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 Dagogo.com 
douglas_schroeder

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 dagogo.com 

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.