Fixed (Easy!) a Major Design Flaw of the Ohm Walsh Model F

Not sure if it affects all units, but I see it in several images. They obviously didn't care about actual mirror image build back then. They likely didn't think it would matter, but it does. I also do not know whether this has ever been discussed previously in forums, magazines, etc; I'm not willing to search to see, because it doesn't matter that much to me whether it's been discussed previously. If so, great, the Ohm community is on the ball. 

I refer to the nearly haphazard alignment of the metal braces for the driver, which are not aligned in the same places on both speakers. In my work to get this speaker to sound as wondrous as they say it should I noted an irritating beaming of the treble. I have encountered such prior when speakers with tweeters such as ring radiators were on axis. I recognized the vertical metal braces were not symmetrical, and from a lot of experience in the past with performance non-conformity I knew that could be a major contributor to the issue. 

Solution? Let go of the idea of both cabinets being parallel, and make the driver housings/drivers (with the metal braces) symmetrical. Beautiful, a nice tightening of the center image, chasing away of an annoying over emphasis on LF due to a touch more mid-bass filling in unobstructed, and more midrange peeking through. This is an easy fix if you are plagued with this problem, and if you and the furniture authority you live with can handle it.  

I also went with a parallel (double) speaker cable setup by using two sets of cables with banana terminations. I used spade adapters to accommodate a set of spades, and they have hollow backs which allow the second set of banana terminations to be added. This is most definitely do at your own risk, and note that I have bypassed the fuse as well, so I'm a bit more daring with this set than I would with other speakers. I have not that much into them, so if they blow up, they blow up. They were on the way to the dump when I adopted them and had them rehabbed, so I have done a great audiophile work, earning all kinds of points as a Music Lover!  ;) 

I am disproving the old adage - at least in my world - of them needing 300 Watts and blowing up at 301 Watts. I have 600wpc on them and with the double speaker cables (parallel) they are responding beautifully. Still the characteristic muffled mid/bass which will not be eliminated. Please, not interested in arguing that; I hear dozens of speakers in my room and I'm talking about direct comparison to ones I use(d), so if your perspective is different, great. So be it. YMMV etc. 

I'm not pushing them to the limit, but more than I thought I might. I have done perhaps a dozen discrete systems to get them to this state of being very enjoyable. They have responded well enough that I probably won't get rid of them. The one trick I didn't use yet in this setup is to put them on hockey pucks to elevate the soundstage and alter the tonal mix at the ear and decouple from floor. Must remember to try that! 

Current setup:
Small Green Computer sonicTransporter and SONORE Signature Rendu SE
Clarity Cable Supernatural USB
Eastern Electric Minimax Tube DAC Supreme with Staccato discrete opamps
-DAC direct to amp; absolute necessity of using software attenuation in ROON! Do NOT go direct to amp without attenuation!)
Legacy Audio i.V4 Ultra Amplifier (NOTE: channels of this amp are NOT to be joined; I am using bewaring from one channel to achieve the speaker cable doubling for the single terminations of the Model F)
Iconoclast Cables with BAV (Belden Audio/Video) PCs 

I'm gonna have my new friend who has the Tekton Moabs come over to hear.  :)

All equipment with exception of Ohm speakers have been previously reviewed for 
Nice job bringing a unique pair of old speakers back to life without having to break the bank. 
mapman, thank you! It is fun to see how far an older transducer can be taken in terms of performance. It's an interesting juxtaposition between the inventiveness of the omni and the lack of concern over the placement of bracing. Imo, audio was not nearly as exacting in absolute terms back then. It is probably more accurate to say the standard in terms of precision has changed due to tech development. When one hears the significant change due to proper alignment of the metal supports, i.e. parallel to each other and aimed at the respective ear, it is clear enough that it makes me wonder how they couldn't have seen/heard it? I conclude it is a prime example of persons in the industry thinking it wouldn't make much of a difference. But it does. Nearly any manufacturer today would avoid such things. 

The more exacting designs today elicit superior performance. Now that big watts, double speaker cables and subs are used with the Model F, it is a very nice experience. The 600wpc and double cables make the mid to upper treble shine nicely, and there is lovely decay on cymbals and chimes. The delicacy of the treble is quite nice. But, the paper cone going into the big bass bin is not up to the task in relation to better tower speakers' mid-bass on down. Newer towers have more taut, precise bass. The cone firing into the bass bin is a potential distraction, like sealed boxes with larger drivers that excite the cabinet. The subs help to mask it fairly well. 

I am very pleased by how the metal posts aimed right at the ears blocks the beaming of the tweeter so as to allow more appreciation of the upper midrange and omni dispersion pattern. The speaker finally sounds quite detailed, yet with warmth in voices. 

Still the characteristic muffled mid/bass which will not be eliminated.


Have you tried experimenting with the batting inside the cabinet?

The density and the thickness of the batting does effect the SQ of the mid/bass specifically.

Certainly true for my Walsh 4's


uncleang, yup, I did so. On my other thread here to the effect of resurrecting the Ohm Walsh Model F, posted when I first obtainted htem, I disucss the rehab process and my discovery of how much of a benefit it was to remove half the stuffing from inside the cabinets. 

What specifically did you do with the Walsh 4's? 

Post removed 

Hi Doug,

My experimentation with the 4’s started in 1998 when I sent in the cans for a re-foam. At that time I noticed that the ’tufflex’ inside the cabinet was disintegrating.

I contacted JS at OHM and he said to go ahead and experiment with different batting material; my wife makes quilts now and then so I used that batting at first. That material was less dense than the tufflex so I used about 1/2" (two layers).

The original ’cradle’ that held the tufflex was ’U’ shaped made up of two nylon straps held in place inside the cabinet by 2" wide duct tape.

JS had told me that the straps should be placed 1/3 of the way down the cabinet and that the batting should be well tucked into the corners.

My first experiment was to lay the straps flat 1/3 of the way down as opposed to a ’U’ shape still using 1/2" of batting. I was shocked by the difference; more bass and treble but slightly recessed mids. mid/bass on voices was not neutral with chesty male voices and veiled female voices.

Out of curiosity I decided to use 1" of batting on the flat straps. More but sloppier bass, attenuated treble, sounded like a cheap box speaker and the mid/bass was a disaster.

My speakers are in the basement on carpet with thick dense under-padding layed over a cement floor. Since the vent is at the bottom I know this affects the overall SQ. With that in mind I placed the speakers on 1/4" acrylic plexi-glass (16"X16"). Well that certainly brings out the bass but I found the overall sound to be too live with too much reverb and accompanying listener fatique.

Back to the drawing boards. A few years ago my wife bought some batting for Christmas decorations i.e. snow on mantles look. This batting was thinner but denser than the quilt batting. So I decided to play with that.

I quickly realized that this new batting enabled me to dial in nuances that the other batting couldn’t. This stuff is just over 1/8" thick. I experimented with varying layers from one sheet to six. I also experimented on the flat vs: ’U’ shaped cradle..

What I’ve ended up with is a ’U’ shaped cradle with two sheets of this new batting. The treble and mid/bass are dialed in like never before. Female voices have an air that rivals electrostats and Leonard Cohen’s baritone is marvelous. The bass is not as prominent but very well defined and tight. That said, on recordings that feature bass like Nirvana’s ’Unplugged in New York’ it sounds very well balanced.

Got the cans back a month ago (2nd re-foam). John does a good job of making sure that they’re in sync prior to shipping... and they are.

Over the years I probably have spent around 200 hours trying to dial in the 4's to my preferences.... don't know of anyone else that has done that.  OHM's newer models don't offer that flexibility as that cans are not attached to the cabinets with 4 wing nuts.  However the newer models (since around 2003+) have the vent venting to a wooden base which most likely affords more predictable SQ.  

Can't make a comparison between my 4's and newer models as I've never heard any other OHM speaker other than an F back in 1976 which absolutely blew me away.




uncleang, serious commitment to the cause! Kudos! It's fun to try tuning a speaker to optimum performance. I am not so committed to this particular speaker system, as it's an ancillary interest. It's never going to be in the echelon of the other speakers I use. Even the recently acquired Wharfedale Opus 2-M2 bookhself speakers have fundamentally superior incisiveness and cleanness, i.e. better microdynamics and without the relatively muffled character of the large paper ends of the Model F's drivers firing into the cabinet. It can be moderated, but it will not go away entirely because of the design. 


Because the cabinets are junk literally, having a rift along two axes of one cabinet, I  have thought of experimenting with using a doorknob hole saw to punch holes into the cabinets at the bottom to make ports. Could be fun! It may transform the speaker in a very good way, or ruin it! :)  I could put about three of them on the back side and see what happens. If they get ruined, so be it. LIke I said, it's not a high dollar commitment to the experience. This is for fun and experimentation. In principle I do not make vintage my attempt on SOTA. The new Model F5 is superior holistically, as seen in my review at 

This all reminds me of when prior to reviewing I bought piecemeal three sets of cables to do my own verification of efficacy of cables. It was a great time of learning. Cost something, but wow did it transform how I build systems!  :) 


My friend set fire to the drivers in his Ohm Fs by clipping his Hafler kit amps. College days! Never been a fan of this speaker, but I have never heard them with what I believe would be adequate power. I would think the speaker would be very limited regardless of electronics used.



Well Doug, keep us posted; and if you decide to butcher the 'F' cabinets with your hole-saw.... well that will make for some interesting reading.  Hell, you might just get rid of that mid/bass muddiness, you never know.  If it works you'll have JS scratching his head thinking 'why didn't I do that 45 years ago.

Keep us posted. BTW, love your reviews on Dagogo.