Ohm Speakers, thoughts?

Out of curiosity, what did you find inside of the "sealed can" in yours ? Please be as descriptive as possible. Sean
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John, if those A's ever become available, PLEASE let me know. I will drive to pick them up. As to the F's, drop me a line if you pick them up and we can compare notes. I have two different sets of modified F's that i dearly love and will never part with. There were more than a few variations during their production run, so one set can vary from another. How big of a difference there is between them would depend on how far apart they were in production.

Noel, the original owners of Ohm had sold it to the current owner, John Strobeen. While i guess that he is very good to work with and takes care of his customers, i think that the newer products are WAY different than the "old school" models that you remember them by. If you ever saw that insides of one of their "Walsh series" of speakers, you would be HIGHLY afraid to spend the money on them. Jon Risch described them as being "built and designed by a child on drugs". While they do offer a completely unmatched ( at least in the speaker industry ) amount of time as a trial period, I know too much about their internals to take them seriously. Let's just say that their newer "Walsh's" are not "Walsh's" as you or i would think of them. That is why they say "no user serviceable parts" within their "sealed cans". They don't want you to know what is in there. If you did, not only would you feel sick, the mystique would be gone. Sean
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There is another Canadian based company that takes the "improved" Walsh ( aka "Dick's Dipole Driver" or "bending wave transducer" ) that GP makes and modifies it. It is supposed to blow smoke and walk on water. That is, if you're into the type of presentation that a 360* driver delivers. Can't remember their name, but i want to say it was of Irish descent. If i remember correctly, the price on them was about $18K - $20K for a pair.

John, are these being shipped to you ? If so, drop me an email. I can give you some hints on how to save the drivers. They are EXTREMELY fragile at this point in their life and will need to be "TLC'd" all the way. Sean
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Talk about coincidences !?!?!?! Huff is the manufacturer that i was talking about. As luck would have it, he will be demo'ing his products at the next Chicago Audio Society meeting. Boy, i can't wait for this : ) Sean
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http://www.huffloudspeaker.com/

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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Unsound, 7p62mm described the newer "Walsh" series. My only comment to what was stated is that it does not use what is historically known as a "Walsh Driver". Instead, the newer designs use a conventional woofer that is loaded face-first into the top of the box. What you hear coming out of the "can" is the backwave of the driver i.e. the sound leaking out of the holes in the drivers' basket. The front wave of the downward firing woofer is vented from within the box. Since there is limited cone exposed through the drivers' basket and upper mids and treble are highly directional, they augment the woofers high frequency output with a tweeter.

In comparison, the original Walsh driven Ohm A's and later version called the Ohm F's use very different drivers from the newer versions. While both use one full range driver ( no tweeter or crossover network ) that radiates 360* horizontally and looks like a "pylon" or "road cone" mounted on top of a sealed box, the designs are quite different from each other.

The A's used a greater flare rate near the end of the cone and somewhat resemble the old horns on Victrola's. The cones were made up of two sections ( top and bottom ), each one making use of different metalic materials that were internally damped. The suspension was rubber based. As such, the surrounds do not decay and would not need "refoaming" unless ripped, etc... Efficiency on the A's was said to be in the very high 70 dB range. I'm guessing somewhere around 78 db's or so from what i've read about them. Impedance was spec'd at 8 ohms but later models were much, much lower impedance. As such, it was a phenomenally tough load to drive, especially with the amps that they had available back then. As far as i know, there are VERY few pairs of these remaining.

The F's were basically an attempt to refine the A's. The cones on the F's have a more linear taper and make use of three different materials and arranged in a top, middle and bottom section. Each material was selected for specific attributes within specific frequency ranges. There are even "slashes" that were strategically cut into the bottom section to help break up standing waves along the length of the cone. While the impedance is rated at 4 ohms nominal and 3 minimum by the factory, they actually average closer to 2.5 ohms and dip below 2 at low frequencies. Efficiency was factory rated at about 87 dB's but my experience says something closer to about 82-83 dB's or so. Once again, these were tough loads for most amps back then ( and even today ) to deal with. I have run into problems with some very well respected amps trying to drive these.

Both of these speakers take a tremendous amount of power to function at their best. I remember an old review of the F that stated "anything less than 60 wpc is just not suitable". Personally, i think that an amp that can do at least 300 wpc at 2 ohms without a fuss would be the minimal requirement. Even with that in mind, i have had amps that were rated for 400 wpc @ 4 ohms begging for mercy with these speakers. Obviously, this pushes a LOT of amps out of the equation and proves that not all amps are created equally, regardless of specs.

As to sound, both the A's and F's ( when running right and in good condition ) are known for tremendous low frequency output. I recently had a set doing FIVE Hz ( !!! ) at high output levels. It sounded like a helicopter was inside the house : )

Soundstage is phenomenally wide and deep with a very natural presentation. Notes tend to effortlessly float in the air. This is probably related to the dispersion pattern and fact that you have one driver producing all the sounds in phase with each other.

Midrange sounds very cohesive and seamless, as all the primary notes & harmonic overtones from both instruments and voice are reproduced with no crossover points or multiple drivers to disturb the signal. Highs are very crisp and clear with bell like qualities. Most of that may be attributable to the metalic section of the cone. To minimize "metalic ring" like you get with metal domes, they applied a thin layer of glue and foam inside the driver itself. Not only does this help to absorb high frequency reflections and standing waves inside the driver and box, it also damps the metal membrane.

There were quite a few revisions during the production run of these speakers. Some obvious ones were the design characteristics of the frame used for the driver. I have two sets of these and they are visibly quite different from each other. Other things not noticeable from the outside were the types and quantities of internal damping materials.

These speakers are limited in terms of SPL and dynamic range. They work best for listening at low to medium levels. They can play at higher levels, but attempting to do so for an extended amount of time will almost surely result in either the amplifier or speakers coughing up smoke. Keep in mind that i like "LOUD", so my "medium" listening level might not be the same as yours. Either way, when used within their limitations, they do some things that most other speakers can only dream about. That is why i own TWO sets of them : )

The last Ohm's that i know of that made use of what i would call a "Walsh driver" would be the Ohm G's. These were a short lived model that did things very differently from the earlier "Walsh" speakers. Not only was the height and radiating surface of the driver reduced, the materials used were quite different. Besides that, the Ohm G made use of a passive radiator design rather than a sealed box. This was obviously done to augment low frequency output but also maintain a small amount of damping for the driver. I guess that they were trying to use a smaller, lower mass Walsh to achieve greater high frequency capabilities. By doing so, they ended up losing both mass and surface area in the attempt. Both of these are major factors when it comes time to reproducing deep bass. Anything after the G is simply a "Walsh" in name for advertising purposes.

Obviously, this is just my point of view. Take it for what it is worth. If anyone is interested in further info on "vintage" Ohm's, drop me a line. Sean
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7p62mm, i wish i still had the digital pictures of what the insides of those "cans" looked like. I'll just say that i'm NOT "guessing" at what is inside of them.

I have also discussed this with a local dealer. Not only is he a former authorized Ohm dealer, he is known nation-wide for speaker repairs. As such, he has seen the "guts" of many speakers, including the later "Walsh" drivers. In his own words, he stated that the Walsh series used a "conventional" woofer and was not anywhere near the speaker that the A's and F's were. Knowing what was inside of them and also hearing the lack of performance ( compared to earlier models ), he had a hard time selling them. As such, he dropped the line. I think that this may be a large portion of why Ohm can no longer be found in dealerships.

I do have one question for you. Given the overall height of the original F driver, which is 16" tall, what kind of "Walsh" could you fit inside that little mesh "can" ? Now figure out how you're going to mount both a tweeter and crossover components inside that can. Believe me, it's NOT pretty or even well executed.

If you are feeling brave ( don't do it while "relaxing with a drink or two" ), take your "sealed can" apart. While this will affect your attitude of how you look at those speakers after doing that, it should not alter the level of respect that you have for how they sound or their presentation. If you are happy with them and what they do for your musical enjoyment, my suggestion is to STOP looking at threads like this and start listening to more music. I need to take my own advice and do the same thing. I think that we would all be a lot happier. Not only that, i could actually spend time getting things done and quit blowing so much money on stuff that i don't really need : )

Unsound, thanks for the kind words. I do what i can with what i've got. Obviously, that means that i've got too much "unproductive" time : )

I've often wondered about doing something similar to what you discuss. It is something that i will probably check into in the future. Right now, i just have too many other projects going on to consider it.

As to what model i would strive for, i think that this is obvious. I would look for a GOOD set of Ohm F's. Only problem is that many ( if not most of them ) will need an overhaul or have been physically damaged to the point of no return. The foam will have rotted, voice coils may be damaged, the spiders ( part of the driver suspension ) will be sagging, etc... As such, you would be looking at quite an undertaking should you want to take on such a project.

Most people that have these speakers or do purchase a pair have probably never really heard what they are capable of. Those that have will not part with them. Even with the less than optimum performance that they will deliver in the average installation, it has been stated about them ( and i quote from a review ) "The Ohm F is an extraordinary loudspeaker. It has only one driver, which acts as a pulsating cylinder, translating the electrical impulses of the operating amplifier into sound without disturbing the phase relationships of the impulses. What this means in terms of sound quality is remarkable. The "coherent" sound produced by this speaker is clear, full and undistorted. It may well be the finest speaker on the market, and is certainly without a doubt among the top few. It requires a tremendous amount of power to operate: amplifiers of less than 60 watts per channel are just not suitable. But given the proper associated electronics, the Ohm F is capable of providing almost absolute realism in the listening room."

Keep in mind that even most "expert" and "professional" speaker repair facilities HATE working on Walsh drivers and some won't touch them with a ten foot pole. The second pair that i bought was just about ruined by an extremely well respected and well known "speaker rebuilder" and tube gear manufacturer. Even with as poorly as the speaker was performning when he was done with it, it impressed him enough to try and design his own version of it. He is currently marketing them on a direct purchase basis and claims that they work like no other speaker.

I have since had the second set repaired but not without consequence. Needless to say, i don't have many kind words to say about the first "expert" that worked on them. I have thought about starting to repair these drivers myself, but i would first need to find a pair or two of "basket cases" to experiment with. I'm not about to "gut" the two pair that i have for the sake of advancing my knowledge of them. Sean
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Hififile, thanks for confirming my previous statements. I'm glad that you took the same stance that i did as far as saying it all boils down to enjoying the music.

My main problem with the whole "Ohm ordeal" is that they are marketing their current products as having Walsh drivers and they are not Walsh's as we know them. Other than that, these speakers may do everything that someone is looking for. However, I did feel it necessary to state that those that were familiar with the original Walsh based products might feel let down by Ohm's current offerings. Given the amount of time that has passed and the technology that has accumulated, they have done little to nothing to improve upon what was already an excellent design.

As i've tried to make clear before, i try to limit my input here to personal experience or information based on reliable sources. While i've seen the insides of the speakers being discussed, the digital photos that i had came from another source. If i was to pass on information from someone else, i would only do so if i felt they were reliable and the information was verifiable. Obviously, sharing someone else's opinion or subjective findings is done strictly as a contribution to a conversation. It should never be taken as "gospel" that everyone should hold or share that point of view.

Please don't take this to mean that i'm saying that i am always right ( far from it ). Like most others here, I do try my best to be as accurate as possible. If i am wrong or overlook specific aspects of a situation, i always ask that people more familiar with the situation correct me. Not only do i not want to screw something up for someone else, i want to know so that i don't continue to pass on "misinformation".

Hopefully, none of us are above being corrected or have stopped learning from each other. Sean
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Mbiker: I had a very well known "professional speaker repair facility" refoam a set of my F's years ago and they did the same thing. It caused the driver to bind up, resulting in much lower spl capability and limited low frequency output. I had to pay another "professional speaker repair facility" to disassemble the freshly glued ( non-brittle ) surrounds, which did result in damage, and re-install the proper surrounds in the proper fashion. After all of that, this set ran fine after all of the repairs, but not quite as good as my first set that i also still have.

With all of that in mind, refoaming an F is a tough job. MUCH tougher than a standard woofer. For one thing, you can't get around shimming the voice coil with these. Due to the length and mass of the cone, the driver tends to "wobble" in the gap. ANY type of binding due to a lack of centering of the voice coil WILL result in quick driver failure. This in itself isn't a big deal, but looking at the F will tell you how "not easy" it may be to get a shim into the necessary area.

As part of installing the shims, you're likely to encounter the foam damping material that is installed on the INSIDE of the Walsh cone. This foam is probably relatively brittle and may crumble when physically "brushed" as you try to install the shims. The loss of foam will change the resonant, transient and damping characteristics of the driver. Obviously, extreme caution needs to be taken here.

Besides that, you really need use the proper density foam surround for this driver. Due to the aforementioned length and mass of the driver itself, and the way that the driver is mounted on the baffle, the surround acts as a major portion of the suspension of the speaker. Compared to a standard driver that fires horizontally, the surrounds on the F's are working WAY more than "double duty". Use the wrong surrounds and the suspension will either be too stiff ( causing driver binding and a lack of output ) or too soft, with a lack of damping and excessive ringing.

From what i've been told and probably due to some of the reasons listed above, most "professional speaker repair facilities" consider the Ohm F to be the toughest dynamic driver to properly refoam.

With the above info, you may be able to make a more informed opinion of whether or not you are up to to tackling this type of a task.

Other than that, the amount of TRULY "deep" bass that these speakers are capable of is pretty astounding, isn't it? When you say "5 Hz", most people will think that you're joking or exagerating. Those of us with F's that are really working well know exactly what you mean though. I know this because the Ayre Acoustics disc starts off at 5 Hz and my F's are "pumping away" at great amplitude. Enough to shake the house like you wouldn't believe. Sean
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PS... If you want to drop me an email, i can share with you a few competent speaker repair facilities and one to avoid like the plague.

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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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
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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
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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
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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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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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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.

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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Line: You've lost me in terms of "where do the extra spl's come from?". What "extra" spl's are you talking about? Sean
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Line: I'm not going to go into the design of the German Physiks vs the Ohm A's and F's as i think that they are more similar than dis-similar. Other than that, i'm still trying to figure out what these "extra spl's" are that you're talking about??? Sean
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The Ohm versions of the Walsh drivers suffered from very poor assembly techniques. That is, the voice coil was not properly placed in relationship to the magnet / pole piece and the suspension ( spider, surrounds, etc...) were not properly slected. The end result is less than optimum performance in most every respect and drastically reduced efficiency / drastically increased compression.

This is why Bill Legall of Millersound referred to the Ohm A's & F's as being "broken from the factory". Addressing these problems basically means rebuilding the driver, but the results can be staggering to say the least.

I'm quite certain that the increased efficiency of the DDD stems from FAR greater attention to detail in the design & assembly of the driver. By limiting bandwidth of the driver, efficiency is also increased. If one were to read Walsh's original patent info, Walsh specifically stated that this design could be built to cover a VERY wide frequency spectrum. Only problem is that the wider the spectrum, the lower the efficiency.

Line: I'm lost as to what you're trying to say. Then again, i've not gotten much sleep in the last few days, so...

Unsound: The German Physiks speaker uses a passive crossover, not an electronic crossover. While the passive could be considered "electronic", that terminology is typically reserved for an "active" crossover. Don't know if that's what you meant, but thought this should be clarified for those that aren't familiar with the design. Sean
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Trelja: Now you know why i said what i did in a ( WAY ) earlier thread on Agon. That is, even though they most certainly have their flaws, i don't plan on giving up my F's anytime soon. I'm quite certain that mine don't perform to the level of Bill's "completely re-designed" Model A's, but none the less, many of the sonic attributes are still there to a lesser extent. Even with just that hint of performance to them, i knew that they were "special" from the very begining. Sean
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Frap: I would tend to agree, but maybe from a different perspective. The Walsh makes music with both depth and ambience whereas other speakers may produce FAR greater "hi-fi resolution". As far as being immersed in sound, as one is at a concert or sitting nearfield of a bunch of acoustic musicians, i know which one is more realistic. This could be because you don't strictly have a left /right presentation with the Walsh's like you do with more conventional speakers.

Either way, i like the presentation of the Walsh design. I also like specific attributes of other more conventional designs. That's why i have several different systems, all quite different from one another. They all have their drawbacks to one extent or another. Some are just far more blatantly lacking in certain areas. Sean
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I have no doubt that the Walsh driver stomps all over Maggies, which are the best selling "audiophile approved" speaker in the world. As such, i'll use them as a point of reference.

By re-designing the Walsh motor structure and suspension, thereby making it more efficient and higher in nominal impedance, you make it easier to drive. As we all know, Maggie's aren't the easiest to drive and are also "finicky" when it comes to placement. In this regard, the "modernized" Walsh walks away from the Maggie.

On top of that, the Walsh's have TREMENDOUS bottom end, something that you couldn't pry out of a pair of Maggie's. In this regard, the Walsh RUNS away from the Maggie.

The Walsh's also have the deepest and widest dispursion of any driver / speaker system that im aware of, making for a FAR more "engulfing" musical experience. One can gain the sonic "wrap around" feeling that one normally only obtains from listening VERY nearfield, a presentation so "thick" that it feels like you're walking through it ( varies with recording ). Compare that to the presentation of the Maggies, which sounds "ambient" and "spacious" only when sitting in a limited area, and the Walsh once again wins.

Given the single driver point source with no crossover parts to soak up power or add their sonic signature, you don't have time or phase errors. The "one driver, direct drive" approach also produces excellent harmonic structure, prat and coherence, as many of the "full range" afficionado's will testify to. Maggies have a crossover, use multiple drivers and lack the warmth and bottom end required to have great "prat" ( in my opinion ).

To sum things up, it is a fabulous driver with GOBS of potential that absolutely kills the "audiophile reference". Would the average audiophile recognize this? My answer is NO. Most audiophiles are sheep and led by their noses via printed reviews and the herd mentality of the internet. Even if the glossy rags and internet "herd" were to jump on the bandwagon, it would be a short-lived ride till the "next best thing" comes along.

Most audiophiles are more concerned with dimunitive size in a speaker ( monitors ) OR MEGA sized boxes with a lot of drivers. Maggies are kind of a cross of these two i.e. large frontal section but very "petite" in terms of depth. On top of that, the Walsh's are so unconventional in appearance, operation and placement that many would be turned off.

As such, i think that it would become a niche product, just like those using SET's, single drivers, nearfield listening, etc... That's because the design approach and presentation wraps up several different aspects of what these people love and are after, all into one package. As we all know, those specific types of listeners are but a small part of the audiophile market, which is why i think it would be doomed to remain a product of interest to only a select few. Much like it is now, but on a slightly wider scale. Sean
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PS... To be honest, i've never heard a Heil system that was worth listening to. Having said that, i'm quite certain that the installations and support componentry were to blame. This is probably most of the problem with those that had complaints about the Ohm's too, especially "way back when".

The technology behind the Heil driver, much like the Walsh, is pretty incredible as compared to more conventional designs. It's too bad we don't have any designers / engineers around today that are willing and capable of introducing and properly implimenting "ground breaking designs" like these. Instead, we keep getting re-hashed "monkee coffins", albeit better designed and better sounding "monkee coffins".