It's been 6 years since I've tinkered with building my own Walsh drivers. It seems like yesterday - the years do fly by. I was involved with the DIY Audio Forum then and my contributions to the thread start here:
http://www.diyaudio.com/forums/multi-way/30689-ohm-acoustics-walsh-f-speaker-remakes-2.html
Here's my old post with the parts and materials - then costing about $200!
Build your own Walsh loudspeaker for about $250 in parts and materials:
Woofer: PIONEER W25GR31-51F 10" BUTYL SURR WOOFER (http://www.partsexpress.com/pe/showd...number=290-088)
Tweeter: TANG BAND 28-847SA SHIELDED NEODYMIUM DOME TWEETER
http://www.partsexpress.com/pe/showd...number=264-822
6.8 uf high pass capacitor (metalized polypropylene) to tweeter (http://www.partsexpress.com/pe/pshow...Number=027-427)
4 ohm power resistor in tweeter circuit.
Sonotube: nominal dia. = 12.5 inch height = 37 inch
Stuffing: acoustastuff ~50% of internal volume
SPEAKER REPAIR GLUE 1 oz. BOTTLE http://www.partsexpress.com/pe/showd...number=340-076
This speaker glue has consistency of Elmers glue when wet, dries fairly quickly (water base) to form a clear and very flexible soft clear rubber with excellent damping characteristics.
Walsh Loudspeaker: two-way X-over first order (6dB/oct) high pass filter to tweeter at 8 kHz
Woofer full range (no crossover)
Alignment: Acoustic suspension (Vb=2.5 cu. Ft; Qtc = .816; Fc = 49 Hz (-3dB))
Frequency Response: 49 - 20,000 Hertz (-3 db, +0db)
SPL: 89 dB/watt Max Power: ~100W
Illustration: Cone with felt damping applied with speaker repair glue.
Photos #1(schematic) and #2: woofer with felt dampers and felt variovent in dustcap. Variovent consists of ¾ dia. Hole cut into center of dustcap and hole covered with three laters of felt to provide resistive vent.
Photos 3-5: final loudspeaker.
Photos of the loudspeaker are posted at the forum link above. Now the purists will say that this is not a true Walsh because the cone angle does not provide for perfect phase-time alignment - I don't know. The thing is, the proof is in the listening and these loudspeakers sound so good. In fact, I'm still using them as the fronts for my dedicated home theatre. Guests are awestruck by the wrap around seamless sound field with such clarity (I am using side and rear conventional box speakers for the side and rear channels of course). My trusty Kinergetics bsc-100 stereo subwoofers are still performing yeoman's service after over 20 years (thank you Louis Nolemi). Now maybe my improvised Walsh has slight time-phase error, and perhaps passes a parallelogram rather than a square wave - I don't know. I've come to the opinion that the ear cannot hear small timing distortions but can hear frequency response-power response disparities. Anyway, for a few dollars and a few hours of labor, you can build these and I do predict you will like the sound a lot. In fact, these were so easy to build and the materials so inexpensive that I built three pairs and gave two pairs away to a neighbor and the church pastor.
Previous to this project, I built some true Walsh steep cone drivers. Yes, they sounded excellent. But, the time and effort needed to build them was great indeed. You can achieve excellent sound from properly selected conventional woofers using the modifications I listed above and careful cabinet alignment, with a lot less time and effort.
I visit Dale Harder's site periodically and his work is just gorgeous. I have had a hankering to buy a pair of his true Walsh F loudspeakers but I can't justify it at this time. I have my Walsh 5000s and I love them. I listen to them every night and pray that they never fail; because I've finally gotten by system to sound just right in my dedicated listening room.
While I would love to build another Walsh project with different higher quality drivers in mind, I will likely never get there. My medical practice is very busy and leaves little time left over for family. Also, after a 20 year hiatus, I picked up the french horn again 7 months ago. Practice is time consuming, exhausting and rebuilding one's performance and endurancer takes many months. My goal is to win a seat in amid level amateur orchestra. I want to get back on stage - I miss performance with a good symphony orchestra. I don't know if I'll get there but I will do my best and stick with it.
