Sean,
Try to contact Judith Fulkerson, aka JBL Judy, at 248.628.5051. She is in the Oxford, Michigan area. I have used her in the past to repair some beloved JBL L65 speakers. You may have to ship the parts/speakers to her...give her a call! P.S. Area codes change here often so try 586 if the 248 fails. Good Luck!
Regards, |
Ok, you've got me and I'm sure others curious. Kind of like seeing a dumpster in your neighbors yard, you gotta know what that project is all about. |
Let's just say that one of my Ohm F's is terminated and another is limping along due to my local power company. I've been having bad problems with the AC lately and today was the topper.
In the last two months, my power has gone down at least a half dozen times. On two different occassions, the pole transformer on my street caught fire. Other times, the power simply blinked out and then came back on a short period of time later. This time, the power shut down and then popped back on about two minutes later.
As to how the F's were damaged, I was using a set of them as temporary fill-in's on my HT system. I don't normally have these speakers in this system, but i pulled my HT mains apart. I don't know if this was simply fate or bad timing for me to have them in this system, but what's done is done. Now i've got to try and clean up the mess.
What happened is that when the power came back on, the CD that was in my Denon 2900 began to play. Somehow, probably due to the voltage glitch, the volume was cranked WAY up on my Pre / Pro. Once the sound started, there was a horrendous amount of racket coming from one speaker and then nothing. After checking the noisy speaker, the coil exploded and the driver is now bound up. The other speaker kept chugging along but doesn't smell nor sound too good.
After making a few phone calls to different speaker repair professionals, i was given some very good information. Bill of Millersound gave me quite a bit of helpful info pertaining to upgrade modifications to make to the drivers. He figured that so long as i have to have them rebuilt from the ground up, i might as well do them up gung-ho. Only problem is, Bill is really busy and these upgrades / driver rebuilds are so time consuming that he said that he could not take on such a job at this time. On top of that, he said that he doesn't see the time coming up to do anything with them in the near future either. Talk about getting one's hopes up and then having them smashed to pieces.
Having said that, Bill was kind enough to make me aware of the parts needed and what was involved in doing this work. Only problem is, i simply don't have the time to do this myself. On top of that, i'm going to end up filing a claim with my local electric provider, so i can't dilly-dally in terms of time or shopping around for a bunch of estimates.
As such, what i'm looking for is someone that can dis-assemble my Walsh drivers, clean everything up and rebuild them using very specific parts that i'll specify. From what i can tell, these are VERY unorthodox parts that nobody would ever think to use on this driver. This would primarily be due to all of the modifications involved to get them to work properly as they were never designed to work on this type of driver.
In effect, these drivers would be completely re-designed in terms of the suspension used and the electro-mechanical characteristics. Given that these are the hardest dynamic drivers to work on in stock form ( i've been told this by several different speaker repair facilities ), i can see why the average "speaker refoamer" doesn't want to tackle such a project. I'm not against doing it myself, but as i stated, time may be of the essence once a claim is filed. Any suggestions as to who to talk to about such a project? Sean
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PS... During my conversation with Bill, he spoke phenomenally highly of these drivers, both in stock and "super-rebuilt" form. His thoughts were that no other driver that he has ever experienced offered the bass response and extension that this driver did. As i've mentioned before in these forums, i also share the same thoughts. The fact that they have the potential for very drastic improvements over what they offered in stock form really has me stoked. Maybe this isn't going to be such a bad thing after all : ) |
Sorry about your loss.
I really doubt that you can get anything out of the power company. It is a fact of life that power goes off and back on from time to time, and electronic equipment that can't withstand this is arguably faulty. When you tell the court how many watts you have hooked up to these drivers it will be all over.
If you don't want this to happen again (power coming on again) what you need is a "latching relay" in your AC power...maybe just for the prepro. Or fuses in your speakers. Simple fix either way. |
I guess i'll have to wait and see what happens with Commonwealth Edison. I've been pretty good at negotiating insurance claims in the past, but i've never dealt with them before.
Other than that, these speakers have fuses in them from the factory. A lot of good they did i.e. they are still intact. As far as the value goes, i can't recall what they are. I know that i've popped them in the past and replaced them with whatever was in there from the factory. I normally don't like fuses in the signal path, but with the lack of repairability on these drivers, i figured that i'd live with the sonic sacrifice. Then again, i've never had them hooked up to an amp that could deliver 2500+ wpc into them on demand either. Maybe that is a bit too much power for these speakers. Sean
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Sean: I trust Bill implicitly. It sounds like such a major job that perhaps your best bet is to get a replacement pair. He clearly doesn't want to take on a project that involved and believe me he knows what a truly proper repair really is. He will do some major rehabs but if he says its simply too much - its simply too much. What did Ohm tell you- |
2500+ wpc (...) on demand (...) maybe ...is A BIT too much power for these speakers.. Sean: tsk, tsk, tsk (my emphasis). I'm sorry for the resulting complications -- and I doubt you could have done s/thing in advance to avoid this (the fuses would hardly be fast enough to save the game) -- other than implementing the relay El mentioned. Good luck |
Freeman-Tuell, 214-324-1132. in Dallas Well known among both home and pro audio folks. Give em' a call. |
Mechans: Bill has done this very job many times before from what he told me. As such, it is nothing new to him or too complicated to handle. He simply can't dedicate the amount of necessary time to do the job now. If he were to do that, he would end up loosing money and alienating other customers, which he won't do because he's a good businessman.
Other than that, Ohm doesn't work on these speakers and hasn't done so for several years now. As it is, i wouldn't want to use the stock parts after having talked to Bill and knowing what i do now.
Woodman: I'll try giving them a call in the morning and feel them out. Thanks for the info.
As a side note, i pulled apart a set of Polk 10's that i had sitting in my basement last night. The mid-woofers had previously been replaced with newer, higher grade drivers by my Brother. One of the binding posts had broken off, so i repaired that problem. While i had the one apart, i decided to rewire the cabinet. I replaced the stock tweeter wiring with 22 gauge Silver / Teflon twisted pair conductors. The mid-woofers, which were originally wired "daisy chain" fashion with something like 18 gauge or so, each received their own 12 gauge Silver / Teflon twisted pair feedlines. I used Cardas solder on all connections.
After firing them up, i was expecting to be killed by the typically bright sound of fresh Silver cabling, but i was pleasantly surprised. The sound was actually much smoother than anticipated. Bass was drastically improved in terms of attack, definition and over-all tightness i.e. much less overhang. Bass had surprising "slam" for having only two 6.5" mid-woofers with a 10" passive per cabinet. Then again, the lack of overhang and improved impact may have to do with the rest of the system. Given that i've never had the Polks hooked up to a true voltage source that can easily deliver 1200+ wpc into their 4 ohm load, the sheer "gripping power" of this type of amp may have something to do with this also.
The warmth region now sounds much cleaner, but is a little lean sounding. This is something i've noticed on previous re-wiring jobs i.e. the sound tends to fill out a bit as the wiring / connections settle in. I know that some folks may have a hard time believing something like this, and i did too at first, but i've almost come to expect this now.
The treble response took a change for the better too. Overall, it sounds noticeably cleaner. On one disc that i listened to, the drummer kept striking the "bell" ( center dome ) of a cymbal repeatedly. Quite honestly, i was amazed at how sharp, clean and "real" this sounded. Then he started wailing on the cymbals and everything went back to the old Polk treble that i was used to, but not quite as bad. That is, the treble was smeared and lacking definition. My guess is that individual cymbal strikes are handled reasonably well by the tweeter, but it just doesn't have the transient response to keep up with high intensity rapid fire reproduction of multiple signals all at once.
For now, these will have to suffice for the mains in my HT system. This may give me some added incentive to get busy on the original speakers i had in that system. Not only did i pull them apart to do some more work on them, i also lent out the matching rears that i had for that system. I'm rebuilding some speakers for a friend, so i gave him the towers that i was using as rears to use until i could get his speakers done. As such, my HT system is a real hodge-podge of mix-n-match speaker brands and designs. Sean
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Sean, during a conversation with Bill yesterday, we discussed your plight.
He said you were an incredibly nice individual(which I told him - he didn't know you and I were friends), and hoped that he was able to steer you in the right direction. He gave me so much information on how to rebuild the speakers that after a while, my head was spinning.
In his opinion, these are perhaps the finest speakers ever designed from a conceptual perspective. However, there have never been a pair from the factory that were assembled correctly. They are, in essence, broken from the day they are made.
That being said, with his pointers, which made a lot of sense to me, most of the flaws can be corrected, and the dream of this concept seems to have the potential to be realized. Again, he feels they are probably the BEST speakers ever made - at least once his modifications are implemented.
Sadly, Bill doesn't really tackle audiophile's projects anymore. He will do the occasional side job for someone close to him (what he did to my Coincidents was astounding). He really only wants to rebuild drivers, though the Ohms aren't something he'll get involved with anymore. He does have his own pair, which he told me he keeps putting off.
Inevitably, being around him enough shows you the greatness of the man. The MOST costly and/or highly regarded designs of the so - called experts usually have such flaws that he almost cries. His gift lies in taking a look and listen to the speaker and figuring out exactly what is wrong, and correcting these issues in shockingly simple and CHEEEEEEEEEEAAAAAAAAAAAAAAP ways. I honestly believe that he does more to improve a loudspeaker with $10 than most any manufacturer's $1000 upgrade. I have just seen it time and time and time again. I wish that more people were able to see the magic this man's soul possesses, manifested to us through his mind and hands.
I am sure your conversation with him left you a lot better able to attack this job than you were before. Hopefully, it will turn out great! |
Joe: When i was talking to Bill, i was going to mention your name, but i ended up getting sidetracked with the conversation that we were having. Needless to say, i was glad to have found someone that shared my love of this speaker and the specific design & performance attributes that it brings with it. This is especially true given Bill's level of exposure and experience with hundreds upon hundreds of various drivers and loudspeaker designs.
As you mentioned, Bill is very high on these speakers as they are from the factory, even though they could have been done better. He also mentioned to me that they are unrivaled once fully modified in the manner that he discussed. As i've mentioned in some other threads, these speakers, even with the less than optimum assembly from the factory, do some things so well that i will never part with mine. While they do have their shortcomings, Bill seems to think that his modifications fully address those problems. After discussing things with him, i can see how / why these problems / design shortcomings come about and how easy they would be to correct. I now realize how much better they may be after performing such mods to them.
Having said that, i've come up with a few design innovations that take his tweeks a bit further. The nice thing is that they involve the same amount of work, so they wouldn't be any tougher to impliment. Given that i'll probably end up rebuilding these drivers myself, i'm going to incorporate these ideas into the rebuild and see how it goes. My thoughts are that Bill's suggestions should improve performance quite drastically with my revisions simply adding a hair more icing to the cake.
Quite honestly, i've very seriously thought about producing a speaker similar to these, but made in a much more modern design. I've gone over a million different electro-mechanical design revisions in my head and keep coming back to one specific concept. This is all still in my head though, so maybe i'll be able to try out some of these ideas on my F drivers if / when i get around to rebuilding them.
At the same time that all of this is going on, my Brother is currently trying to build a prototype of a driver that he designed. I've tried to get him to work with me on the design of the driver that i have in my head, but he's got his mind on his own projects. While he is interested in the design that i came up with and would like to tinker with it, he wants to build his design first. His design is both easier and more conventional in operation than what i want to do. If he can get it to work as he thinks it will, that technology could be applied to my design too. Having said that, there's not a driver made that operates like what he has in mind, so even it is not exactly a "normal" dynamic driver. This driver should offer a phenomenal amount of control, transient capabilities and excursion capacity without generating near as much reflected EMF or impedance variations. Coupling those qualities with a Walsh based full-range omni-directional driver could prove to be a great thing. Needless to say, this is all a pipe dream at this stage of the game : ) Sean
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Sean...Why the tease? You have told us that the Walsh driver has all these faults, and you have ways to fix them, but we have not the slightest idea what you are talking about. Quite frustrating to your readers. |
El: As i mentioned, i've actually contemplated building and marketing such a design from the ground up. I've been thinking about this for quite some time, but it is probably "just a thought". Either way, i've bitten my tongue in this area on purpose, at least publicly, for this reason. I have worked with a few people privately in terms of performing simple tweaks to their F's, which can noticeably improve the performance of this speaker system.
There is another factor involved here though. There were several different production changes to this driver while it was alive. As such, they vary in performance and what needs to be addressed. Without really looking at the drivers, cabinets and damping materials themselves, it is pretty hard to give vague and generic advice.
Much of this is why Bill at Millersound doesn't want to take on these types of projects anymore. He told me that due to production tolerances and differences, it may take him up to 3 complete assemblies & dis-assemblies to get the driver where he wants it to be. Given that this is a VERY difficult driver to work with in the first place, we are talking about a massive amount of time & labour. This is one of the reasons why he considers the drivers to be "broken from the factory".
For those that are interested, I will say that these speakers benefit massively from bypassing the internal factory wiring. The effects of this are NOT subtle to say the least. Altering the type / density / placement of damping material within the cabinet can also make a big difference, improving the transient response and damping characteristics of the driver. How much material and what to use will vary depending on the individual characteristics of the driver being used.
The Walsh's will also benefit from damping the frame rails and motor structure as they are modulated by the motion and the output of the cone. This is not to mention the diffraction that takes place due to having the frame rails in close proximity to the source of radiation. I've devised a much better way to get around this, but i can't impliment it without building a driver from scratch.
As far as modifications go, the really tough stuff comes down to altering the mechanical design of the driver itself. I can see dozens of ways to improve this, which should be obvious to those familiar with speaker design. Then again, most of these involved gutting the driver and almost starting over from scratch. Starting completely from scratch would actually be best, but at the same time and as you know, the likelihood of success is much higher when starting off with a proven commodity.
The fact that Bill offered very specific suggestions as to what he's found to work best in terms of upgrading / addressing some of those problems really helped me out in that area. The fact that i discussed this with several professional rebuilders / reconers and it left them dazed told me that most non-professionals wouldn't be interested in such info. It gets very involved as the parts used require modification for use, so you can't even resort to "off the shelf" substitution.
As such, i refrained from posting such info. Someone attempting to perform such work without basic levels of experience will most assuredly destroy an irreplaceable driver that i dearly love. This is much the same reason that i had previously refrained from posting specific info about AC systems, as i didn't want to encourage potential hazards with even more serious potential results. The only reason that i did so was at the private request of several different Agon members who are / were dealing with that situation at the time. Sean
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Sean...Although I am a long time admirer of the FR Walsh driver I am not familiar with details of how it is assembled. However, as an engineer, I offer the following suggestions.
1. Big picture...The existing design appears to be difficult to build, nearly impossible to repair, and requiring a lot of skilled manual tweaking. It seems to me that this design was taken from the lab directly to production, without the essential step of industrial design/producability engineering. Redesign the thing so as to retain the basic concept of the traveling wave down the tapered cone, but with simple more automated fabrication as a primary goal. (What is the patent status of the Walsh driver?)
2. I always wondered about the basket legs getting in the way. Why not use a massive "C" structure instead of a basket?
3. Don't worry about efficiency. Powerful amps are cheap today, and (with digital technology) getting cheaper.
Send me a copy for evaluation :-) |
Why not use a massive "C" structure instead of a basket Shape it as a sphere (no sharp angles) while you're at it. Get rid of some of thems standing waves & feedback. * Also, pls extend usable FR 120-22kHz, if possible, w/out a wizzer. * Pls provide a +24T strength magnet (for wont of better matl, alnico is aceptable). Cheers |
Gregm...Sphere? I don't understand. You do realize that the sound comes off what most people would think is the back of the cone. My C structure really gets rid of all the basket legs except one, and that one would need to be strong. |
Hey Sean,
Thanks for all the tech advice you gave me. I don't know where you are located but Bill Thalman's company might be able to help you. Just in case you don't know, Bill is the former designer/chief engineer of Conrad Johnson who formed his own company: Music Technology. The company also offers speaker repair service. Try: Musictechnology.com/askatech.html
Hope this helps.
Best regards! |
El, I just meant that the leg could be curved. Sorry. |
No "support legs" necessary. I figured that part out long ago ; )
As far as a frequency response of 120 Hz - 22 Khz, "decent" Ohm F will do WAY below 20 Hz up to somewhere between 15-17 KHz. If anything, i'd rather sacrifice some of the bottom end for a little more top end output and extension. This would help to even out the tonal balance as the bottom end on these things is P-O-T-E-N-T !!! Sean
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Sean -- are you accepting pre-orders?? |
Greg: All i can say to that is.... BWA-HAhahaha... You would have better luck investing in venture capital with junk bond king Michael Milliken than you would waiting for me on a project of this magnitude and scope. Too many different projects and a lack of motivation to get them all done. I'm so spread out it is ridiculous. The bad thing is, i know i'm throwing away gobs of money on so many different ideas and marketable products ( not only electronics ) that i have in my head that it isn't funny.
If you learn one thing from and about me, learn this. Most Irish people are great tellers of tales and history, not the actual people that go out and make history happen. If the opposite were true, the corner saloons and pubs would be empty. All of those sitting round nursing a drink and spinning great and enjoyable yarns would get up off their ass and become the subject of those types of stories, not telling people of others' exploits. then again, those bar stools ( and computer chairs ) can get quite comfortable. Know what i mean? Sean
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PS... To those of you that are of Irish descent and have their act together, i'm sorry for lumping you in with the rest of us. Drop me an email and share your secret with me, will ya? : ) |
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Sean...It would be interesting to read a A-B comparison review between the F's and Ohm's latest Walsh. I know they are different in many, many ways; the fact that they both have inverted cones may be the only thing left that they have in common and even at that, the cones are radicaly different. That being said...i have read a few reviews by people that did have the F's and traded them in for the latest Walsh and prefered the new ones, but they also got new electronics. Before i ordered the latest Walsh, i asked John at Ohm about the F's and he said the Walsh 5 MK-2 sound better. Another thing he said about the F's that i did not know, is that being that they are omni-directional, placement of the speakers becomes critical and sweet area becomes much smaller.
I would find your review on the Walsh 5 MK-2 very interesting, but as far as i know, you have never heard them. I have heard the F's once in a Shop a very long time ago and just remember i liked there spacious sound, but at that time i did not have two dimes to rub together. |
Line: I can rattle off all kinds of reasons as to why the F's are ( theoretically ) technically superior to anything that Ohm makes today. I've covered some of that in previous posts pertaining to Ohm's and their Walsh series of products.
The fact that all of their newer products are vented compared to their sealed designs in the past tells me that they are no longer the same company. When one fully understands the design benefits & drawbacks of each approach, it would be hard to switch from one to the other, especially in the manner that Ohm did. Then again, vented boxes are cheaper to produce than sealed boxes are, so that may explain part of the equation in itself.
As to asking John at Ohm as to what he thinks sounds better, what type of response did you think you were going to get? Read the comments above about the complexity of this driver and then you'll understand why they stopped producing them. The fact that the amount of time that it takes for them to hand build one F driver is probably equivalent to building an entire set of their current speakers may explain some things. That is, time equals money. The less time and labour that you have in a product that you can sell for the same price equals a higher profit margin. Less cost on the drivers, less cost on the cabinets and same or even higher asking price. Hmmmm....
On top of that, you're comparing notes with John who owns Ohm. How many different makes / models of high end speakers do you think that he has gone out of his way to hear and actually listened to in-depth? Now compare that answer to Bill at Millersound, who has seen / repaired / listened to thousands of different makes and models. Given Bill's level of experience and exposure, the comments that he made pertaining to the performance potential of this speaker should tell you something. Sean
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PS... Anyone that tells you that the F's have a "small sweet spot" is either a blatant liar or is "confused" and knows not of what they speak. A small sweet spot boils down to a lack of horizontal dispersion. Between an omni driver and one using a focused array, can you tell me which one is going to be more limited in horizontal dispersion??? I'll give you a hint. Once i was able to get them dialed in with the proper support components, my F's have produced the deepest and widest soundstage that i've ever encountered. |
Sean
I have a pair of F's from Bill at Miller sound, and they are impressive. I found him while trying to get my G's repaired and like you was impressed with the conversation with him. So after a few talks with him he told me that I could do it myself and so I have. I had a good time doing it and they all have come out great. I get my parts from Tom at WVS (recone.com) 260-424-5463.
The problem is they are time consuming just to clean out the epoxy alone, and man if you are not careful it is lost. Imagine trying to find another cone.
I am sure Bill told you that if he did do it you should not ship them (lost or damaged and it is all over), only personal delivery. I praise Bill for what he has taught me about the repairs.
I could go on about this forever, but I will say that damn can they handle power now. BILL DO NOT READ THIS lets say the meter has danced between 200 and 400 watts quite a bit. As for the sound try The Devil Went Down to Gorgia will make your hair stand up. |
