Ohm Walsh Speakers

[Ron Texas]

Anyone have any comments on Ohm Walsh speakers?

 

[pozz]

Are they supposed to be omnidirectional speakers with a transmission line for bass?

 

[Dogen]

I heard a pair of floor-standing Ohm Walsh speakers a few years ago. They have the charms and drawbacks of omnidirectional speakers. Diffuse sound that “fills the room” and a consistent stereo image around much of the room. I sort of like that in certain situations, where you might want be anywhere in the room and have consistent sound. But, I wouldn’t want them as my only option, losing a more precise stereo placement. They have their staunch fans and detractors.

I have a pair of small omnidirectional Mirage speakers in one of my rooms, and I enjoy them for what they are. Great speakers for when we have guests over - no one gets sound that’s too wonky.

 

[anmpr1]

Audio Critic #4 and #29 have reviews, one of an early version, and then a later version. Both are on line with a search. The following is a short history of the speaker, by Peter Aczel. Of note: Aczel did the early to mid-70s ads for Rectilinear, the company mentioned in his narrative below. The first review (#4) was pretty hard on the speaker. #29 was done by Don Keele, with plenty of measurements.

The origin of the unique Walsh drivers appears to have been forgotten, or at least allowed to lapse into some kind of vague folklore, over years; the following is the ‘official’ version, which I can confidently tell, because I was there.

Ohm Acoustics was founded in 1971 by Martin Gersten, a self-taught loudspeaker designer, for no other reason than to become employed again after he had lost his job at Rectilinear (a speaker company that went out of business many years ago). Gersten had several silent partners with a financial interest in the new company; I was one of them. (I was still in the advertising business at the time; three years later I sold all my stock back to the company, so for the past 29.5 years I’ve had nothing to do with Ohm.

At first the company made only conventional ‘monkey coffins’, but soon Lincoln Walsh, whom Gersten had known for some time, entered into negotiation with Ohm to have his patented loudspeaker invention developed, manufactured, and marketed. (I would never have become involved with Ohm—whose name was actually my suggestion—if I hadn’t known that the Walsh speaker was coming.)

Lincoln Walsh was a veteran engineer, a member of the team that had developed radar during WW II and the designer of the legendary Brook triode amplifier. His loudspeaker invention was based on a simple insight: no speaker cone is actually a piston, in the sense that its perimeter moves the same instant as its apex is set in motion by the voice coil. It takes a finite amount of time for an impulse to travel from the apex to the perimeter. A good woofer cone appears to be a piston only because the wavelengths it reproduces are so large that the transmission time from apex to perimeter represents only a tiny fraction of the wavelength and does not result in a perceptible ripple or breakup. A cone reproducing the full audio range, however, inevitably ripples and breaks up, because the HF wavelengths are only inches and the cone is relatively large, requiring several cycle durations for the signal to travel from apex to perimeter. This is true of all cones, regardless of cone material or geometry. They are, in essence, transmission lines, albeit poor ones.

So Lincoln said, “If a speaker cone is not a piston but a transmission line, let’s make it a good, well-organized transmission line! He inverted the driver and turned the apex up, so it fired downward into the enclosure, with the sound coming off the convex side of the cone. He made the cone material stiff, so that the sound waves were transmitted at a calculated speed that was much higher than in air, and he made the slope of the cone exactly such that the horizontal vector of the transmission synthesized a coherent cylindrical wave front in the air.

…in the real world there were huge problems—efficiency, cone material issues, resonances (and what resonances!) inadequate termination of the line at the surround, etc. …the perfect Walsh driver has yet to be made; if it were made it would be the world’s most beautiful, most unproblematic speaker design. Perhaps the German Physiks speaker has come closest to it, at a very steep price, since the expiration of the patent.

 

[GradyBeach247]

I purchased a pair of Walsh 2000 Tall speakers in April. They are not truly omnidirectional in that they have an acoustically absorbent material at the back of the inverted cone to reduce radiation to the rear of the speakers. The stereo image is definitely not as tight as traditional box speakers, but is better than my nearly 40 year-old DCM Time Windows. The image usually appears to be in-line with the speakers to a little behind. The 3-D imaging is very successful with close-miked instruments like with jazz groups, less so with classical obviously. The image appears to hold better with vinyl than streaming, although this is likely due to my own perception and bias rather than anything that can be measured.

Considering that the living room where they are situated is not ideally arranged for listening from a fixed sweet spot (furniture and doorway openings are not in ideal locations, room has a sloping ceiling, layout deeper than it is wide, etc.) without seriously compromising the functionality of the room (let alone marital harmony). The location of the speakers did require some minor tweaking, but placed about 16 inches away from the wall they sound great to me. They work well with my stereo/streamer box as well as the tv, so family happiness is maximized.

Of course I secretly lust after a pair of Klipsch Forte III's or possibly some Cornwalls, though my marriage would suffer (K-horns are out of the question, would need to build or buy a house for them).

 

[Ron Texas]

I see a definite trend here. Some will like them, others want a more defined sound stage and would prefer conventional speakers. Zeos loves his, but that's just one guy with a Youtube channel.

 

[radio3]

I actually have gotten the impression that most people who have actually heard them love them. That’s why I wish I could find a pair to listen to. They don’t really sell to Europe, though. I also find them objectionable visually. On the other hand, I think it’s actually the single most raved about speaker I know of, from people who have actually heard them.

The particular reason I would like to hear them is that the idea of a speaker that sounds great all over the room is very compelling. After all, if we’re going to only listen from specific listening positions for one person then it’s almost like we’d actually be better off just using headphones. To me a large part of using speakers instead of headphones is that it makes music social. But it’s not exactly social when only one listening position sounds good. Especially while entertaining groups of people (e.g., dinner parties etc).

 

[mhardy6647]

Well, the thing to bear in mind is that there were/are "Walsh" loudspeakers and "Walsh" loudspeakers.
The "real" ones, like the Ohm Walsh F, were -- rather remarkable in their own, bizarre way.
Proprietary, full-range drivers with foam suspension -- truly "omnidirectional" (well, at least radially speaking) and very insensitive.

The later, lesser, and cheaper Ohm "Walsh" loudspeakers are very different beasties. At least the pair that I have here (which I believe to be Ohm Walsh 2) basically have a cone driver (woofer) mounted upside down at the top of a vented enclosure, with a top-firing woofer sort of aimed off in space a la some of the midrange Bose loudspeakers of the 70s and 80s.

The latter ain't bad -- and they're more practical and more sensitive than the "real" ones -- but still, they're sort of imitations and not das Ding an sich.

IMO, of course.

 

[anmpr1]

I actually have gotten the impression that most people who have actually heard them love them. That’s why I wish I could find a pair to listen to. They don’t really sell to Europe, though.

In Europe I imagine you could find the German Physiks speaker which has their version of the Walsh driver.

https://www.german-physiks.com/

 

[Duke]

The idea of a speaker that sounds great all over the room is very compelling. After all, if we’re going to only listen from specific listening positions for one person then it’s almost like we’d actually be better off just using headphones. To me a large part of using speakers instead of headphones is that it makes music social. But it’s not exactly social when only one listening position sounds good. Especially while entertaining groups of people (e.g., dinner parties etc).

There is another, somewhat unorthodox technique for getting a wide sweet spot, which works with controlled-pattern speakers.

By way of background, you need to know this: The ear localizes sound by two mechanisms: Arrival time, and intensity. If the arrival times from both speakers are identical, the image will be shifted towards whichever speaker is loudest. And if the intensities are identical, the image will be shifted towards whichever speaker's output arrives first.

What I'm going to suggest is sometimes called "time-intensity trading", as the off-centerline listening locations which have a later arrival tme from one speaker make up for it with greater intensity (loudness) from that speaker.

Briefly, start with speakers which have a very uniform radiation pattern roughly 90 degrees wide over most of the spectrum. Then toe them in severely, such that their axes criss-cross in front of the centeral "sweet spot".

For an off-centerline listener, the NEAR speaker now "wins" ARRIVAL TIME, BUT because of the aggressive toe-in (and radiation pattern shape), the FAR speaker "wins" INTENSITY. Here is a photo taken at an audio show. As you can see, from the listening position where the photo was taken, the listener is well off-axis of the near speaker but on-axis of the far speaker. The far speaker is actually louder:

Photo by Eric Franklin Shook of Part-Time Audiophile.

The two localization mechanisms (arrival time and intensity) approximately balance one another out, and you get an enjoyable spread of the instruments even way off to the side where this photo was taken from.

The KEY to this working well is, the output of that near speaker must fall off SMOOTHLY and RAPIDLY as we move off-axis. This technique will not work with most loudspeakers.

Of course the imaging will be best up and down the centerline, but elsewhere in the room the soundstage will hold up considerably better than normal.

As long as the speakers have good radiation pattern control, the tonal balance will hold up well throughout the listening area and even into the next room. No one is ever on-axis of more than one speaker at a time, so nobody is getting the directly-on-axis highs from both speakers at once. I like to include a bit of user-adjustability in the tonal balance of the top end, for adaptation to different room acoustic situations.

I don't claim that this is necessarily BETTER than an omnidirectional speaker at giving you good sound throughout the room, but it is competitive, AND it still gives you precise localization and normal-size sound images when you are in the sweet spot.

So if you don't have access to Ohm Walsh speakers in your country, maybe this technique will be useful with speakers that you do have access to.

Here is a paper on the subject, I don't know who the author is:

http://www.libinst.com/PublicArticles/Setup of WG Speakers.pdf

 

[anmpr1]

As long as the speakers have good radiation pattern control, the tonal balance will hold up well throughout the listening area and even into the next room. No one is ever on-axis of more than one speaker at a time, so nobody is getting the directly-on-axis highs from both speakers at once.

I don't mean to trivialize a point, or state the obvious, but I want to digress a bit. In the days of mono the idea of a 'sweet spot' and 'imaging' were generally unimportant, since most people listened to their hi-fi with one speaker (the exception being a very few who owned and listened to two or even three channel open reel tapes). Paul Klipsch designed his loudspeaker to fit in the corner, allowing the monophonic sound to radiate throughout the room in a 90 degree spread.

Of course with the advent of stereo it was 'back to the drawing board'. Because of the 'artificialness' of early stereo most people were unhappy with the phantom center image, which often was more like a hole in the middle of the sound field. A work around was a center channel simulation (Dynaco and Klipsch designed kludges for this 'problem'). One big factor was many early stereo recordings were done without the benefit of much practice, and some were recorded with three channels to include a center, which was then mixed out for stereo records.

In order to properly listen to early monophonic records it is better to listen to one loudspeaker, instead of two, where one matches levels in order to properly localize a single channel from two loudspeakers.

Your point about 'shifting images' is why (IMO) all preamps should incorporate a balance control. But a lot of them don't have useful controls, anymore.

The phenomenon of tonal balance 'into the next room' is variable. When Richard Heyser reviewed the Klipsch corner speaker he was unable to obtain an 'accurate' image of a piano because, in his words, the two loudspeakers created a 'larger than life' spread--I suspect this was partly due to the specific room requirements of this particular loudspeaker, and not due to a 'Bose 901' type of effect. On the other hand, Heyser wrote:

"...it is one of the few sound reproducing systems which sound natural when one walks into another room. This is an interesting subjective illusion that I cannot explain. We have all had the experience of hearing a live musical instrument being played in an adjacent room; it still sounds natural and we can tell that it is not artificially produced. The piano recording with which I had had trouble with in the listening room actually sounded 'live' when I was in the adjacent room."

One of the most interesting stereophonic 'sound effects' I've heard from a loudspeaker was the old Harold Beveridge speaker. It was a tall line source incorporating a clever top to bottom 180 degree lens that loaded the electrostatic membrane. The backwave was heavily damped within the big half-cylindrical box. The speakers were placed close to the middle of the room facing each other. Quite unconventional. They 'oozed' out the sound which enveloped the listener. There was no 'sweet spot' really. However, as one would imagine, the sonic image they produced was pretty different than anything out there. At least anything I'd ever heard before.

Of course Harold's creation was totally impractical: they couldn't play very loud; no substantial LF output--the primitive subs didn't integrate well with the panels; flaky direct drive tube amps; the speaker's 'larger than nature intended' form factor was overwhelming to any domestic environment; they were over the top expensive; and if you bought one you could forget about service because the company soon went south. Everything you ever wanted in the 'high-end'! LOL

As far a toeing in speakers? I don't think there are any hard and fast rules, although I've read many articles that claim to offer a 'one size fits all' solution. With small box loudspeakers it is easy to experiment with placement/rotation. A theoretically perfect Walsh driver shouldn't require any of that, although the Ohm implementation had other problems than its omni radiation pattern.

 

[EJ3]

I don't mean to trivialize a point, or state the obvious, but I want to digress a bit. In the days of mono the idea of a 'sweet spot' and 'imaging' were generally unimportant, since most people listened to their hi-fi with one speaker (the exception being a very few who owned and listened to two or even three channel open reel tapes). Paul Klipsch designed his loudspeaker to fit in the corner, allowing the monophonic sound to radiate throughout the room in a 90 degree spread.

Of course with the advent of stereo it was 'back to the drawing board'. Because of the 'artificialness' of early stereo most people were unhappy with the phantom center image, which often was more like a hole in the middle of the sound field. A work around was a center channel simulation (Dynaco and Klipsch designed kludges for this 'problem'). One big factor was many early stereo recordings were done without the benefit of much practice, and some were recorded with three channels to include a center, which was then mixed out for stereo records.

In order to properly listen to early monophonic records it is better to listen to one loudspeaker, instead of two, where one matches levels in order to properly localize a single channel from two loudspeakers.

Your point about 'shifting images' is why (IMO) all preamps should incorporate a balance control. But a lot of them don't have useful controls, anymore.

The phenomenon of tonal balance 'into the next room' is variable. When Richard Heyser reviewed the Klipsch corner speaker he was unable to obtain an 'accurate' image of a piano because, in his words, the two loudspeakers created a 'larger than life' spread--I suspect this was partly due to the specific room requirements of this particular loudspeaker, and not due to a 'Bose 901' type of effect. On the other hand, Heyser wrote:

"...it is one of the few sound reproducing systems which sound natural when one walks into another room. This is an interesting subjective illusion that I cannot explain. We have all had the experience of hearing a live musical instrument being played in an adjacent room; it still sounds natural and we can tell that it is not artificially produced. The piano recording with which I had had trouble with in the listening room actually sounded 'live' when I was in the adjacent room."

One of the most interesting stereophonic 'sound effects' I've heard from a loudspeaker was the old Harold Beveridge speaker. It was a tall line source incorporating a clever top to bottom 180 degree lens that loaded the electrostatic membrane. The backwave was heavily damped within the big half-cylindrical box. The speakers were placed close to the middle of the room facing each other. Quite unconventional. They 'oozed' out the sound which enveloped the listener. There was no 'sweet spot' really. However, as one would imagine, the sonic image they produced was pretty different than anything out there. At least anything I'd ever heard before.

Of course Harold's creation was totally impractical: they couldn't play very loud; no substantial LF output--the primitive subs didn't integrate well with the panels; flaky direct drive tube amps; the speaker's 'larger than nature intended' form factor was overwhelming to any domestic environment; they were over the top expensive; and if you bought one you could forget about service because the company soon went south. Everything you ever wanted in the 'high-end'! LOL

As far a toeing in speakers? I don't think there are any hard and fast rules, although I've read many articles that claim to offer a 'one size fits all' solution. With small box loudspeakers it is easy to experiment with placement/rotation. A theoretically perfect Walsh driver shouldn't require any of that, although the Ohm implementation had other problems than its omni radiation pattern.

Another way: The now out of production:

Bang & Olufsen Beolab 5 Loudspeakers
Finished in a combination of matte black and polished aluminum, the Beolab 5 stands 38" high, though its taper makes it look smaller. The cone shape is interrupted by three silver-surfaced discs of different sizes, and a narrow "neck." In this four-driver design, the signal is handed from the 15" woofer to a 6.5" upper-bass/lower-mid unit, then to a 3" fabric-dome for the upper midrange, and finally to a .75" fabric-dome tweeter. Each driver has its own digital power amplifier, so there’s no need for a conventional passive crossover network, which avoids the inevitable compromises such circuitry involves. Instead, the Beolab 5 is an "active" loudspeaker that performs the required crossover and equalization functions using flexible low-power electronics that effectively sit between the preamp and the multiple power amps. These amps have a total power output of a massive 2500W, with 1000W each for the lower and upper bass drivers (where substantial, power-consuming equalization is used to keep the enclosures compact), plus 250W each for the two higher-frequency drivers.

 

[anmpr1]

Another way: The now out of production:
Bang & Olufsen Beolab 5 Loudspeakers

The '5' was a wonderful design. At least from my demo. An all-in-one product with LF EQ and ICE amps, there was not much to criticize from a sonic standpoint. Perhaps vertical dispersion was as good as horizontal, but in a sitting position that wouldn't matter. Who listens jumping up and down? Very futuristic looking.

 

[Feanor]

I owned Ohm F speakers many years ago but sold them after only 6-7 years. Came to regret selling them, (especially considering the speakers I replace them with, B&W DM7's).

The Walsh drivers, then as now, are truly omni directional and wouldn't work well in my current listening room.

 

[Chromatischism]

There is another, somewhat unorthodox technique for getting a wide sweet spot, which works with controlled-pattern speakers.

By way of background, you need to know this: The ear localizes sound by two mechanisms: Arrival time, and intensity. If the arrival times from both speakers are identical, the image will be shifted towards whichever speaker is loudest. And if the intensities are identical, the image will be shifted towards whichever speaker's output arrives first.

What I'm going to suggest is sometimes called "time-intensity trading", as the off-centerline listening locations which have a later arrival from from one speaker time will make up for it with greater intensity (loudness) from that speaker.

Briefly, start with speakers which have a very uniform radiation pattern roughly 90 degrees wide over most of the spectrum. Then toe them in severely, such that their axes criss-cross in front of the centeral "sweet spot".

For an off-centerline listener, the NEAR speaker now "wins" ARRIVAL TIME, BUT because of the aggressive toe-in (and radiation pattern shape), the FAR speaker "wins" INTENSITY. Here is a photo taken at an audio show. As you can see, from the listening position where the photo was taken, the listener is well off-axis of the near speaker but on-axis of the far speaker. The far speaker is actually louder:

View attachment 79630
Photo by Eric Franklin Shook of Part-Time Audiophile.

The two localization mechanisms (arrival time and intensity) approximately balance one another out, and you get an enjoyable spread of the instruments even way off to the side where this photo was taken from.

The KEY to this working well is, the output of that near speaker must fall off SMOOTHLY and RAPIDLY as we move off-axis. This technique will not work with most loudspeakers.

Of course the imaging will be best up and down the centerline, but elsewhere in the room the soundstage will hold up considerably better than normal.

As long as the speakers have good radiation pattern control, the tonal balance will hold up well throughout the listening area and even into the next room. No one is ever on-axis of more than one speaker at a time, so nobody is getting the directly-on-axis highs from both speakers at once. I like to include a bit of user-adjustability in the tonal balance of the top end, for adaptation to different room acoustic situations.

I don't claim that this is necessarily BETTER than an omnidirectional speaker at giving you good sound throughout the room, but it is competitive, AND it still gives you precise localization and normal-size sound images when you are in the sweet spot.

So if you don't have access to Ohm Walsh speakers in your country, maybe this technique will be useful with speakers that you do have access to.

Here is a paper on the subject, I don't know who the author is:

http://www.libinst.com/PublicArticles/Setup of WG Speakers.pdf

My speakers meet these criteria and I'm told work well in this configuration. I need to try it soon.

I've been curious about the semi-omni Ohm Walsh for a couple of years now, but I'm not seeing them in my current system.

 

[Chromatischism]

I owned Ohm F speakers many years ago but sold them after only 6-7 years. Came to regret selling them, (especially considering the speakers I replace them with, B&W DM7's).

The Walsh drivers, then as now, are truly omni directional and wouldn't work well in my current listening room.

The current ones have a conventional tweeter on top that is mounted at an angle. You place the speakers straight and the tweeters cross naturally near your position.

 

[Killingbeans]

Who listens jumping up and down?

 

[EJ3]

The '5' was a wonderful design. At least from my demo. An all-in-one product with LF EQ and ICE amps, there was not much to criticize from a sonic standpoint. Perhaps vertical dispersion was as good as horizontal, but in a sitting position that wouldn't matter. Who listens jumping up and down? Very futuristic looking.

Reasons (not including jumping up & down): If some people are standing, others sitting & still others going to& from the kitchen or in & out of the dining room sliding glass door (to the back porch) or just because my wife is 5", my mother is 5"4' & I am 5"8'. Sometimes it's not all about me. That allows me to be all about me at other times (without any flak).

 

[anmpr1]

Reasons (not including jumping up & down): If some people are standing, others sitting & still others going to& from the kitchen or in & out of the dining room sliding glass door...

An omni-directional full range spherical driver (or half sphere if placed against a wall) would likely solve this radiation aspect, but has anyone ever made one?

The only practical loudspeaker design that essentially minimizes vertical dispersion problems is a full range, single driver floor to ceiling line source. The ones I've heard and are familiar with have been electrostatic (Beveridge, Acoustat, KHL et al), other planar (Magnepan), or ribbon (Apogee) designs. Some of these were actually hybrids, featuring separate panels and/or cone drivers for lower mid and bass. They each more or less 'solved' the vertical dispersion problem, but introduced other trade-offs.

Mounting numerous dynamic drivers vertically in a tall line is one attempt to 'solve' the problem (think Infinity QLS or the tall McIntosh speakers), but then you have an additional problem of integrating a dozen or two drivers, each contributing their own individual radiation characteristics, into a coherent whole. Don Keele's curved 'Constant Bandwidth Transducer' designs are another example of this type.

People walking in, around, and out of the listening 'sweet spot' are probably not interested in the overall sound quality, as they are doing other things. Unless it is one's waifu, and unless she is named Kathleen, and unless you happen to be an audio reviewer. In that case she will be able to immediately tell whether you changed your preamp even though she is in the kitchen making sandwiches.

 

[radio3]

I like that Ohm speakers are not totally omni-directional. They have the backside damped to prevent undesirable reflections and perform optimally pushed all the way up against wall. I also like what they do with the tweeters, which are angled such that you get good sound seated or standing anywhere in room. The tweeters basically do what Duke has done with his speakers in the photo above but not only in lateral plane but also in vertical. Lastly, I like how efficient the approach is for producing bass from a slim enclosure.