsinks from Surplus Sales
Heatsinks, plate heatsinks, one surface heatsinks, two surface heatsinks, cpu
Electronic Goldmine
The Electronic Goldmine stocks millions of unique and hard to find electronic circuits, robot kits, solar kits, flashlights, LED, LEDS, motors, switches, transformers, motors, solenoids, relays, switches, sensors, power supplies, batteries, solar panels, capacitors, boards, fans, PC boards, amps, soldering irons, solder, wire glue, strobes and other hard to find electronic items at discounted sale prices.
Electronics Surplus
Wayjun Technology (terminal blocks)
Wayjun Technology | Led light|High Power|Through Hole|SMD|Super Flux|PCB|Pluggable|Screwless Terminal Block|Flashlight : The Shopping Cart - Pcb Terminal Blocks Pluggable Terminal Blocks Screwless Terminal Blocks Fuse Terminal Blocks Feed Through Terminal Blocks Big Terminal Blocks Pin Header Female Header IC Socket IC Bootch IC Female DIP Switch.Tact & ZIF Socket DIP Plug connector IDC Socket D-SUB Connectors and D-SUB Hoods USB Connector USB/RS-232/RS-485 converter LED (All Color) LED Lights LED Displays ecommerce, open source, shop, online shopping
Stackable prototyping boards for microcontroller and general electronic development. Our prototyping boards make it easier to develop systems quickly.
Micro Ohm - Precision Resistors

Loudspeaker Drivers

Parts Express
Madisound Speaker Components
Creative Sound Solutions
Speaker City
GR Research
GR Research offers speaker kits, drivers, and accessories for loudspeaker building. Woofers, tweeters, and midranges from Focal, PHL, Orca Design's Raven and our own GR series low and high frequency drivers.
[ SoundSplinter Subwoofers - High Excursion Professional Subs - DIY Audio Drivers ]
High excursion subwoofers for use in home theater and car audio DIY applications.
AE Speakers --- Superb Quality, Unforgettable Performance, Definitely.
Rythmik Audio DirectServo Subwoofers
HUMAN Speakers
Loudspeakers Plus
Subwoofers, Speakers, guitar speakers, pa speakers, high frequency drivers, replacement high frequency diaphragms, replacement speaker baskets from 18 sound, Eminence, Fane, PAudio, Jensen, Selenium, Peavey, EV, Neutrik, eighteen sound and more! We also carry replacement JBL speakers, JBL diaphragms and JBL horns.
Speakers components for home stereo, Home Theater and studio monitoring, electronic components, home theater speakers
Sonic Craft
Meniscus Audio
BMM electronics
Audio electronics on the web the starting point for every AUDIO hobbyist and professional
NHT drivers and electronics surplus sale
NHT driver surplus sale.
Mach 5 Audio
Mach 5 Audio : - IXL Series M Series SPL Series Router Jigs Terminals and Hardware Speaker Parts ecommerce, open source, shop, online shopping
Surrounds and PR kits
Wondering how to replace your speaker edges with new foam? The answer is our DIY surround replacement kit also called re-foam or re-edge repair kits.


DazyWeb Laboratories freeware!
Grenander Software Workshop (LoudspeakerLab)
Speaker Workshop
SPEAKER PRO - Loudspeaker Simulation Software
LinearX Systems
Bodzio Loudspeaker Software
IJData LspCad
AJ Design online Software
Provides bandpass, sealed and vented subwoofer box design software and science, math and engineering programs and freeware
Eric Wallin's Homepage
ChadGray Soundeasy demos
Chad Gray's Web Site with information on DIY Speakers, Asset Managment and Cold Fusion.
Basta Loudspeaker Simulator

RAW Acoustics (Surrey, BC)
Elliott Sound Products
North Creek
True Audio
SVSound - Home
SV Sound - Thanks for stopping by SVS, The Sound Authority (TM). If you're in the market for a new subwoofer, speakers, or both, for your home theater, or just want to read more about bass and sound, you've come to the right place.
Circle Stereo - Vintage Electronics Restoration
SB Acoustic :. Luxurious .:
Tangband Speakers
Custom Wood Speaker Cabinets - Weiland Industries, California
Weiland Industries will create custom Speaker cabinets to your specifications in most woods. High quality to match any interior or system design. We provide the finest craftsmanship on custom hardwood flooring, interior molding, wall panels, speaker cabin
UBER-STEALTH AUDIO - Custom Cabinet Fab
CNC by Design - Ogden, UT
CNC by Design - Ogden, UT. Design and Manufacturing. Let us help you with your next craft project
MiniDSP manufactures low cost digital signal processor kits for the DIY/OEM market. Our flexible audio platforms are software controlled and easily upgradeable.
Heatsink USA

Enthusiast Web Sites

list of DIY websites
Mark K's Speaker Pages
Linkwitz Lab - Loudspeaker Design
Music and Design
Quarter Wavelength Loudspeaker Design
Derivation and Correlation of a General Acoustic Model for a Fiber Filled Transmission Line Loudspeaker.
Art Ludwig's Sound Page
Monte Kay's Loudspeaker Projects Page
Keith Kidder's Audio Site
argos homepage_combining art and sound
JPO's SpeakerBuilding LinkList.
Jeff Bagby's Galileos on Photobucket
Gainclone Amplifier Web Ring
This webring is for all DIY'ers who like to build amplifiers based on the IC's from National Semiconductor, LM3875 and LM3886 and similar. Manufactures are also welcome, everybody in fact who have som

Loudspeakers - Design and Technical

Baffle Step Info

Baffle Step II
Baffle Step circuit - Elliot Sound Products
True Audio TechTopics Diffraction Loss
Linkwitz on Diffraction
Baffle step compensation using boost at low Freq

ESP Tech Articles
Elliott Sound Products - Articles, How does the Neville Thiele Method (NTM) crossover work, and what does it do?
Motivation for using Active Crossovers
Active Vs. Passive Crossovers - what are the factors that make active the only choice for serious hi-fi? Driver control is not well understood, but perhaps this article will help.
The Subwoofer DIY Page v1.1
Quasi-Butterworth 5 Alignments
Satellites and Subwoofers
DIY-dipole: H and U frame woofers
DIY Molded Port Flares
Using a heat gun to make your own Port Flares
Port Flares - Evaluation of noise
Details of tests carried out on flared ports to determine usable velocity
Loudspeaker Designers Selection Guide
Loudspeaker Cable Characteristic Impedance
What is the effect of the characteristic impedance of a loudspeaker cable? Is it important to match the cable to the speaker load impedance, or is this simply a marketing ploy?
Power matching
Variable directivity
Jeff Bagley's Xover Tips on audioDIYcentral
Enter a brief description of your site here
Optimum frequency response curves in the bass range.
The placement of a subwoofer
Quarter Wavelength Loudspeaker Design
Derivation and Correlation of a General Acoustic Model for a Fiber Filled Transmission Line Loudspeaker.
Proper Grounding Practices
Power amplifier limited SPL for a dipole woofer
Electro-acoustic models for dipoles
Acoustical and electrical models for the design of a dipole loudspeaker with numerical examples for the PHOENIX project.
Acoustic resonance of cylinders, cones and boxes
Using piezo tweeters wisely: a "how to"
Using piezo tweeters wisely: a "how to" Speakers
Subwoofer Measurement Tactics: A Brief, Topical Overview & Method Comparison — Audioholics Home Theater Reviews and News
You often see us measuring subwoofers using various methods such as: groundplane, in-room nearfield, outdoor on a pole, anechoic, quasi anechoic, etc in our product reviews and technical articles. This article discusses the different approaches to measuring subwoofers as well as tabulates the pros and cons of each method. Depending on the resources on hand of the reviewer, we will typically apply one or more of these methods and will note them as such in the reviews. The idea here is to eliminate external influences that complicate the measurements to yield similarly correct results for each methodology employed. The scope of this overview is limited to subwoofers only and the amplitude response frequencies range of 10 Hz to 320 Hz.
A Bessel Filter Crossover, and Its Relation to Others
deleterious effects of driver offset
Klippel Techincal Publications
Porous Absorber Calculator V1.55
Helmholtz resonator designer
Berechnungs-Werkzeuge zum Boxenbau
various absorbers and bass traps
Variable Amplifier Output Impedance
ESP Project Pages - Variable Amplifier Impedance. Visit the other ESP pages for more audio projects and articles

Measurement Tips

Leach Vented Box Article, vent tuning
Measuring Loudspeaker Driver Parameters
Thiele-Small parameter measurements
Constant Voltage Speaker Measurement Circuit

Tips for using Ports/Vents
Recommendations on using Port Flares for loudspeakers and subwoofers based on experimental evidence

Chip Amp Design and Technical

Power Supplies

Solid State Power Amplifier Supply Part 1
Pwr Supply Basics
Building a chip amp power supply
hi-fi, GC, 'chip amp', PSU, guide.
ESP - Linear Power Supply Design
ESP - The Audio Pages. Linear power supply design information - Learn how to design your own high performance amplifier power supply.
Power Supply Wiring Guidelines
Power supply wiring guidelines. How to wire a simple power supply for a project amplifier or any other use.
Grounding - Tricks and Techniques
Earthing (Grounding) Your Hi-Fi. Detailed explanations of the safety and sonic aspects of proper earthing (grounding) techniques

Basic LM3886 amp
Audio projects modifications
ESP - Heatsink design and transistor mounting
ESP - How to calculate, design and size heatsinks for amplifiers, power supplies and other electronic equipment. Includes device mounting, thermal resistance, measurement techniques, etc.
Simplest Ever Bridging Adapter for Amplifiers
ESP Project Pages - Simple Bridging Adapter. Visit my other pages for even more!
Parallel amp servos schematic
Neil Davis' page on Alesis Amps
multi LM3886 amplifier design notes
LM4780 datasheet

Line-Level Circuit Design and Technical

Active Filters and EQ

various Active Filter circuits by S.Linkwitz
Active Filter Design Techniques
Graphic Equalizer
The five band graphic equalizer described here was designed to connect between two video recorders, so that the frequency response can be corrected somewhat.
Parametric Equaliser
ESP Project Pages - Parametric and Sub-Woofer Equaliser. Just one of the many circuits available.
Parametric EQ's and more
Adjustable graphic equalizer - slyt134
Equalizer Design at bottom
The Active Universal Filter
Design and Dimensioning of Aktive Low-Pass and High-Pass Filters. Sallen-Key and Multiple Feedback Topologies, Spice Netlist Generator.
Universal Active Filter IC - UAF42
<P>The UAF42 is a universal active filter that can be configured for a wide range of low-pass, high-pass, and band-pass filters. It uses a classic state-variable analog architecture with an inverting amplifier and two integrators. The integrators include on-chip 1000pF capacitors trimmed to 0.5%. This architecture solves one of the most difficult problems of active filter design&#151;obtaining tight tolerance, low-loss capacitors.</P><P>A DOS-compatible filter design program allows easy implementation of many filter types, such as Butterworth, Bessel, and Chebyshev. A fourth, uncommitted FET-input op amp (identical to the other three) can be used to form additional stages, or for special filters such as band-reject and Inverse Chebyshev.</P> <P>The classical topology of the UAF42 forms a t
UAF42 Application Guide
EQ and filter circuits

Online Books

EBook: Electronic Filter Design
Electronic filter Design by Taylor
EBook: Analog Circuits Cookbook
Analog Circuits Cookbook

Signal Generators

Wikipedia: Relaxation oscillator
PWM Controller
single op amp PWM
PWM circuit with dead zone
Triangular wave oscillator
PWM LED driver by Rod Elliot
ESP Projects - LED Lighting Dimmer/ Motor Speed Controller
LM311 comparator
LMV393 - EQNs for square wave oscillator
LM339-D as squarewave oscillator
555 square wave generator
The Electronics Club
555 Square Wave Calculator
Astable 555 Square Wave Calculator, Palm Springs, Cathedral City, Palm Desert, La Quinta, Desert Hot Springs, Indio, Thermal, Thousand Palms, Rancho Mirage, Coachella Valley, Southern California, computer service, requires JavaScript
Simple PWM generator circuit
triangle wave Generator by TLC271
The circuit has both square-wave and triangle-wave output. The left section is similar in function to a comparator circuit that uses positive feedback for

Regulated Voltage Supplies

Regulator articles (Walt Jung)
Decoupling and Bypasing in Power Supplies
Improving Pwr Supply Rejection (Maxim)
This application note describes techniques for improving the rejection of power line artifacts while maintaining low operating current.
Links to info RE Power Supplies
Power Supplies and Regulators for Hi-Fi Audio
Small Power Supplies and Noise reduction
Low power supplies, traps, pitfalls and the downright lethal
LM317.pdf (application/pdf Object)
LM317HV regulator
LM337.pdf (application/pdf Object)
LM337HV regulator
Using 3-pin regulators off-piste: part 1
..the what, why and even some of the how to setup your room for listening
Simple Voltage Regulators Part 1: Noise
AN007 - High Power Zener Diode
ESP Application Notes - High Power Zener Diode
AN008 - How to Use Zener Diodes
ESP Application Notes - How to Use Zener Diodes
78xx/79xx series example

Op Amp Applications Handbook
AN-31.pdf Op Amp circuit collection
LM555 Timer Circuits
Power Supply Wiring
Power supply wiring guidelines. How to wire a simple power supply for a project amplifier or any other use.
Balanced Line Driver IC DRV134
INA 134 Diff Line Reciever
Offset Adjustment in Op-Amp Circuits
This article discusses various DC offset adjustment circuits using electronic potentiometers for op amp circuits and the advantages and disadvantages of each.
Power Amp Clipping Indicator
ESP Project Pages - Power Amp Clipping Indicator. See exactly when your power amplifier is reaching the maximum output level
Audio Amp Power Limiter
ESP Project Pages - Audio Amp Power Limiter. Visit my other pages for more audio projects and articles
Six channel volume control using Analog SSM2018T VCA’s
Analog Devices: SSM2018T: datasheet
The SSM2018T represents the continuing evolution of the Frey Operational Voltage Controlled Element (OVCE) topology that permits flexibility in the design of high performance volume control systems.
Silonex Inc.: Audiohm Optocouplers

PCB design

PCB-printed circuit board design!PCB123 providing complete circuit board solution design
Free PCB layout software - Low cost circuit boards - Top quality PCB manufacturing
Sprint-Layout PCB design


Wood Products

Rockler - Woodworking Supplies (Concord, CA)
Shop for Woodworking Tools, Plans, Finishing and Hardware online at Rockler Woodworking and Hardware. Find thousands of woodworking supplies like drawer slides, hardwoods, cabinet hinges, and knobs and pulls. Plus, Rockler has great tools like router tables, clamps, roller ball stands, and more for your workshop.
Woodcraft (Sacramento)
woodcraft offers woodworking supplies, tools, accessories, hardware plans and projects from brands like Dewalt, Rikon and Leigh. Read woodworking articles, get free advice and display your own woodworking projects.
Curved Plywood, Dieboards, Drumshells Aitwood Home
Anderson International Trading
Bamboo Veneer
Neat Concepts - fleible wood products
Neat Concepts - manufacturer and supplier of MDF panel products – sold through a world-wide network of industrial and retail distribution partners
Tape-Ease Wood Veneers & Edgebanding
Better Bond Heat-Lock™ Veneer Glue


RILL | Caster, set of 4
IKEA products
BRANÄS | Basket 9x9x9 $6
IKEA products
HOL | Side table 20x20x20
IKEA products

Williams Foam
Williams Foam specializes in custom fabrication of Polyurethane, Polystyrene, and Polyethylene foams for packaging, architectural and the special effects industry.
Astrofoam Stock Boxes / Coolers
J.D. Crane is a service, repair and installtion company of overhead cranes and hoists. We are also suppliers of new and used crane & hoist parts.
Expanding Foam
Wholesale/retail sales of composite and fiberglass materials, including epoxy, adhesives, carbon fibers, urethane foam, urethane casting rubbers
Fiberglass Supply - Pour Foam
Product Catalog listing the two part Pour Foam materials for flotation and insulation carried by Fiberglass Supply with product descriptions and pricing.
EAGER PLASTICS-CHICAGO Two component rigid urethane expanding polyurethane foam. Stiff, Rigid, 3, 5, 15 lbs per cubic foot Expanding Casting Foam. A B two-part foam.
Cubicon Corporation
Foam by Mail
Welcome to FOAMBYMAIL.COM. Here, you will find a variety of foam products at very inexpensive prices. Foam by Mail Products, Sound Proofing Foams, Seat, Cushion, Mattress, Pad, Pads, Pillows, Seats, Cushions,
Martin Sound, parts and surrounds
Welcome To Boston Felt Online
The Booth Felt Company
TAP Hollow Glass Microspheres
Styrofoam and EPS Foam spheres
Foam Balls by Shape Formation - We manufacture Styrofoam and EPS Foam balls, foam moldings, columns, signs, and more!.
Smoothfoam 12" styrofoam Ball
We are the North American Manufacturer of Dylite Foam shapes, Antenna Balls and Antenna Toppers. Dylite is a smooth plastic foam, similar to styrofoam.
Connector Bolts - Rockler
Knock Down Fittings and Connectors: Connector Bolts
Universal Connector - Rockler
Knock Down Fittings and Connectors: Heavy-Duty Universal Connector
Nichols Paper Products Co.
MDF FAQ - Tutorial
MDF (Medium Density Fiberboard) FAQ
The Foam Factory, Open Cell Foam
The Foam Factory, foam products, cushions, mattresses, pillows, seats, sound proofing,THEFOAMFACTORY.COM, THEFOAMFACTORY.COM - The Foam Factory, foam products for a variety of applications. These products include mattresses, cushions, seats, sound proofing, pillows, comfort items, and many others.
Bonded Logic UltraTouch™ Multi-Purpose Roll
Bonded Logic UltraTouch™ Multi-Purpose Roll UltraTouch™ Cotton Insulation is made from high quality natural fibers. These fibers provide for extremely effective sound absorption and thermal performance. UltraTouch does not itch and is very easy to handle. UltraTouch contains no chemical irritants or VOCs (volatile organic compounds). UltraTouch is also a Class-A Building Product and meets ASTM testing standards for fire and smoke ratings, fungi resistance and corrosiveness. UltraTouch contains 85% post-industrial recycled natural fibers making it an ideal choice for anyone looking to use a high quality sustainable building material. This UltraTouch Multi-Purpose Roll is the perfect choice for small household insulating jobs including sealing gaps around air conditioning wall and window units as well as spaces around doorways, windows, ductwork, pipes, and other small open wall cavities. One roll is 2'' thick by 16'' wide by 48'' long. It has an R-value of 8.0. To install, simply use scissors or hands to cut or tear the desired amount of insulation. Push pieces snugly into the opening to be filled. Note: UltraTouch Natural Cotton Fiber Insulation should not be used adjacent to flame or heat producing sources, including electric heat coils, nor should it be used in spaces surrounding metal chimneys, fireplaces, or flues. Specifications: - Dimensions: 48'' x 16'' x 2'' - R-Value: 8.0 - Origin: USA Additional Information: - Manufacturing Process Presentation - UltraTouch Product Benefits Presentation - Recycled Content Certification (pdf) - UltraTouch Product Installation Presentation - LEED Information Sheet (pdf) ...

Tuners and FM Antennas

Vintage Tuner Information
Antenna Performance Specialties
Radio X Tuners
Specializing in tuner alignment and modification
Wideband Vertical "X" Omni
FM antenna designs and simulations
FM Yagi Antenna designs
Lightning Suppresors | Arrestors
Neets Module 10-Introduction to Wave Propagation, Transmission Lines, and Antennas
DIY FM modified cubial quad antenna
DIY custom frequency T-type FM antennae
zbconline.commodified cubial quad antenna
Sony XDR-F1HD Technical Review
Radio Station Locator
Comprehensive listing of all of the Radio Stations in the World with Web Pages
FCC Fact Sheet on Placement of Antennas
DIY J-pole antenna

ncdiyaudio - NorCal DIY Loudspeaker group
FRD Consortium
Audio/Video Component Archive
AUDAX driver spec sheets
Audax Industries - Haut-parleurs et kits - Ce site vous presente les gammes de produits et vous donne acces a un forum de discussion, a des conseils techniques...
Online Speaker Design at mh-audio
DIY LoudspeakerSite -Stone Texture spray paint
If it's worth protecting, it deserves Rust-Oleum. There's a whole spectrum of rich, beautiful colors in a variety of unique finishes: Gloss, Textured, Satin, Hammered, Metallic. Even specialty coatings like High Heat for the grill and Appliance Epoxy.
Thiele/Small parameters - Wikipedia
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Cross·Spectrum - Mics and calibration services
Hire Cross-Spectrum Labs to measure the performance of your sound and vibration instruments