Fostex Full Range Drivers
What is a full range speaker? Ideally, there will be one driver reproducing the entire audio range (commonly considered to be 20 Hz to 20 kHz). There will be no crossovers needed, no integration issues between two or more separate drivers, and no time alignment, phase or polarity errors.
The output of the amplifier, therefore, would be connected - via the speaker cable of choice - directly to the speaker driver. The result would be extraordinary clarity and freedom from distortion.
Jun 16, 2004 - The audio show I went to had an impressive pair of fullrange driver speakers, but I've found out they weren't Fostex though looked very similar.
If this was possible - remember I said 'ideally' - the result would be, quite simply, revolutionary. In the real world, there are many drivers and designs that try to cover as much of the audio range as possible, but usually require complex enclosures to maximize their bass responses. This project recognized the limitations in current driver technology, and planned for the use of subwoofers from approximately 95 Hz on down.
After I have watched his talk I was convinced that I want to pursue a simple life, no matter what anyone else thought about it. Telugu motivational videos for success in life download. Nevertheless, he is probably happier than 90% of the people who live in the Western hemisphere and after you have watched his talk you will understand why. I believe that owning less and living a relatively simple life can lead to more happiness than consuming all the things that you are supposed to have but never need. The fact that I learned to live on less than $800 a month allowed me to save a lot of money for my business and to live a happier life. I stumbled upon his video when I was looking for information about minimalism.
Technical stuff: for a 20 liter, floor standing enclosure for a Fostex 164 (or 168S - see below ) 6' full range driver. The design goal for this speaker is -3 dB at about 85 Hz to mate with a sub, and control of the limited Xmax through the use of a sealed enclosure. Max SPL (based on Xmax) is around 98-100 dB at the listening seat which is about 8 feet from the plane of the two speakers. The inside is covered with 2 inch 'egg-crate' acoustic foam. Internal wiring is Analysis Plus Oval 12. There is a built-in sealed 'base', which is filled with about 20 pounds of sand.
Spiked feet are used - Remington Power Hammer threaded studs, pn 100760, which have 1/4'-20 threads. The drivers are mounted using T-nuts. All exterior edges, except around the base, are routed with a 1/2' quarter-round bit. The total system weight is 65 pounds per finished speaker. The Qts of the Fostex driver is raised by.12 due to the 3.5 ohm output impedance of the tube amplifier. This lowers the f3 from 110 Hz to approx.
For more information on the Fostex FE164 driver,. You'll see an almost amazingly flat frequency response and good sensitivity of 92 dB, with a minimum impedance of 8 ohms.
This sensitivity suggests a driving amplifier of approximately 20-60 watts. I used extensive bracing instead of thick walls, which are 3/4' MDF. Since opposite walls move in opposite directions, cross bracing IMO is very effective in reducing vibration. Bosch wff 1201 service manual: full version free software download.
I used 8 - 3/4' x 3' x 6 3/4' pieces of MDF placed somewhat randomly. Five of these are in contact with the front and side panels. There is one placed at a diagonal across the interior of the top. The cabinet plans can accommodate the volume of up to eight of these braces. The goal is to 'create' many small and dissimilar sized panel areas, so that vibration frequencies will be small in amplitude and not concentrated at one frequency. Random spacing of the cross-braces is very effective for this. The upper rear panel is removable and screwed to a gasketed frame of 2 x 2s.
June, 2002 update: The removable upper rear panel was included for easier access to the interior to add stuffing or make other changes. It turned out that it was not needed. If I did this project again, I would not include the removable back.
Note: I don't have the tools to cut sheets of wood accurately, so I contacted a local cabinet maker. They supplied the wood and cut it using the drawings above. It took about 45 minutes using their saws, and they charged just $60, including the sheet of MDF. I assembled the enclosures using Titebond II adhesive, and then brought them back to the cabinet maker for the edge routing, for which they charged an additional $15. The total cost including the drivers and all materials is $299.00, including the outboard Zoebel networks.