View Full Version : Celestion Ditton 66 recap
Seeing as a few Celestion speakers have been recapped on here lately i thought my 66's should have some love :)
Finished in the rare walnut veneer and cabinets marked Nov 1974 the caps are surely out of spec right? They sound so good so can they be improved?
https://s26.postimg.org/in3rk64i1/IMG_1118.jpg
Here's a little mystery,the crossovers are different in the caps fitted,the mid uses a pye 24uf and an 6uf elcap electrolytic,total value 30uf.
1 crossover board is correct,the other just has the pye,all caps except for the LF caps (which i changed last year) appear to be original to both crossovers.
https://s26.postimg.org/qekhiq8nd/IMG_1113.jpg
Hmmm the plot thickens!
When removing the huge mid drivers i noticed they are the prefered newer spec MD500,the early ones being MF500.These use a total cap value of 24uf so 1 crossover is correct.
https://s26.postimg.org/e2hl58ksp/IMG_1116.jpg
So either someones added the newer MD500 mid drivers or these are right on the change over period,there is a stamp on the driver but its small,it looks like INSPEC 76 8OHMS.
If this is the date then it would appear they have been added by someone later,as i doubt Celestion would have used 2 year old cabinets back in 1976? but what do i know :)
I await the postman with all the caps,new binding posts and fresh copper cable,im hoping to have these back up and running by the weekend.
Oooh, interesting! As is seeing the internals of my old speakers... :)
Hope it all works out, mate. Which make/type of caps are you going from and from where? :cool:
Marco.
P.S I'd keep hold of the original caps, just in case you need to revert back for any reason.
yes its intriguing isn't it.
im using the same basically as ken did,alcaps for the LF, Mundorf +1% ansar poly for the MF and ansar polys for the HF .
am i right i thinking ken compared his 66's with yours/mine at a show? i recall reading this somewhere on here and the general view was your mid range was better at the time,this would explain why as the md500 driver has a more forward sound than the earlier MF500 which should on paper be fitted on yours/mine.
Yeah, the comparison took place at one of the NEBO meets, with the outcome you've mentioned. Aside from the drivers, the caps in the crossovers would've also been totally different.
In the end though, Ken's modded 66s spanked (then) mine, so the gains are there to be had! :cool:
Marco.
In the end though, Ken's modded 66s spanked (then) mine, so the gains are there to be had! :cool:
Marco.
well if my respond that well i'll be over the moon!
The 66's and replacement 661's have a gentle response rather than an assertive one, but the Ansars are lively and I suspect perfect for this job :D
While the drivers are out, any thoughts on steel lining the cabs? Might make them less likely to be pushed over;)
thats weird dave,i was thinking about steel plates to the top and bottom as they do resonate a bit when rapped with the knuckles,the sides are fine in that respect as they are well braced.
rodthebod
10-01-2017, 20:39
Hi Jamie
I just noticed you posted a link on your reply to Ken's thread on the 66 restoration, looks like there was some upgrading going on with the mid (MD500) drivers, have you measured the capacitance from the PYE/elcap and just PYE cap? it's possible someone just removed the elcap 6uf to balance the drivers capacitance wise without knowing the relationship between the two types of cap.
On the subject of lining with steel panels, we (my old company) did some work with Royd Loudspeakers (as a manufacturer) some twenty years ago building prototypes in solid hardwood for a new range of theirs and he insisted on steel panels on the inside of the cabs to 'balance the sound and more importantly according to him to - speed up the transients'. But this was on much, much heavier, solid kiln-dried ash hardwood 18mm thick cabs which is in complete contrast to the lightweight particle board used on the Celestion cabs. They were heavy!
From what we learnt, it's is very important to have a liveliness, which is frequency friendly akin to a musical instrument, to a loudspeaker cabinet otherwise the life or pace literally dies from the music, as Ken has said to me in earlier postings, on his resto thread, he had no problem sonically with the Celestion 66 cabinets other that maybe adding some mild damping to the top and bottom panels with bitumen sound deadening panels. I would agree with this to a point, not even having heard the speakers as an original pair yet, but knowing a bit about how cabinets work (hopefully). Just a side thought which is more important than my experience, Celestion would have done much research to get the sound just right on their flagship cabinets back in the day. I would respect the foundations of their endeavours.. hey they sound good don't they, so why mess with it! (unless modern knowledge makes it a no brainer)
I just wouldn't go adding mass (not modern knowledge) to the Celestion cabs, steel panels do speed up the transients, sort of, on much heavier cabs, but not on lightweight chipboard, you have all the liveliness you want already in this well though out elegant design. Thinking back, adding steel panels to the insides of cabinets is a bit of a nightmare anyway, caused no end of problems from memory - bonding material/positioning etc.
However some others may have great results with other types of design, that's the great thing about hi-fi there are so many paths to take to get results.
This (steel panels) just sparked a few memories about what was tried back in the day to get better results, hope you get some benefit...
wow,cheers for the info,i will leave them as they are.
re the 72uf caps,falcon do these,they are not low loss though and to be honest i cant remember if mine were as i did them a while back.are yours marked LL?
http://www.falconacoustics.co.uk/alcap-claritycap-solen-audio-capacitors/alcap-electrolytic-capacitors-high-power-100v/alcap-72-00uf-100v-dc-high-power-electrolytic-capacitor-nonpolarised-reversible-series.html
edit ken has confirmed they are not low loss so sorry for the confusion :)
fatmarley
12-01-2017, 09:22
From what we learnt, it's is very important to have a liveliness, which is frequency friendly akin to a musical instrument, to a loudspeaker cabinet otherwise the life or pace literally dies from the music,
There are two schools of though regarding cabinets. There's the thin walled cabinet with mass damping - This gives a clean midrange and treble, but because the cabinet can flap about, the low frequencies aren't as tight as they could be.
The other Is a rigid cabinet that drives the resonances up high in frequency. I don't think you can get the resonances high enough to take them out of the pass band but you can add damping to try to stop them ringing.
I'm not convinced that the cabinet should act as a musical instrument. As far as I'm concerned, a speaker should reproduce sounds, not produce them.
My own diy cabinets use constrained layer damping to give a rigid but well damped cabinet.
rodthebod
12-01-2017, 11:35
Hi Jamie
Perhaps using a 'musical instrument' as an example is a bit misleading, as you say, the instrument is designed to work with more limited frequencies to produce those sounds. I've always found on modest sized cabinets, your latter example, using a more rigid cabinet using steel with carbon fibre where possible to keep the enclosure light but very stiff works well - it's surprising how little damping is required if the cabinet is tuned and braced correctly. My point was really to say that mass damping can lead to lifeless, dull sound.
I think I'll be ordering some of the Alcaps from Falcon, I can't see the originals fairing too well - the 72uf measure well out of spec.
Still haven't heard anything from Wilmslow about the 22uf Mundorf E-caps supplied as RAW not PLAIN.... not good customer service.
A small update,
im still waiting for the Ansar super sound 1uf caps.
I did however do as much as i can until they arrive on 1 board.
In the meantime the Monitor Audio R852's are doing sterling service :)
https://s26.postimg.org/4zymep8ax/IMG_1142_1.jpg
who's been a busy boy today then??
the 1uf caps arrived today,this was no 5 minute job and my backs killing me!
im aiming to have them up and running tomorrow :)
https://s26.postimg.org/4clxjy79l/IMG_1168_1.jpg
rodthebod
22-01-2017, 07:12
Looking good Jamie, my boards should look the same once I get the replacement Mundorf 22uf e-caps in the PLAIN type.
Wilmslow Audio finally got back in touch, they seem to be quite slow in replying to emails, but they did state that they sent the Mundorf 22uf e-cap RAW types in error and are sending replacements which was encouraging. (The RAW types are a fraction of the physical size of the PLAIN type as you have so are easy to spot) I also mentioned the 'out of tolerance' Mundorf e-caps which they said they would try to rectify.
What type of connecting cable did you go for, it looks similar gauge to the original cable used, and what is the foam packing material?
Looking forward to hearing about the results when you get them together
hi rod,
its 7.25am here in the uk and im just about to start putting them back together :)
for the internal wire i used Van Damme Blue Series 0.75mm Studio Grade i just cut the sleeving off,as for the foam its for welding helmets,its stuck to the band that goes around you forehead to stop it rubbing your skin.we have loads a work.
rodthebod
22-01-2017, 07:50
That's good to know about the cabling - I think I'll just use some thin white polyethylene dense packing foam for my pads, or as you did whatever I have at hand - I would twist the cables where you can as this simple technique helps with screening the signal through the wires.
Should have then up and running before lunch?
Oooh... I can *feel* your excitement! :eyebrows:
Look forward to reading about your impressions :)
Marco.
all finished a sounding much better,not night and day as the old cliche goes but definitely better.
the balance between drivers has improved,the sound is more integrated if you know what i mean.the mid range has also benefited from the mundorf electrolytic and 1% poly mix as detailed in kens restoration thread.
1st pic is the new binding posts fitted.
https://s26.postimg.org/xt1jmddmx/IMG_1170.jpg
i took the trouble to swap out the HF2000 tweeters for some red label HF2000's i bought from ken,these are supposedly earlier and better made.
https://s26.postimg.org/uapjpzcqx/IMG_1171.jpg
crossover fitted,
https://s26.postimg.org/x62mwugqx/IMG_1173.jpg
its been a long slog doing these,id like to give the baffle board a freshen up with stain and also the grill cloths need some attention but for now im going to enjoy them.
happy days :)
Nice one, Jamie. Glad it seems to have worked out well! Looking forward to seeing the finished articles (in terms of your tarting up of the speakers physically), and some more thoughts on how they sound, once your ears fully adjust to all the changes :cool:
Marco.
walpurgis
23-01-2017, 23:27
Hi Jamie. Have you considered experimenting with the crossover location? Maybe situating it on the floor of the cabinets, away from any driver magnets, which could possibly have influence over the inductors.
hi geoff,no i didnt want to go that extreme,id had enough by the time i finished the recap lol
So how's it all sounding then, Jamie? Could you outline what the sonic improvements you perceive are from the re-cap? :)
Marco.
hi,
yes in a little while,im putting some hours on them first :)
No worries - enjoy :cool:
Marco.
Well ive been listening to these for a week now after the recap.
They have benefited mostly in the mid frequency ,as Ken wrote in his thread obtaining the cap value of 24uf using Mundorf lytics and a 1uf Ansar poly has really improved the sound .im listening to Rumers cd Seasons of my soul and her voice sounds so silky smooth and rich,the accompanying piano is also very realistic,id say it was worth all the hard work for this alone.
Now here's the rub,the HF2000's now seem distance,they are there but its like having a thin veil over the tweeters,not how i remember them,the original tweeters were changed as one measured 5ohms,the other 9.8!
the spare pair i have and fitted both measure 5ohms.
Now either the Ansar polys for the tweeters need some time to burn in or the old caps were so out of spec they reduced the output for the mid? can this happen?
They do seem to be getting better or maybe im getting used to them,or they are fine and this is how they are meant to sound?
Your thoughts gentleman please!
Interesting... Having owned these speakers before, sonically I certainly couldn't detect any issues with the tweeters being out of spec (even though obviously they were), as you've measured them, nor did they sound in any way 'veiled' - quite the opposite, actually! :)
Therefore, it might be an idea at some point to put the original HF2000s back in, out of spec or not, using them with the new upgraded caps, and see what that does.
Marco.
Interesting... Having owned these speakers before, sonically I certainly couldn't detect any issues with the tweeters being out of spec (even though obviously they were), as you've measured them, nor did they sound in any way 'veiled' - quite the opposite, actually! :)
Therefore, it might be an idea at some point to put the original HF2000s back in, out of spec or not, using them with the new upgraded caps, and see what that does.
Marco.
Thats my first job on Saturday! lol if only to put my mind at rest.
we also between us didn't notice that 1 crossover had a mid range cap value of 30uf and the other 24!
they still sounded sweet as!
im sure its just me not being used to the sound now they are back in spec,i will know for sure once my TT is back in action and i listen to some floyd :)
Lol - too right... That's the trouble though with making too many changes at once. I've been guilty of it before, too. In hindsight, it would've been better to have fitted the new tweeters after the cap changes, in order to reduce the number of variables from your upgrades, but shit happens! :eyebrows:
Anyway, let us know how you get on when reverting back to the original tweeters.
Marco.
I don't know how Celestion selected the individual components when building their speakers but when I worked for Harbeth each driver was tested and measured to conform with the design parameters and each crossover was made to suit each driver, the slight variances in the drivers compensated for with higher or lower component values on the crossover.
Maybe that is why there were differences with the 66's crossover parts.
Bloody hell!, that almost sounds intelligent :lol:
Mmm... I guess that's entirely possible [good call], but also remember that the original spec of electrical components drifts after time, so when you're talking about 40-year old speakers, stuff deteriorating/going out of spec with age is hardly surprising.
Marco.
That is very true, Samsung TV's packing up because the capacitors in the power supply failing...I know this because I had one and Samsung replaced the board free of charge as it was a known problem.
I guess it's just one of things we have to live with if we want to keep these lovely old pieces of kit alive.
just put the original hf2000's back in and BINGO! we are back to normal!they are noticeably louder :guitar::fingers::harp::grouphug::gig::gig::partyt ime::rave::hairmetal::yesbruv::dance::concertina:
i must say a big thanks to paul at RFC for the advice,many thanks :)
just put the original hf2000's back in and BINGO! we are back to normal!they are noticeably louder...
LOL.....
See what happens when you think you're 'upgrading' something, and you're not? ;)
Nice one - glad it worked!
Marco.
rodthebod
01-02-2017, 07:28
I think this definitely means I should keep the original crossovers as untouched and have a good listen first then try to change components in stages.
Sounds like the bass and mid section benefit most from component upgrade or are you hearing better things now from the top end than before changing to the ansar caps?
What were the ohm's readings on your 'red labels' and on your existing tweeters again, could this make that much of a difference or could it be a different type of coil design perhaps.....
Glad things are working out well for you, must be a big relief
I think this definitely means I should keep the original crossovers as untouched and have a good listen first then try to change components in stages.
Sounds like the bass and mid section benefit most from component upgrade or are you hearing better things now from the top end than before changing to the ansar caps?
What were the ohm's readings on your 'red labels' and on your existing tweeters again, could this make that much of a difference or could it be a different type of coil design perhaps.....
Glad things are working out well for you, must be a big relief
Just as a tip to those reading this:
You cannot go off DC ohms ratings to determine the suitability of a "like for like" tweeter swap. The impedance with frequency is what matters which will determine the impedance value at crossover, along with the matching acoustic response, both of which will determine the crossover values. The tweeter sensitivity also has to be known. Use the tweeter that came with the speakers unless you know how to re-design the crossover to accommodate a tweeter with different T-S parameters (as this may also necessitate altering the low-pass section of the mid bandpass filter).
As I mentioned to Jamie yesterday, Celestion had it right as they designed these, so like for like values depending on the earlier or later versions, is the way to go. Tolerance on caps matters far more than brand. If you try brand "A" and decide you prefer brand "B", what is the real reason? Often tolerance can be further out on one than the other, affecting crossover point, phase, and audible SQ. The originals probably were not specified to anything better than 10%. KEF often hand picked their caps in their more complex filters to ensure when new that they were to 1% and more typically, 5% but not all companies, Celestion included, went to these lengths.
For large values in the LF, make up with 2 or 3 caps (electrolytics to match original ESR) as this will even out any variance in tolerance and get you closer to the values needed, ditto for the high pass part of the mid band pass. For the mid low pass with the tweeter and the tweeter values, you are safe using polys for better sound quality and do not have to bridge or bypass any value under 10uF, just pick a modern 3 or 5% tolerance PP capacitor from whatever brand, and this will get you as close as the factory originals. You do not have to worry as much about ESR with the mid or tweeter for lower cap values as the ESR variance at higher frequencies with low values, is far less than with large values, therefore you wont get any appreciable shift in crossover by doing this.
The main issue I see with Celestion factory crossovers (board mounted) is the spacing and orientation of inductors. They are too close together and will likely couple.
Following a re-cap of the boards as described above, re-spacing of the inductors and orienting them more appropriately should improve SQ by reducing the effects of coupling the EM fields on the air cores.
Hope this helps.
The main issue I see with Celestion factory crossovers (board mounted) is the spacing and orientation of inductors. They are too close together and will likely couple.
Hi Paul,
Just trying to learn here... In this context, what do you mean by "couple", and why would that be a bad thing? Also, what then, in your view, would be the best way to mount inductors on a crossover board? :)
Marco.
Hi Paul,
Just trying to learn here... In this context, what do you mean by "couple", and why would that be a bad thing? Also, what then, in your view, would be the best way to mount inductors on a crossover board? :)
Marco.
Hi Marco,
The thing, especially with air cored inductors, is that when you apply a voltage (signal) through them, they emit an electromagnetic field which can induce a current into nearby wires (or other coils!) causing distortion, and the greater the voltage, and larger the air core (generalisation #1!) the greater the electromagnetic field, as the strength increases This couples (induces current into) with close-by inductors, and apart from cross-talk issues, can lead to inductive leakage, actually altering effective inductance values.
Anyone who has an inductance meter can try a little experiment. Hold the inductor near to (touching) a metallic surface and take a reading. Now move it away (at least 200mm away) and take a reading. The first reading, I'll bet, is a far bit lower than the second. That is why if you design a crossover on a wooden board then place it in an aluminium orother metal box, chanves are, the crossover points change causing gross distortion. It's a no-no.
To combat the coupling issues with inductors, there are ways to orient them such that the electromagntic fields don't create as much problems.
Troels has published some of his experiments and produced a useful little guide which you can read HERE (http://www.troelsgravesen.dk/coils.htm)
The gist of it results in a useful cheat sheet which I have copied and pasted below:
http://www.troelsgravesen.dk/coils_files/coils_9.gif
I have a little experiment which I sometimes demonstrate to customers here, where I use a Tannoy DC drive unit, take a coil of the same type and value as used in their GRF Memory speaker design, whereby the LF coil was placed very close to the back of the drive unit magnet within one of the speakers I worked on.
I then send a signal generated from the PC consisting of some music and apply that signal voltage through a resistor to provide a load, with the large air coil connected in series and placed close to the back of the drive unit.
What happens is that the music then clearly emits from the horn! This is a hint that crossovers (inductors) should not be placed so close to drive units!
Where ferrite, Permite or E&I steel cored inductors are concerned, the spacing can be much closer as they emit a much smaller EM field around them, so a few inches spacing is usually more than adequate for those.
Hope this explains things more fully.
rodthebod
01-02-2017, 12:27
Thanks for the comments Paul
I'll try to implement those tips when I eventually recap the 66's by moving the orientation of some of the inductors so they interact better and, of course, when I make up a 'centre speaker' version of a 66 without the ABR. Just a thought, do you think Celestion took the possible interaction into account when they designed the crossover so adjusted the values to suit - after all, the speakers are renowned for their sound and the inductors aren't affected by age.
Moving the 66 crossover board to the base of the cabinet so it lies flat - would that be a good idea in terms of achieving the greatest distance from the bass driver or is it best to keep it vertical at the base of the cabinet behind the ABR?
Thanks for the detailed explanation, Paul, and taking the time to post what you did. Much appreciated, and I understand now what you mean. I hadn't considered the electromagnetic field angle :)
Marco.
Re 66's
I tried reorienting and re-spacing the coils and locating the boards in the lower chamber and that's how they were when I sold them on.
I know this is following best practice and on some designs it might have a significant impact, but to be honest on the 66's, if there was a difference, it was very small.
On the other hand, in my case, the capacitor renewal made a huge difference.
If I was doing another set of 66's I would keep the stock boards/location and do the simple recap, it will get you 95%+ of where you want to be, for a fraction of the work and it sits well from an originality point of view.
Each to their own though, if your after the last once out of them and want to sleep better at night, go for it. :)
well ive learnt something new today,i spoke with the guy from falcon acoustics who told me that the early hf2000's tweeters with the red metallic sticker on the back are in fact the last type celestion produced. they dont work like the original ones so they are going straight on ebay.
for me the recap hasn't made a huge difference,they are however sounding better for it.
once again id say the best thing to do is just change like for like caps.
I think this definitely means I should keep the original crossovers as untouched and have a good listen first then try to change components in stages.
Sounds like the bass and mid section benefit most from component upgrade or are you hearing better things now from the top end than before changing to the ansar caps?
What were the ohm's readings on your 'red labels' and on your existing tweeters again, could this make that much of a difference or could it be a different type of coil design perhaps.....
Glad things are working out well for you, must be a big relief
it is a great relief yes! lol
the red labelled hf2000's measured 5ohms each,so on paper they are perfect. i dont know what speaker they came from originally.
my origainal hf2000's measured 5 and 9.8 so go figure??!!
if you dont mind keep taking the crossovers out,i would change each drivers caps in stages,that way you can hear the changes more.
Jamie - The Red label tweeters are HF2000's, they came out of some B&O speakers - Beovox 5700.
I think Celestion used Red labels on items they supplied to other manufacturers, but don't quote me on that.
I was always under the impression that the tweeter and mid range in these were exactly the same as those on the 66's and 44's(tweeter) that opinion is certainly out there if you google it and they are often sold as such on ebay?
See some here: http://www.diyaudio.com/forums/multi-way/159819-modification-restoration-destruction-vintage-b-o-classic-mid-range-query.html
I did an Impedance frequency sweep on them using DATS and the plots looked very similar to my other HF2000's. That said, of the 6 Tweeters I measured, no two were exactly the same, but still they were all very close.
Maybe there is some subtle difference in their make up :scratch:
Edit: Just caught your post #42, that's interesting to know for the future.
Strange that they would change them though and not give them a new number, as it means they would not have been backwardly compatible as a spare part any more. Still stranger things have happened with British Hifi companies.
ah that explains it then (i think)
the guy from falcon said the b&o hf2000's are 4 ohms.
ah that explains it then (i think)
the guy from falcon said the b&o hf2000's are 4 ohms.
Hmnnn, wouldn't that make em sound louder, being less of a load?
What ever the reason, I trust your lug holes when you say they were back in the mix compared to the originals.
i havn't got a clue to be honest,im just going by what i was told by falcon acoustics,its all over my head if im honest,i can solder and read the value on a cap and order the same value and put it in,the theory and what is does is beyond me.:D
Jerry from Falcon is an expert in these matters. I'd take his word on what he told you. If he said they were different, they were different and will not be a like for like replacement. As you say Jamie, like for like recap (polys in the upper frequency end of the bandpass and for the tweeter caps), and best practice on inductors....job done. Essentially, you cannot change what the designer intended by fiddling round the edges. That would take a complete speaker redesign, to alter fundamentals.
Hi Paul, I wasn't doubting Jerry when he said they were different, just curious as to what was changed for future reference.
Received my order of a pair of 12" Scanspeak Woofers from him, on Monday of this week.
When I was looking for some close matching caps, he even offered for me to go down and sit with a box of caps and measure/match them myself as close as I liked.
Very knowledgeable and accommodating chap from my experience.
Today i have removed the Mundorf lytic/Ansar poly mix for the MD500 mid and replaced it with 2 low loss 12uf Alcaps, 24uf LL are not available anymore. Now the crossovers are total as per originals,like for like replacement caps.
Job done and no more messing about!
https://s26.postimg.org/54308k7d5/IMG_1204.jpg
It's not usually considered a good idea to have all the inductors orientated the same way, particularly ones that are close together. Are they like that for a particular reason?
Edit: Oh, I see Paul has already covered this. The interaction between coils is very well known and widely documented. In addition, as Paul says, it is very easy to measure. I have also tried measuring inductors in close proximity to metal sheets and, again, the effect is very easy to measure and quite significant.
hi,
thats the way celestion placed them.
im just going to enjoy them for a while now :)
Hmm... strange that they should ignore the protocol. Have you perhaps replaced the coils with air-cored variants? I say this because air-cored replacements are invariably much larger than the ferrite cored alternatives and produce a significantly larger radiated field.
no ive not touched the inductors,they are original to the crossovers,same as kens 66's,you mentioned the same thing on his thread,memory loss?:eek:
with all the grief with the hf2000's tweeters it has lead me to look at suitable replacement rather than gamble again buying second hand. the seas unit spring to mind and has been mentioned a lot.
the other is the Hiquphon ow1,not much info and what there is is over my head,anyone know if it would be ok?
Sorry if I am repeating myself, I'll but out :) I'm only mentioning it in an academic sense, it's not a big deal, it's just interesting ;). Enjoy is what I say!
rodthebod
05-02-2017, 09:09
I've said this before but I think you have to have some faith that a well established loudspeaker company, such as Celestion, would have listened to the speakers with the crossovers in situ, with the inductors placed the way they are, measured them and pronounced them OK.
Back in the day would the process be: design an ideal crossover circuit first on paper for the drivers in question, not necessarily taking inductor interaction into account (but they would know all about how they behave in proximity), or try out several specifications and pick the one that works best in the cabinets and sounds and measures best, then publish the ideal values in a diagram that you know works.
We have to assume that Celestion/Kef had testing facilities and that changes to the crossover were made taking measurements from testing/listening with the cabinets complete.
Enjoy them Jamie, as they they have been for decades from a company that knows something about producing good speakers.
It is interesting to know Mark about how inductors interact so much with each other it may be why I've had issues getting my other, non Celestion, speakers working properly in the bass area.
I'm now getting my meter out to measure what's going on with the paired inductors in question, a quick orientation change to one might help - so thanks for the input.
ToTo Man
19-07-2018, 13:39
Today i have removed the Mundorf lytic/Ansar poly mix for the MD500 mid and replaced it with 2 low loss 12uf Alcaps, 24uf LL are not available anymore. Now the crossovers are total as per originals,like for like replacement caps.
Job done and no more messing about!
https://s26.postimg.org/54308k7d5/IMG_1204.jpg
Jamie, do you mind if I ask why you chose to swap out the Mundorf Ecap and Ansar combination in the MF circuit for LL Alcaps? Did you just do it to preserve originality or was there a sonic reason? What was the resulting change in sound? I'm currently renovating a pair of 66's (http://theartofsound.net/forum/showthread.php?59279-Another-Celestion-Ditton-66-Renovation-thread&p=995285#post995285) and am about to re-cap the crossovers.
if you read from post 25 it will explain the red label tweeters and what happened,there are measurements of the tweeters too,in regards to the caps i just wanted to go as close to the factory ones as possible and changed them as a results of fault finding regarding the low output high end .
hope that helps :)
Patrick Dixon
20-07-2018, 12:09
with all the grief with the hf2000's tweeters it has lead me to look at suitable replacement rather than gamble again buying second hand. the seas unit spring to mind and has been mentioned a lot.
the other is the Hiquphon ow1,not much info and what there is is over my head,anyone know if it would be ok?
I replaced the HF2000 tweeters with Hiquphon OW1 in my 66s some time ago. I also rebuilt the crossovers using new capacitors with some additional series resistors, as per various mammoth threads on diy audio with contributions from people who know much more about speaker design than me.
To fit the OW1s you need to enlarge the hole slightly and tweak the crossover HF attenuation a bit.
I am very happy with the results although I only use the 66s with the TV (driven by a Rega Brio R).
My speakers had one dead tweeter and one re-capped crossover when I bought them, so there didn't seem much point in trying to keep them original.
I have also replaced HF2000s in a couple of 44s using the SEAS tweeter. The 44s never sounded quite as good as the 66s although I think that's down to the midrange as much as anything else.
My 66s are about 4" off a solid floor.
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