I OWNED OHM F AND LATER WALSH 5 + MANY OTHER OHM SPEAKERS.. bOTH VERY GOOD IF YOU HAVE GOOD AMPLIFICATION.. WISH I KEPT THE F'S.. DIDN'T HAVE A GREAT AMP OR ROOM AT THE TIME SO LET THEM GO BUT A FRIEND DID AND THEY WERE VERY NICE IN HIS SYSTEM. OHM SPEAKERS AND I HAVE HAD MANY OVER THE YEARS INTEGRATE VERY WELL INTO ALMOST ANY ROOM.. VERY IMPORTANT.. CURRENT WALSH PRODUCT IS HIGH ON MY WISH LIST
Hey bud is this the correct coating?
Micro Coat Gloss: Microscale Decals
I figured if someone like myself missed it in a posting this will bring them up to date...
Btw if you would be so kind i would love to enable my ohm F speaker cones.....PDF the patterns please any other advice for the ol Walsh drivers?
Lawrence
replacement for the Pioneer W25GR31-51F?
Now that the driver used for this clone has been discontinued, any thoughts on what driver, if any, would make a good alternate?
Pioneer W25GR31-51F 10" Butyl Surround Woofer 290-088
It makes me a bit crazy that Pioneer has been discontinuing some of their drivers that have been so popular with the DIY community. I understand the economics, but I will miss these drivers, such as this one & the Pioneer BU20F20-51F.
I have followed this thread since its inception, and finally have come near the time (about 3 more months, actually) when I could try building this Walsh clone. Now the best candidate for a driver is gone. Arrggh.
I can search for similar parameters, but part of the magic I think is that the cone of this driver is steeper than many of its counterparts.
Now that the driver used for this clone has been discontinued, any thoughts on what driver, if any, would make a good alternate?
Pioneer W25GR31-51F 10" Butyl Surround Woofer 290-088
It makes me a bit crazy that Pioneer has been discontinuing some of their drivers that have been so popular with the DIY community. I understand the economics, but I will miss these drivers, such as this one & the Pioneer BU20F20-51F.
I have followed this thread since its inception, and finally have come near the time (about 3 more months, actually) when I could try building this Walsh clone. Now the best candidate for a driver is gone. Arrggh.
I can search for similar parameters, but part of the magic I think is that the cone of this driver is steeper than many of its counterparts.
I'm a little late in this thread, and am wondering if it still active. I'm also not able to view any of the photos.
I've read about 1/2 way into this, and I've noticed that up to that point, nobody had mentioned attempting to use a Walsh type tweeter, ala Infinity rather than a dome.
I have some experience with these tweeters, as I helped the guy who came up with the idea build some of the first prototypes that went to Infinity. Probably built 50 or so on my kitchen table, and I can assure you they aren't that difficult to build
I've read about 1/2 way into this, and I've noticed that up to that point, nobody had mentioned attempting to use a Walsh type tweeter, ala Infinity rather than a dome.
I have some experience with these tweeters, as I helped the guy who came up with the idea build some of the first prototypes that went to Infinity. Probably built 50 or so on my kitchen table, and I can assure you they aren't that difficult to build
Would you consider building another tweeter and taking pictures and providing a description for the rest of us? I remember being at Henry Radio when Arnie and company brought the towers in with the Walsh tweeters in the top sector. The competition was a system with piezo electric tweeters in a row around the top of the box and a single 12 inch woofer. The Infinity speakers crushed them.
Bud
Bud
Bud-
I am going to build a two way Walsh similar to a prototype we built back in '72 or '73. It may take a while, as I have recently moved and have not yet unpacked everything. I am happy to discuss what went into the original tweeter and post photos of my build.
I was contributing to a thread about the Walsh tweeter in Audio Karma, but the interest there was rebuilding their old Infinity's. I am more interested in pursuing a speaker based entirely on the Walsh principal, up to, hopefully a full range.
The Walsh tweeter was originally the idea of a fellow named Bill Seneca, who was Las Vegas' resident guerilla audiophile guru. He was and still is on the cutting edge, but his ideas don't sit well with the mainstream.
The tweeter was originally built and sold as an add-on- it was packaged in a cylindrical cage that was wrapped with foam, and used a shunt 6 dB crossover. It was patched in like today's passive sub-woofers.
The original crossover point was around 2 Khz, and it used a Seas 1.5" dome tweeter that was found in the old Dynaco 2-way. That speaker crossed at 1.5 Khz, if I remember correctly. The dome was selected because of it's low Fc and it's electrical robustness. It could be disassembled and reassembled easily, and the mylar dome could easily removed from the voice coil former with an Exacto knife (if you were careful).
Unfortunately, it was expensive at $10-15 each at a time when the average cost of a tweeter found in Infinity's product cost 2 bucks. More on this later.
The original cone material was made of styrene which we got from stationary stores in the form of document protectors. It worked, and was open, but sounded like hell- very shrill and brittle.
Seneca tried dampening the cones with all manner of goos with some success, but suddenly came up with the idea of laminating aluminum foil to the styrene. There may have been some discussions with Marty Gersten at Ohm about this. Marty was very willing to discuss his baby and would sometimes mention something in passing that spoke volumes.
The first attempts used silicone heat sink compound, both clear and white, and there was an order of magnitude of sonic improvement.
Unfortunately, the heat sink grease was difficult to work with- very messy and it got everywhere, including the seam where the cone was glued into it's shape.
Ultimately 3M 33 spray adhesive was settled upon to both laminate the foil to the plastic and hold the seam together as well.
When we actually got to see an Ohm F the first thing we noticed were the striations in the metal parts of the cones and the slits in the paper parts. Seneca immediately built a tweeter with that diamond pleated foil you could get at the supermarket back then, and the improvement was very noticeable.
Until this point, Seneca was selling these things as add ons, and he took a pair down to Chatsworth for Arnie to listen to. Arnie cut a deal with Seneca and got a license from Marty at Ohm. I don't think anybody got paid.
I'll pick this up later- I gotta run.
I am going to build a two way Walsh similar to a prototype we built back in '72 or '73. It may take a while, as I have recently moved and have not yet unpacked everything. I am happy to discuss what went into the original tweeter and post photos of my build.
I was contributing to a thread about the Walsh tweeter in Audio Karma, but the interest there was rebuilding their old Infinity's. I am more interested in pursuing a speaker based entirely on the Walsh principal, up to, hopefully a full range.
The Walsh tweeter was originally the idea of a fellow named Bill Seneca, who was Las Vegas' resident guerilla audiophile guru. He was and still is on the cutting edge, but his ideas don't sit well with the mainstream.
The tweeter was originally built and sold as an add-on- it was packaged in a cylindrical cage that was wrapped with foam, and used a shunt 6 dB crossover. It was patched in like today's passive sub-woofers.
The original crossover point was around 2 Khz, and it used a Seas 1.5" dome tweeter that was found in the old Dynaco 2-way. That speaker crossed at 1.5 Khz, if I remember correctly. The dome was selected because of it's low Fc and it's electrical robustness. It could be disassembled and reassembled easily, and the mylar dome could easily removed from the voice coil former with an Exacto knife (if you were careful).
Unfortunately, it was expensive at $10-15 each at a time when the average cost of a tweeter found in Infinity's product cost 2 bucks. More on this later.
The original cone material was made of styrene which we got from stationary stores in the form of document protectors. It worked, and was open, but sounded like hell- very shrill and brittle.
Seneca tried dampening the cones with all manner of goos with some success, but suddenly came up with the idea of laminating aluminum foil to the styrene. There may have been some discussions with Marty Gersten at Ohm about this. Marty was very willing to discuss his baby and would sometimes mention something in passing that spoke volumes.
The first attempts used silicone heat sink compound, both clear and white, and there was an order of magnitude of sonic improvement.
Unfortunately, the heat sink grease was difficult to work with- very messy and it got everywhere, including the seam where the cone was glued into it's shape.
Ultimately 3M 33 spray adhesive was settled upon to both laminate the foil to the plastic and hold the seam together as well.
When we actually got to see an Ohm F the first thing we noticed were the striations in the metal parts of the cones and the slits in the paper parts. Seneca immediately built a tweeter with that diamond pleated foil you could get at the supermarket back then, and the improvement was very noticeable.
Until this point, Seneca was selling these things as add ons, and he took a pair down to Chatsworth for Arnie to listen to. Arnie cut a deal with Seneca and got a license from Marty at Ohm. I don't think anybody got paid.
I'll pick this up later- I gotta run.
Yeah, I guess it has been a long time. Sorry about that- I got waylaid by a nice pair of Martin-Logan hybrids and sort of forgot about the Walsh project.
A required read for anyone playing with these things is the original Walsh patent. It is available on line, although the copy I found was missing a couple of drawings.
There is a relationship between the propagation velocity of the cone and the speed of sound in the air. If this is not met, the vertical dispersion of the driver is adversely affected.
This is why I never played with off the shelf drivers simply inverted and dampened. You have to get down and dirty and replace the cone with a more suitable material at a steeper angle. This means you have to add length to the basket and move the surround.
I made a couple of prototypes that sounded quite good, but didn't last too long.
Something to think about......
A required read for anyone playing with these things is the original Walsh patent. It is available on line, although the copy I found was missing a couple of drawings.
There is a relationship between the propagation velocity of the cone and the speed of sound in the air. If this is not met, the vertical dispersion of the driver is adversely affected.
This is why I never played with off the shelf drivers simply inverted and dampened. You have to get down and dirty and replace the cone with a more suitable material at a steeper angle. This means you have to add length to the basket and move the surround.
I made a couple of prototypes that sounded quite good, but didn't last too long.
Something to think about......
I dug up this old thread and became excited about it all over again. Bit deflated after your comment. My resistance to flipped drivers was mostly aesthetic - kind of liked the idea. But Mamboni fell silent. Not to mention Chinese.
What you say makes sense though (purely intuitively). Pity if it's true. With enough enthusiastic fiddling just about anything can be made to work. I'm just not sure whether I have the time right now.
Thanks for replying...
What you say makes sense though (purely intuitively). Pity if it's true. With enough enthusiastic fiddling just about anything can be made to work. I'm just not sure whether I have the time right now.
Thanks for replying...
Don't get discouraged. Configuring a driver to work as a Walsh line is not as hard as it sounds. There is a guy here, I think his name is Dale Harder who builds a mid high Walsh driver for home builders. He also repairs Ohm Walshes, (and lasers I think).
I have his web address on my other 'puter, as well as some photos of his driver.
PM me your email addy, and I will sent you some photos of his driver. If you study it a while, you'll begin to get an idea of how to build your own from an exsisting unit.
The headache is finding a driver that is robust and also has extended bandwidth. That's why people are bemoaning the disappearance of some of those Pioneer and Radio Shack drivers- But if you look around, you can find a suitable one.
I've seen kids in Europe take cheap 8" speakers and replace the cone with plastized paper (after extending the basket) and rave about the clarity.
There are a number of drivers that look to me like they will work without modification as well. One outfit was selling an 8" with a graphite cone that looked really promising.
Again, let me did through my desktop- I probably still have the link.
The ideal set-up would have enough bandwidth to eliminate crossing into another driver, either on the high or the low end. Any time you have a crossover, especially in the presence band it ruins the coherency of the image.
Ohm gets away with it because they cross at a very high (9-10 Khz) frequency. Pity they don't cross into a walsh tweeter- they own the bloody patent after all. By the way, you can easily build a very nice walsh tweeter on your kitchen table if you are brave enough to cut a cheap dome tweeter up with an Xacto knife.
Harder makes it work by crossing at a low (not low enough IMHO) frequency.
By the way, one of the reasons I never posted any further was no one seemed interested anymore. You are the first guy to reply after all of that time.
So- don't lose your enthusiasm. I will go ahead and finish the step by step directions for building your own walsh tweeter and post. Good place to start-
Cheers
I have his web address on my other 'puter, as well as some photos of his driver.
PM me your email addy, and I will sent you some photos of his driver. If you study it a while, you'll begin to get an idea of how to build your own from an exsisting unit.
The headache is finding a driver that is robust and also has extended bandwidth. That's why people are bemoaning the disappearance of some of those Pioneer and Radio Shack drivers- But if you look around, you can find a suitable one.
I've seen kids in Europe take cheap 8" speakers and replace the cone with plastized paper (after extending the basket) and rave about the clarity.
There are a number of drivers that look to me like they will work without modification as well. One outfit was selling an 8" with a graphite cone that looked really promising.
Again, let me did through my desktop- I probably still have the link.
The ideal set-up would have enough bandwidth to eliminate crossing into another driver, either on the high or the low end. Any time you have a crossover, especially in the presence band it ruins the coherency of the image.
Ohm gets away with it because they cross at a very high (9-10 Khz) frequency. Pity they don't cross into a walsh tweeter- they own the bloody patent after all. By the way, you can easily build a very nice walsh tweeter on your kitchen table if you are brave enough to cut a cheap dome tweeter up with an Xacto knife.
Harder makes it work by crossing at a low (not low enough IMHO) frequency.
By the way, one of the reasons I never posted any further was no one seemed interested anymore. You are the first guy to reply after all of that time.
So- don't lose your enthusiasm. I will go ahead and finish the step by step directions for building your own walsh tweeter and post. Good place to start-
Cheers
Just so you don't lose heart- Back in the early '70's, I was involved with a guy who may have built the first walsh tweeters that Infinity started using. Who built the first one has been the subject of considerable debate. I know built quite a few on my kitchen table and assumed they were going to Infinity.
Towards the end of this adventure, we built a protoype 2 way we dubbed the "Prometheus X" loudspeaker. We actually had a backer (local cabinet company) and were going to go into production, but the backer immediately started looking for ways to cut costs. We weren't willing to compromise the sound, so we backed out of the deal.
The speaker consisted of a 10" off the shelf CTS woofer with a dampened cone which we inverted, and a hand built walsh tweeter built using a $10 Dynaco tweeter.
The thing actually sounded good, and quite a few of the local audiophiles made very favourable comments about it.
I know what I said about crossovers- we didn't know any better back then. The point is, aside from the cabinet, we built the whole thing in my kitchen with almost nothing in the way of tools. It just takes patience and enthusiasm.
Towards the end of this adventure, we built a protoype 2 way we dubbed the "Prometheus X" loudspeaker. We actually had a backer (local cabinet company) and were going to go into production, but the backer immediately started looking for ways to cut costs. We weren't willing to compromise the sound, so we backed out of the deal.
The speaker consisted of a 10" off the shelf CTS woofer with a dampened cone which we inverted, and a hand built walsh tweeter built using a $10 Dynaco tweeter.
The thing actually sounded good, and quite a few of the local audiophiles made very favourable comments about it.
I know what I said about crossovers- we didn't know any better back then. The point is, aside from the cabinet, we built the whole thing in my kitchen with almost nothing in the way of tools. It just takes patience and enthusiasm.
While you're day dreaming of your Walsh build, go back through this thread and re-read what Bud Purvine has to say. Bud put a lot of effort into taming the cone break-up that is destructive to a coherent image.
Lincoln Walsh used various termination methods at the surround end of the "cone" (inaccurate term- we are building a terminated transmission line) to achieve similar results.
Lincoln Walsh used various termination methods at the surround end of the "cone" (inaccurate term- we are building a terminated transmission line) to achieve similar results.
Walsching again
Thanks for that! Knee-deep in work right now but I'll send you my address. Would love to see...
Thanks for that! Knee-deep in work right now but I'll send you my address. Would love to see...