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  1. #1
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    2nd Posting - Someone Please Advise!

    Can somebody tell a female who is only just about to attempt a speaker repair for the first time how to tell what is wrong with a mid-range driver in a 3-way speaker? What should I do to tell whether it's the actual speaker cone or the wiring or cross-over which is at fault please? I have looked all over the Internet for advice to no avail. Failing that can anyone recommend a beginner's easy to understand book which would take me through from the beginning. The fault by the way is a sort of fuzziness at higher volumes, I have swopped speaker cables around and it's still the same speaker so it's not my amp or cd player or anything. Thanks in anticipation. The speakers in question are vintage Celestion Ditton 66s, I know I will have to probably wait a long time to find the replacement part required but these speakers are so amazing I won't give up on them. Failing that can anyone recommend a speaker repair Docter in Berks or Oxon please.

  2. #2
    Forum Regular Mike Anderson's Avatar
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    I'll tell you the answer, as soon as I figure out how your being female figures into it.
    There's an audiophile born every minute. Congratulations; you're right on time.

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  3. #3
    Big science. Hallelujah. noddin0ff's Avatar
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  4. #4
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    Quote Originally Posted by Mike Anderson
    I'll tell you the answer, as soon as I figure out how your being female figures into it.
    You're right - it doesn't, guess I'm pretty desperate to get my hi-fi sounding right again.

    It looks as if I've managed to track down the right cross over and what looks like the right driver and thought if I bought these I would have every possible component for every possible fault but when I look inside my speaker I now see it also contains a circuit board - as you can see I am a pretty ignorant re what happens inside a speaker. I would be very grateful for any advice you can give - Celestion UK (I reside in the UK) have told me that they will no longer service and repair these amazing vintage speakers, gutted.

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    Quote Originally Posted by noddin0ff
    Thanks, I'll do that.

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    Forum Regular Mike Anderson's Avatar
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    You're right - it doesn't, guess I'm pretty desperate to get my hi-fi sounding right again.
    I was just joking though, hope you didn't take it the wrong way.

    It's the second time in a week I've seen someone point out that they're a woman in order to get help -- Not that there's anything wrong with that mind you.
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  7. #7
    Forum Regular hermanv's Avatar
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    Almost all components such as those used in crossovers fail catastrophically, that is to say they open or they short out. Rarely will this kind of failure result in a degradation of sound, mostly the sound from that driver just quits. Not always, many here will think of examples where this might not be true but driver failure is really quite common.

    So, odds are that the driver is damaged, recone services are easy to find (just type "recone speaker" into Google for example).

    There are people who have done this recone themselves, it requires a great deal of manual dexterity and a good supply of tools. The drivers could be replaced by more modern ones but most liklely the crossover design would need to change. Given your original question you may not have the background or desire to learn this stuff.

    Many here and on the DIY site will help, if you have the patience and time. One problem is finding the truly knowledgeable as opposed to those who merely think they know (moi? )

  8. #8
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    [QUOTE=hermanv]

    Thank you Hermany, this is the sort of advice I am looking for. I don't quite understand what you mean with reference to my first posting. I have since that posting located a correct cross over at a low price and possibly the correct driver but was dismayed when looking inside the speaker to see a large circuit board too as well as wires and drivers - speakers are more complex than I thought. Assuming it is the driver, thank you for your help and advice, I would not want to put a modern equivalent in - this particular mid-range driver in the Celestion Ditton 66s is what makes them truly amazing, these speakers were only recently made redundant by the British Broadcasting Corporation and came from them to me. If the driver for sale is the correct and identical one and is not ridiculously expensive then I will buy it, it would re reassuring to have spares for these speakers so it wouldn't matter if the driver turned out not to be at fault or if the original needed re-coning and could be done. By the way I know what the cone is but in the bass drivers the cone is easy to see, I am confused by this mid-range driver - the centre of the speaker contains a tiny cone over a metal cone and there is very little outside 'cone' to see - which bit is actually the cone and should it be easy to see if it is damaged, I can see no tears or holes or anything
    Last edited by Laneyflower; 10-28-2005 at 06:04 AM.

  9. #9
    Class of the clown GMichael's Avatar
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    Do you have any pics?
    WARNING! - The Surgeon General has determined that, time spent listening to music is not deducted from one's lifespan.

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    Forum Regular hermanv's Avatar
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    One more thought

    Posted too soon. If you are determined to isolate the problem, one safe technique would be to swap midrange drivers from one speaker cabinet to the other. If the problem follows the driver ta da! If not obviously the crossover or some other internal speaker part is faulty.

    Be sure to note the polarity of the wires when you remove them. Also note that the driver is probably glued to the front baffle (air leaks are not allowed) so it may be difficult to remove it. Prying is dangerous because you might distort the driver frame or mounting flange. Internal clearances from voice coil to magnet or frame are often 1/50mm or less, drivers can be delicate.

  11. #11
    Forum Regular Florian's Avatar
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    Quote Originally Posted by GMichael
    Do you have any pics?
    But only if they are tasty Just kidding!
    Lots of music but not enough time for it all

  12. #12
    Forum Regular N. Abstentia's Avatar
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    Actually that circuit board IS the crossover.

  13. #13
    Forum Regular hermanv's Avatar
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    Quote Originally Posted by Laneyflower
    I don't quite understand what you mean with reference to my first posting. ................ I am confused by this mid-range driver - the centre of the speaker contains a tiny cone over a metal cone and there is very little outside 'cone' to see - which bit is actually the cone and should it be easy to see if it is damaged, I can see no tears or holes or anything
    Certainly nothing about your basic ability was meant, it's just that speakers involve a great deal of very speciallized knowledge and based on the way you asked and also the closing line on your recent post implies you have little driver knowledge.

    The description of the cone you supply reads more like an inverted cone driver or could you be looking at the tweeter? Midrange inverted cone drivers are usually 5 to 15 cm in diameter and are convex instead of concave. Almost all tweeters are made this way but their diameters usually fall into the 1.5 to 3 cm range. Midranges may have convex or concave dust caps whose diameter can be anywhere from 10 to 70% of the cone diameter, some have a phase plug which is mostly shaped like a missle nose cone, centered and usually does not move with the main cone.

    In any event, many driver failures can not be seen because they happen inside the motor. A very common driver failure is a distortion of the cone supports, this allows the voice coil inside the driver to rub on an internal part, usually this is awful but if it just barely touches at high excursions, it might cause a "fuzziness" Cone supports are a "spider" at the base of the cone (at the back outside the cone) usually pleated and a surround ring at the front outside edge of the cone which may be pleated paper, doped silk or some kind of rubber.

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    Thanks Hermany, G Michael and N Abstentia and everybody. I will post some pics later. The cross over I am being offered on Ebay as the correct one for my speaker looks as though it would replace some but not all of the components on the circuit board. ????? I will swop the mid-range drivers over, I can do that and will post my results along with pics of the driver. What I also don't understand is that the tiny little paper cones covering metal sort of gridded cones in the centre of both mid range drivers have come away but the other driver plays perfectly so these can't be the cones??? It looks as if the glue has given out, both of these little paper cones are intact. I will post pics later.

  15. #15
    Forum Regular royphil345's Avatar
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    Sounds like the mid drivers could use repair or reconing. Sounds from your description like the dust caps have come unglued. They can be glued back on with a special glue for speakers. A loose dust cap or any other part of the driver coming unglued will cause a "buzzing" or "fuzzy" sound at higher volumes (from vibrating against other parts). This may be your only problem or just part. It's not a good idea to use the speakers with loose dust caps. Dust can build up between the voice coil and magnet structure and cause damage. A damaged voice coil can also cause the "buzzing" or "fuzzy sound. Like hermanv suggested, run a search for speaker repair or speaker reconing and ask a few places if they can restore your particular driver to original specs. They will tell you how to ship the drivers without causing further damage. No need to find a local place. I would have the mids on both speakers repaired / reconed at the same time to make sure they sound exactly the same. Do make sure you don't mix up the polarity (+ -) when reinstalling the drivers.

    The PC board in your speakers is the crossover network. A more complex crossover network can include a good many parts. I would agree it's probably not the culprit. However, the capacitors on older crossovers can wear out and go out of spec. They could be easily and inexpensively changed by someone who knows what they're doing. Wouldn't be a bad idea on any older speaker. Probably not something you should try youself with limited experience soldering, parts / polarity matching though. As far as wiring goes... I'd just clean anywhere there is a connection that isn't soldered with a good contact cleaner.

    I'd probably lean more towards getting the drivers rebuilt (although some can't be rebuilt) and the crossovers recapped (capicitors changed) than replacing old, worn-out drivers and crossovers with other old, worn-out drivers and crossovers.

  16. #16
    Loving This kexodusc's Avatar
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    Have you tried the obvious? Sometimes a midrange starts to fuzz just because the screws that lock it in aren't tight, or the wood/MDF/particleboard it's screwed into gives way. I've had this happen to me on 3 different speakers now. Some screws just don't get along with MDF all that well.

    Hopefully your driver swapping will reveal a bit more to us.

  17. #17
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    its really hard to say without knowing exactly what the sound that it is making is. the driver could need repair. I have been successful with lifting most cone assemblies out of their basket and repairing deformed coils, or removing debris with out really any damage to anything. another thing it could be if you find it is the crossover when you switch midranges around is that there is probably a bad capacitor in the crossover which isnt properly holding voltage.

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    Celestion Ditton 66 Studio Monitor - Driver At Fault!

    Thank You so much to Hermany and everybody else here that has advised me. I had already tried using the system with the loose dust covers removed - fault still there and I had already removed/sorted out some loose screws - fault still there. (I will purchase the correct glue and glue the dustcovers back on) I have just swopped drivers from right to left speakers and the problem followed the driver - hurray, fault found. I had already some time ago with previous speakers tried to find a speaker repair service in the UK to no avail so have now gone international and am awaiting replies from two companies in the USA as to whether they can recone/repair this driver - I have sent them all the specs written on the back. Hopefully I will find a company to repair this wonderful driver (I will have both done) and I am waiting for an Ebay seller to get back to me as to whether his Celestion mid-range driver in perfect working order is identical to mine so it looks as though I may be able to sort out my problem!! I have uploaded a pics of a C Ditton 66 Studio Monitor for anyone who wishes to see these wonderful speakers - the unit in the bottom is not a driver, I have read on the net what it is, it sort of deepens and resonates the bass, hence their wonderful sound and have uploaded a pic of the offending driver in the cabinet. I will update as to my progress with sorting this problem, thank you everybody.
    Last edited by Laneyflower; 10-28-2005 at 09:13 AM.

  19. #19
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    2nd Photo


  20. #20
    Forum Regular hermanv's Avatar
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    Just curious

    Do you listen with those square holed grilles on or off the speaker? (I think grilles is how the British would spell it ).

    They look like metal, my experience with any kind of metal grill is not good, they ring.

    If you listen with them on, try tapping one with the end of a pencil eraser, does it ring? If so, and you must have the protection, some speaker cloth streched over them will dampen the ringing.

    I hope your project ends up sucessfully, I am surprised that recone services can't be found there. It just seems a more British thing compared with the US culture of conspicuous consumption and newer is better.

  21. #21
    Silence of the spam Site Moderator Geoffcin's Avatar
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    Congrats on sorting out the problem!

    Quote Originally Posted by Laneyflower
    [IMG] Hopefully I will find a company to repair this wonderful driver (I will have both done) and I am waiting for an Ebay seller to get back to me as to whether his Celestion mid-range driver in perfect working order is identical to mine so it looks as though I may be able to sort out my problem!! I have uploaded a pics of a C Ditton 66 Studio Monitor for anyone who wishes to see these wonderful speakers - the unit in the bottom is not a driver, I have read on the net what it is, it sort of deepens and resonates the bass, hence their wonderful sound and have uploaded a pic of the offending driver in the cabinet. I will update as to my progress with sorting this problem, thank you everybody.
    Keep up the prog reports!

    Celestion has a big fan base with Guitar players. A lot of good guitar amps & cabs use Celestion speakers. Some of the older ones with alnico magnets go for big bucks!
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  22. #22
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    I've Taken The Grills Off ------------------------

    Quote Originally Posted by hermanv
    Do you listen with those square holed grilles on or off the speaker? (I think grilles is how the British would spell it ).

    They look like metal, my experience with any kind of metal grill is not good, they ring.

    If you listen with them on, try tapping one with the end of a pencil eraser, does it ring? If so, and you must have the protection, some speaker cloth streched over them will dampen the ringing.

    I hope your project ends up sucessfully, I am surprised that recone services can't be found there. It just seems a more British thing compared with the US culture of conspicuous consumption and newer is better.
    ------- and they do indeed seem to sound even better, I'd never thought about that before! Now I am wondering - I played the system with the loose dust cap removed but what about the small round metal grill/covers over the dust caps of the mid-range drivers, could that be a problem/part of the problem/the problem????? I will have a listen with those removed tomorrow. What is strangely puzzling now is that since swopping the drivers around and hearing the bad driver sound distorted at higher levels in both speakers and the good driver sound good in both speakers. since I have put both back in their original cases the bad driver sounds much better, perhaps my ears are just weary after all this listening and fault-finding. I have texted a musican friend as to whether he knows of any company that will recone/service, I know that no local audio repair company will now repair speakers, I can't find a UK one on the web and Celestion Ditton themselves won't touch these speakers, they emailed me yesterday and said so. I'm not surprised I cannot find a speaker repair service, Britain is sadly very much a throw-away society too but I won't start on that one, wrong web site - if you want to see how bad GB is check out Greenpeace UK, we're not very far behind the US. Thanks for all your help, even faulty these speakers are incredible, I think I need to start collecting spare parts for them!!

  23. #23
    Forum Regular royphil345's Avatar
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    Now I see that it's a dome midrange. The picture isn't very clear, but there probably isn't a dust cap. Has the whole dome come unglued? If so, that's the problem. It's probably responsible for keeping the voice coil centered in the magnet structure and preventing it from rubbing (not to mention properly disbursing the sound). That would explain the noise.

    You may not be able to get them rebuilt. Rebuilders can generally do a good job with cone type speakers, even if the original parts aren't available. Not sure if anyone could rebuild those domes without the original parts being available.

    May have to try and find some used like you've been trying to do. As a last resort, you could try to find new dome midranges that would fit the opening. The main problem there is that slight differences in the efficiency and resistance of the replacement drivers will likely cause them to play too loud or not loud enough, trashing the overall smoothness of the speaker system unless adjustments are made to the crossover. Though, changing a dome midrange is alot easier than changing a woofer. Don't have to worry about cabinet dimensions etc... A diver of the same size will probably be able to handle about the same frequency range as the original. Finding something with a similar magnet size is a place to start if you don't have efficiency specs for the original driver. Though a slightly different resistance rating can still effect the relative loudness of the new driver.

    Finding new dome midranges that fit the openings properly might be a long shot. They aren't so common, but there are some out there I've seen for sale.

  24. #24
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    You might try posting your thread on:

    http://forum.hifichoice.co.uk/

    They have a large group of DIY and many resources to draw from for the U.K.

  25. #25
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    Quote Originally Posted by royphil345
    Now I see that it's a dome midrange. The picture isn't very clear, but there probably isn't a dust cap. Has the whole dome come unglued? If so, that's the problem. It's probably responsible for keeping the voice coil centered in the magnet structure and preventing it from rubbing (not to mention properly disbursing the sound). That would explain the noise.

    You may not be able to get them rebuilt. Rebuilders can generally do a good job with cone type speakers, even if the original parts aren't available. Not sure if anyone could rebuild those domes without the original parts being available.

    May have to try and find some used like you've been trying to do. As a last resort, you could try to find new dome midranges that would fit the opening. The main problem there is that slight differences in the efficiency and resistance of the replacement drivers will likely cause them to play too loud or not loud enough, trashing the overall smoothness of the speaker system unless adjustments are made to the crossover. Though, changing a dome midrange is alot easier than changing a woofer. Don't have to worry about cabinet dimensions etc... A diver of the same size will probably be able to handle about the same frequency range as the original. Finding something with a similar magnet size is a place to start if you don't have efficiency specs for the original driver. Though a slightly different resistance rating can still effect the relative loudness of the new driver.

    Finding new dome midranges that fit the openings properly might be a long shot. They aren't so common, but there are some out there I've seen for sale.
    Hi Royphil345

    I am now very confused! The 'what I thought I'd learned was a dustcap' is completely off of the other mid-range driver in the other speaker yet that speaker plays perfectly!

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