• Links for the Hi-Fi Speaker Enthusiast:
    Everything you ever wanted to know about active electronic filters and active speaker design.

  • Linkwitz Lab
    Active Filter design
  • Chris Caudle's Linkwitz dipole loudspeaker
  • Design and Dimensioning of Active Filters
    Javascript utiliies to help you to quickly design and dimension your active Sallen-Key or Multiple Feedback topology low-pass or high-pass filter.
  • Filter Design and Analysis
    Software links
  • Active filter design software
    AktivFilter is a powerful software for the design of active bandpass filters, highpass filters, lowpass filters and bandreject filters with operational amplifiers.
  • Active Filter Synthesis
    A simple tool for designing active filters using voltage-feedback opamps.
  • Elliott Sound Products
    Professional results for the Do-It-Yourself enthusiast.
    Free project and design articles.
  • CommLinx Solutions Schematics
    Audio filter, preamp circuits & power amplifier schematics.
  • Electronics Zone
    Contains thousands of electronics circuits and do-it-yourself circuits for hobbyists, students, professionals etc.
  • Linear Team
    Freeware speaker design software for Windows 9x/NT. You can design closed, vented and bandpass boxes. Calculates different types of filters too.
  • Calculators on-line center
    Over 15'000 calculators
    (Engineering: Electrical & Computer; Science: Physics, Astrophysics, Chemistry; Mathematics & Statistics).
  • Electronics Calculator Website
    Please choose your calculator from the left hand panel. When your calculator appears, enter your variables in the form boxes provided. Simply enter the variables you know, and the unknowns will be computed and displayed.
  • Steve Ekblad's Audio Software
    Free audio software and on-line audio tools.
  • SpeakerBuilding.Com
  • True Audio, the Loudspeaker Design Center
  • Art Ludwig's Sound Page
  • The Subwoofer DIY Page
  • Complex Systems, Inc.
    A source for active electronic crossovers.
  • Power Supply Design Tips
    Things you won't find in the data books.

  • Single Full Range Speaker Design
  • Horn Loudspeaker Response Analysis Program
    The program calculates the theoretical acoustical impedance, SPL response, electrical impedance and diaphragm displacement vs frequency characteristics of finite and infinite horn loaded loudspeakers.
  • Dedicated to the single full-range driver loudspeaker.

  • Prototype Boards & Software


    Olimex, in Bulgaria, offers fast turn around on prototype boards. While their panel sizes are fixed, they panelize and depanelize (to rectangular cutouts only) for free so you get as many boards as will fit their standard panel size. The boards include component side silkscreen and component side/solder side soldermasks. Their standard panels are 0.062" but they will supply 0.031" for $5 extra.

    3-5 working days for prototypes with solder mask and component print.

    Click here to get all information!

  • PCB Heaven - Electronic designs and schematics, tools and a forum for your projectlog!
    PCB Heaven - Electronic designs and schematics, tools and a forum for your projectlog! - Click here to connect

  • Free PCB routing and schematic capture software

    Click here to get your free copy!

    French language only!

  • Score Schematic Capture for Windows

    Click here for your free copy

  • EAGLE Layout Editor for Windows or Linux

    CadSoft offers user friendly, powerful and affordable solutions for PCB design, including Schematic Capture, Board Layout, and Autorouter.
    You can test drive EAGLE with a Freeware version!

    Click here for Eagle Freeware

  • Oscilloscope for Windows

    Windows application that converts your PC into a powerful dual-trace oscilloscope. Oscilloscope is free for personal use. Software written by Konstantin Zeldovich.

    Click here for Oscilloscope for Windows

  • Free Borland Software

    The Borland C++ Compiler 5.5 Free download.
    Also, free Turbo Debugger

  • Al B. Coltrane's original Filter.exe
  • Sherlab's FILTER.EXE (programmed by Al. B. Coltrane) calculates active Linkwitz/Riley-, Butterworth and Bessel filter circuits, as well as the one with critical damping. The calculated circuits can be optimized according to the available and standardized parts.

    Furthermore FILTER.EXE enables the calculation of optimized T-filters to correct the drivers frequency response at its resonant frequency.

    Important: Sherlab's Filter.exe is a DOS Program and does not run with Windows NT, XP or Vista. Run it on your old Dos only, Windows95 or Windows 98 computer!

    Click here for a free download!

  • Antique Radio Schematics and Capacitors
  • JustRadios is specialized in antique radio schematics and capacitors (high voltage film, electrolytic, silver mica, ceramic disc and safety capacitors) for old vintage tube radios. They carry antique radio schematic diagrams and electronic circuit service information for American, Canadian and European antique radios.
    Other services: Vintage CB Radio Schematics, Vintage Amplifier Schematics, Transistor Radio Schematics, old Car Radio Schematics and old TV Schematics.