Now I have F's with rotten surrounds, but rest look nice, perfect even. Cones, spiders look great.
One surround is done, decimated. Other is intact, perhaps replacement as is not identical.
Perhaps I try replacing surround? Any new and improved surround options? Willing to replace/ get repaired more, if necessary.
Cursory search doesn't reveal any drop in replacement. Or, am I wrong? I see the Ohm return/upgrade to newer version options.
Experienced and insider opinions sought. I'm not cheap, and I'll spend the money to obtain the exceptional if needed. So, what are the likely and less likely options TIA What is that one "clone", HHR? Need to check... i heard it at a show years ago.
I was reading on another thread here - possibly even this one - that Bill Legall only does one pair per year and he's not happy about that because it's so labor intensive and time consuming. I have great respect for what John Strohbeen has done to keep the company going and remain viable, but the omf upgrade he offers is really just putting a new generation driver on the old cabinet, and requires you to send in your old Ohm F drivers. Speaker exchange in Tampa Florida still rebuilds them. I think they still sell the spiders in the foam but they no longer sell the voice coils. Properly rebuilt, they are a superb speaker. Yes there are modern speakers that are far more sensitive and have characteristics that are very desirable, but there's nothing quite like the F. Bill did the rebuild on mine for the previous owner. He was a guy who jumped around from one speaker to another, and I was lucky enough to snag them at a very good price. I actually had a guy here in Raleigh come and hang out this afternoon to listen to mine, because he has a pair of high-end monitor speakers that have phenomenal presents and imaging but the sweet spot is so small that if you move your head a few inches to either side, you lose significant amounts of sound. I don't think he has made a decision yet, but I think for his purposes the new model 2000 is probably a good fit.
Douglas, certainly you cannot compare your F's to the original F's, as none exist as a new F anymore. No one can be sure of its sound once the putty dries out, or the foam in the cone falls apart, as compared to a just-manufactured F speaker.
There are other ways to check, such waveform output. The F has the ability to output a "reasonable facsimile" of a square wave as one reviewer put it, and as shown in the Ohm literature. If one is able to restore the cone to like-new, it should be able to output this kind of waveform, to validate the restoration. If a speaker could pass this test, that would demonstrate phase accuracy over a wide range of frequencies.
Since you hear a sound that you find not to your liking, like the treble response you noted, you took some of the foam out of the enclosure, and said that helped ("The rebuild was successful in the end mostly because of my foam removal. The driver was terribly constrained until I half emptied the cabinet to let the driver work more freely.") That action changed the system Q, and could reduce the damping to the driver in the bass frequencies, perhaps increase ripple in the frequency response.
But as you said in the latter part of your posts, as long as it sounds good enough for you, you really don't care if the fixes approached the original F sound or not. I thought you wanted to preserve the F sound to as close to original as practicable. My comments were directed to assist in that direction. Sorry if I misunderstood your intent.
The HHR speakers use the platforms of the Ohm A and F designs, and take them farther that could be done in a commercial setting. I think Dale sells his speakers on a build-on-order basis. If I get the opportunity, I'd like to hear his speakers, as I've heard the first Ohm A's and later owned F's.
LOL It's all good. I'm wowing the world with my 15$ Walmart watch that looks like a high end Samsung smart watch (As if i really care. It just looks nice.)!
@mickeyb....I'm not a bank, either....which is why I DIY....
I heard and liked the original F's.....and my wallet froze shut, even back then. Still like Lotus cars after all these decades....same problem. The only Porsches' I like are the F1 'cars'. Even more impractical.....;)
I’d added an additional 'rant ’n rave' to the above, but luckily for y’all I hit the wrong key at the right time and kept your screen from melting like a Dali pocket watch....
+1....oh, 'ell....+10 to the tenth power, @douglas_schroeder ....
(...the world is full of surprises, no? *G*;)....)
"Submitted for your consideration..." as R. Serling used to intone....)
Any vintage speaker that has undergone repair will perform differently than the original when it was new. That variance will vary from slight to severe, driven by the use of contemporary materials, adhesives, and techniques of restoration. Unless 'museum level' restoration protocols are applied, Anything (paintings, sculpture, or speakers) will vary from the original to some degree.
A restored painting, if subjected to minute inspection, will exhibit the restoration. To expect a speaker to perform Exactly like an new original is fallacy....Unless, of course, you've sent your 'contemporary' Ohms or MBLs in....that's Different. Having a 'mint', in the box original would be the only fair comparison/contrast test....A~A+/-...*G*
If what you've done or had done pleases one's ears, call it a 'win' and move on.
There is (imho) the psychoacoustic factor involved....
I've noted when I've been elsewhere for a period of time (on an out-of-town installation for a month as an example), exposed to anything but my own speakers, that they will sound 'different' for awhile.... An hour or two, perhaps a day.....until mind & ears 'snap back' into their 'ruts'. Visiting an audio convention might prove to be an extreme contrast, depending upon the individual.
I suspect that this scenario might be the root of 'buyers' remorse' occasionally....but, just an observation on my part....your experience likely varies...
pch300, yes, your explanation is appreciated and logical.
My goal in this has never been to achieve "original" sound, or else I would have demanded the OEM parts. There's a slight problem with that, however; the manufacturer of the equivalent OEM parts does not sell them to repair shops. The cost to do a rebuild of these drivers with new parts is in the thousands, and a very important consideration for me was to absolutely avoid shipping them. Having experienced three different shippers (DHL, FedEx and UPS) absolutely destroy speakers shipped to me, that's not an option. Even custom shippers I have seen with skids having lift trick forks stuck through the box. So, in order to attempt an "original" sound one is forced to go to HHR to get parts, and by necessity spend quite a bit more on rebuild. That's where the choice not to seek spending thousands on this comes into play.
And, it was the correct choice, imo. Who can say how much degradation would happen to the sound if the putty was dried out? Only a direct comparison to a new unit, kept pristine, would suffice. All this discussion of the sound being altered is moot. The rebuild was successful in the end mostly because of my foam removal. The driver was terribly constrained until I half emptied the cabinet to let the driver work more freely. That changed the sound from the treble on down. I strongly urge anyone with a vintage set to consider whether they wish to do such a fix. Again, this is a Do At Your Own Risk activity, given the potential for there to be asbestos in the foam.
This is all conjecture, the discussion that I and others are engaging in, as regards the original sound and whether I am achieving anything close to it by using alternative surround and spider. Do I care if the unit has "original" sound? Not at all. Frankly, given my work with the foam removal I saved this speaker. It was on the disappointing side with longer and closer listening than the first impression ("sublime"), and I went at it with a goal to make it much better. I did. So, frankly, I could care less whether I'm achieving original sound. If I'm going to keep a vintage speaker, it had better perform at least in the range of my others. If it's not going to do that, it will go by�e bye.
This community lives on conjecture. Daily I see people saying, "I think..." in reference to comparison of products that they have never used or never compared actually. This is no different. None of you can say what the original could sound like in comparison to this unit with inexpensive parts. The fact is that with the foam removal, my "version" would likely sound far better than the original. But, again, only a comparison with it would matter, and we're not going to have that. So, moot point.
The modified speaker just makes it into the category of worthiness to stay, to be used as nice foil to others. When I set up a formidable set like the Kingsound King III electrostatics, there is an adjustment period for soundstage - there always is when changing speaker tech. But, once that accommodation to the radically different dispersion pattern happens, oh, my the King III is in SUCH a different class in terms of refinement. It makes the Ohm sound relatively muddy, even after the fix. But, that, too should be expected. You're not going to get that level of definition and cleanness from a mixed material omni. Not going to happen, especially when, imo, desperation fixes such as putty are used.
My analysis is that the intent to be novel, to use avant-guarde materials was a top priority, and the putty was a fix. I think the metal would ring like a bell and had to be calmed. Why would anyone produce a speaker like that? Novelty of soundstage, and for sales as putatively superior. You will notice that Ohm speakers today do not use mixed materials. It's just not anywhere close to ideal. And, it doesn't sound close to ideal, either. Between the full range driver and the omni dispersion, it's a fairly distorted result, with less accuracy and more atomized, ballooned soundstage. I accept that as a result of the technology used, and as a pleasing alternative to more traditional speakers. It's fun to listen inside a "bubble" soundstage, or what I call the "mushroom cloud" soundstage.
If I recall correctly from visual memory, my drivers do not have any putty; they have foam across both sections of metal, titanium and aluminum. I'll have to look again to confirm. So, another missed opportunity to have "original" sound - and to avoid what appears to be an original potential for failure of the driver. Knowing about the putty would I want it? Would I seek it in restoration? I can't say for sure, but with the sound I have, I sure would not seek it. If that's not "original" sound, who cares? I'm not going to sell these or try to showcase them as if restored to original.
One thing is for sure; as long as that foam would remain jammed into the cabinet to suffocate the driver, this was not a great vintage speaker. Now, with my fix, it is. Let's keep in mind, too, that if a person seeks the HHR restoration, they are not getting the "original" sound anyway. If they were, that would be a tragedy. Purportedly, they are getting a vastly superior sound quality. But, again, unless a speaker is compared directly, no one can say that the difference between them would be great. Theoretically, with the improvements in materials and build the HHR should be noticeably superior, but you're not going to have certainty on that apart from a direct comparison - or perhaps, measurements. Again, this is no comment on the quality and sound of HHR, as I have not used an HHR speaker.
So, basically, my response to the foam, putty, surrounds, spiders, etc. as not yielding the "original" sound is - who cares? Only someone who would theoretically have the OEM parts and seek a perfect reconstruction of it, without any help/parts to improve it. The old speaker is not coming back, and I don't care. I'm not starting a museum, and the only thing that matters in this instance with this set is performance. Now, I have it. What the performance was before, I really do not care. :)
Douglas, the putty on the inner surface of the titanium section of the Ohm F cone will dry out over time. It is a known issue for older F's. The speakers will play but the treble sound from that part of the cone can be different. As an engineer, this makes perfect sense to me, as follows.
The putty acts like a dampening material for the wave travelling through the upper segment of the cone. To dampen the wave, it has to have just the right 'flexibility'. When the putty turns hard, it is less flexible, and becomes more rigid-like, and the cone can't flex the same way as when the putty was new.
You are already aware of the foam degradation on the inside of the aluminum section of the cone.
An important parameter for a wave transmission cone is that the impedance of each interface between sections are designed for passing the wave across the boundary, with minimal reflections back up the cone, interfering with the subsequent waves coming down. The same needs to occur at the surround at the bottom of the paper part of the cone. That is why the surround is not replaceable by just any foam surround that physically fits the dimensions.
Hope that clarifies why the sound may be different, if the putty can't be replaced correctly.
*S* Thanks, @mapman .... At this time, I'd love to Loan you a pair just to have an omni fan have a critical listening session. 'Ell, I'd like to have a 'next version' pair for my own ears. I've got most of the items amassed to do so, it's the assembly routine that's pending....
First thing I do is to break them in as the 'manufacturer', since everything about them is basically experimental. The next step is to try to blow them up, since the 'warranty-er' is Me.
That in itself is a response to the old comment on the original Fs'; "Sound Great @ 200 watts, blow @ 201...." I'm OK with doing that myself...it'd be embarrassing to have it happen in your hands.
One personal goal is to enter a pair with a matching sub into the unlimited category @ the MWAF, hopefully this year (Covid conditions allowing such). Apparently, no diy omni has even been entered according to them. Good, bad, or indifferent, it'd be a "Now for something entirely different" experience for the judges and the crowd.
I've considered a raincoat as apparel for the tomato and egg response, since I'd be there and a target....*L*
".....selling a pair?" At this stage, I'd sign and date them. 'Functional Art', as any production goal is a pipe dream....and we can debate what's in that pipe.... ;) One consideration is to fuse the crossover to keep enthusiasm from frying the works, as that's where I've blown any up.
....but Thank You for the comments. What you'd get would be light years from whatever you saw....;)
Thanks for forgiveness, Doug. And for giving me a kudo for my diy activities, as that nod helps push me forward.
Having 3 working pairs that have similar characteristics, even given their different sizes, is a huge push to carry on, despite any discouraging words, anyway.
Being a partner with spouse owning a growing business has tended to absorb much of the free time to spend on it is depressing in its' way, but it does allow for buying 2 mil titanium and aluminum for 'rolling a cone'....
That, in itself, is a Good Trick. I finally came up with a means to do that in a predictable fashion...
I've avoided on purpose to 'do' a 3 segment F-style cone, and have taken a different tack at it. As I 'write', I'm listening to Spotify with a 'bookshelf' version that, as F. Zappa once noted, makes 'noises agreeable to the ear'.
My larger 'mains' in the next room 'do better'. ;)
Perhaps, one fine day in the near future, I'll loan you a pair for critique'.
I'd like to have a serious listener do a 'serious listen' to them. I can only go so far with a calibrated mic and various programs. Who better than a reviewer? *Ingratiating Smile* ;)
Meanwhile, I'm wondering How I can convince spouse that the 1.2K$ that appeared in our checking account (Thanks, Feds!) could be applied towards a 3D printer that can 'print' 2 mil carbon fiber cones instead of an automated catbox....
"It's too big, and looks like a weird front-load washing machine with slumped shoulders..." don't fly with her. That...and the cats prefer my lap to hers. The 'mother duck, being followed by the ducklings' doesn't fly either...*L*
Enjoy your revived F's (I'm jealous)......and Thanks again, J
avsjerry, all is forgiven. I wouldn't presume to debate you in terms of technical knowledge. Anyone who is building their own speakers I consider to be worthy of respect.
I do believe that the factors involved in the restoration are such that the weekend warrior would have slaughtered them. The repair shop commented on how tricky it is to align the cone properly, even with the supplied shims for alignment. I did not give serious, ongoing consideration to doing the repair myself, and that was a wise decision.
Douglas, pardon my mistake. I've read of more botched repairs than successful ones when it regarded vintage Ohms. And congrats on the repair...
Now I'll slink off and dine on some vintage worms, and reconsider offering an opinion on a subject that I have some experience with, albeit on my mere enthusiast level.
Playing Peter Gabriel "Sledgehammer " at level of about 88 dB from listening position, about 10' away. They can take it louder than I typically listen. Sweet success.
The foam/cabinet fix turned the entire project. :)
I for one would be very interested in the full pro review of how these specific restored Fs sound and compare to the modern competition, if the thought is that this kind of restore was worthwhile. Others who have actually heard fully functional Fs in the past might even be able to chime in and help paint a picture of how these compare to their recollection of the sound. Maybe even to newer Ohm Walsh models. Would be very interesting at least to me. I know time is valuable though and perhaps better spent on current things that more people might care about.
avsjerry, What kind of misinformation are you speaking of here? Some of your points are simply wrong, including that the "gook" inside will destroy the cone if you try to remove it, and that the surround would have to be hand made. Wrong, and wrong! Replacement parts (not OEM, and HHR has reserved its right to not sell new parts for such repairs; I don't argue with that; he's protecting his sales) for both the spider and surround are in stock. You're talking as though it's a lost cause without moving to the full restoration. That is flat out wrong.
This particular set of F speakers did not give up, far from it. The "gook" did not destroy the cone, the recon was successful by Midwest Speaker Repair. They were able to remove the old ferrofluid and get the speaker back into great operating condition! Kudos! Good on them, and they had 3 other sets to work on when I went to pick up mine.
COST? $400! GLORIOUS SUCCESS!
So, why am I still being told that I could have done better by pursuing a full restoration? No one here can tell me that I would prefer to have spent another $7K on this. I happen to be working with an extreme hybrid speaker right now, and I did drop money on it. You want the unvarnished truth? I have heard the HHR prior, and it was not sufficiently impressive for me to chase the full restoration. OUCH! You guys keep pushing, as though you know better, but you seemingly think that I need to be schooled, as though I'm going to be enlightened on it. I simply do not consider this particular design to be worth that much in light of the fact that I have several other speakers for reference. So, let's settle down on the advice that I'm somehow messing up if I don't throw a bunch more money into it.
YOU think this design is all that? YOU think it's the ultimate? YOU would not dream of the cheap fix? Great, for you! I do not happen to have an iron clad adherence to omni, nor to this design. It's a variant, an option for me, another flavor. Let's put it this way; I would not have pursued full range omni had these speakers not been brought to me. Clear enough?
I don't have a dilemma, and I don't have a problem. I never had a problem with this, only options. If it didn't work, I could throw them out. You guys all say you would do this or that; well, be my guest! Go ahead and put your money where your comments are. If this is SO fabulous, SO important, why don't YOU act on it, get the cabinet, get the full bore redo? It's rather easy to tell someone else what to do in terms of a restoration when it's not your money, and you have a completely different set of circumstances. The fact is that a restoration would be a very poor investment in this speaker. Return on it would be very low, and I can get a lot more from the hybrid I'm buying.
No one who is doing a refurbish is obligated to put big money into it. Some fans of particular speakers and companies cannot tolerate the idea that someone just doesn't care enough to spend what is considered by myself to be a serious chunk of money in order to get an unknown quantity, that is, a non-comparable result to the original. Comments keep coming to the effect that I made a poorer choice. What nonsense! No one here can tell me that I made a poor choice, given that seemingly no one here has an original F and another, newer model - aside from Dale, and he is, as excepted, as a party with vested interests (no issue with that). Especially since I saved the speaker by redoing the foam in the cabinet, I scored a BIG win on this. I have no desire whatsoever to spend a bunch more on it, for it's now performing remarkably well for a tired vintage speaker.
Let's be clear on this as well; as a reviewer, I have no obligation to support vintage products with a potential for sales of newer ones. I do not need to support HHR and spend $7K simply because I'm a reviewer and am supposed to pursue every option as though the world will end if I elect to do the inexpensive one. As can be seen, I push back on that tacit idea. Does Dale need the business? Sorry, but not my problem, as this is unrelated to my reviewing.
This reminds me of the fanaticism that Maggie fans display. As if there is some moral obligation to spend more, to "do right" by an old set, to attempt to recapture the glory of the old unit. Sorry, guys, but this is pathetic, the paternalizing (like "good luck and cheer up") in regards to what has been a particular success. You guys just need to accept that these speakers are just not that important to me, and that I have what I consider holistically more impressive speaker tech at my disposal. :)
Douglas....as one who diy’s Walsh drivers (although not in the scale of an F)....Dale @ HHR.....
When an old F gives up, you ought to as well. The ’gook’ inside the cone will destroy the cone if you try to remove it. The surround would have to hand-made and you’ll go nutz maintaining alignment.
Take you dilemma to Dale. His look like yours....just Better. Price is reasonable, all things considered. I can’t, so I roll my own.
Good luck, and cheer up. Consider it a "cross-grade" that’s actually an ’Up’. ;) J
mapman, yes, it's all good, and we understand each other and respect the preferences. :)
You're right that single driver coherence is very important to you, as both designs are "full range", single driver in that respect. I appreciate the beauty of such things, too.
I'm having very enjoyable listening sessions now with the reformulated F. That was the goal, and it's happening, so I'm fulfilled in the project.
@douglas_schroeder I think we are getting into the very subjective areas of hifi here in other words different flavors all of which can be enjoyable as opposed to any inherent superior approach. No one has all the “advantages”.
Personally I do seem to levitate towards “coherent” designs above all else. That has everything to do with “wave launch”.
My current Ohm Walsh and recently acquired KEF ls50s Metas with the latest refinement of their UniQ approach both float my boat in this regard currently.
The sound of each is different in some regards but cut from the same cloth in terms of coherency as well as tonality and even imaging to a good extent.
I think you are spot on with your conclusion that it is best to not screw around with the inner coatings of the F in restoration, at least if the goal is to get close to the original. Heaven knows I don't have the chops of the original designer, but still, there had to be some significant challenges if putty was used. I think there was intent to get exotic with materials and solutions had to be invented. I don't know of too many companies today that intentionally merge fundamentally different materials in drivers, because it can harm the continuity of wave launch and cause problems with consistent tonality. It's really cool that HHR has kept the original vision alive, but if I'm correct, Ohm abandoned multi- material drivers and probably for superior coherence and specificity in application.
One last thought to my above comments on wave launch. Omni speakers do have a more coherent wave launch than dynamic, line source, etc. However, what is not typically discussed is the potential deleterious effects of the room interaction. The 360 radiating pattern causes far more potential for destructive room interference with the primary launch. That cannot be ignored as well when discussing soundstage. :)
mapman, well, you have a certain degree of image density, whether you want it or not. It's a parameter, a function of stereos and varies according to the design of the speakers. I would say that image density is inversely proportional to the image size, with panel, large line source and omni as champs in the latter. Conversely, I assert that resolution is a function of the system's electronics, not speakers alone. I can often make any given genre of speaker on hand outperform any other in terms of resolution. It's not hard to do.
Image density is a particularly beautiful aspect of sound reproduction, and it happens with differing degrees dependent upon the tech used. The most image dense speakers, imo, are classic dynamics, and they also imo have the highest capacity to focus the center image. The most tightly imaging speakers, along with being the most coherent in terms of wave launch are full range. This is why they are so favored in terms of presenting what is considered exceptionally fine resolution of voice and acoustic instrument. Especially when hearing vocals and instruments produced from a point source, the image density, or solidity is an exceptionally pleasing thing! Some people think that if you explode the images, you are hearing more resolution, while others insist that by focusing the images you hear more resolution. It's all manipulation of the wave to give a sense of pleasure, and I see both perspectives have merit depending upon the goals of the listener.
"Location" for omni speakers is far more nebulous than dynamic speakers. There is no clear fixing of the artists in relative location on the soundstage, but they float disembodied in the air. It's not that there is no center image, but that it is so widened as to be cartoonish as any point source instrument or voice. There is a pleasing distortion added through use of two 360 degree drivers, but this does not simulate well the tightness, the focus of especially the center image. To my ears the image is exploded and suspended in an unnatural way, relative to most live performances. That, I believe is one reason why most do not use omni speakers; they bring a lot of distortion to the "picture" in front. It's an intentional distortion, and has some very pleasing effects to it, including the immersive ness, but it's not imo accurate to what would meet the eyes.
You mentioned the 3-D aspect of music as well, an it varies from the close field full range tightly captured soundstage to the, "it's in your head" effect of the headphone. That is another parameter on a spectrum, and in that respect no other speaker than omni has as much of that umbra of sound, short of headphones. But, it is a matter of trade offs in terms of the particular characteristics of the sound. I enjoy the variety of characteristics that each technology brings, and try to accept the enhancements with each as a beautiful form of reproducing music. Others have strong preferences as to what sounds right, and are content only with one expression of it. Thankfully, we have enough types of speakers to accommodate most visions of what is considered reality in stereo.
I laugh about it now; many years ago I was a hard core panel fan to the point that I was trying to convince others that it was the correct wave form. Now, I think that was so stilted. The entire affair of stereos is about manipulation of the wave form and launch, and novelties capture our imaginations. I find it a wonderful, fascinating experience that even after all these years when I sit down to a different genre of speaker, there is an adaptation period, a time of what used to be about a week, but now is more like hours, where the fundamentally different character of the speaker seems "off" due to it's uniqueness. But, with time, the mind adapts, and soon the sound is striking the ears as normal and with emphasis on the strengths of the speaker's capabilities.
With all this critical analysis of omni you might think I have some thing against them. Not not at all; if I did, I wouldn't have paid any attention to the Model F opportunity, or own the King Tower. :)
I think I read on the Ohm website or somewhere that redoing the material inside the cone was one of the major barriers faced in properly restoring the Fs and a key reason why Ohm abandoned that. The original F Walsh driver was a finely tuned device. Everything was there for a reason and understanding of how it worked exactly is not common. So it’s probably a safe assumption that most any modern restoration will sound different than original. I would bet on that. It’s likely a moot point what they sounded like originally but even these days those who actually heard them new still can’t seem to get that sound out of their head.
I worked at Tech Hifi back in the latter days of the Fs. Heard pretty much every model back then .... except Fs. The store I worked in sold mostly refurbed gear to college students and a pair of Fs never came our way. My loss.
Image density? Not sure why I would want that. Omnis do location very well when set up well. As well or even better than most. Not pinpoint imaging. Maybe that’s more of a image density thing?
pch300, no, nothing was done to the "putty", as the drivers were in what I would all good shape in that regard. And, if something was done, it would be different from the original, anyway. Perhaps someone is using the original putty and can claim it's perfectly restored. If so, good for them. I believe moving into that aspect of a rebuild would have been a wild card, an unnecessary opening of a Pandora's box. I'm glad I had the wisdom to avoid that.
I don't see how, apart from measurement or direct comparison of two sets, you can say, "...the sound will be audibly different from the original F," if the putty is not replaced. What data do you have to reach that conclusion? I would not accept perception without comparison for such a conclusion. If a person had two units with fundamentally different condition, build, then it would be logical to assume there to be potential for audibly different performance. But, I am not ready to accept uncritically the suggestion that aging has so altered the sound of the driver that it is audibly/distinctly different from the original, at least in this case where the putty is in quite good shape.
I would think the matters addressed, the spider and surround, to be monumentally more important to the character of the drivers, given that the "putty", frankly, it appears more to be like foam than putty. If it is putty, I suggest that the designer had more issues to resolve than I thought! When you have to put a putty on metal to tame it, you have some very serious resonance issues to contend with. Frankly, it's probably a miracle this driver worked halfway well at all, given the oddball materials and construction.
Regardless, the speaker was languishing, and showing warts. I have resurrected it and transformed in a striking fashion its performance. So, in the end I care much less about whether the rebuild is true to original, and more about the absolute performance. Imo, I won big time on that front. The putty removal would have done little to address the pervasive mechanical issues of the foam and tighter airspace for movement of the driver. I'm not saying a re-putty could not engender better sound, but I'm content to conclude that these drivers with original putty in great condition are not significantly negatively impacted.
Now, we'll see over time; if the putty begins to break off and fall into the speaker, turing the titanium portion into a dinner bell, well, then I didn't do so well! LOL So, maybe I'll not blow them up but crack them up! We'll see, but in the meantime, I'm enjoying the refreshing changes. :)
Douglas, in the restoration, did they do anything to the 'putty' like stuff that's lining the inside surface of the titanium portion of the cone? I doubt they did that. If nothing was done, as it's difficult to do this, the sound will be audibly different from the original F.
Different forms of detail with different genres. Omni wins in terms of scale, atomization of images, which can seem to be more info. It loses when it comes to image density and localization, which is a loss of info.
Music is a 3-d experience to various degrees live. When a 3-d soundstage is maximized as I have heard uniquely possible with omnis, it is possible to discern a lot of detail that may be lost in the congestion otherwise.
mapman, yes, I concur; this has been rapid testing, and comparison of same location for a quick read on the performance of the Ohm and the King Tower soundstage. The positioning had nothing to fix the inherent problems I discovered and addressed. I would presume that somewhat different location of these omni speakers might be optimal over time.
The speaker now "breathes" as I imagined it could. The upper end of the spectrum is transformed. I had been thinking, "Well this stinks; these would need super-tweeters to save them," but the fact is, they wouldn't, not with the speaker in that condition. It wouldn't tighten up the bass, or truly balance the frequency spectrum. I wouldn't add anything to the resolution problem cased by the overstuffed cabinet.
The additional treble now is sufficient that they sound pretty well balanced. I would say they lean to the soft side of treble, but nowhere near the faint treble they had before moving half the foam down to the cross member of the cabinet. The driver was literally being suffocated by operating with a constrained air space. It literally had nowhere to push the air! One can imagine how that would dampen the materials of the cone! How can one get a natural ring to treble when back force is pushing on such light material? It's stunning to think that the design gave so little consideration to it, considering how basic and immutable the laws governing it. But it's easy to be an armchair critic of the past when assessing with half a century of tech development in culture. I am guessing it was seen as a brilliant move, along with the driver design.
Soundstage has such a pervasive influence upon the listener. When approaching a new speaker, I try to actively assess, then lessen attention to the character of the soundstage, as fixating on it can cause someone to overlook issues with performance. I am happy that I used my experience to pick apart the performance, because it has led to this speaker being upgraded quite nicely.
Given the difference in dispersion patterns between those two as I understand it, I would wonder if the same location can serve both best. The Fs are full omni so probably will benefit from more distance from all walls I would expect. Never heard Fs but have heard mbl and GP. Mbl in particular only sounded uniquely and mind blowingly 3 dimensional in a very dealer custom showroom with lots of distance to walls, especially rear wall, non parallel side walls to the rear, and treatments (old United Audio showroom in Annapolis Junction MD) Same setup at shows: way more meh. Also I seem to recall Fs even new only spec’ed to 16 kHz whereas most speakers in their day were spec’ed to 20 kHz. Most people raved about the imaging but not about the high end extension. Separate super tweeters would be an interesting add I would think.
Thought experiment; Imagine taking a megaphone in order to shout out clearly over longer distance. But, as a requisite condition, you must hold a dense pillow 1" from the mouth of the megaphone! You see, the rules are such that the gap between the pillow and the megaphone must be maintained.
THAT, my friends is the equivalent illustration to the design choices used in the old Model F! I did the foam removal, and I'm not going to talk about the potential for asbestos. As I say with other sensitive maneuvers, IT IS A DO AT YOUR OWN RISK ACTIVITY. So, let no one say I told them to remove the foam inside the Model F, not without pointing out their responsibility to acknowledge potential issues. I am presuming the old foam would likely have properties that might militate against safety today.
Now, on to the great news! IMO, this speaker has been resurrected! I'm WAY more excited about it now that when I said it was sublime. The removal of half the foam has allowed the driver to work as it should! The indistinctness, lack of high end sparkle, muted, weak bass was all really getting to me! For a design that was supposed to be all that it was not doing it.
It had to be at least in part due to the foam. You don't take an open moving driver and stuff thick material 2" away from it, and not expect the driver to choke! This speaker is a study in the convergence in the '70's of a brilliant, innovative driver, and at the same time awful construction methods that absolutely killed a LOT of the speaker's potential. It's hilarious that such a loser move with foam reduced this wonderful driver to a pathetic performance.
Well, NOT ANY LONGER! Now, the driver is acting as I would expect, a MUCH closer approximation - as would be expected - to the HHR Exotic model that I have heard. That was a big part of the frustration with continued listening; it just was not great. It was big soundstage, and that was about all worth praising. Now, the speaker has indeed come alive! Now, the driver sounds as it should, with respectable sparkle as well as spaciousness. The top to bottom frequency balance is commendable, though not SOTA. The soundstage is FULL now, not anemic and struggling to expand. The dynamics are SO much improved. The driver does not sound squelched, but has pop, and the bass is a big bonus, as the cabinet half full has a great, solid and powerful bass response!
There are so many insights from this to be gained, including not to hold an older/vintage speaker as sacrosanct, such that it would not be improved from futzing with it. Another lesson is that a designer might be brilliant, but the conventional aspects of speaker making of the day can reduce what would be an even more brilliant design. Yes, of course, the standards have changed; that's part of the reason I was not accepting the performance. Free air motion of the driver is SO important, and without the back force of the foam blocking the driver's operation, this IS A RESURRECTED SPEAKER!
Now, it's not a charity case, but an authentically reasonable selection for listening to as a quality transducer. These speakers probably within a fairly short period of time would have been on the way out - somewhere. Now, they will stay, because this one change has brought a cascade of positive changes, and the driver is operating closer to my expectations.
With this final fix, the restoration is a big success! Now, beyond a shadow of doubt, this IS the best $400 speaker I have ever owned! It now may take its place longer term alongside my other speakers, and because it has been resurrected to play with above respectable levels of sound quality, it will be used in rotation.
Have I overstated my conclusions? No, I have not. This was a roller coaster of changes, thankfully most of them leading to a more favorable result. Had I been too timid to rip into the foam, treating it as though it was sacred material, this never would have resulted in my finding deeper pleasure in them. But, as it is, speakers that are not mostly cutting it need to be reassessed, and I do not care whether it is iconic or not. NOW it performs along the lines of what I expect a great omni to perform.
Conclusion? YEEESSSSSSS! I now have a vintage speaker restored to a quite respectable sound quality level, and I am most gratified that I futzed around with it to make it happen!
Now, to give some balance, are these suddenly replacing my other reference speakers? Of course not, but neither will they languish as an also ran, nice idea project that failed. That's where they were heading before I motivated to try the foam removal. They will be a pleasant alternative, and a respectable one, to build systems for enjoyment, and even for reviewing. The change has been good enough, I feel, that they can be used occasionally for reviewing. Prior, I wouldn't have dreamed to do so.
WOW, what a difference removing the pillow makes!!! Again, those with older model F's are not being told what to do, and consider your bravery if you want to alter this iconic speaker. But, performance is SO important to me that this was THE solution to the speaker's foibles.
Now, I think I am done. The restoration is acceptable to me, the performance as good as I was hoping. It has solidly moved along the spectrum from "sublime" quite a bit closer to sensational. No, not drop jaw on floor, but much closer. I now consider it a brilliant move on my part to seek the affordable fix, and to trust my instincts in regard to pushing the speaker further along. I am SO happy I did not accept the weaknesses, but made better things happen. BTW, note that this all happened without burn in. I am an advocate of change to systems, a system builder, and that is a fundamental reason why I ended up with a positive outcome. Waiting would have done nothing to address the fundamental issues, and being active has gotten me a very nice vintage speaker redone performance-wise within a couple weeks of return from repair. BIG, BIG WIN! This has been the singular best turn with a vintage product I have had, but then again, I was more aggressive about altering it than I have with other vintage gear. Nice lesson learned, with all upside. :)
Thank you gentlemen, for your thoughts! All input is appreciated!
Today I tried to blow them up! Not really, but I did as mentioned and laid a lot more amp output on them. I stared with an alternative class A/B integrated (Kinki Studio EX-M1+ with sundry discrete opamps inserted), and pushed the speakers to pretty high levels, perhaps 85dB. NO problem! They seemed not to stress, which is ideal.
But, the resolution, as russ69, recalls well in his comments, is nothing to write home about. I returned to the aforementioned "magic" amp, and yessir, this is certainly a magic amp! Wow, what a class D! Combo with the Exogal Comet DAC is pushing the speakers even better and with more resolution. Now the resolution is listenable, but nowhere near exemplary.
Yes, the single driver firing into a box is not exemplary resolution. The mid and upper treble is more pleasing when they are driven harder and the convergence of the omni fields is in more effect. At low levels, not nearly as inspiring, as might be expected. The "sublime" comment initially was at quite a lower level, but now I will not hesitate to play them harder.
For comparison, both the King Tower and Ohm Model F restore were placed in identical position, and here are some results; there is a sizable resolution gap between the capabilities of the King Tower, and the Model F, across the frequency spectrum, with the King Tower dominant in that respect. The soundstage is not as coherently "mushroom cloud" with the King Tower and is taller, as also would be expected. The fullness of the soundstage and encroachment (or perhaps "intimacy" and "immediacy") upon the listener is superior with the Ohm Model F. It seems to shift the soundstage forward toward me about four feet, such that the umbra is about three feet ahead of me, versus the umbra of the King Tower being about 7 feet ahead of me.
That is the calling card for the Model F and this rebuild. One has to excuse a fair bit of flabbiness and indistinctness, but the mushroom cloud is distinct with full range omni, and that helps to offset some of the disappointment in indistinctness and resolution. There is a curious tie in with other full range speakers, and the Tannoy Glenair comes to mind (reviewed). I can mentally image the Glenair's driver pointed downward similar to the Ohm, and capture the affect of it driving into a pile of foam. I really do wonder whether I should remove some of the foam. I suspect the speaker would wake up quite a bit. After all, it didn't strain when I put it to higher levels, so what's the harm? I am very curious how the driver's nature would change, as well as the cabinet coloration. The cabinet is really dead now, and I suspect the speaker would benefit greatly from a bit of "Harbeth treatment", i.e. hollowing out the box somewhat. Maybe I'll try that next.
None of this should be surprising, but overall I am very happy that they are tolerating higher levels of massive power, the best outcome that I believe possible for a vintage set. What will be particularly helpful to me ongoing is having another soundstage to work with. I now will have full range omni, quasi-omni, quasi-line array, and big ESL, as well as open baffle horn hybrid. There is another speaker making a splash, with its own unique soundstage, but that is a different story for another time, a review actually.
Overall it's been worth it, and I pleased that the are not falling apart with some pushing. That makes them worth keeping and using occasionally.
What do you guys think about the idea of removing perhaps 1/3 of the dense foam pieces in the cabinet? I think it may be a winning idea. I don't know that the removal would adversely affect the driver much, as it's a pretty sizable cavity and with some open space between the driver and foam. What say ye? This is basically an ongoing experiment, play time, so I may as well do it. I was willing to take a risk that they speakers would fail, so why not do foam remediation? I am wondering whether this would aid the resolution, and at this point I think it likely would. Only one way to know! :)
@douglas_schroeder , I'd be interested in listening to the Kings Audio King Tower. They look super cool. I'm also glad that the majority of posts have been spot on and helpful. Bob
My recollection from back in the day is that OHM-Fs did not have shimmering highs, nor could really loud sound levels be played without some loss of control. What they offered was room filling sound and a good soundstage at moderate volumes. IIRC my memory from this long ago is suspect.
Doug, as a check point to your repairs you might speak with Harry Weisfeld. He has a pair of restored stacked Ohm F at the VPI house. I haven't heard them, but perhaps he has some ideas to help bring out the best in the F.
I'm going to put the Model F back in and jack em up. They're no good to me treating them like paper mache. If they break, they break. I've already gotten a valuable, yes worth the money and time, comparison between speakers. Consider this exploration for the sake of humanity, like Space-X, only on slightly smaller scale. ;)
For those appalled at this decision, I remind that this was a set with major damage and on the way to the dump. I would never ever treat review or more valuable gear in such fashion. Feel free to check with any manufacturer whom I have reviewed, or my sales of my gear.
I'm pushing the issue, building systems at advanced pace to get to the end of the matter. In a day or two I will know whether the F is worthy of more time. It could perk up. I'll build yet another rig for more perspective.
Once again, as consistent in this stream of consciousness discussion, not a review, I make no claims or promote no expectations of either HHR or current Ohm products.
So far, the best aspect of this project has been getting the King Towers back into the rig. Man, am I happy to have them! It's great to have direct comparison to a full range driver omni. It will be fun to switch between in order to gain appreciation of each technology.
I find it refreshing return to my earlier days, when I defended inexpensive audio. How many times have I been accused of "selling", as though my primary goal is not performance, but convincing others to spend money. Let this exhibit stand as an example of the blowback that happens when fans of a certain brand or speaker chide someone who could, but choses to take the economical route!
This makes me a hero for the budget audiophile! ;)
+1 @trudat IOW it’s the HHR Exotic that proves the merit of Walsh’s conception-- or maybe a
German Physiks. A $400 restoration of a Ohm F is a straw man.
Nostalgia can be a strong force in the decision making process of the audiophile, but in my experience over decades, in every instance where I put money/effort into a vintage product, it did not yield acceptable performance. After a dozen experiences or more, at what point does the system builder conclude it is a less productive activity, at least in respect to pursuit of extreme sound? I am pretty sure that were I to put the $7-8K into a more extensive rebuild of these, and procured new cabinets, I would still end up at the same conclusion; nice, but not overwhelming.
After a while, when you have heard hundreds upon hundreds of speaker systems, many in your own home, you are able to globally assess the technology's capabilities. There are fundamental, hard limits on each tech, and with a realistic assessment of the limits, decisions can be made in regard to whether a certain investment into upgrade will be worth it. Most often, I rather enjoy diversification into a different genre, than an attempt to idealize one genre of speaker. Experiences available through a variety of speakers is unparalleled, imo, with focus on one genre. So, my motivation to try to turn the Ohm Model F into "the One," is not strong. I have chased the mirage of the One many years in the past, and it always ended up disappointing, primarily due to allocation of resources into a narrower range of performance. I'm not willing to push on that button again. I have learned to know myself enough as a system builder to avoid what are for me less productive changes.
However, there is another omni speaker sitting here... I may today put the Kingsound King Tower omni speakers into the rig to see informally how they compare with the Ohm Model 7.
The story regarding the King Tower is interesting, and as a reviewer with curiosity I was in the right place at the right time. Over the years I spent plenty of my own money attending shows across the country. I was not paid to go as a reporter, so this was extra expenditure for unpaid work! How stupid, right? Except that I knew there was no other way to gain extensive experience with gear except by getting exposure to it. I knew I could pick some winners for my ownership if I could hear them. It was that willingness to spend money that most would consider a waste that led to some very cool outcomes, including the King Tower. If one does not have the vision to invest into potentialities, then the future is more limited.
It was at one of the RMAF shows that I first saw them. I believe they were shown two years at the show, and they were shunted off to the side in a little system with mbl mono amps. They looked stupid, with bright blue foam balls in-between the bass and midrange modules. No wonder they didn't get attention, as they looked ridiculous. But, as I surveyed the larger design, I thought, "Ignore the stupid blue foam balls..." The design had potential, I thought, so I asked Roger DuNair, the importer at the time, to fire them up for me. He did, and I thought, "Wow! This really has potential!" I also thought that it could prove to be a SERIOUS contender to lower end Maggies.
I bugged Roger for about two years to review them, but eventually he called and said he was not going to distribute that model in N. America. Did I want the demo pair? YOU BET! SEND THEM! The miracle of the story is that while I have had three other smallish tower speakers destroyed by the likes of UPS, FedEX and DHL over the years, these arrived intact! AUDIOPHILE MIRACLE! So, even though they are not my primary speakers, they have a nice set of memories associated with them. I believe they may be the only pair in North America.
The first thing I did was apply myself to removal of the stupid foam balls! Thankfully, they were easy enough to remove and as the cabinets' downward wave guides were anodized, I was able to successfully remove the adhesive with zero cosmetic blemishes! YESSSSSS! Now, they look respectable, and sound better. I consider the existence of the blue foam balls to be a reason that they were never sold at the show. It can pay to have a bit of proactive imagination in regard to a product! :)
The King Tower I already know will have scads more resolution, with its larger omni ribbon tweeter and super tweeter atop. It also suffers from cabinet coloration, as does the Ohm Walsh Model F. No getting around that, but I had thought of perhaps opening up the cabinets on the King Tower and treating them to dampen some of the resonance. I may still do that.
I am looking forward to hearing the completely kick ass new amp under review with the King Tower. The best part is that the King Tower, unlike the Model F, can be bi-wired. That means I can use two more channels of 600wpc of super-pure power on the King Tower. Frankly, it would expect it to outshine the Model F significantly in some respects, and I would be quite disappointed if it didn't.
I'll say this; if it were a choice between getting this new amp under review or upgrading the speakers, it wouldn't be a difficult decision - THE AMP, no question about it. I wouldn't dream of opting for upgrading the old speakers and missing out on this amp. The amp is revolutionizing all the speakers I use. That is far more important to me than upgrading one speaker.
pch300, you sound like you really want to do the upgrade. If you have the means, why not? This thread may be the catalyst for you to realize a dream. If so, great! I get it when it comes to adoration of a certain genre of speaker; I lived that for a long time. So, if it's a dream of yours, then go for it! :)
pch300, the sound is well, vintage. It lacks a lot of top end sparkle that I have come to expect from superior speakers. But, that is reasonable, given the age and design. They simply never were able to create the shine that is with newer technology. The big call to fame was the mushroom cloud soundstage, and they have that. Am I going to add some super tweeters to open up the top end. No, I’m not putting any more money into them, as there are fundamental limitations that are obvious.
They will be curiosities, something to put in the system when I am bored or want to hear the omni sound pattern. It’s a good thing I have a radically clean rig, or else I couldn’t take them at all, as they would be horridly mushy.
I was fairly realistic in my assessment of what to expect from the repair. I didn’t expect the world, and they have not given it to me. For a few hundred dollars they work fine. I haven’t pushed them yet, but I will at some point. If they die, they die. I’m not going to keep them as a souvenir that is not worth opening up and running. They have physical defects, i.e. the cabinet compromise and some ferrofluid stains on one upper paper driver, so they’re not worth much.
This does confirm once again that most vintage equipment is beneath my expectations nowadays. I have yet to work with any vintage equipment that I could stand in the primary rig for more than a day or two. The sound is simply far too compromised. The price is right, for sure! But I don’t have to settle for bargain speakers. So, why did I in this case? Again, because they were presented to me as a speaker charity case that I knew I could revamp on the cheap. I don’t need another reference speaker, and this will definitely never be close to that. I just wanted a fun project. We’ll see if over time they "blow up" in a good way, or in a bad way. But, I’m not going to keep them forever if they never have the capacity to thrill. Having a unique soundstage simply is not enough to entice me to love them forever. I slowly upped the level and it didn’t seem to phase them. But, I got bored and put the Kingsound King III ESL speakers back into the mix. Much more excitement and prodigious. Who knows, maybe they can take a lot more; I was very light with them.
So, what do I expect for a couple hundred bucks? About what I got. Good enough for now. Next run I’ll push them harder to see if they have more to give, because I handled them with kid gloves this time, and they didn’t really shine in terms of the orb soundstage they can do. They’re either going to bring satisfaction, or be destroyed. I will not harbor low cost speakers that long term do not bring fun. Well, "destroyed" is a bit too harsh; they simply would sit around and perhaps be sold cheap to recover the costs or given away. But, please, people, do not contact with offers to take them off my hands. They're for fun and I don't know how long I'll be entertained. It's not your free speaker project. :)
I will put the Kingsound King Tower omni speakers back into the rig soon. I want to gain a clearer picture of the fundamental differences between that omni and the old F. I was going to sell the King Tower omni, but maybe not quite yet.
I was going to redo the batting in the bottom of the cabinet, but I wonder if the drivers would react differently, potentially have too much excursion if the fairly solid batting was not kept in place. It would be stupid to remove the pretty solid mass that acts as an air brake, then push the drivers such that they had too much excursion. I think I’ll let that one go.
Been quietly following this thread, and glad that you got the F's fixed.
There's been a lot of talk about the hair-trigger watt limit to blow up the F speakers. As long as you don't tempt fate, it should be fine. I've run my pair of F's for may years with a 300 W/ch (into 4 ohms) power amp, and really never needed to put more than a few watts to get loud enough in the room.
Let us know how the speakers sound when you get them fully set-up. Congratulations, again.
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