| No. |
Crossovers & Effects | Description |
Flags |
| 08 | 2-Way Electronic Crossover |
Conventional 3rd order electronic crossover | |
| 09 | 24dB/Octave 2/3-Way Xover |
Linkwitz-Riley alignment and phase coherent !! This is an extraordinarily nice crossover, and is suited to top of the line hi-fi or professional installations.
 Revision B boards now shipping |
30May
 |
| 9a | A Reader's Xover |
This is well worth reading if you can't decide. Text and photos all supplied by the reader (some editorial comment) |
|
| 18 | Simple Surround Sound Decoder |
A line-level version of the "Hafler matrix" decoder |
|
| 21 | Stereo Width Controllers |
2 to choose from. Expand or contract the stereo sound stage |
|
| 26 | Digital Delay Unit |
Digital delay, and all the info to construct a complete surround system (Note - The delay IC no longer available) |
02Sep |
| 28 | Parametric / Sub-
Woofer Equaliser |
A simplified version, which performs surprisingly well and has more options than most of the more complicated circuits |
05Apr |
| 48 | Sub Woofer Processor |
Using the ELF™ "Extended Low Frequency" principle, this processor is designed to operate a sub-woofer driver below its resonant frequency. This means that the box is small, resonance can be (comparatively) high, and the load is completely predictable. (Updated 07 Jan 2004). Original PCBs are no longer available. |
|
| 48A | Sub Woofer Processor, Revision A |
Operates much like the original P48 (above), this new version of the P48 processor is designed to operate a sub-woofer driver below its resonant frequency. The latest version is far more flexible than the original. (Created 12 Jan 2009) |
12Jan |
| 63 | Multiple Feedback Bandpass Filter |
This is the basis of the expandable equaliser and analyser mentioned below as up and coming projects. Marginally useful in it's own right, it is the ideal building block for these projects, and can also be used to build a vocoder! |
19Jul |
| 67 | Fast Audio Peak Limiter |
This peak limiter is simple and very effective. Using a discrete FET as the gain control element gives low distortion and very fast response times. |
26Aug |
| 71 | Linkwitz Transform Circuit |
The Linkwitz Transform circuit is an equaliser to provide extended bass response from any loudspeaker in a sealed enclosure. The effect is similar to the EAS equaliser described in Project 48, but the range is no longer only below resonance, but encompasses the normal frequency range of the driver. Updated |
24Mar
|
| 75 | Constant Q Graphic Equaliser |
This is a novel constant Q design, that allows the maximum boost and cut to be varied with a single pot. This project can be made using as many or as few sections as you need. |
22Feb |
| 78 | 3-Way 12dB/ Octave Crossover |
This is a contributed project, and describes a simple high performance 12dB/ Octave crossover network. |
28Apr |
| 81 | 12dB/Octave 2-Way Xover |
Linkwitz-Riley alignment and phase coherent - another very nice crossover where 24dB/ octave is not needed (this uses the P09 PCB, with only a few additional wire links - no tracks to cut) Revision B P09 boards now shipping |
30May |
| 84 | Subwoofer Graphic Equaliser |
This is a constant Q design, with eight 1/3 octave bands covering 20Hz to 100Hz. With up to 14dB boost and cut, even the most recalcitrant subwoofer installation will be brought into line, ensuring the best possible performance. |
03Jan |
| 103 | Subwoofer Phase Controller |
A standard phase control circuit. Nothing extraordinary about this project, but after many requests I have finally added it to the list. |
12Mar |
