Are Ohm Walsh Speakers the Poor Man's MBLs?

mail,

The OHM Walsh drivers tend to radiate more upwards than downwards. You will hear a distinct drop-off in teh top end if you listen from a vertical location below the drivers. For this reason, it is generally not good for the drivers to be mounted too high. At the same time, the cabinet is ported on the bottom to help with low end extension, so some height is needed for that.

Marty,

Have you tried listening near field with the 100s?

I have found I am able to percieve front to back soundstage better and more in line with what I heard with mbl listening just a couple feet or so in front of the speaks as opposed to my normal listening position 8-10 feet or so back with theF-5s in my larger room.

My listening location is more near field normally in my smaller room where the 100s are also and I can notice a similar effect there.

"So the tweeter being limited has only the benefit of increasing placement options. "

I believe increasing placement options for most users is the intent of OHMs design decision to attenuate the omni sound levels in wall facing directions. The tweeter being omni or not would not matter because I would assume they would/could be damped easily as well if desired.

There are several benefits of the more conventional tweeter used in the OHM Walshes compared to the original OHM Fs and As, which, other than the GP Unicorn, are the only designs I know of using only a single wide range Walsh driver:

1) lower cost
2) greater durability
3) higher SPLS possible without damaging the driver

The disadvantage is that the conventional tweeter does reduce sound stage size somewhat. I can hear this when I adjust the tweeter levels on my F-5s. The soundstage expands slightly and becomes more transparent at lower tweeter levels and appears to shrink somewhat and become less transparent at higher tweeter levels. At any level, soundstage and transparency is extremely good however.

Another disadvantage which does not really matter much in my opinion is that you will hear a slight but noticeable roll-off of the very top end if you stand behind the speakers. Coherency is not affected however which means you can listen from almost anywhere with mostly just a change in perspective in relation to the instruments and recording tracks within the soundstage.



" Is there a price to be paid in sound quality for the ease of placement? "

I think the price to pay might be the depth of soundstage at least compared to mbl, as Marty suggested.

Never heard Morrison or Dueval so I cannot speak to those, though I've heard good things about both. Both use more conventional drivers compared to OHM, mbl, or GP, but in a unique configuration for their omni sound, I believe.

I've heard various OHMs over 30 years and currently own 2 pair.

I've also heard mbl 111s.

The technology is totally different. mbls are fully omni-directional and require more distance from walls to sound best. OHMs are largely omnidirectional but not fully and can go closer to walls.

Both owning largely omnidirectional radiation patterns, they tend to image and do sound stage similarly at least in the area in front of the speakers.

Tonal balance/timbre is noticeably different but I have never heard both on the same system so some of this may be due to different systems behind them.

Dynamics are good with both.

OHMs start at $1000. Small mbls start at $12000 or so I believe. mbl 111s list for over $30,000.

mbl 101s ($60000+) do low end dynamics better than mbl 111s I am told probably resulting from the unique bass driver technologies used on those.

"Are Ohm Walsh Speakers the Poor Man's MBLs?"

I'd say draw your own conclusions on that.

You may not see very many poor men with mbl, or German Physiks. Probably not many with OHMs either.

The big OHM f-5 series 3 in my system were a decent stretch for me and the most expensive speaks I've ever owned.

Westborn, have you ever heard Dynaudios? Do they sound muddy or plastic-y to you? I run Dyns concurrently with OHMs in different rooms off the same system and other than greater authority in the low end and the omni design, the OHMs sound very similar to the Dyns overall.

I prefer to think of MBLs as really snazzy and very hot looking OHMs!

Marty,

You may be right about the front to back imaging in that the mbl demo was as good as I have heard in that regard, particularly with a state of the art reel to reel orchestral recording as the source, but I would have to hear both, probably larger 300s or 5s on the OHM side, in the same larger, acoustically conditioned room that I heard the mbls in to be sure.

I'd attribute the mbls exceptional performance in this regard somewhat to use of omni drivers for the high end whereas OHM Walsh speakers are not omni in the uppermost frequency range that most people can hear. Original Ohm As and Fs were.

OHM speakers also use a single Walsh driver for most of the frequency range (all of the frequency range covered in the case of original As and Fs) which gives them an edge in overall coherence I believe.

OHM and German Physics use similar technology based on the Walsh driver concept but their Walsh driver technology and speaker designs are quite different, I believe.

GErman Physiks uses the Walsh driver for the top end and supplements that with conventional woofers on the low end in most models (except the horn loaded Unicorn, I believe), as does mbl with the exception of the 101s.

OHM does the opposite. The omni Walsh driver covers the low end, mids and some highs but supplements that with more conventional cloth dome tweeters for the high end in the newer series 3 models.

Interestingly, we were informed here on another A'gon thread recently by John Strohbeen, the man behind OHM, that they now have a distributor in GErmany, mbl and German Physiks home turf.

I wonder how well they will do there?

Very good questions!

"(I)t seems that a lot of Omnis do no(t) limit the tweeter (Deuvel and Morrison come to mind) . "

"Does limiting the tweeter from being full omni help the coherence but hurt the imaging? "

No. I think coherence is mostly due to sonic waveforms being in phase at all frequencies top to bottom. Crossovers and multiple drivers present an extra challenge in accomplishing this I believe. A single Walsh driver that covers a wide frequency range has an advantage here I think.

"Does it also make it easier to place by letting it be closer to the rear wall? "

In general, yes. However there are other ways to accomplish this otherwise with any omni driver.

OHm Walsh speakers accomplish it by design with acoustic dampening material inside the cage and around the drivers that attenuate SPL of sound from the omni Walsh driver in the wall facing directions.

I believe it is possible to special order CLS Walsh drivers from OHM that do not use the acoustic dampening material to attenuate sound in wall facing directions if desired. This would be more mbl and German Physiks like in radation pattern and resulting effect on optimal location of speaks relative to walls. I think OHM may use this approach for some of their Walsh A/V surround sound speakers, but I am not certain.

Marty,

Just curious, no need to create work for experimentation, especially with a holiday weekend coming up!

After hearing the mbls, I did do some experimentation with my F-5s to try to reproduce the front to back imaging I heard with the mbl 111s. I'm a bit handicapped in my room to emulate the mbl setup I heard, but I did find listening near field does move the OHMs F-B imaging more in the direction of the mbls.

I only enjoy listening nearfield as a switch off, not the norm. I prefer to listen far enough back to geometrically simulate what I would chose as an optimal seating location at a live performance. I usually do not like to sit in the front row.

I did find the mbl F-B imaging to be of benefit mainly with large orchestral works, where there is greater distance between the players in the front and the players in the rear. They did an exceptional job of reproducing that, perhaps the best I have ever heard.

I have found that this aspect of mbl sound can be simulated pretty well with the OHMs, perhaps better than could be with may speaks, but perhaps not to the same extent as the mbls in the room they were in, at least not in my listening room. The room the mbls were playing in had a good 12-15 feet of wide open space behind the speaks. None of my rooms at home are a reasonable approximation of that.

---------------

Here's a post I did to my system page a while back shortly after hearing the mbls that addresses listening location and perceived soundstage:

"I've been doing some experimenting listening to the big OHM f-5s from various locations in my listening room.

The one thing only omni's that I have heard, like OHMs and mbls, can do, is enable you to listen from most any location in a room forward of the speaker location with the noticeable change being only the perspective from which you perceive location of recording elements, much like what occurs if you listen to a live performance from various seats in the venue.

Tonal balance/timbre, size of sound stage and location of recording elements within the soundstage remains essentially the same.

Normally, I listen from a not so unusual sweet spot location when I can, about 8-10 feet in front of the F-5s.

The last few days I have been listening near field, from about 2 feet directly in front of the left speaker, and up close to left wall.

The main difference is that it is easier to perceive location of recording elements from the front to back of the soundstage and these also tend to occupy a larger area within the overall soundstage and the soundstage extends from directly behind the left speaker to the far wall directly across from my listening position.

Everything remains very focused and more holographic in that the sound seems even more completely disassociated from physical speaker location, very much like sitting in the front rows of a live performance.

I tend to like to listen from a bit further back, still the speakers ability to allow this is very cool and makes for a nice change of pace on occasion!"

Marty,

I do think the omni sound radiation pattern is a key for image depth and acoustic dampening of the Walsh CLS driver in the wall facing directions would tend to limit this somewhat compared to what I heard with mbl.

Maybe John Strohbeen is out there reading these posts and might chirp in?

I wonder if other true omnis like Dueval and Morrison can do what the mbls do?

I would not see much benefit in biamping Walsh speakers in any case. Most of the sound except the extreme top end comes from a single driver.