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Multi-Way Conventional loudspeakers with crossovers

Celestion 66 needs mid-range
Celestion 66 needs mid-range
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Old 19th September 2018, 06:39 PM   #1201
moermusic is offline moermusic  Canada
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Hi Alan & all others. I sold my 66's in March 09, around pg 80 in this thread. Well I found a pair only 2 blocks from my new place, in 2015, & they are now being listened to as I type.
Just for chitter chat, they are unadulterated originals, teak fronts. Do not plan to to any upgrades on this set. work for me as is.
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Old 2nd November 2018, 04:16 PM   #1202
alan-1-b is offline alan-1-b  United Kingdom
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Default Your True Love !

Hi Doug ,

Hey ... so you could not live without Ditton 66s ! ... well those Yamaha PA speakers you mentioned previously certainly do not have sound like 66s.

You are fortunate to have now found a pair of 66s that give satisfactory listening without any reconditioning or modifications required.

If nothing is too worn out in them you will be hearing them as like their designers intended ... and which most Owners now have not , thus you may be fortunate indeed !
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Old 3rd November 2018, 05:16 PM   #1203
moermusic is offline moermusic  Canada
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Sold the Yammys this summer.
Re a recap for 66's thinking Alcaps for the lytics & clarity for the rest
attached is a pic of my xover & the tbc circuit.
WHERE in the photo is C5 ?
Attached Images
File Type: jpg 66 xover 5.jpg (118.2 KB, 55 views)
File Type: jpg 66 circuit diagram.jpg (102.8 KB, 53 views)
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Old 3rd November 2018, 05:59 PM   #1204
moermusic is offline moermusic  Canada
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EDIT
Where is C 4?
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Old 9th November 2018, 08:12 PM   #1205
alan-1-b is offline alan-1-b  United Kingdom
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Default E-cap , not Alcap

Hi Doug ,

There is no C4 in your 66s.
Celestion stopped using the C4 , likely because it was causing crossover too low to the mid-dome.

C5 is the 24uF in your photo.
For C5 use ClarityCap PX 25uF.
"Madisound" still have stock of those.

Madisound also still have stock of ClarityCap PX in 3.9uF and 6uF for the tweeter circuit , and those will work better than the bunches of smaller values in parallel.

I would use ClarityCap PX 3.9uf plus the resistor as I originally advised you for C3 , but if you want to use an electrolytic cap there then use Mundorf E-Cap in their "PLAIN" series ,
because that is the closest to the original type that Celestion used.
Do not use the E-cap "RAW" because that is a lower quality capacitor construction and it will develop a leak sooner than the "PLAIN".

I would still use polypropylene caps for the woofer circuit , but if you want to use electrolytic caps then use Mundorf E-cap "PLAIN" 68uF for C2 , and E-caps "PLAIN" 56uF and 22uF in Parallel for C1 .
68uF with 10uF in Parallel would also work for C1 , but I think 56 with 22 will work better there.
Lay the 22uF along the top of the 56uF but slightly spaced from it , not touching it because two capacitor bodies touching when vibrated against each other by the sound pressure level inside the cabinets will cause microphonics which will be audible through the woofer as result of the Piezo-electric effects within each touching capacitor.
If you want them touching then put BluTak -{ Blu Tak }- between them to reduce fast vibration between their bodies.

"Partsconnexion" in Canada have the Mundorf E-Caps.
The "PLAIN" type are the lower voltage options.
The high voltage options are the "RAW" type which I do not recommend.
Click on each capacitor value and to open the page with its picture and look closely and you will see which ones have "Plain" printed on them and which ones have "Raw" printed on them.

There are no more "low-loss" Alcaps for 24uF or 72uF , and the available Alcaps for those values are etched foil caps which will develop leaks sooner than the low-loss type , thus I will not recommend the other Alcaps , and especially not for C5.
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Last edited by alan-1-b; 9th November 2018 at 08:41 PM. Reason: to add two digits plus four sentences.
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Old 11th November 2018, 04:55 PM   #1206
alan-1-b is offline alan-1-b  United Kingdom
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Default alternate E-Cap option for woofer crossover filter

Hi again Doug ,

I have been thinking further after recommending connecting 56uF and 22uF in Parallel for C1 of the woofer filter to sum to 78uF there to compensate for the 68uF at C2.

Another option , and which I think may cause better audio result is to use three Mundorf E-Cap PLAIN in Parallel to sum to close to the original 72uF , and in particular use:
33uF + 22uF + 15uF in Parallel = 70uF , which is close enough to 72uF for the three in Parallel configuration to be used for both C1 and C2.

Electrolytic capacitors have significant colouration , and can be as a resonant narrow-band around a particular frequency area , thus if instead of using 1 electro cap use 3 of staggered values in Parallel so that the resonant colouration areas of each do not co-incide , hence will be a broad band-width of lower peak colouration.

Electrolytic caps have sufficient ESR to be able to connect them in Parallel without the Pulse Rise Times through each being significantly different ,
{ unlike with negligible ESR polypropylene caps } , thus for Listeners who prefer the audio characteristics of electrolytic caps I recommend trying the above configuration.

However if you want to stay with the simplest use of minimal parts , then use 68uF E-cap PLAIN for C2 , and 68uF + 8.2uF E-Cap PLAIN in Parallel for C1
- which I should have put in my last Post but I had not noticed the 8.2uF E-Cap PLAIN then.

{ I do not recommend staggered values connected in Parallel for polypropylene capacitors - I recommend using equal , or near equal , capacitances for Parallel connection of polypropylene capacitors.}

To fit into the narrow space on the 66 crossover board , stack the 3 capacitors with the 15uF laying on top of the 22uF laying on top of the 33uF , and with BluTak or Silicone tape in between their bodies to reduce contact resonances as I explained in my previous Post #1205 on this page.

Silicone tape is available for Electrical and Handy-man use in brand names such as "Rescue Tape".
After putting some between the capacitors , some more can be wrapped around the stack of the 3 to hold them securely , and then tie them to the circuit board with Nylon ties
-{ Not with metal wire , because looped wire will collect magnetic field by Induction from the nearby large Inductors and will then have an electric current circulating around the capacitors }.


With C3 in polypropylene connect 1.8 ohm 5 watt resistance in Series.
With C5 in polypropylene connect 1.5 ohm 5 watt resistance in Series.
Preferably use the Mills MRA-5 wirewounds I recommended previously in this thread ,
or try Mundorf's 5 watt MR5 metal oxide resistors if you don't want to use the Mills.

If there is still a little excess midrange after the above , then swap the resistances around and put the 1.8 ohm in Series with C5 and the 1.5 ohm in Series with C3.
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Last edited by alan-1-b; 11th November 2018 at 05:23 PM. Reason: to add a word , and change part of one sentence , and add one sentence
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Old 14th November 2018, 03:12 PM   #1207
moermusic is offline moermusic  Canada
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thinking of making a complete xover new board, so as to keep original.
c1 & c2 = Alcap 72uf
c3 = alcap 4uf
c5 = alcap LL 12uf ( x2) in parallel
c6,7,8 = clarity px 3.9uf
c9,10,11,12 = clarity px 2.2uf & 3.9 in parallel
roughly 40 -50 dollars (CA) for 5 new inductors . parts express have Jantzen at more cost than Madisound brand.
thoughts?
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