Ohm Speakers, thoughts?

Lngbruno: I have all of the various Audio magazine buyers guides dating back to the mid 1970's. If you give me a specific year, i'll look up the MSRP ( Manufacturer's Suggested Retail Price ) that Ohm submitted for that given year. I had a 1980 "Complete buyers guide to stereo / hi-fi equipment / speakers edition" handy and it showed a price of $2300 per pair. This was using the standard finish with other finishes rising in cost.

Having said that, i have talked to MANY people that have told me that the F's were marketed at WAY, WAY above MSRP by specific dealers i.e. much like Harley's were in the past. Due to their unconventional looks and specific performance attributes that no other speaker could match, some dealers jacked the price of the F's WAY, WAY up. This not only made them appear to be even more "exotic" i.e. the average person couldn't afford them, but also made them more desirable for those equating price with performance.

Between price gouging and discounting, MSRP's are simply a reference point that may / may not be of any value. Some look at it as reference to deduct percentages from, others ignore it all-together and charge what the market will support.

Line: The German Physik's DDD driver HAS to have some type of suspension to it. You can't rigidly mount the mouth of a dynamic driver and expect it to work for any period of time, especially if feeding it any type of measurable power. The fact that you have to displace larger quantities of air also dictates that the driver has to be able to move a reasonable amount in order to produce "reasonable" spl's. If the drivers were rigidly mounted at the mouth and driven by a free floating voice coil, they would literally be "trembling" or "ringing" when fed signal. The end result would be a driver that was phenomenally limited in output, extension and linearity.

The bottom line is that you are reading WAY too much into the marketing hype from a couple of different manufacturers. Sean
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Unsound, reading this over, I could not find any signs of mechanical cross-overs.

http://www.german-physiks.com/NewFiles/WhiteBook.html

Sorry: I posted the wrong link for 'two cans and a string'.
Here's the right one.

http://science.howstuffworks.com/question410.htm

Does anyone know if the DDD driver used by German Physiks has any built in mechanical cross-overs like the Walsh driver used by Ohm?

To complicate this subject even further, IF I understand this link

http://home.swipnet.se/~w-61372/artiklar/article3.htm

correctly. DDD's generate (what I would call) surface wave ON the cone, like waves on the surface of water and the Ohm F's generate (what I would call) compression waves IN the cone, like two cans and a string. (If you don't know what I mean by two cans and a string, here is a link.

http://home.swipnet.se/~w-61372/artiklar/article3.htm

The DDD's and the F's generate sound in two distinctly different ways. I believe the DDD's do not have a spider or a surround for that very reason. What do you guys think?

Lngbruno, I have never owned Walsh or German Physiks speakers. If I could afford them the Huffs would certainly merit an audition.

Unsound, thank you for pointing out the German Physiks again. I guess you must own a pair of their speakers. So, I will ask if you ever had the Ohm F's and would share your thoughts on how they are similar or dissimilar in overall sound? I am interested in a true Walsh driver, which has no crossover and stands up to the riggers of day-to-day performance.

Sean, I do recall from an earlier thread/post about you contemplating the possibility of taking on this type of project/venture. It would be nice if one of the smaller DIY companies out there would take this on. I mean between you and Bill Legall, there is a wealth of knowledge that could be shared with the right party. Right? When I look around Audiogon, Audio Circle, Audio Asylum, and other sites, I see dozens of sole proprietor speaker builders. Heck, with China now very serious OEM electronic/speaker builders, one might subcontract them to build the drivers by hand and have the bases built here in the States, or visa versa.

Someone out there must know someone who skilled, talented, and would be curious /willing enough to take this challenge on.

What was the MSRP of the F’s back in the mid to late 70’s? I can’t recall because when I purchased mine pair it was part of a package deal which included an amp and preamp and I traded in a pair of EPI 201’s (another great speaker in its day).

Jamscience, now we can argue over...'Is John actually marketing what he had patented .

When I said, "the cans are not diffusion cans", what I meant is that the meshed cans are not employed to create a the widely dispersed sound that they are know for. That widely dispersed sound is still there with the cans removed.

And what I mean by acoustically transparent is...If I were to put a singing canary in one of those meshed cans, I personally, would not be able to distinguish a difference in sound of the canary, (Is the singing canary in or out of the can?). Similarly, when I am inside the house listening to birds that are outside through an open window, I cannot distinguish the difference in sound weather there is a screen on that window or not.

I did eventually affix the cans back over the drivers for shipping purposes, they would be more vulnerable to damage without them. The foam that lines the interior of the cans is there (I believe) to help keep out dust and potato chip crumbs etc. The foam is thin, in the area of 1/32" or 1/16".

I know what the Mk-2 driver looks like, because I can see it without removing the can with the use of an LED flashlight, and the picture Jamscience posted of the FRS-11 is reminiscent of the Mk-2 in looks. The sound absorbing material that is so unattractive is no longer visible; the driver is no longer ugly. The tweeter and it's mounting DO look quite different from the picture of the FRS-11. The tweeter and it's mounting is now much more attractive.

I do not know which earlier models are ugly, except for the one's I had, which were the 4XO's.

This type of design would have to be hand built using custom parts i.e. minimal off the shelf componentry. As such, it would be a relatively large economical undertaking for someone to attempt as compared to starting up a speaker company that uses off the shelf parts. On top of that, the market for such an item isn't all that big in the grander scheme of things, hence the lack of anyone jumping in with both feet.

Having said that, i can see this type of thing taking off if someone were to build "one off" products out of their garage. That is, IF they could achieve the type of results that we know this design to be capable of AND doing so with a high level of consistency. I have thought about this myself, but not too seriously. Sean
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PS... Due to their radiation characteristics, these speakers are more difficult to set up. They also don't have a high WAF due to the placements required. This further limits their marketability.

If anyone has any doubts about what exactly constitutes Ohm's new version of a "Walsh" speaker, check out John Strohbeen's Patent #4440259. It is all spelled out. (Click on the images button to see the drawings)

Lngbruno, I believe that Ohm has claimed that their original technicians have all retired and that they could not find suitable replacements. German Physiks have done just what you have suggested. The German Physiks speaker line does deviate slightly fom the original Walsh description. Most are augmented with additinal woofer/sub-woofer(s) with added cross-overs. Some use mulitiple Walsh type drivers. Most would consider their offering on the expensive side.
All in all, I agree with you complelety. While I haven't actually heard them in decades and I don't trust my memory of those experiences, the Walsh drivers still look like the most promising design to date. I would imagine that they may even be more relevant today than yesteryear.

Very nice information being posted. Thank you.

Question - What is preventing a Manufacturer from building an authentic Ohm F again?

Is it the licensing?
Is it the technology?
Is it the patent?
Is it the cost of producing them correctly?
What is it?

It has been approximately 30 years since they first appeared with such great potential, but later proven to be flawed. Why hasn't someone taken today's computer based designing techniques and applied them to this speaker in an effort to make them a reality. IMHO, there would be a viable market for them in 2-channel as well as HT.

I would definitely put my name on the list of future owners if they weren't priced ridiculously. Heck, when I purchased them in 1974 I was just out of undergraduate preparing to go to graduate school. IOW, I was flat broke but had the foresight to scape enough coins together to purchase them. I now have a coin jar spilling over. LOL

Line, Sean,

Your welcome. As I stated before, I am just searching for the truth.

Line:

One thing I would like to say, is that the cans are not diffusion cans, they are as transparent too sound as grill cloth is.

Sorry, I have to agree with Sean on this one. I know of no grill (cloth or metal) that does not affect the sound in some way. (of course I have not heard all speakers with and without grills; I could be wrong, I could be right!) ; )

Sean:

As far as the Ohm G goes, i think that it is a Walsh driver by basic design, but i'm not sure about the flare rate on the cone. It obviously has a LOT less surface area than the Ohm A or Ohm F Walsh drivers. The "standard" cone driver that you see in the G cabinet is a passive radiator, not a driven woofer. I've never seen one of these in person though, so i'm kinda sorta guessing on this one based on photo's / technical info that i have.

Yes, the Ohm G does use a Walsh driver but is not a "true" Walsh loudspeaker since it uses the energy from the concave part of the driver to power that passive radiator. (I am being a stickler to the original parameters of the patent)

I also have some Walsh "tweeters" that Infinity made, but i've never tinkered with them.

I almost bought a pair of Infinity's with the Walsh tweeter back in '76. I wish I had, it would have saved me money on a Transcriptors Skeleton turntable! (They were both part of a system I was pondering at the time)

If anyone is curious about the Walsh Loudspeaker, I encourage you to take a look at the patent (see previous post). There is a lot of technical information there but there are also things such as:

" A single very large coherent-sound loudspeaker might be built to serve a stadium of 100,000 listeners with high quality music and voice. It might have a vertically oriented conical diaphragm with an angle of 60 to 80 degrees, a diaphragm diameter of approxmately 60 inches and a height of 60 inches. The diaphragm might be of a composite aluminum and elastomer to substantially attenuate 16,000 c.p.s. waves in a vertical distance of 3 to 6 inches, and 4,000 c.p.s. waves in 12 to 14 inches, to obtain good diffusion of sound vertically. It would inherently have uniform diffusion in all directions horizontally. Its frequency range might cover 60 to 16,000 c.p.s. and it could handle well an electrical input of 500 watts with extremely low transient effects and other types of distortion. Its uniformity of response might well be about 1 db over the rated frequency range."

I would love to see this become reality! Any takers?

Also, any takers on my question; is it ethically, morally, politically... correct to keep calling the line a Walsh speaker?

Jamscience: Thanks for all the research and leg-work. I have to agree with all of the points that you brought up. That's one of the reasons why i've "harped" so hard on the fact that these units are NOT actual Walsh drivers. This can be seen on the Ebay photo's that you provided for us. All i can say about that one is that if they had shown the other side of the speaker i.e. where the crossover network is attached, most people would be appalled.

As a side note, these drivers do appear to have some type of a "plastic" based cone material as Line described above. This would lead me to believe that they are the original equipment as supplied by the manufacturer.

As to the basket design, Ohm used two different baskets on the F's that i'm aware of. One has very "skinny" flat metal rails with wood glued to them to damp their resonance. The other has much wider "U" shaped metal channels with wood glued inside of the channel. Common sense would dictate that the thinner rails would cause fewer problems so long as resonance induced ringing was controlled. I have a set of each and to my ears, the thinner flat rails sound better than the wider "U" shaped channels.

As far as the Ohm G goes, i think that it is a Walsh driver by basic design, but i'm not sure about the flare rate on the cone. It obviously has a LOT less surface area than the Ohm A or Ohm F Walsh drivers. The "standard" cone driver that you see in the G cabinet is a passive radiator, not a driven woofer. I've never seen one of these in person though, so i'm kinda sorta guessing on this one based on photo's / technical info that i have.

As far as treble response goes, the internal factory wiring in the F's did a number on that. I would recommend plugging your speaker cables directly into the Walsh driver itself, which bypasses the internal wiring. I could NOT believe how much the 2 - 3 ft of internal wiring could demolish the sound after hearing the difference. I also have some Walsh "tweeters" that Infinity made, but i've never tinkered with them.

Once again, thanks for the legwork and sharing this info : )

Line: The info from the German Physiks website that you quoted sounds more like the design ideas behind the Manger driver than the Walsh design. How someone that manufactures a Walsh based product could confuse the design and description of operation is beyond me. Then again, they are a German based company and maybe something is getting lost in the translation.

As to your comment about the cans NOT acting as diffusors and being acoustically invisible, i almost had to laugh. Just placing a very thin layer of felt on the baffle around a midrange and / or a tweeter can cause major differences in reflections, diffraction and frequency response. This is VERY measurable in most cases and easily audible.

If you don't think that surrounding a driver with a perforated metal screen and placing it directly in the firing path between one's ears and the drivers would make any audible difference, you should think again and / or have your hearing checked. I don't mean this to be rude, but that screen also has grille cloth material in it, making an even bigger difference at high frequencies. Sean
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Jamscience, thanks for the patent info. and picture.

One thing I would like to say, is that the cans are not diffusion cans, they are as transparent too sound as grill cloth is.

Sean,

Glad you are looking at this thread again.

Not being one to accept all claims, I decided to do some investigating. First, I wanted to find out just what constituted a Walsh loudspeaker. I looked up the Patent #3424873 (in case anyone is interested) and began my research.

The following is from the Abstract:

"Abstract of the Disclosure
The coherent-sound loudspeaker is a development derived from a theoretical concept of ideal sound reproduction by means of a conical diaphragm operating as a wave transmission line. Such a conical diaphragm will produce sound as it would be produced by a small cylinder pulsating radially with every portion of its area moving in and out simultaneously, and in phase with the input audio signal. This is coherent sound.
The requirements of the theoretical concept are closely approached by a sound producer of the following character:
(1) The angle of the conical diphragm, measured from a plane perpendicular to its axis is quite high, causing the speed of the mechanical vibratory waves in the diaphragm to be greater than the speed of sound in air, and to have a component in the desired direction of sound radiation equal to the speed of sound in air.
(2) Absorbing material absorbs the wave energy in the diaphragm to eliminate or minimize wave reflections from the non-driven end, so that a vibratory wave transverses the diaphragm substantially only once.
(3) Sound is radiated to the listener only from the convex side of a vertical conical diaphragm to obtain full frequency range, high quality sound omnidirectionally from a single radiator."

Four models are mentioned in the patent. Models B and J's diaphragm were made of felted fiber. Models L and M's diaphragm were made of aluminum. Other variations between the models are described. If you want to know more about them, lookup the patent (it's in file DImg-11.tiff).

Quoting from the results:

"The low end of the useful frequency range of all of these loudspeakers is approximately 40 cycles per second. The upper end was about 14,000 c.p.s for Models B and J, 16,000 c.p.s. for Model M and 34,000 c.p.s. for Model L. The frequency range of the Model L extending to 34,000 c.p.s., well beyond any person's audibility limit, confirms the theory that this new loudspeaker can be designed for any frequency range desired, although at some sacrifice of efficiency for wider ranges."

Throughout the patent, several items are mentioned to "fine tune" the design. One item is the basket for the driver. Normal drivers usually cover 30% to 100% of the convex side of the driver. A Walsh driver should be obstructed by less than 20%. The only other item I will mention is that the angle of the conical driver must be at least 50 degrees.

From the patent, I have concluded that only the Ohm A and F meet these criteria. The Ohm G is a hybrid version and is therefore not a true Walsh loudspeaker. (as you have already said) All of the other models are not "true" Walsh loudspeakers.

However, a Walsh driver can be "designed for any frequency range desired". So the claim that Ohm's "Walsh" line of speakers use a Walsh driver could be true.

I had asked a question earlier (please see prior post) that if Ohm is not using a Walsh driver, how could they reproduce the midrange using a downward firing driver? (still looking for an answer) I went looking for any photos that would help verify Ohm's claim and I came across these Ohm FRS 11's (I think).

From Ohm's website:

"The FRS-11 is a tall square tower with each corner cut about 2''. One of the cut corners displays the Ohm logo near the top, just below the grill. The FRS-11 is a true Walsh speaker designed for small to medium sized rooms. They create a precise stereo image from a very wide Sweet-Sweep. We call the effect Full Room Stereo and we named it after this benefit."

Looking at the picture, if indeed this is an unmodified FRS 11 (except that the diffusion cans have been removed) there is no Walsh speaker/driver to be seen, and it is truly just a conventional woofer/tweeter combination.

My question now is, is it ethically, morally, politically... correct to keep calling the line a Walsh speaker?

Sean, I appreciate you sharing your knowledge, but there is something I don't understand after reading this quote from the German-Physiks files.

The transmission line type has commonly employed a steep, straight-sided cone and a fairly conventional voice coil and magnet assembly. But where it differs from an ordinary mass loaded cone is that the diaphragm is securely anchored at its mouth and flexed by the motions of the voice coil rather than pushed to and fro. Sound propagation is normal to the slope of the cone rather than parallel to the path of the voice coil in the gap as is the case with a mass loaded cone.

The diaphragm is securely anchored at its mouth. Wouldn't this mean that there is no spider employed ? And is sounds as though there is no surround employed ether.

What I am trying to get at is; the F's do employ a spider and a surround, and I am wondering if the sound emanating from the F's is a mix of conventional speaker sound and transmission line sound. What do you think? Am I missing something?

http://fullrangedriver.com/forum/viewtopic.php?pid=6485

If you read this thread, you'll find someone else commenting on the type of drivers used in newer production "Walsh" series. For the record, i never posted to this thread in any way, shape or form, even if one of the participants shares the same name.

As a side note, there's a "funny" story pertaining to the design motivations behind Decware's "Radial" speaker mentioned in this same thread.

John, the owner of Van L Speakerworks ( aka Chicago Speakerworks ) had previously verified to me that newer "Walsh series" used conventional design woofers firing face down into the cabinet. He has re-foamed many of these drivers over the years.

Yes, the F uses a spider. Sean
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That post didn't look like a joke, so I did a little research too find out just how fast sound does travel in some of these materials and here is a little of what I found...>>

In general, sound travels fastest through solids, slightly less fast through
liquids, and slower through gases.

This is because the particles (atoms or molecules) in a solid are touching
each other and rather fixed together. That is why a solid is "solid." Since
the particles are bonded together, a sound wave moving one, immediately
transfers the motion the one touching it. A sound wave hitting one, is
almost immediately transferred to a neighbor.

In a liquid, the particles are touching each other, but they are not fastened
to each other quite so strongly as they are in a solid. Some of sound's
energy is wasted pushing the particles around because they can slide past
each other. Some of sound's energy is wasted that way and that is why it
moves slower.

In a gas, the molecules are rather far apart. For sound to travel through a
gas, the molecules must move quite a distance before they collide with other
molecules. Sound energy cannot move as quickly when the molecules are not in
contact with each other.

Here is another from a different site...>>

In air at room temperature, sound travels at about 340 metres per second. In water, sound travels about four times as fast as it does in air, while in steel, the speed of sound is about fifteen times as great as in air.

Here is one I found interesting,..Why do we sound like Donald Duck when we talk with helium...>>

We talk like Donald Duck because sound travels faster through helium and, in effect, shrinks our heads.

When we speak, the sound speeds from voice box to lips. Since sound travels faster in helium, the sound reaches our lips sooner with helium than air. It’s as if the path were shorter. The faster sound speed raises the resonant frequency of our vocal tracts. We, sort of, become Oz Munchkins with high squeaky voices.

Every pipe, from our vocal tracts to an empty Coke bottle, has a resonant frequency. Blow air across a bottle. The deep sound we hear is the bottle’s natural frequency in air. Fill the bottle with helium and blow across the top. Now, sound travels faster and the tone sounds higher. The resonant frequency of a tube depends on the length of the tube and the speed of sound through it. The faster the sound speed, the higher the frequency.

Well anyways, I bought my first pr. of Ohm speakers from a big box store called ABC Wharehouse purely on what I was hearing out of them, and at that time I did not know what was going on under that can, just liked what I was hearing.

Some 15 years latter, I started hearing something that I should not be hearing out of one of them, so I opened it up and found the surround tore and replaced it with a new one. I left the can free so I could slip it on or off any time I wanted to. "And yes, I always wondered what they would sound like with the can off." So, many times I would listen for a different in sound between the can off and on, and I could 'not' here any difference.

The driver is not a mass projection driver; this is very apparent when it is looked at. They look hand built, and I believe they are. This tells me that this driver is NOT ordinary. No; I can not know what is going with this driver by looking at it. The cone is some sort of plastic, the magnets look massive, and the can is essential to protect some kind of (what I believe to be) some kind of sound absorbing material that is placed is certain places. The driver is not pretty, in fact, I think it is ugly, but it can't be seen anyways.

I don't have the XO's anymore because I upgraded too the Walsh 5 Mk-2 drivers and mounted the on the original trapezoid cabinets. I do not know what the new divers looks like with the can removed.

Now Ohm does have models that are box speakers, and I would bet that the drivers in them are production speakers, (not hand built).

Sean, I have a question for you...Do the F drivers have a spider? I think that they would have to.

Here is a link to a description of the 'bending wave DDD driver'
http://www.german-physiks.com/NewFiles1/DDD.html

Where does German Physiks come into the discussion? can any comment on their version of the walsh driver. i have read that they are a great speaker however i've also read that the drivers were prone to warpage.

Line: I understand this and was joking. One of the basics of physics teaches how sound conducts through various materials, etc.... I'm sorry if my attempt at levity failed and / or was unclear. What i was attempting to do was to show how marketing can be used to manipulate one's point of view and understanding of a subject, let alone bamboozle one into thinking that they have something other than what they really do.

As to the drivers having a mechanical crossover, this is true. Due to the aforementioned differences in conductivity of materials, the rate of transfer between them will come into play. As i also mentioned, the flare rates on the Ohm A and F drivers themselves are different.

Like i said, look inside of the mesh can. There's a reason why these speakers are built in this fashion. After all, we all know that placing a grille in front of a driver changes the sound, so do you really think that placing all of the drivers behind a resonant metal screen would be of benefit to the sonics? Could it be that they simply want to keep something "secret"? Do you really think that there are no user serviceable parts inside? Sean
>

Sean, The term "super sonic" literally means faster then the speed of sound in "air". Sound travels faster in solids then it can in air. Therefore the sound wave traveling down the cone material of a Walsh driver, is at "super sonic" speeds. This is a scientific fact. How much faster the wave travels down the cone depends on the material being used to form the cone and the speed determines the angle of the cone. The correct angel lines up all the waves generated in the air to form a single coherent sound source, with no time-smear or time-delay distortion.

Sound travels at different speeds in different materials such as steel, plastic, water, air, etc. No, it does not create a sonic boom because there is nothing traveling in the air itself at "super sonic" speeds, the wave is traveling down the material. This is how the F's work and all speakers that work on Walsh's principal.

Line: Stop reading and believing the propoganda put out by various manufacturers and start learning for yourself.

Pull your Ohm's apart and find out what you've really got once and for all. Once you find that out, maybe then you can tell us what the "special materials which have a super-sonic velocity of sound propagation" really are.

I'm not certain that i'm ready to hear or experience a "sonic boom" up close and personal. Sean
>

Sean, I purchased my first pr. of OHM WALSH on Nov.3 1987, the 4-XO's. A Technical White Paper came with those speakers to explain too the purchaser how they operate and here is what it says in part....

This cone is fabricated of special materials which have a super-sonic velocity of sound propagation. By engineering the cone angle and propagation velocity properly, a coherent, cylindrical sound field is synthesized in the air around the cone; the listener, in fact, receives simultaneous sound.

As described previously, the apex of the cone is initially dent, and a sound-wave originating at the apex moves into the air at 1100 feet per second. Similarly, every point on the cone contributes its output at exactly the right time for ALL the wavelets to coherently merge into a cylinder, as shown in Figure 3. Wherever the listener sits, all the sound produced by one pulse reaches the ear at the same instant. There is no "time-smear" or "time-delay distortion". END QUOTE

That is a description of a Walsh driver; the angle of the cone is just different from the F's angle because the material used to make the cone is different. The speed in witch sound travels in materials is dependent on what kind of material is being used and the cone angle has to be adjusted accordingly. This is why the angle of the cone in the newer Walsh drivers is different from the F's cones.

Just because the newer Walsh drivers are not mounted on a sealed cabinet does not change the fact that the driver itself is operating as described above.

What Eldartford said:...That there is a mechanical crossover at the point where the two dissimilar materials meat, is indeed a crossover.

The Ohm A's used two different sections of cone and the F's used three different sections of cone, all seemed together mechanically. The Ohm A's had a larger cone with a non-linear flare rate whereas the F's had a smaller diameter cone that maintained the same flare rate for the length of the driver. The differences in materials, cone mass and driver geometry all add up to differences in radiation pattern, transient response, etc... As such, even though the A's and F's are TRUE "Walsh drivers", even they differ from one another in design and performance.

As a side note, the Ohm G used a smaller version of the Walsh. Due to the cabinet design, the radiation pattern was not nearly as omni as the A or F. This not only changes the sound that one hears, but also negates many of the spatial properties that make the Walsh design special.

Due to using a smaller cone with the reduction in piston area, Ohm was looking for a way to augment the bottom end of this driver. They did this via the use of a passive radiator. Passive radiators have the slowest transient response of any vented design*. As such, the bass on such a design typically sounds very "heavy" i.e. thick and powerful, but lacking in definition due to slower rise times and a lack of damping i.e. excessive "ringing" once excited.

While passives are great for HT use where "earth shaking" bottom end is more desirable, they really have limited use in a "hi-fi" system. Passives are, once again, another form of venting that achieves "quantity" over "quality". Sean
>

As I recall the driver was made of metal for a couple of inches at the top (near the voice coil) and this part of the driver supplied the high frequencies. In other words, the HF did not propogate all the way down the cone. So, although there is no electronic crossover, there is a mechanical crossover, a point that I stress for all single driver designs.

While not quite the single driver, cross-overless design of the original Walsh drivers, the Huff and German Physiks speaker systems may be the closest thing to a properly designed Walsh speaker currently available, albeit at a price.

Ohm is still one of the classic lines

Totaly agree and they are available now. But I did post this on a different thread....."From what I have read about audio and video, what I would like, is not available, at least not yet, and that would be 75" SED TV and a pr. of properly designed Walsh speakers."

ohm is still one of the classic lines

I'm glad you've once again joined the conversation, Sean!

I spoke to Bill in regards to you at the time you were contacting him about your F's. He said you were a true gentleman, and quite enthusiastic and knowledgeable - which I concurred with wholeheartedly.

Your suggestion of documenting the modifications and tweaks of the Ohm Walsh driver is something that should definitely get done - thank you. A close friend of Bill and I, Vinh Vu, owner of Gingko Audio, has always told me he was going to record Bill just saying what he always does (tremendous kernals of loudspeaker and modding knowledge) all day long, and put these words up on a website. I'm thinking that we need to make that happen, the Walsh driver stuff being one of these features, definitely.

As I read through this thread this past week, I appreciated your input in regards to your Ohm Walsh F. All I can say is that you are right on the money. Your statement of them going down to 5 Hz is something I can more than vouch for. As I said, I have NEVER had the contents of my intestines just taken and shaken by any other loudspeaker. To be truthful, it can sometimes be a bit scary, as it literally feels as if you could lose control of your bowels - I have read somewhere this happens with a 4 Hz signal. I took one of my buddies who owns a speaker company over one day, and when one of these bass notes hit, he was just like, "!!!!***WTF***!!!! Oh my God, was that just what you told me about?!?" When Bill's mods get implemented, and they are able to run on just a few watts, "No, they are NOT inefficient, they're tremendously EEEEEEEEEEEEFFICIENT." - Bill Legall; it's as awe inspiring, yet natural a sounding speaker that probably has ever been produced.

Trelja: While i briefly discussed some of the basic mod's that Bill suggested over the phone quite a while back, i'm hoping that he has somewhat "documented" this latest adventure in rebuilding / re-designing Ohm's version of the Walsh drivers. While i can understand his not wanting to perform this type of task for customers due to the amount of time / labour involved, i'm hoping that he will be willing to share his knowledge and experience so that others might benefit from it.

Other than that, i'm glad to see that you enjoyed this listening experience as much as you did. If one goes back and reads some of my comments about these speakers, i think that you'll find that i hinted at how great they could be. Even in stock and mildly modified form, they do some things that no other driver / speaker system that i've ever heard offers. Since Bill has found a way to correct the mass majority of drawbacks that have been noted about this driver / speaker system, primarily by re-designing the motor / suspension system, i've no doubt that it would be a force to be reckoned with. Even with the simple modifications that i've done to mine, i was already "in love" with them for many different reasons.

Line: What sounds "best" to someone is strictly a matter of personal opinion. As such, what you, I or anyone else prefers is up to the individual.

In terms of comparing the Ohm A's and F's to the newer "Walsh series", let's do some math.

The A's and F's use a point source omni-directional Walsh driver to cover the full range. There is no crossover involved due to using only one driver, so the amplifier is directly connected to the driver. Since there is no crossover to divide the signal and / or multiple points of radiation from different sources, this means that the sound that one hears is both time and phase coherent. At least, as far as the speaker is concerned.

The cabinets were sealed, which increases damping, reduces the rate of roll-off below the point of resonance and keeps all of the bass radiated in phase with higher frequencies. Using a sealed and stuffed design, this system will have one moderate bass peak at resonance.

As far as the drawbacks go, due to their original design and less than adequate driver assembly / construction, these speakers are quite in-efficient and suffer from dynamic compression. This is besides the fact that they are low impedance, making amplifier selection quite difficult at best.

As to the newer Ohm "Walsh series", they do not use a Walsh driver at all, but in fact, use two conventional drivers per cabinet aimed in different directions, causing phase / time delays. The radiation pattern of this design is not omni-directional, nor is it consistent. Due to the manner that the two drivers are implimented, there is a vast difference in radiation characteristics as frequency varies.

Due to using multiple drivers, a crossover is required. The crossover introduces time and phase anomalies into the signal. Due to the multitude of parts placed between the amplifier and the drivers, signal losses are incurred and further time and phase shifts take place. The newer "Walsh series" are vented cabinets, which introduce faster roll-off rates below resonance, reduce damping characteristics, introduce phase shifts and doubles the resonant peaks within the bass region.

The "Walsh series" are a far more benign load in terms of impedance, making them easier to drive. They are also more efficient, making it much easier to select an amplifier. They will also play louder than the A's and F's in stock form, making them more suitable for a wider range of music.

Technically speaking, there really isn't much of a comparison to speak of. These are completely different designs using completely different technologies with completely different presentations from completely different approaches. Which one you, i or anyone else prefers is, once again, a matter of personal preference. As i've said many times before, one should buy and use what they enjoy, regardless of what anybody else thinks. Nobody has to listen to or even like their system except for themselves. Regardless of how "accurate" or "high fidelity" the system is, when all is said and done, it's about enjoying the music. Sean
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I owned a pair of Ohm F's for a couple of years and loved them. I sold them thinking I would be able to pick up a pair of the new and improved ones down the road. Ha! Man was I wrong. Why can't someone or company deconstruct and then commercially manufacture the F's again. Regreted selling them but based on what I leaned from Sean several years ago, it would have been a moot point since they may have died of natural caused based on the explaination above.

Longing for F's again
L

Line, no, I was speaking of the first Ohm Walsh series ever built, the Walsh A. These were the ONLY iteration that Professor Walsh has his hands in. I was told he was at work, bringing forth a few prototypes to work out a few final kinks, when he passed away.

Ohm never fully understood what it was that Dr. Walsh was trying to build. And, from what I have heard from people who understand what it's supposed to be, they still do not. As such, see the comments has Sean made, and those in my previous post. Let's just say that it doesn't work, as implemented. But, if one understands the design, and in the right hands, ala Bill Legall, who can get them corrected, they are certainly fabulous. Knowing what is wrong with the stock loudspeakers makes me think there isn't a pair I'd be interested in as they are.

Sean has owned the Ohm F's and loves them. I own the Ohm 4.5 MX II and love them. But Sean has never owned the latest Ohm's and I have never owned the F's. So Sean nor I really knows which are better. Agreeing is not the same as experiencing.

The Ohms are far from being hip looking, but thankfully they sound a lot better than they look. I agree that the older Ohms look better, if I ever need speakers for a larger space, I'd look for an old used pair, and have the guys over at Ohm install the latest drivers.

Bartokfan...If you were really interested in the best sound you would get a different listening room (or wife) :-) I never owned the original Ohms, but I agree with Sean that they are (alas, were) the best.

Ohm decided to try to finish them, and bring the product to market.

Ttelja, are these the new series 3 you are talking about?

They sure aren't beautiful!

Seriously, though, my dear friend and loudspeaker guru, Bill Legall of Millersound, finally completed rebuilding his Ohm Walsh A loudspeakers. There are only a few pairs in the world, as Professor Walsh unfortunately died just before the prototypes were completed. At any rate, Ohm decided to try to finish them, and bring the product to market.

While some may say the rest is history, Bill maintains EVERY pair of Ohm Walsh derivatives was literally broken the day they were made. I don't want to go into too much detail here, but suffice it to say that their double edged sword reputation of being tremendously power hungry, yet giving them a few more watts than they require to get moving will kill them speaks to their implementation.

Now, Bill will not, under any circumstances, go through Ohm Walsh speakers for customers, but he had to get his own pair up and running. All I can say is that it is perhaps the finest loudspeaker ever devised. When one actually sees Bill's analogy of how it works in regards to just about every other driver created, apart from maybe a horn, every other driver looks flat out WRONG. It simply is a night and day better impedance match with the air.

Unlike the stock Ohm Walsh speakers, Bill's get by on just a few watts (they're tremendously efficient), and even driving them with a cheap satellite radio and $200 Kenwood amplifier, I hear and feel things no other speaker I've been around can do. Believe me, having the contents of your intestines rattled is both scary and awe inspiring. Never felt a speaker do bass like that! He claims they must go down to just about DC. And, this same driver produces the highest of highs. As the single driver/no crossover people believe, the seamlessness, coherence, and naturalness of such a design is simply without peer. The dynamics and speed are just flat out explosive. No need to go into the imaging, as it's what made the speaker legendary. However, the greatest compliment I can pay the speaker is that it simply is natural sounding and easy to listen to.

Oh but they sound sooooo good. I do have the older Walsh 4 cabinet but I wouldn't care if I had a set with the new cabinets. The Ohms are amazing. As they say, "my cup of tea".

Cheers

I also think it's ugly; the older models look good to with that trapezoid cabinet.

You want my thoughts? I just looked atnthe ohm web site. My wife would never allow me to place taht speaker in my listening room. Its ugly.

I have the Walsh 4.5 Mk II and find them so very easy to live with. There is no divorce in sight, I am in love.

I heard the F's some 40 years ago and did not have the coin in which to buy.

What I have never come across is an A/B listening test between the F's and the 5 Mk II, but I would put my money on the 5 Mk II as coming out on top.

Sean,

The following is quoted from a Six Moons' review of Ohm's Walsh Micro speakers.

Ohm Acoustics manufactures two very different types of loudspeakers - the usual cone'n'dome variety (certain models incorporating different ideas on dispersion) and their claim to fame, a complete line of speakers using the Walsh driver based on the work of the late Lincoln Walsh. Years of refinement have created what Ohm calls the CLS or Coherent Line Source driver. Picture a typical cone woofer elongated in depth akin to a megaphone - but not quite. Now point this driver downward so that it fires into the top of the speaker's enclosure. Sound propagates off the back of the driver rather than front, and by virtue of its open-air surroundings, in a 360-degree rather than narrow-directivity dispersion pattern.

States Ohm Acoustics on the subject: "The CLS system uses an inverted cone driver with the speaker coil driving the peak of the cone. The sound vibrations travel from the top down and out to the rim.

By using a cone material in which sound travels faster than it does in air (supersonic) and by carefully aligning the angle of the cone, the driver generates a vertical wave front, radiating sound equally in all directions like an expanding drum. Because the inverted cone driver radiates in all directions, it sounds the same in all directions." In other words, the driver is naturally time-coherent and omni-directional. But Ohm feels that, with certain circumstantial exceptions, an omni-directional response in the treble is undesirable. Rear-wall reflections at these frequencies can become confused with the original sound and consequently blur imaging. Hence, in addition to the CLS main driver, Ohm adds a "super tweeter" mounted vertically at the Walsh driver's top and angled inwards so as to cross its main axis well in front of the listener. This tweeter is reportedly pressed into service around 8 kHz which eliminates a crossover network anywhere near the critical 2-6kHz range where human hearing is most sensitive to discontinuities.

IF the description is true to the design, I find it hard to believe that the CLS driver is not a derivation of the original Walsh driver and is just an inverted speaker. True, the Ohm F's had a longer ~12" cone (not including the motor), but it also covered the complete audio range (37 - 17,000hz). The new CLS cone (I am talking about the Walsh 5 Mk II) is only ~5" - 6" tall (hard to tell from the drawings) and only covers the claimed 20 - 8,000hz range.

Think of it this way. If you took a full range driver, mounted it into a cabinet ABW (ass backwards), would it still be able to produce the mid to high frequencies as a correctly mounted driver?

I am not saying I am right. There just seems to be too many inconsistancies posted. Just trying to find the "truth" (if that is possible).

Ohm is high end, the misinformed 3x0 guy don't know what he's talking about.

I have the walsh 2, 2xo and pro 200 and happy with them.
I agree about the OHM F, they where considered in the 70's the best loudspeaker in the world according to a lot of reviewers.
I remember reading the stereo review articles on them.
I like ohm when they had the various models that last thru the 90's like the FRS, SOUND CYLINDERS and the F2, F3'S...
Besides the 300 MK 2'S, I wouldn't consider any of the smaller current ohm's like micro walsh and the 100mk2, or 200 mk 2...
I like the old design and cabinetry you find on the F'S, G'S, 2,3,4, 5.

I wished ohm went back to the original driver and cabinet designs with the many choices.
It sounds like a lot of old high end companies have downsized their designs. Infinity and polks are good examples. At least ESS SPEAKERS still uses their old design in both cabinet and driver.
Klipsch being older than these companies at least custom make to their OLD designs by special order.

What matters is that you are happy with what you have and what you hear both old and new. I love the old stuff myself.
When it comes to speaker designs, there are few companies who make new systems i admire, for the most part, i like yester years designs like i mentioned with OHM, infinity, polk, klipsch, ess, magnepan, acoustat, apogees, altec lansing, JBL, and many more. Newer is not always better.
There are things in life in which you don't need re invent the wheel. Some of us like turntables and no matter how many types of digital products come out, howbeit they're marvelous, they're not vinyl turntables and a different form of a music source, the same with cassette decks and open reel, you simply can't replace them by cd or dvd or mp3 digital players, totally different music source.
That's why it's hard to get rid of analog, there always be enthusiast and followers, and the same with vintage speakers such as OHM'S!

Interesting review on updating Ohm 4's
http://www.6moons.com/audioreviews/ohm/ohm.html

Line: Most of my comments are based on the "antique" series of Ohm speakers i.e. the ones that used free-standing Walsh drivers, not the regular drivers that are housed in a cage that increases diffractional losses making them sound more "ambient". The newer "Walsh series" are of no interest to me what so ever. That is my personal opinion though, so take it for what it is worth.

Other than that, i do agree that power helps with these designs, as it does with most any other design. That is, so long as the quality does not suffer in order to achieve the quantity desired. Sean
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Nanderson and Sean...There is a Blue Circle amp. review i think would be of interst to you guys. This review shows that it takes ample power to turn the Ohm speaker into truly high-end speakers. Just Google "Soundstage Blue Circle Audio BC8"

Personal taste is whats it all about. I upgraded from the OHM 4XO to the OHM 5 about a year ago and love them, they just sound right to me. They will play VERY loud with lots of power. I use a Sunfire amp. that produces 600 watts per. ch. at 8 ohms and 1200 watts per. ch. at 4 ohms. This kind of power realy gets a grip on these speakers. I used to use an amp. that produced 200 watts per. ch. at 8 ohms and 325 watts per. ch at 4 ohms; this amp. would clip at higher volume levels. These speakers do go into the 4 ohm area, so it's good to have the power there.

My thoughts they are decent speakers,they are not
highend speakers, As far as I remember, they were
demolished by my KEF 104,I dont think they are
musical,I dont think they can compete with speakers
like Totem,Norh speakers 6.9 or marble 9,the VR2
are also better.I forgot to mentioned I used to own
the Walsh 3,my brother in law, still own them.The
company has a excellent service.