Ohm Walsh F Hope of Resurrection

Loved the Ohm A.....you needed Boulder Dam to power them though

Not sure who is around anymore with experience fixing those.
You could try contacting Dale Harder. He may be able to provide insight.
Ohm would provide very good sounding upgrades for the Fs but not repair for the original design which is different.
I have Ohm F5 series 3 model which is latest drivers from around 2008 on Ohm F cabinets that I bought from Ohm. That was series 3. Current drivers are further refined next series, the latest 5000 drivers. I can post pics if interested.

Call Dale Harder at HHR Exotic. He is the only person I know that is reproducing a version of the Ohm F. His is called the TLS-1. He is an expert on this design and will give it to you straight. 

I am actually saving up for a pair of TLS-1s at the moment. 

I thought at one time Bill LeGall at Millersound was repairing these but I may be mistaken.  If anyone can fix them he's one of the few, good luck.

FWIW, here’s a shot of my F5s, made at Ohm factory in Broooklyn for me ~ 2008:

https://photos.app.goo.gl/et3PRwzdYj5wSebCA

A lot of speaker built using refurbished Ohm F cabinets for the $5500 asking price at the time.

This is the info you need. 

https://ohmspeaker.com/legacy-products/f/#main

@russ69 -- the Ohm people haven't repaired the original Ohm As & Fs for many years now. They had one fellow who knew how to do it but he retired 10, 15 or perhaps more years ago. These days Ohm will only replace the driver with one of their current models.

As others have noted, Dale Harder is the only person I know of that works with the original drivers, so the OP would want to discuss his situation with Dale if he is determined to rescue his drivers.

The info on the OHM website says " All Ohm F’s are beginning the end of their functional lives. There is a foam damping material used around the base of the driver and inside that is failing from old age. We have never successfully repaired an Ohm F that was failing this way (the cone gets modified when you remove the old material and no longer sounds the same). For years, we replaced the old drivers with new ones. The last of these were made when the last craftsman retired. No more originals are available. But a series of upgrades with second generation drivers are available."
Worth a phone call I think, just to hear what the options are.

contact Bill Legal of Miller Sound in PA

(215) 412-7700

I appreciate all the information and encouragement! 

This thread is what the best of Audiogon is about :-))))))

We’re not a bank Jerry. Contact bill deal at first federal. A little movie reference  for y’all .

cheers 

Douglas, I've been enjoying my Ohm F speakers for one year now. Mine are rebuilt using 3000 series drivers. I reached the decision to buy following an informative and unhurried phone conversation with the owner of Ohm Acoustics, John Strohbeen. You probably should reach out to him (he answers the corporate phone...) so you're aware of the options, as he sees them. Good guy. Good luck, (and keep Ohms in your listening room!)

So you have a pair of Ohm F’s that have been "saved", and now want to know if they have a hope of being "resurrected"?

Hmmm. If the original drivers are irrepairable, but modern replacements are available, are we looking at putting new wine into old bottles??

Sorry, couldn’t resist!

Duke

Imagine if every high end manufacturer had a "rebuild" program similar to Ohm's?

Definitely call John Strohbeen at Ohm Acoustics (OA) before having a third party refurb the Ohm F’s.  He was very helpful with me in a number of situations regarding different models of Ohm speakers (Walsh 4s purchased in ‘87, microWalsh set for surround setup purchased in ‘06). 
OA have made upgrades which improve their vintage models, and have newer models that sound better and have improved power and size efficiencies. 
It’s pretty impressive how well OA supports their products. Buying my Walsh 4’s just after getting my first real job was one of the better decisions I made.

Not just rebuilds.   They provide parts, trade-ins and upgrade services for every model they have ever built and they have been around since ~ 1970 or so.  Options for each model are outlined on the website. Nobody else I know of does that.   

Duke,
Great analogy! The original quote was about wineskins. New wine could not be put into old (already stretched) wineskins, because the fermentation would rupture them. 

Speaking of rupture, one of the seams along the front of cabinet is splitting, so that would have to be considered, too. I'm sure there could be discussion of how the restorer might address it. 

My recollection is the Ohm trade-in policy is that cabinets have to be in good enough condition for restoration so they can be refurbed and reused. Drivers do not matter.

I traded in an old pair of Walsh 2s and a pair of C2s towards mine and that lowered the price substantially. Plus it was summer sale time.

Looking at some very interesting options. Thanks to everyone who has participated! 

Hooked them up; even though the surrounds look ratty and the one spider sags, they are sounding pretty (given condition). Frustrating info on these pertains to some driver refurbishers not wising to even redo the surround. To send them back for complete overhaul of speaker, to make the old boy like new, we’re talking likely close to $7.5K, maybe more incl. shipping. I wasn’t looking to drop several grand on this.

Add to it that the cabinets are toast, would have to be replaced. So, in a sense, the speakers in terms of complete refurb are worth about a negative $100. Not my ideal of an inexpensive retro project.

Running into all sorts of conflicting info on merits of reconditioning driver, parts, etc. Spoke with Dale Harder, an encyclopedia on the speaker. I have a call in to Bill at Millersound to see about that possibility. BTW, everyone has been super-supportive and helpful! Thanks!

Isn’t that the way it goes? You think you may have a fix, perhaps in your back yard, Chicago area. No, they say, it’s thousands and half way across the country.

It gets to the point you say maybe do it yourself. Then you hear you get one shot, the slightest slip on this driver’s alignment and it’s over. It’s not like there are multiples of these cones are sitting around everywhere. Bummer.

Comments, suggestions, especially from people who have refurbished, redone drivers, more recently? My ideal would be to not have to ship (I would drive 150mi or so from Chicago area), and to start with replacing the surround to see if that is good enough.

I’m told that the spider can be helped by turning the unit upside down when not in use, and someone put a "stiffener" on it (coating) without hindrance.

My initial goal was to do an inexpensive repair and have some fun. But, I"m open to all comments.

BTW, I'm not trying intentionally to be cheap. I don't need a new reference speaker. This is supposed to be inexpensive fun. I'm torn between what I can get away with in terms of using it, and what it could be. But, a few hundred bucks to $1K, and $7K is a BIG gap. 

Doug, depending on how old the F drivers are, your surrounds rotting is expected but quite overdue. I had F’s from 1977, and surrounds rotted in 1995. The spider suspension also sagged from the years under a heavy cone. Both are non-repairable by Ohm Acoustics. Furthermore, the inside of the cone has foam damping on the aluminum section. That also was flaking off on my speakers, but only if I touched those parts.

I first tried to repair the surround by ordering a similar sized surround from a place in Florida, if I remember. Installation was easy, took some patience, working methodically, and carefully scraping the old glue off the paper/cardboard part of the cone periphery. Gluing the replacement surround was about the same, making sure it’s centered so the voice coil doesn’t scrape against the magnet, and the edge of the cone is circular, not oval from the handling. This was the cheapest fix for me.

The completed surround repair will let you play the speaker. Ohm says it won’t sound as intended, due to the specific absorption of their surround to properly mechanically terminate the cone edge, that an aftermarket surround couldn’t do.

The other two options were to trade-in the drivers toward currently available speakers at a discount, or trade-in for the F3 driver to mount on my F cabinets. The F3 was clearly the most value.

I decided to upgrade to another Ohm Walsh speaker, and also take the F3 option. All four are in play, two as stereo, or all four as theater main and surround speakers.

Ohm currently appears to have 5 options for upgrading the F now. Good luck.

I was in a similar situation but I have a big room and I was encouraged by John to go the F-5015 route.  Here is how it played out for me.  John and Evan of Ohm and I started discussing changing a pair of Ohm F's that I had into some F-5015s starting in 2018.  I ended up deciding to trade in my F's, received the standard 25% off of the list price, and I ordered new F-5015s with one inch thick birch plywood cabinets.  I also had the option of sending in my F's and having them changed into F-5015s at a lower cost point where my cabinets would be rebuilt and re-veneered.  They actually encouraged me to do this and said the sound would be the same except at very high levels, but in the end, I decided to spend more for completely new.  I recall that it cost around $250 to buy all the packing material and to pay UPS to send in the two cabinets and the driver magnets to Ohm in Brooklyn from Michigan.  My traded in cabinets were in very good shape with the only damage being that the lower corners were very slightly rounded due to contact with objects.  There was no damage to the particle board under the veneer in these locations.  These were acceptable to Ohm for the trade-in.  Never asked what they did with my traded in cabinets.

I was a bit shocked that the newer Ohm speakers are not true omni. I had never bothered to look,  and it's radically different  than the Walsh.  I am only interested in a true omni. 

Should have known by visual assessment; you can't do true omni when you have a metal  plate and electronics behind. As I'm after an actual omni, I wouldn't consider it. It's either fix this or replace with similar. No longer interested in current Ohm products for this project.  

Doug, If you are referring to the 4 switch control on the grill, this is only on the 5000 series and the 4900 (1 switch control) speakers. The 4000 series speakers and smaller do not have this. Presuming you have a decent sized room, you can get 4000 or 3000 series with their upgrade program. Just send in the F magnet assemblies / cabinets and pay the amount cited on their legacy page - slightly less than $3k for the 4000 series and slightly more than $2k for the 3000 series. If you want to consider this, contact John or Evan at Ohm and tell him your room size. He can recommend which speaker would work best for your situation. I also thought that they could sell you a current technology replacement driver that sits on top of your existing cabinet. Not seeing that option documented on their website now unless I have incorrectly interpreted the cited offers/costs above as being for completely new speakers and they are really for drivers for your existing cabinets.

Doug, consider asking Ohm whether they are willing to make the speaker omni, by not installing the damping pad on the back side of the cylinder, and turning the supertweeter upward as for the surround speakers, for example. I also preferred a full omni (as in the F) vs. the newer Walsh drivers (thousand series) with controlled directivity design. However, with a full omni the central image does shift when you're not along the centerline between the two speakers (the F), whereas it is remarkably near center with the latest Walsh drivers. The latter is of great advantage in a home theater setting, as well as stereo listening if you're casually listening while sitting off center. I get an enjoyable sound even sitting beyond the left speaker, but not past the 90-degree line from the supertweeter axis.

With true omni designs, your choices are more limited. As mapman wrote, call Dale Harder for his versions of the F and A speakers. Otherwise, it's  either MBL or German Physiks, as far as I know.

This is quite long, but vintage and rare omni buffs may find it interesting... 

I had a great discussion with Evan at Ohm; very helpful, and I can see the beauty, interesting nature of what they are doing with their design. I already have a hybrid omni, the Kings Audio King Tower, and I do not wish to move farther from that style of speaker if I can see if there is a possibility of moving up in terms of scale and quality. Doing a current Ohm product would take me mechanically, operationally further from that. So, I am letting go of that idea. I know there are enthusiasts, but no amount of adjustment would make a 15" and soft dome into a true omni. I don't care to debate anyone about that, and I'm not making a value judgement of the Ohm products, because I have not used them in my room and have not reviewed them. I'm simply not seeking that design. 

My options seem to be:
+Replace just the surround IF I can find a person to do so within 150 mi of Chicago. 

+Replace just the surround myself - and thinking through the tasks involved, and considering I have never done so, I think that would be far too risky to the vintage cone, and the odds are great that I would not get it centered properly. 

+Send them off to get them redone. Incurs shipping costs and potential damage through shipment, which, sadly, is a fairly high possibility. But, I could get the spiders replaced and get them closer to original condition. I realize this would not be to spec, but so what? I'm not spending $7-8K, either. 

+ Go full boatload, and have HHR Exotic Speakers build a new vintage set. If I send in the three parts usable I incur shipping costs, which probably would drain most of the benefit of the parts being sent in, but it's a whole new ball game in every respect. Cost between $7-8K I estimate. Big money for a project that I didn't intend to spend money, and a commitment to an omni as a reference, when it has always been a for fun genre. Would it be "worth it" in terms of quality? No doubt, absolutely. But, do I want to support that much for another speaker that I literally do not need? It is a way to get a large chunk of HHR Exotic performance for about half price of a redesigned model. 

I know, what miserable problems to have. It just shows that none one should ever give speakers away! It just brings problems to people! LOL 
The previous owners would probably be amazed at the level of concern, time, and perhaps money spent on this, given that they were going to take them to the dump. 

I see Dale's rebuild of the classic as a beautiful opportunity. I also think that a competent rebuild by Bill is just as compelling, given the price differential between the two. There are very serious disagreements in terms of the sound quality of the speaker given both scenarios. That is the most difficult to cipher. Dale believes the compromises to having the current drivers rebuilt by anyone else ruins the pristine nature of the speaker. Others say pretty doggone good sound can come from a rebuild, or even just re-surround. I get both perspectives, and I have heard hundreds of systems in my home, so I get the spectrum of performance. I see both points. 

Given that they do work, and I am not hearing distortion at reasonable levels, to find someone in midwest to redo the surround I think is also a compelling thought. I am thinking of the possibility of treating the spider by placing the driver upside down, then applying some form of fabric stiffener to attempt to strengthen it. There are a number of serious risks with that, including 1. Altering the sound audibly, 2. when turning the speaker upside down, the severely compromised surround may be entirely destroyed with another 1/4 to 1/2 inch travel. That is a very real possibility, and 3. It may not work well to boot. 

As I consider doing the surround replacement myself, I wonder if leaving the spider assembly in place would allow me to center the surround far better. I would presume I could GENTLY press on the spider to move the voice coil and see how the gap is, whether there is some rubbing. Perhaps I could tack down the surround in a couple spots to try to fix it in place while allowing for some movement. That way I'm not full bore fixing it, then finding out the possibility of a problem. 

Frankly, I also should pull out the current speakers and run a real world comparison, trial of the Walsh F. They were just thrown into the room for viability, but I should position them and see whether I consider the alternative sound to be worth perhaps going full bore for a rebuild. 

NOW FOR ANOTHER, ENTIRELY DIFFERENT SCENARIO! 
What if I were to just try the self-repair, or at the most pro repair of the surround, and maybe with about $1K limit or so on the Ohm, shift my goal to upgrade the Kingsound King Tower, a hybrid omni?

It's a terrific small tower, and I believe has big potential. I have thought for years about juicing it. I believe it would benefit from the following: 
+Replacement of 10" and 6" drivers with superior ones
+Replace internal wiring
+Replace internal caps, or maybe entire crossover
+Treat "cabinet" modules for resonances

I do wonder about that rebuild, because it would be tricky. But, then again, someone assembled them, so I figure it has to be possible. Probably smart to not pull the wiring from the super tweeter and "can" omni tweeters, but leave them in place. 

If you want to see the King Sound King Tower, do a search for that phrase, then select the option to see Images. The speakers with an mbl amp, an image from RMAF, will show up. Those are my speakers, perhaps the only ones in N. America. Getting info not this speaker is like a top secret project; there is pretty much been a wiping off of documents on the net. I have a glossy brochure of it, THANKFULLY, with a small image of the internals, and I did not know that there appear to be tubes, like an SVS subwoofer, built inside for the dual/stacked bass drivers in the lower cabinet, and the mid driver in the middle cabinet. If there is no access from the bottom, then a rebuild idea is dead, because I'm not ripping off grills on the top of modules to do it. BTW, I ripped out the silly blue foam balls, and it's much better without them!  

I have gotten some pretty cool sound out of it; the speaker is a "poor man's" mbl. I think that would be a nifty project, too. My dream result would be to get both of these speakers going in good shape, and not have to junk one project for another. 

What do the esteemed aficionados think? Hit me with all your critiques and brainstorming! It is most appreciated! 

Remove the cones, pack carefully and send to one of the shops that repair speaker drivers. Get new surrounds and maybe new spiders. Repair cost should be less than $1K. Re-install the refurbished cones atop the cabinets. I'll bet they will sound real good!

My Ohm Sound Cylinders are still sounding excellent!! They are the "controlled-directivity" type. Astounding 3-D sound from anywhere in the room!

OOPS; I had said,

"I had a great discussion with Evan at Ohm; very helpful, and I can see the beauty, interesting nature of what they are doing with their design. I already have a hybrid omni, the Kings Audio King Tower, and I do not wish to move farther from that style of speaker if I can see if there is a possibility of moving up in terms of scale and quality. Doing a current Ohm product would take me mechanically, operationally further from that. So, I am letting go of that idea. I know there are enthusiasts, but no amount of adjustment would make a 15" and soft dome into a true omni. I don't care to debate anyone about that, and I'm not making a value judgement of the Ohm products, because I have not used them in my room and have not reviewed them. I'm simply not seeking that design." 

After further discussion with Evan, I now fully comprehend the drivers and implementation of the modern Walsh driver, with its omni mid-bass to treble driver with directed tweeter,  and it is back on my radar as (for most intents and purposes) an omni. Mea Culpa 

When I replaced the surrounds on my Fs, that was the first time I had tried a surround replacement on any driver. To me, it was fairly straightforward. I would not attempt to replace the spider - too much risk of damaging the titanium part of the cone. 

The surprisingly easy, but time consuming part was to carefully clean the paper cone periphery of old glue, without damaging the paper periphery, after removing the old surround from the cone and metal rim of the basket. 

The new surround should fit over the periphery exactly, if you order the right size diameter of the surround. Measure carefully before you order and double check after you receive the new surround. The  surround fits over the outside surface of the paper cone periphery, and also to the upper surface of the metal rim of the basket (like in the existing surround).

I had the driver upside down, put the surround over the cone and slide it below the periphery, applied the glue to the outside of the cone periphery, and pull the surround up over the glue slowly to make it positioned evenly around the cone. At this stage it helps to orient the driver right-side up to achieve a even, planar circular interface between surround and cone. I suggest minimal glue to minimize the mass change at the edge. Let glue set. 

Centering the cone periphery was also fairly easy. I had the driver oriented upside down on a table. While holding the cone near its middle height, tilt the cone left and right while gently sliding it up and down. Do the same fore and aft. Find the center point between where you hear slight scraping and no noise, in four perpendicular tilt directions. mark where the surround edge for each center point. Glue it down to the rim, taking care to not radially stretch the cone either outward or inward. 

If you take this route, you can still opt to do more repair later with someone like Dale Harder, or get his TLS-1 speaker. 

Doug, just saw your post. I was writing my previous response when you posted.

Just to fill in some info, I found a few things that differ from the F vs the W5000 speakers, in my room. The F subjectively seems to go deeper in the bass than the W5000, in the sense of very low bass, the room-shaking kind, despite the low frequency bandwidth specs of 37 Hz vs. 25 Hz, respectively. I speculate that the faster roll-off of the W5000 (a vented design) vs. the more gentle roll-off of the F (a sealed system design) may have something to do with this impression. For music, this makes no difference. For movies, I have subwoofers to cover the lowest frequencies, about equivalent to that of the W5000. 

Both the F and the W5000 drivers can produce an impression of surround sound from only two-channel material. In the movie Flyers, there is a scene where a fighter jet flies from-behind to overhead and then to in-front of another jet. The sound, from inside the second jet, with only two front speakers projects the sound movement matching the video. 

The F requires a power to get to reasonable sound levels; the W5000 takes less power. The latter, with a powerful amp will give added headroom to play live recordings at live SPL levels, not that one needs to do this routinely.

I also seem to recall that the power handling on the modern Ohm drivers is much better than in the F. Another related thing is a review of the Walsh 5 showed a linear tracking of output volume and power input, saying that higher power causes little "power compression" of the sound. I never tried to check this on my system, but that is a good indicator to me for the speaker capability to produce correct musical dynamics.

My opinion on the stiffener on the spider is a no.

Conceptually, stiffening the spider or surround causes the raising of the resonant frequency of the driver. The effect of that may raise the low cutoff frequency for the speaker, among other effects, perhaps changing the Q of the system tuning.

pch300, some great tips, and it may be that I end up doing the surround myself. 

Was it Elmers glue that you used? ;) 
I presume not; what did you use? Do you recall? Some surround replacement kits have adhesive included. 

Thanks to you, pch300, I think I'm going to do this repair myself. I have been thinking about the project, and I believe I have come up with a winning idea on how to ensure success with avoidance of rubbing of voice coil. 

I would take all your suggestions, essentially, which are superb; thank you! 

But, in addition, when I got to the part where I would secure the outer rim of the surround to the metal basket, the thought struck me, why not use some painter's tape, or similar, to temporarily anchor the surround's outer edge, then play the speaker to assess for rubbing? If it rubs, I move it and reattach with tape. The tape should not damage the new surround, and it can be moved at will. In that way I should be able to then work around the bottom of the surround with glue, removing the tape locations and ensuring the proper position of the surround. I can also mark the edge, as you suggested for extra caution/precision. 

Obviously, I do not want to crank them up in that condition, as the tape might pull on the driver paper. One has to use some sensibility. I could even, perhaps, use some narrow weights of some sort to place on the surround as an anchor. I would be able to find something suitable. 

I think I'm going to remove the drivers baskets today from the cabinet, and turn the drivers over to settle the one spider that's sagging. I also can begin to work on replacing the wiring and posts, which are antiquated and by today's standards poor. 

Sounds  feasible. Ideas, concerns? 

Thanks to you, pch300, I think I'm going to do this repair myself. I have been thinking about the project, and I believe I have come up with a winning idea on how to ensure success with avoidance of rubbing of voice coil. 

I would take all your suggestions, essentially, which are superb; thank you! 

But, in addition, when I got to the part where I would secure the outer rim of the surround to the metal basket, the thought struck me, why not use some painter's tape, or similar, to temporarily anchor the surround's outer edge, then play the speaker to assess for rubbing? If it rubs, I move it and reattach with tape. The tape should not damage the new surround, and it can be moved at will. In that way I should be able to then work around the bottom of the surround with glue, removing the tape locations and ensuring the proper position of the surround. I can also mark the edge, as you suggested for extra caution/precision. 

Obviously, I do not want to crank them up in that condition, as the tape might pull on the driver paper. Then again, I have bigger problems if the surround anchored to the paper pulls away! That had better be right! One has to use some sensibility. I could even, perhaps, use some narrow weights of some sort to place on the surround as an anchor. I would be able to find something suitable. 

I think I'm going to remove the drivers baskets today from the cabinet, and turn the drivers over to settle the one spider that's sagging. I also can begin to work on replacing the wiring and posts, which are antiquated and by today's standards poor. 

Sounds  feasible. Ideas, concerns? 

Doug, I did the surround because I really didn't have much choice. Either fix it or get it fixed so I can use the speakers. Again, it won't be like the original F, because the surround characteristics is different than what Ohm had. It will play, however, as a interim solution until I got new Ohms.

I didn't use tape of any kind, because I was afraid the tape could tear the surround attachment part. The new and old surrounds could have different attachment ring diameters. I just thought of an idea that you could use the painters tape to mark the original edge of the surround attachment to the metal rim say in four perpendicular locations, but not on the surround itself. When you try to attach the new surround, it will either be smaller diameter which makes it easier to center relative to the tape, or larger diameter which you'd have to mark the new diameter with more tape and compare the original and new marked positions for centering. You could also measure the new surround diameter and mark that with additional tape relative to the original surround diameter tape marks.

I don't recall what glue was used for the surrounds. I ordered the surrounds from Stepp Audio Technologies in North Carolina. I supplied them the relevant dimensions and cone angle. I cannot find that company anymore on the web. It was 25 years ago!

The spider sagging is from years of weight on it. It could be permanently deformed. I would doubt that turning the driver over will do much in correcting the position, but it's worth a try to see what you get over a given time. 

If you're talking the internal cabinet wiring and the binding posts on the bottom of the cabinet, that's conceptually easier to do. I would caution on working on the binding posts on the metal struts holding the magnet assembly, as these attach the fragile wires that go to the cone internal wiring.

If you do fix the surrounds on the F, your could then try an experiment that I did in the mid-'80s, with a musician friend.

Remove the grilles. Have a friend listen to the same musical selection. Without him knowing or seeing what you do, remove the fuses and replace it with a short wire. Play the music. Go back to the fuse, and play the music. Then go back and forth. Without telling him what you were changing, ask what he heard for the two configurations. Get a good description. For my friend, it was clearly and consistently audibly different, and repeatable in his descriptions.

As for the internal cabinet wiring of the F, I bypassed it by directly attaching the speaker wire to the binding posts on the driver struts, and left the internal wiring unused.

pch300, that is a terrific idea (if one wishes to bypass), to go direct to the inputs on the driver struts! Superb! That will be my game plan, should the speaker's renovation come out ok. Excellent, and beneficial advice! Personally, this has been among the most practically� beneficial threads I have benefitted from on Agon.  :) 

In preparation for the reconditioning of the spiders and surrounds of the Ohm Walsh F, I removed the assembly to discover VERY stuffed cabinets! Wow, talk about jammed to the gills with what appears to be a mesh sack full of foam chunks! My first thought is, "Well, that would deaden a speaker pretty quickly!" 

I'm planning on removing this sack of debris and conducting tests with other materials. I presume that if the cabinet is left sparse, the sound signature will change radically, and likely for the worse. I wonder, however, if the mid to high frequency response will improve if a mountain of foam is not literally semi-blocking the drivers. 

As I'm thinking this through, I suspect the reason the bass bin was jammed so full was to force the sound to emanate from the driver versus emptying into the cabinet, and I also suspect the delayed propagation of the wave into the cabinet might be pretty ugly sounding. But, who knows until tried? 

I would think that a different foam might confer a nice improvement to the speaker's sound. I think I'm going to start with an empty cabinet beneath to assess the range of effects. 

Has anyone else experimented with that aspect of the speaker? 

The Ohm F is a acoustic suspension speaker system, which means the cabinet is a sealed box. Because of the sealed cabinet and no crossovers, the system should roll off at 12 dB/octave below the cutoff frequency. I think the foam stuffing so full in the box is there for a specific purpose. You'd have to ask Ohm whether the stuffing is there for the purpose I think is.

In an acoustic suspension speaker box design, lining the internal cabinet walls with absorptive material is one method used to damp the sound wave reflections inside, reducing standing waves. Stuffing the box loosely-full will change the thermodynamics inside the box as well. This makes the box act as if it were bigger than its actual physical internal dimensions. That lowers the resonant frequency, so extends the bass when using a smaller cabinet volume that otherwise would have been bigger. There is a tradeoff with this - lower efficiency, for example. If I remember, this affects the system Q (resonant peak width) too, through damping.

The stiffness of the surround and spider along with the moving mass (plus damping) contributes to defining the resonant frequency of the driver. That in conjunction with the cabinet size and stuffing determines the system resonant frequency in the bass, among other things. Any changes you make to the surround or spider stiffness will affect these things. 

I suspect that in the Ohm F, the internal stuffing plays another role, that of absorbing the acoustic wave emitted by the inside surfaces of the cone. Otherwise, the internal reflections will interfere with the later sound waves travelling down the cone.

Pch300, yup, parallel thoughts here.  :)
I'll just have to experiment,  and of course keep the original stuffing in case I need to revert to it. However,  as with many things in audio, I have found that a decent design may be improved. Emphasis on "may", as no one knows unless tried. That's how I came up with the Schroeder Method of IC Placement.   I'm guessing it will be really ugly without any damping,  but I want to explore the spectrum  because I suspect an even better result is attainable.  

Should be an interesting project.  

Initial assessment of drivers upon removal of the top assembly (anchored by wing nuts) is that they are repairable. Cones are in great shape, and I'll be going for a replacement of spider and surround, leaving the original voice coil intact. This may not be the premium fix, but I understand a complete rebuild would be more touchy and more expensive. I'm out to have affordable fun - after all, they were free, and I was not seeking a reference omni. 

Suggestions for batting/damping material? Perhaps a trip to the local hobby shop or sewing center is in order. I wonder if furniture foam would be ideal? Frankly, that seems to be the chunks in the bag in the cabinet. 

Be carefull of the $$$ scammers out their, 7 - 8 Grand in just insane period. The two names mentioned here, Dale and Bill are perhaps the last two people that can do them correct. Mr Bill LeGall told me about 15 years ago he only did maybe a couple a year. Bill had agreed to do my F"s but I then backed out. Have owned many nice pairs over the years, but its always like walking on eggshells their so fragile to overpower.

Had the 3000 series for Ohm 4XO install breaking in, then a right ch. tweeter went and i returned and got my funds back. Did have Ohm redo my 4XO drivers. Funny mine weight twice as much as them 3000 series drivers. Still love the model F ..... just not scrambled eggs!

musicbox78, some great pointers; thanks! I am not an aggressive listener, and I am not about trying to recreate live listening level. I do respect vintage gear, so I think the odds of destruction through use are reduced. 

I think I'm in contact with the right people, ones with experience, including discussion with Dale and Bill. To clarify, the estimated $7-8K was for Dale to use the old cabinets and build an entirely new speaker with new parts, not recondition of the old cone. I feel that is a very fair price all told, but my interest was not to seek a reference, or add a big gun speaker, but to see if the freebies could be used regularly. I will be putting some money into them, but looks to be reasonable expenditure. I feel pretty good about the connections I'm making. 

If I had no other speaker to enjoy, I would be very tempted by the complete rebuild by HHR Exotic. I would likely guide most owners to seek the rebuild of the entire speaker. My situation is unique for many reasons. 

7-8 grand to redo with old cabs would be very tempting for me were I not completely happy with my F5s.

I agree with mapman. If it is 7-8 grand for new drivers from Dale, I'd have gone for it before. Maybe it's worth a call to Dale even now. I still have the F cabinets.