installing the resistors
I described a suitable way to install the Caddock resistors, but forgot to for the Welwyns, thus as follows:-
For all axial resistors it is best to not bend their leads at the junction with the body of the resistor -
that weakens the joint and in some applications it reduces the electrical effectiveness of the resistor.
Leave at least 1/8", and preferably 1/4" of lead extending straight out, then bend.
Install the resistor supported by the bent leads as these are quite thick strong leads in this case.
Keep the body of the resistors not touching any surfaces, and especially not touching any capacitors or inductors.
I described a suitable way to install the Caddock resistors, but forgot to for the Welwyns, thus as follows:-
For all axial resistors it is best to not bend their leads at the junction with the body of the resistor -
that weakens the joint and in some applications it reduces the electrical effectiveness of the resistor.
Leave at least 1/8", and preferably 1/4" of lead extending straight out, then bend.
Install the resistor supported by the bent leads as these are quite thick strong leads in this case.
Keep the body of the resistors not touching any surfaces, and especially not touching any capacitors or inductors.
Hi Alan – I’ve added the resistors as per your suggestions and specifications.
There certainly seems to be more 'life' to music now. I'm noticing more of the fine detail that gives interest and a sense of space to a recording. I’m using less attenuation on the mid-range than previously. Vocals and plucked strings are more realistic, still without sounding hard or strained. Backing singers too sound more realistic, with some space for them to have their own fun. Previously, I felt that although the hard edges had been knocked off the sound, it could be a bit bland and too polite. To get back some of the ‘attack’ of music, without it sounding hard or shrill, is very welcome. There seems to be a bit more wallop when drums are whacked too. My partner thinks there is still something missing, although we’re moving in the right direction.
With some acoustic guitar it can seem as if the lower strings are a little exaggerated, not to the point where it’s a one note drone, but enough to be noticed. Some male vocals (Leonard Cohen, I’m your man) have a slight exaggeration in the lower registers too.. This is also noticeable on piano, where the lower registers can seem a bit thickened.
I’m not sure about the bass. My current impression is that it actually sounds a little less clear than it did, although that could be down to the observations above.
I think the remedial resistor work is well worthwhile. I notice a little thickness occasionally, and I’d like it to soar a little more perhaps. It’s definitely started bopping along now though. A wee bit more and it would be toe-tapping.
I'll post the l-pad settings after a bit more listening. I'll take my time seeing as I'll have to live with the results...
There certainly seems to be more 'life' to music now. I'm noticing more of the fine detail that gives interest and a sense of space to a recording. I’m using less attenuation on the mid-range than previously. Vocals and plucked strings are more realistic, still without sounding hard or strained. Backing singers too sound more realistic, with some space for them to have their own fun. Previously, I felt that although the hard edges had been knocked off the sound, it could be a bit bland and too polite. To get back some of the ‘attack’ of music, without it sounding hard or shrill, is very welcome. There seems to be a bit more wallop when drums are whacked too. My partner thinks there is still something missing, although we’re moving in the right direction.
With some acoustic guitar it can seem as if the lower strings are a little exaggerated, not to the point where it’s a one note drone, but enough to be noticed. Some male vocals (Leonard Cohen, I’m your man) have a slight exaggeration in the lower registers too.. This is also noticeable on piano, where the lower registers can seem a bit thickened.
I’m not sure about the bass. My current impression is that it actually sounds a little less clear than it did, although that could be down to the observations above.
I think the remedial resistor work is well worthwhile. I notice a little thickness occasionally, and I’d like it to soar a little more perhaps. It’s definitely started bopping along now though. A wee bit more and it would be toe-tapping.
I'll post the l-pad settings after a bit more listening. I'll take my time seeing as I'll have to live with the results...
Experiments to try now
Hi Stuart,
Re: your paragraph (1) comments, this is what I expected would occur if all the components and installations of are close enough to the optimum,
and I am pleased that it has been for your case - congratulations on achieving that !
The "missing" may be simply the limitations of what is possible from those drivers and/or enclosure, but ... perhaps more can be achieved.
Is the current "missing" a something which either of you have heard from these loudspeakers previously ?
OR, is it something which has become apparent to you only now after the improvements elsewhere have left a weakness exposed ?
The "attack ... wallop" MAY improve a LITTLE more when the L-pad is replaced with a suitable resistor.
Re: paragraph (2) :- lower guitar strings start with the fundamental of about 82Hz for the open bass E string, though usually the 2nd Harmonic is dominant, and thus from 164 Hz upwards to approximately 400Hz is the area you seem to be hearing, as this includes the lower registers of male vocal and piano.
All this is below the notional 500Hz crossover point, thus will likely be eminating from the woofer and/or resonant colourations from the cabinet walls, or interior.
The Experiments:-
(A) - when you next open the enclosures, look to see if all the internal damping materials are still evenly placed within both cabinets, and that none is flopping about -{unless it is intentionally a loose-fill, such as wool, in your samples}, and that there is still some at both the top and bottom panels, AND then that all drivers and the Terminal Plates are securely in place with no air leak gaps from under and around them.
(B) - place your fingertips lightly on the middle of a side-panel, and next on the front baffle between the mid-dome and the woofer, to feel the relevant degrees of vibration present when the "exaggerations" and "thickening" both ARE and AREN'T occurring - do you detect any significant differences ?
(C) - at suitably low volume level playing, place one ear very near to the centre of a woofer, and next to a mid-dome, to determine if all or most of the colouration is eminating from woofers and little or none from mid-domes -{which are producing some sounds below 500Hz - down to at least 250Hz to some audible degree BUT should not be overly resonantly so, but may be if a fault is beginning in them}.
Another way to detect this is to place one's head sideways, with one's nose at the edge of the woofer, so that one ear is towards the mid-dome and other is towards the centre of the woofer.
Easier to do this is when the cabinet is placed sideways, on a non-wobbly or rattlely support, or with cabinet lying on its back,
because then one ear is not confused by reflections from the floor.
Hear if the colourations are more from one side or the other, or if centrally placed ... ?
{I often do the above when fine-tuning crossover networks.}
Re: your brief paragraph (3) :- an improvement in clarity in one or more parts of the audible spectrum will expose whatever lesser clarity exists elsewhere.
Sorry, but we may have unbalanced the design a bit !
OR, you may be hearing the differences resulting from the distinctly different capacitor types now in upper spectrum to lower spectrum,
but do the testing as above still, and Post the results here.
I have more ideas, but the above have to be considered first.
Warning:- if you decide to listen to individual drivers with one or more of the others disconnected from the crosover you MUST connect load resistors in place of the disconnected drivers because that crossover has several anti-resonance electrical paths through which there will be close to electrical short-circuits presented to your amplifier when loads are not connected.
Use 4.7ohm {or 3.9ohm}/10watt minimum, wirewound in place of a woofer, and same will work in place of a tweeter.
Use 8.2ohm/10 watt, -{or 7.5ohm or even 6.8ohm if neither other available}- in place of a mid-dome.
Even at low volume levels you may be surprised to feel 10watt resistors warming up in woofer circuit, thus be careful with volume levels if you are listening from a distance.
Cheap cerment coated wirewounds are OK for this application, and good because they will emit odour -{and eventually smoke}- if overheating, before they fail !
Hi Stuart,
Re: your paragraph (1) comments, this is what I expected would occur if all the components and installations of are close enough to the optimum,
and I am pleased that it has been for your case - congratulations on achieving that !
The "missing" may be simply the limitations of what is possible from those drivers and/or enclosure, but ... perhaps more can be achieved.
Is the current "missing" a something which either of you have heard from these loudspeakers previously ?
OR, is it something which has become apparent to you only now after the improvements elsewhere have left a weakness exposed ?
The "attack ... wallop" MAY improve a LITTLE more when the L-pad is replaced with a suitable resistor.
Re: paragraph (2) :- lower guitar strings start with the fundamental of about 82Hz for the open bass E string, though usually the 2nd Harmonic is dominant, and thus from 164 Hz upwards to approximately 400Hz is the area you seem to be hearing, as this includes the lower registers of male vocal and piano.
All this is below the notional 500Hz crossover point, thus will likely be eminating from the woofer and/or resonant colourations from the cabinet walls, or interior.
The Experiments:-
(A) - when you next open the enclosures, look to see if all the internal damping materials are still evenly placed within both cabinets, and that none is flopping about -{unless it is intentionally a loose-fill, such as wool, in your samples}, and that there is still some at both the top and bottom panels, AND then that all drivers and the Terminal Plates are securely in place with no air leak gaps from under and around them.
(B) - place your fingertips lightly on the middle of a side-panel, and next on the front baffle between the mid-dome and the woofer, to feel the relevant degrees of vibration present when the "exaggerations" and "thickening" both ARE and AREN'T occurring - do you detect any significant differences ?
(C) - at suitably low volume level playing, place one ear very near to the centre of a woofer, and next to a mid-dome, to determine if all or most of the colouration is eminating from woofers and little or none from mid-domes -{which are producing some sounds below 500Hz - down to at least 250Hz to some audible degree BUT should not be overly resonantly so, but may be if a fault is beginning in them}.
Another way to detect this is to place one's head sideways, with one's nose at the edge of the woofer, so that one ear is towards the mid-dome and other is towards the centre of the woofer.
Easier to do this is when the cabinet is placed sideways, on a non-wobbly or rattlely support, or with cabinet lying on its back,
because then one ear is not confused by reflections from the floor.
Hear if the colourations are more from one side or the other, or if centrally placed ... ?
{I often do the above when fine-tuning crossover networks.}
Re: your brief paragraph (3) :- an improvement in clarity in one or more parts of the audible spectrum will expose whatever lesser clarity exists elsewhere.
Sorry, but we may have unbalanced the design a bit !
OR, you may be hearing the differences resulting from the distinctly different capacitor types now in upper spectrum to lower spectrum,
but do the testing as above still, and Post the results here.
I have more ideas, but the above have to be considered first.
Warning:- if you decide to listen to individual drivers with one or more of the others disconnected from the crosover you MUST connect load resistors in place of the disconnected drivers because that crossover has several anti-resonance electrical paths through which there will be close to electrical short-circuits presented to your amplifier when loads are not connected.
Use 4.7ohm {or 3.9ohm}/10watt minimum, wirewound in place of a woofer, and same will work in place of a tweeter.
Use 8.2ohm/10 watt, -{or 7.5ohm or even 6.8ohm if neither other available}- in place of a mid-dome.
Even at low volume levels you may be surprised to feel 10watt resistors warming up in woofer circuit, thus be careful with volume levels if you are listening from a distance.
Cheap cerment coated wirewounds are OK for this application, and good because they will emit odour -{and eventually smoke}- if overheating, before they fail !
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jwt - are you still following ?
Hello jwt, if I haven't lost you as result of not sooner replying to the remainder of your Post, and I apologise for the long delay in returning to that.
Did you see my initail reply to you at the bottom of #301 on Page 31 ?
On your other points:-
There were variations in Blackies - see reports by sba in some of his Posts about his 66s.
Probably you have one from each of two different-time manufactured batches, but don't worry too much about that as both can be got to sound sufficiently close to the same as each other.
The "louder" one versus less loud other will likely be a result of different degrees of deterioration in the old capacitors in each.
The two ABRs need only be of same weight each - the colour of each does not matter, -{except to look at}.
I have recently discovered a UK seller of some seemingly good sound for crossovers' capacitors at less than silly prices.
Do you still require such ?
I do need to know details of the Dynaudio mid-dome to be able to advise if it requires a parallel-connected resistor to correctly match its Impedance to the 66 crossover, thus do Post at least its Model Number here.
Hello jwt, if I haven't lost you as result of not sooner replying to the remainder of your Post, and I apologise for the long delay in returning to that.
Did you see my initail reply to you at the bottom of #301 on Page 31 ?
On your other points:-
There were variations in Blackies - see reports by sba in some of his Posts about his 66s.
Probably you have one from each of two different-time manufactured batches, but don't worry too much about that as both can be got to sound sufficiently close to the same as each other.
The "louder" one versus less loud other will likely be a result of different degrees of deterioration in the old capacitors in each.
The two ABRs need only be of same weight each - the colour of each does not matter, -{except to look at}.
I have recently discovered a UK seller of some seemingly good sound for crossovers' capacitors at less than silly prices.
Do you still require such ?
I do need to know details of the Dynaudio mid-dome to be able to advise if it requires a parallel-connected resistor to correctly match its Impedance to the 66 crossover, thus do Post at least its Model Number here.
Last edited:
Hi Alan - I've attempted to upload a copy of my current circuit diagram, so everyone can see where we are and what we were talking about.
PLEASE DON'T ANYONE ASSUME THAT THIS IS A DEFINITIVE CIRCUIT. IT IS STILL A WORK IN PROGRESS!
In reply to your last post, the slight thickening to male voice and piano etc. does seem to emanate from the bass drivers. There isn't any significant difference that I noticed in the cabinet vibrations between the front baffle and the sides. All the original foam is in position. I'm not too sure about the cabinets integrity and seal though, they have been hard used in the past, scraped and bashed as if used as a portable PA system. I'll go over all the seams with silicon goo, and think of some kind of removeable seal I can use for the drivers. Some time ago I added threaded rods and nuts in tension from front to back next to the bracing between the drivers to kill some buzzes that were coming from the cabinets. That helped the sound a lot, just as much as putting the speakers on spikes. They are never going to be pretty boxes, so I also intend to make new ones at some point. My cabinet making skills are quite good, so I may change the shape, keeping the internal volume the same, but minimising the size of the front baffle, rounding all the edges and doing away with parallel panels. For the purists, I know it's not a Ditton 66, but I'm trying to make the best of a shabby, well used pair which would otherwise have ended up as spares.
As for the 'missing', I'm sure it was something we've noticed since the crossovers had their caps replaced. It's hard to define, but I used to find myself turning around occasionally, wondering if someone had just come into the room. There was often an element of surprise when a backing singer or an instrument burst into life and sometimes there was a feeling of sounds coming from nowhere near the speakers. Some of this has returned since adding the resistors.
I'm having fun tinkering...
PLEASE DON'T ANYONE ASSUME THAT THIS IS A DEFINITIVE CIRCUIT. IT IS STILL A WORK IN PROGRESS!
In reply to your last post, the slight thickening to male voice and piano etc. does seem to emanate from the bass drivers. There isn't any significant difference that I noticed in the cabinet vibrations between the front baffle and the sides. All the original foam is in position. I'm not too sure about the cabinets integrity and seal though, they have been hard used in the past, scraped and bashed as if used as a portable PA system. I'll go over all the seams with silicon goo, and think of some kind of removeable seal I can use for the drivers. Some time ago I added threaded rods and nuts in tension from front to back next to the bracing between the drivers to kill some buzzes that were coming from the cabinets. That helped the sound a lot, just as much as putting the speakers on spikes. They are never going to be pretty boxes, so I also intend to make new ones at some point. My cabinet making skills are quite good, so I may change the shape, keeping the internal volume the same, but minimising the size of the front baffle, rounding all the edges and doing away with parallel panels. For the purists, I know it's not a Ditton 66, but I'm trying to make the best of a shabby, well used pair which would otherwise have ended up as spares.
As for the 'missing', I'm sure it was something we've noticed since the crossovers had their caps replaced. It's hard to define, but I used to find myself turning around occasionally, wondering if someone had just come into the room. There was often an element of surprise when a backing singer or an instrument burst into life and sometimes there was a feeling of sounds coming from nowhere near the speakers. Some of this has returned since adding the resistors.
I'm having fun tinkering...
Attachments
Hi Alan - I've attempted to upload a copy of my current circuit diagram, so everyone can see where we are and what we were talking about. If this post appears twice, It's cos I always have trouble posting.
PLEASE DON'T ANYONE ASSUME THAT THIS IS A DEFINITIVE CIRCUIT. IT IS STILL A WORK IN PROGRESS!
In reply to your last post, the slight thickening to male voice and piano etc. does seem to emanate from the bass drivers. There isn't any significant difference that I noticed in the cabinet vibrations between the front baffle and the sides. All the original foam is in position. I'm not too sure about the cabinets integrity and seal though, they have been hard used in the past, scraped and bashed as if used as a portable PA system. I'll go over all the seams with silicon goo, and think of some kind of removeable seal I can use for the drivers. Some time ago I added threaded rods and nuts in tension from front to back next to the bracing between the drivers to kill some buzzes that were coming from the cabinets. That helped the sound a lot, just as much as putting the speakers on spikes. They are never going to be pretty boxes, so I also intend to make new ones at some point. My cabinet making skills are quite good, so I may change the shape, keeping the internal volume the same, but minimising the size of the front baffle, rounding all the edges and doing away with parallel panels. For the purists, I know it's not a Ditton 66, but I'm trying to make the best of a shabby, well used pair which would otherwise have ended up as spares.
As for the 'missing', I'm sure it was something we've noticed since the crossovers had their caps replaced. It's hard to define, but I used to find myself turning around occasionally, wondering if someone had just come into the room. There was often an element of surprise when a backing singer or an instrument burst into life and sometimes there was a feeling of sounds coming from nowhere near the speakers. Some of this has returned since adding the resistors.
I'm having fun tinkering...
PLEASE DON'T ANYONE ASSUME THAT THIS IS A DEFINITIVE CIRCUIT. IT IS STILL A WORK IN PROGRESS!
In reply to your last post, the slight thickening to male voice and piano etc. does seem to emanate from the bass drivers. There isn't any significant difference that I noticed in the cabinet vibrations between the front baffle and the sides. All the original foam is in position. I'm not too sure about the cabinets integrity and seal though, they have been hard used in the past, scraped and bashed as if used as a portable PA system. I'll go over all the seams with silicon goo, and think of some kind of removeable seal I can use for the drivers. Some time ago I added threaded rods and nuts in tension from front to back next to the bracing between the drivers to kill some buzzes that were coming from the cabinets. That helped the sound a lot, just as much as putting the speakers on spikes. They are never going to be pretty boxes, so I also intend to make new ones at some point. My cabinet making skills are quite good, so I may change the shape, keeping the internal volume the same, but minimising the size of the front baffle, rounding all the edges and doing away with parallel panels. For the purists, I know it's not a Ditton 66, but I'm trying to make the best of a shabby, well used pair which would otherwise have ended up as spares.
As for the 'missing', I'm sure it was something we've noticed since the crossovers had their caps replaced. It's hard to define, but I used to find myself turning around occasionally, wondering if someone had just come into the room. There was often an element of surprise when a backing singer or an instrument burst into life and sometimes there was a feeling of sounds coming from nowhere near the speakers. Some of this has returned since adding the resistors.
I'm having fun tinkering...
Attachments
Hi Alan - I've attempted to upload a copy of my current circuit diagram, so everyone can see where we are and what we were talking about. I'm having trouble uploading, I seem to end up in an endless loop so this post may appear twice!
PLEASE DON'T ANYONE ASSUME THAT THIS IS A DEFINITIVE CIRCUIT. IT IS STILL A WORK IN PROGRESS!
In reply to your last post, the slight thickening to male voice and piano etc. does seem to emanate from the bass drivers. There isn't any significant difference that I noticed in the cabinet vibrations between the front baffle and the sides. All the original foam is in position. I'm not too sure about the cabinets integrity and seal though, they have been hard used in the past, scraped and bashed as if used as a portable PA system. I'll go over all the seams with silicon goo, and think of some kind of removeable seal I can use for the drivers. Some time ago I added threaded rods and nuts in tension from front to back next to the bracing between the drivers to kill some buzzes that were coming from the cabinets. That helped the sound a lot, just as much as putting the speakers on spikes. They are never going to be pretty boxes, so I also intend to make new ones at some point. My cabinet making skills are quite good, so I may change the shape, keeping the internal volume the same, but minimising the size of the front baffle, rounding all the edges and doing away with parallel panels. For the purists, I know it's not a Ditton 66, but I'm trying to make the best of a shabby, well used pair which would otherwise have ended up as spares.
As for the 'missing', I'm sure it was something we've noticed since the crossovers had their caps replaced. It's hard to define, but I used to find myself turning around occasionally, wondering if someone had just come into the room. There was often an element of surprise when a backing singer or an instrument burst into life and sometimes there was a feeling of sounds coming from nowhere near the speakers. Some of this has returned since adding the resistors.
I'm having fun tinkering...
PLEASE DON'T ANYONE ASSUME THAT THIS IS A DEFINITIVE CIRCUIT. IT IS STILL A WORK IN PROGRESS!
In reply to your last post, the slight thickening to male voice and piano etc. does seem to emanate from the bass drivers. There isn't any significant difference that I noticed in the cabinet vibrations between the front baffle and the sides. All the original foam is in position. I'm not too sure about the cabinets integrity and seal though, they have been hard used in the past, scraped and bashed as if used as a portable PA system. I'll go over all the seams with silicon goo, and think of some kind of removeable seal I can use for the drivers. Some time ago I added threaded rods and nuts in tension from front to back next to the bracing between the drivers to kill some buzzes that were coming from the cabinets. That helped the sound a lot, just as much as putting the speakers on spikes. They are never going to be pretty boxes, so I also intend to make new ones at some point. My cabinet making skills are quite good, so I may change the shape, keeping the internal volume the same, but minimising the size of the front baffle, rounding all the edges and doing away with parallel panels. For the purists, I know it's not a Ditton 66, but I'm trying to make the best of a shabby, well used pair which would otherwise have ended up as spares.
As for the 'missing', I'm sure it was something we've noticed since the crossovers had their caps replaced. It's hard to define, but I used to find myself turning around occasionally, wondering if someone had just come into the room. There was often an element of surprise when a backing singer or an instrument burst into life and sometimes there was a feeling of sounds coming from nowhere near the speakers. Some of this has returned since adding the resistors.
I'm having fun tinkering...
Attachments
Third attempt at this post.
Hi Alan - I've attempted to upload a copy of my current circuit diagram, so everyone can see where we are and what we were talking about.
PLEASE DON'T ANYONE ASSUME THAT THIS IS A DEFINITIVE CIRCUIT. IT IS STILL A WORK IN PROGRESS!
In reply to your last post, the slight thickening to male voice and piano etc. does seem to emanate from the bass drivers. There isn't any significant difference that I noticed in the cabinet vibrations between the front baffle and the sides. All the original foam is in position. I'm not too sure about the cabinets integrity and seal though, they have been hard used in the past, scraped and bashed as if used as a portable PA system. I'll go over all the seams with silicon goo, and think of some kind of removeable seal I can use for the drivers. Some time ago I added threaded rods and nuts in tension from front to back next to the bracing between the drivers to kill some buzzes that were coming from the cabinets. That helped the sound a lot, just as much as putting the speakers on spikes. They are never going to be pretty boxes, so I also intend to make new ones at some point. My cabinet making skills are quite good, so I may change the shape, keeping the internal volume the same, but minimising the size of the front baffle, rounding all the edges and doing away with parallel panels. For the purists, I know it's not a Ditton 66, but I'm trying to make the best of a shabby, well used pair which would otherwise have ended up as spares.
As for the 'missing', I'm sure it was something we've noticed since the crossovers had their caps replaced. It's hard to define, but I used to find myself turning around occasionally, wondering if someone had just come into the room. There was often an element of surprise when a backing singer or an instrument burst into life and sometimes there was a feeling of sounds coming from nowhere near the speakers. Some of this has returned since adding the resistors.
I'm having fun tinkering...
Hi Alan - I've attempted to upload a copy of my current circuit diagram, so everyone can see where we are and what we were talking about.
PLEASE DON'T ANYONE ASSUME THAT THIS IS A DEFINITIVE CIRCUIT. IT IS STILL A WORK IN PROGRESS!
In reply to your last post, the slight thickening to male voice and piano etc. does seem to emanate from the bass drivers. There isn't any significant difference that I noticed in the cabinet vibrations between the front baffle and the sides. All the original foam is in position. I'm not too sure about the cabinets integrity and seal though, they have been hard used in the past, scraped and bashed as if used as a portable PA system. I'll go over all the seams with silicon goo, and think of some kind of removeable seal I can use for the drivers. Some time ago I added threaded rods and nuts in tension from front to back next to the bracing between the drivers to kill some buzzes that were coming from the cabinets. That helped the sound a lot, just as much as putting the speakers on spikes. They are never going to be pretty boxes, so I also intend to make new ones at some point. My cabinet making skills are quite good, so I may change the shape, keeping the internal volume the same, but minimising the size of the front baffle, rounding all the edges and doing away with parallel panels. For the purists, I know it's not a Ditton 66, but I'm trying to make the best of a shabby, well used pair which would otherwise have ended up as spares.
As for the 'missing', I'm sure it was something we've noticed since the crossovers had their caps replaced. It's hard to define, but I used to find myself turning around occasionally, wondering if someone had just come into the room. There was often an element of surprise when a backing singer or an instrument burst into life and sometimes there was a feeling of sounds coming from nowhere near the speakers. Some of this has returned since adding the resistors.
I'm having fun tinkering...
Attachments
Hi Alan - I've attempted to upload a copy of my current circuit diagram, so everyone can see where we are and what we were talking about.
PLEASE DON'T ANYONE ASSUME THAT THIS IS A DEFINITIVE CIRCUIT. IT IS STILL A WORK IN PROGRESS!
In reply to your last post, the slight thickening to male voice and piano etc. does seem to emanate from the bass drivers. There isn't any significant difference that I noticed in the cabinet vibrations between the front baffle and the sides. All the original foam is in position. I'm not too sure about the cabinets integrity and seal though, they have been hard used in the past, scraped and bashed as if used as a portable PA system. I'll go over all the seams with silicon goo, and think of some kind of removeable seal I can use for the drivers. Some time ago I added threaded rods and nuts in tension from front to back next to the bracing between the drivers to kill some buzzes that were coming from the cabinets. That helped the sound a lot, just as much as putting the speakers on spikes. They are never going to be pretty boxes, so I also intend to make new ones at some point. My cabinet making skills are quite good, so I may change the shape, keeping the internal volume the same, but minimising the size of the front baffle, rounding all the edges and doing away with parallel panels. For the purists, I know it's not a Ditton 66, but I'm trying to make the best of a shabby, well used pair which would otherwise have ended up as spares.
As for the 'missing', I'm sure it was something we've noticed since the crossovers had their caps replaced. It's hard to define, but I used to find myself turning around occasionally, wondering if someone had just come into the room. There was often an element of surprise when a backing singer or an instrument burst into life and sometimes there was a feeling of sounds coming from nowhere near the speakers. Some of this has returned since adding the resistors.
I'm having fun tinkering...
PLEASE DON'T ANYONE ASSUME THAT THIS IS A DEFINITIVE CIRCUIT. IT IS STILL A WORK IN PROGRESS!
In reply to your last post, the slight thickening to male voice and piano etc. does seem to emanate from the bass drivers. There isn't any significant difference that I noticed in the cabinet vibrations between the front baffle and the sides. All the original foam is in position. I'm not too sure about the cabinets integrity and seal though, they have been hard used in the past, scraped and bashed as if used as a portable PA system. I'll go over all the seams with silicon goo, and think of some kind of removeable seal I can use for the drivers. Some time ago I added threaded rods and nuts in tension from front to back next to the bracing between the drivers to kill some buzzes that were coming from the cabinets. That helped the sound a lot, just as much as putting the speakers on spikes. They are never going to be pretty boxes, so I also intend to make new ones at some point. My cabinet making skills are quite good, so I may change the shape, keeping the internal volume the same, but minimising the size of the front baffle, rounding all the edges and doing away with parallel panels. For the purists, I know it's not a Ditton 66, but I'm trying to make the best of a shabby, well used pair which would otherwise have ended up as spares.
As for the 'missing', I'm sure it was something we've noticed since the crossovers had their caps replaced. It's hard to define, but I used to find myself turning around occasionally, wondering if someone had just come into the room. There was often an element of surprise when a backing singer or an instrument burst into life and sometimes there was a feeling of sounds coming from nowhere near the speakers. Some of this has returned since adding the resistors.
I'm having fun tinkering...
Attachments
That worked, so I'll try once more.
Hi Alan - I've attempted to upload a copy of my current circuit diagram, so everyone can see where we are and what we were talking about.
PLEASE DON'T ANYONE ASSUME THAT THIS IS A DEFINITIVE CIRCUIT. IT IS STILL A WORK IN PROGRESS!
In reply to your last post, the slight thickening to male voice and piano etc. does seem to emanate from the bass drivers. There isn't any significant difference that I noticed in the cabinet vibrations between the front baffle and the sides. All the original foam is in position. I'm not too sure about the cabinets integrity and seal though, they have been hard used in the past, scraped and bashed as if used as a portable PA system. I'll go over all the seams with silicon goo, and think of some kind of removeable seal I can use for the drivers. Some time ago I added threaded rods and nuts in tension from front to back next to the bracing between the drivers to kill some buzzes that were coming from the cabinets. That helped the sound a lot, just as much as putting the speakers on spikes. They are never going to be pretty boxes, so I also intend to make new ones at some point. My cabinet making skills are quite good, so I may change the shape, keeping the internal volume the same, but minimising the size of the front baffle, rounding all the edges and doing away with parallel panels. For the purists, I know it's not a Ditton 66, but I'm trying to make the best of a shabby, well used pair which would otherwise have ended up as spares.
As for the 'missing', I'm sure it was something we've noticed since the crossovers had their caps replaced. It's hard to define, but I used to find myself turning around occasionally, wondering if someone had just come into the room. There was often an element of surprise when a backing singer or an instrument burst into life and sometimes there was a feeling of sounds coming from nowhere near the speakers. Some of this has returned since adding the resistors.
I'm having fun tinkering...
Attachments
Ask to have the Duplicate Posts removed
Hi Stuart,
indeed Computers can be frustrating things at times, and sometimes one does not know whether something has been accepted or not till after a delay caused by I do not know what !
At the Top of the page click on FAQ
and on the then displayed page go to the bottom-left of and under "New To Site" click on "Contact Us",
and use the Form there to ask the Administrators to remove all the duplicate Posts from #326 <---> #331 inclusive, because #325 is displaying the schematic OK.
Tell them all the additional Posts are adding to the clutter in our already very long Thread.
You will have to list the exact Title of the Thread, plus the exact starter's name :- Mr_White.
You will only be permitted to ask for your "dloper" Posts to be removed,
but perhaps they will remove this Post of mine also when they read what this is about ... otherwise I will ask them later.
Hi Stuart,
indeed Computers can be frustrating things at times, and sometimes one does not know whether something has been accepted or not till after a delay caused by I do not know what !
At the Top of the page click on FAQ
and on the then displayed page go to the bottom-left of and under "New To Site" click on "Contact Us",
and use the Form there to ask the Administrators to remove all the duplicate Posts from #326 <---> #331 inclusive, because #325 is displaying the schematic OK.
Tell them all the additional Posts are adding to the clutter in our already very long Thread.
You will have to list the exact Title of the Thread, plus the exact starter's name :- Mr_White.
You will only be permitted to ask for your "dloper" Posts to be removed,
but perhaps they will remove this Post of mine also when they read what this is about ... otherwise I will ask them later.
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More information please
Hi Stuart,
the "thickening" :-
part of its source may have been previously obscured by the sound of the old deteriorating mids' filter caps.
Do you currently feel any significant vibrations in any of the cabinet's panels when the thickening is occuring that are not there, -{or are a different type of vibration}-, with music/voice sources that are not subject to thickening ?
Do you hear the same degree of thickening regardless of the Vertical Axis you listen on ?
That is, is there any difference when you listen below the mid-driver axis towards or on the woofer axis, compared to if you listen on the mid-driver axis or above, towards or on the tweeter axis ?
What is the usual vertical axis you listen on for critical listening sessions ?
******************************************************
Before you build new cabinets, do Post your intention, because if you decide to change the ratios between the internal's Height v/s Width v/s Depth you may as well do it towards new ratios that can perhaps improve the audible performance rather than towards ratios which can cause audible deterioration.
I will explain more then, and also about curved edges to the baffle, etc ...
For now, do at least try the rolled up woollen sock along the entire under edge of that overhanging lip at the top of the cabinet.
I Posted about that somewhere earlier in this Thread.
After that I have another treble trick for you to try.
It can be tried with your KEF 104s also,
and do Post about those before you buy any new caps for them.
I'll eventually get to what I was going to say about KEF 104 when I have time available.
******************************************************
The "something missing" may be a bit harder to solve, however I fear to warn you it may be related to the new 80uF electros, as may also be the thickening in at least part of its emphasis.
I will explain that next time, but I do need to know the audible results of what I asked above first, so as not to risk pushing you along the wrong path.
******************************************************
The "thickening" and the "missing" issues should be investigated before you replace the L-pads with a choice of resistor,
but do continue to fine-tune the L-pads to decide best compromise position to suit your favorite recordings.
Hi Stuart,
the "thickening" :-
part of its source may have been previously obscured by the sound of the old deteriorating mids' filter caps.
Do you currently feel any significant vibrations in any of the cabinet's panels when the thickening is occuring that are not there, -{or are a different type of vibration}-, with music/voice sources that are not subject to thickening ?
Do you hear the same degree of thickening regardless of the Vertical Axis you listen on ?
That is, is there any difference when you listen below the mid-driver axis towards or on the woofer axis, compared to if you listen on the mid-driver axis or above, towards or on the tweeter axis ?
What is the usual vertical axis you listen on for critical listening sessions ?
******************************************************
Before you build new cabinets, do Post your intention, because if you decide to change the ratios between the internal's Height v/s Width v/s Depth you may as well do it towards new ratios that can perhaps improve the audible performance rather than towards ratios which can cause audible deterioration.
I will explain more then, and also about curved edges to the baffle, etc ...
For now, do at least try the rolled up woollen sock along the entire under edge of that overhanging lip at the top of the cabinet.
I Posted about that somewhere earlier in this Thread.
After that I have another treble trick for you to try.
It can be tried with your KEF 104s also,
and do Post about those before you buy any new caps for them.
I'll eventually get to what I was going to say about KEF 104 when I have time available.
******************************************************
The "something missing" may be a bit harder to solve, however I fear to warn you it may be related to the new 80uF electros, as may also be the thickening in at least part of its emphasis.
I will explain that next time, but I do need to know the audible results of what I asked above first, so as not to risk pushing you along the wrong path.
******************************************************
The "thickening" and the "missing" issues should be investigated before you replace the L-pads with a choice of resistor,
but do continue to fine-tune the L-pads to decide best compromise position to suit your favorite recordings.
Hello Alan
I can't say I notice much difference in cabinet vibrations, whether the 'thickening' is present or not.
Normally I listen on a vertical axis between the mid and treble units. Raising my listening position to tweeter level doesn't make a significant difference, but continuing to a standing position progressively reduces the effect until it disappears entirely, to my ear. It does seem to increase a little if I listen from below the mid unit. All this at a distance of 3m from each speaker.
As for the protruding lips on the top of the cabinets, they were removed some time ago, as they were bruised and unsightly.
For now, I'm off to plug in my Dynaudio Contour 1.8 mk1s again just to remind myself how the 66s sound in comparison. A change might help me when I plug the 66s' back in.
Stuart
I can't say I notice much difference in cabinet vibrations, whether the 'thickening' is present or not.
Normally I listen on a vertical axis between the mid and treble units. Raising my listening position to tweeter level doesn't make a significant difference, but continuing to a standing position progressively reduces the effect until it disappears entirely, to my ear. It does seem to increase a little if I listen from below the mid unit. All this at a distance of 3m from each speaker.
As for the protruding lips on the top of the cabinets, they were removed some time ago, as they were bruised and unsightly.
For now, I'm off to plug in my Dynaudio Contour 1.8 mk1s again just to remind myself how the 66s sound in comparison. A change might help me when I plug the 66s' back in.
Stuart
The Inductors' relative positionings now ?
Hello Stuart,
I have remembered you posted that you rebuilt your x-over boards.
Did you place any of the Inductors differently on the rebuilt boards to how they were on the original boards ?
That is:-
Are any further or closer to any others than they were originally ?
and if so, then which ones, and relative to which others ?
Did you change the physical orientation of any of them - in particular did you place one or more upside-down
to what it was originally -{even if still lying it flat on the new board}- ?
And/or, have you placed any standing on their curved edge now ?
On the original board all the inductors are a bit too close to each other, thus there will be some magnetic coupling between them.
If this has been changed the sound will change, and it can possibly be got to change for the better by specific orientation and placing, but it can also be got to sound worse ... and where-ever in between that is simply different ...
A small change in any of the ways I have described could have caused the thickening of the lower midrange sound you are noticing, even if that is primarily from the bass driver,
because the magnetic coupling between inductors causes each of the coupled inductors to have a different inductance to what it would have if there was no coupling or a different degree of coupling, and thus the audio filtering will be different.
The coupling can be additive or subtractive -{relative to an un-coupled state}- depending on the direction of the winding of one of the coupled inductors to that of the other inductor.
Thus, before I proceed to suggest anything else, Post the current situation of the inductors.
Hello Stuart,
I have remembered you posted that you rebuilt your x-over boards.
Did you place any of the Inductors differently on the rebuilt boards to how they were on the original boards ?
That is:-
Are any further or closer to any others than they were originally ?
and if so, then which ones, and relative to which others ?
Did you change the physical orientation of any of them - in particular did you place one or more upside-down
to what it was originally -{even if still lying it flat on the new board}- ?
And/or, have you placed any standing on their curved edge now ?
On the original board all the inductors are a bit too close to each other, thus there will be some magnetic coupling between them.
If this has been changed the sound will change, and it can possibly be got to change for the better by specific orientation and placing, but it can also be got to sound worse ... and where-ever in between that is simply different ...
A small change in any of the ways I have described could have caused the thickening of the lower midrange sound you are noticing, even if that is primarily from the bass driver,
because the magnetic coupling between inductors causes each of the coupled inductors to have a different inductance to what it would have if there was no coupling or a different degree of coupling, and thus the audio filtering will be different.
The coupling can be additive or subtractive -{relative to an un-coupled state}- depending on the direction of the winding of one of the coupled inductors to that of the other inductor.
Thus, before I proceed to suggest anything else, Post the current situation of the inductors.
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Modelling the Ditton 66 crossover for poly caps
1.
On Friday am taking the Ditton 66s to Wokingham (UK) for John at Audio Components to measure using his PRAXIS system. He will give me an optimum accurate design of crossover for modern components without padding resistors for ESR, and we will build & test his design.
Loudspeaker Measurement
John makes a valid point that, without objective measurement, crossovers tuned by ear will usually end up irregular in response.
This is a commercial service. If the day goes well I may be prepared to share that design for a share of costs incurred (the more individuals, lesser individual contribution).
2.
Have just completed assembly of the kit for this advanced LCR meter:
M3 Digital LCRZ Meter
They can send to Europe although their website says sell only in Canada/US. (They planned to have separate distribution within Europe.)
"We can mail your kit via Priority Mail International for a flat rate of $12.95 - 6 to 10 day delivery and includes tracking. So, depending on which you kit you would like to order, your cost will be $181.95 for the basic kit or $222.95 for the kit including Kelvin Clip cable.
You can make payment through Pay Pal. Our Pay Pal account address is mcubed2@hughes.net. In the remarks block just enter "Payment for LCRZ meter kit"."
This quote was to UK.
The reviews on their website confirm my experience that this meter (only available as a kit) is excellent. It requires some experience with a soldering iron, including soldering of 10 integrated circuits (it is a clever beasty).
If they enhance the program in e-prom, they promise to retrospectively upgrade if you send the meter to them. It is currently on version 2.03.
I have no commercial interest in this company.
3.
I have tried the Peak Electronics meter "Atlas LCR40" and "Atlas ESR60":
Peak Electronic Design Limited - Atlas LCR - Passive Component Analyser - Model LCR40
Available direct from Peak, can send back within 14 days for a complete refund. Peak will soon offer an enhanced version "Atlas ESR70".
These are convenient to use, however chooses the frequency of measurement. The ESR meter only measures at around 20kHz, intended more for radio frequency applications than audio.
(I decided on the M3 meter for automatic and manual choice of frequencies, finer accuracy and wider range of application. The cost of the M3 was about the same as the cost of the LCR40 and ESR60 together ~ £150.)
1.
On Friday am taking the Ditton 66s to Wokingham (UK) for John at Audio Components to measure using his PRAXIS system. He will give me an optimum accurate design of crossover for modern components without padding resistors for ESR, and we will build & test his design.
Loudspeaker Measurement
John makes a valid point that, without objective measurement, crossovers tuned by ear will usually end up irregular in response.
This is a commercial service. If the day goes well I may be prepared to share that design for a share of costs incurred (the more individuals, lesser individual contribution).
2.
Have just completed assembly of the kit for this advanced LCR meter:
M3 Digital LCRZ Meter
They can send to Europe although their website says sell only in Canada/US. (They planned to have separate distribution within Europe.)
"We can mail your kit via Priority Mail International for a flat rate of $12.95 - 6 to 10 day delivery and includes tracking. So, depending on which you kit you would like to order, your cost will be $181.95 for the basic kit or $222.95 for the kit including Kelvin Clip cable.
You can make payment through Pay Pal. Our Pay Pal account address is mcubed2@hughes.net. In the remarks block just enter "Payment for LCRZ meter kit"."
This quote was to UK.
The reviews on their website confirm my experience that this meter (only available as a kit) is excellent. It requires some experience with a soldering iron, including soldering of 10 integrated circuits (it is a clever beasty).
If they enhance the program in e-prom, they promise to retrospectively upgrade if you send the meter to them. It is currently on version 2.03.
I have no commercial interest in this company.
3.
I have tried the Peak Electronics meter "Atlas LCR40" and "Atlas ESR60":
Peak Electronic Design Limited - Atlas LCR - Passive Component Analyser - Model LCR40
Available direct from Peak, can send back within 14 days for a complete refund. Peak will soon offer an enhanced version "Atlas ESR70".
These are convenient to use, however chooses the frequency of measurement. The ESR meter only measures at around 20kHz, intended more for radio frequency applications than audio.
(I decided on the M3 meter for automatic and manual choice of frequencies, finer accuracy and wider range of application. The cost of the M3 was about the same as the cost of the LCR40 and ESR60 together ~ £150.)
Be careful !
John - if he has any experience of the particular vintage loudspeakers that various enthusiasts actually like - should know that "objective measurement" was done by the designers of those speakers.
The limitations of those speakers are resultant of the technology of the drivers and some -{not all}- of the crossover components.
When the degraded crossover components are replaced in such way as to simulate the original design, then one has restored the original design,
and that is the sound the restorers often want, as is obvious from Posts in this Thread and other Threads in this Forum, and various similar Posts in various Forums, along with what enthusiasts tell me in person.
Further tuning by ear - at least within what we are mostly doing here - is very fine-tuning to improve on particular aspects of the original towards the specifics of sound that the owner wants, and when the result is pleasing to the listener the crossover will NOT be "irregular in response", it will be close to ideal in response !
Consider, what is really Regular In Response ?
There have been, and are currently, and will continue to be, numerous loudspeakers designed which have measured responses that are all as close to ideal as can be got at their specific price points, and NONE of them sound identical to others' similar, and some listeners like some of them and other listeners like others of them, and some of them no-one likes, -{and this is not including designs which do have measured anomalies}-,
and those include modern computer-assisted designs, and those include designs which use exactly the same drivers as other designs.
Almost always one has to make a number of measurements to achieve a likeable sounding loudspeaker, and usually with the successful older designs there was listening done and some fine-tuning by ear,
and almost always with modern computer-assisted designs there has to be some fine-tuning done by ear.
I advise any doubters to research widely and you will find the evidence,
{but don't expect most designers to give away their secrets}.
I don't know John's experience, thus he may be well-intentioned -{and I hope he is}- , but he may also simply be selling his Design Services, and hoping to sell some crossover components to follow.
I have no doubt that following the measurements - if they are comprehensive, and if they are then intelligently applied - that a Regular In Response loudspeaker can be achieved using the original Celestion drivers in the original Celestion cabinet, but I highly doubt that it will sound like a Ditton 66 !
If the listeners like the final result, then the new design is a success for them, but I recommend very strongly to all owners of well-liked vintage loudspeakers that you think very carefully about what you like, or don't like, about your loudspeaker before you spend a lot of money having a supposedly "optimum accurate design of crossover" designed for it.
I can take an "optimum accurate design of crossover" and use various combinations of entirely "modern components" in that crossover and make various different sounding loudspeakers - all with exactly the same drivers in exactly the same enclosure ... as can any sufficiently experienced designer ...
Regardless of whether one considers resistors as "padding resistors for ESR" or as for some other purpose, I will be VERY surprised if the final PRAXIS assisted design has no resistors, or is not "irregular in response" if no resistors ! -
but that is quite different to the consideration of the designer and/or owner liking the sound of the final design.
Given as harnfield can afford it, this will be an interesting experiment, and thus please harnfield, do Post and tell us the audible results.
Thankyou for Posting the results of your investigations of the meters.
John - if he has any experience of the particular vintage loudspeakers that various enthusiasts actually like - should know that "objective measurement" was done by the designers of those speakers.
The limitations of those speakers are resultant of the technology of the drivers and some -{not all}- of the crossover components.
When the degraded crossover components are replaced in such way as to simulate the original design, then one has restored the original design,
and that is the sound the restorers often want, as is obvious from Posts in this Thread and other Threads in this Forum, and various similar Posts in various Forums, along with what enthusiasts tell me in person.
Further tuning by ear - at least within what we are mostly doing here - is very fine-tuning to improve on particular aspects of the original towards the specifics of sound that the owner wants, and when the result is pleasing to the listener the crossover will NOT be "irregular in response", it will be close to ideal in response !
Consider, what is really Regular In Response ?
There have been, and are currently, and will continue to be, numerous loudspeakers designed which have measured responses that are all as close to ideal as can be got at their specific price points, and NONE of them sound identical to others' similar, and some listeners like some of them and other listeners like others of them, and some of them no-one likes, -{and this is not including designs which do have measured anomalies}-,
and those include modern computer-assisted designs, and those include designs which use exactly the same drivers as other designs.
Almost always one has to make a number of measurements to achieve a likeable sounding loudspeaker, and usually with the successful older designs there was listening done and some fine-tuning by ear,
and almost always with modern computer-assisted designs there has to be some fine-tuning done by ear.
I advise any doubters to research widely and you will find the evidence,
{but don't expect most designers to give away their secrets}.
I don't know John's experience, thus he may be well-intentioned -{and I hope he is}- , but he may also simply be selling his Design Services, and hoping to sell some crossover components to follow.
I have no doubt that following the measurements - if they are comprehensive, and if they are then intelligently applied - that a Regular In Response loudspeaker can be achieved using the original Celestion drivers in the original Celestion cabinet, but I highly doubt that it will sound like a Ditton 66 !
If the listeners like the final result, then the new design is a success for them, but I recommend very strongly to all owners of well-liked vintage loudspeakers that you think very carefully about what you like, or don't like, about your loudspeaker before you spend a lot of money having a supposedly "optimum accurate design of crossover" designed for it.
I can take an "optimum accurate design of crossover" and use various combinations of entirely "modern components" in that crossover and make various different sounding loudspeakers - all with exactly the same drivers in exactly the same enclosure ... as can any sufficiently experienced designer ...
Regardless of whether one considers resistors as "padding resistors for ESR" or as for some other purpose, I will be VERY surprised if the final PRAXIS assisted design has no resistors, or is not "irregular in response" if no resistors ! -
but that is quite different to the consideration of the designer and/or owner liking the sound of the final design.
Given as harnfield can afford it, this will be an interesting experiment, and thus please harnfield, do Post and tell us the audible results.
Thankyou for Posting the results of your investigations of the meters.
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Modelling the Ditton 66 crossover for poly caps
Yes, Celestion probably used B&K plots conducted in a near-anechoic chamber. In the 70's, I had the fortune to run some plots in Chelsea College's facility (now part of King's College, London) on my Quad ESL57 and assorted other drivers.
It is not just plots of amplitude, it is to find frequencies where the drivers distort. The crossover will divert power away from problem parts of the spectrum, in some designs with notch filters for known resonances. However these drivers should be well-behaved (this was the Studio Monitor used by the BBC) and there is no notch in the original crossover.
I am interested too in the impact of the "lip" at the top of the cabinet on the supertweeter response. If there is an anomaly in that response, I may compare the response "in cabinet" with that when mounted on a simple flat baffle.
The original crossover was designed around electrolytic capacitors. We do not know their precise ESR, and this shifts the effective crossover frequency and (slightly) the slope.
My experience after replacing with poly caps (Solen) was that the balance was out, much too much midrange. I am not sure that padding resistors are succeeding for me.
Modern polys are more transparent, especially as one goes up in quality from Dayton, Solen... If these had been available at the time, the crossover chosen by Celestion would look different, for sure.
I will let you know how it goes.
Yes, Celestion probably used B&K plots conducted in a near-anechoic chamber. In the 70's, I had the fortune to run some plots in Chelsea College's facility (now part of King's College, London) on my Quad ESL57 and assorted other drivers.
It is not just plots of amplitude, it is to find frequencies where the drivers distort. The crossover will divert power away from problem parts of the spectrum, in some designs with notch filters for known resonances. However these drivers should be well-behaved (this was the Studio Monitor used by the BBC) and there is no notch in the original crossover.
I am interested too in the impact of the "lip" at the top of the cabinet on the supertweeter response. If there is an anomaly in that response, I may compare the response "in cabinet" with that when mounted on a simple flat baffle.
The original crossover was designed around electrolytic capacitors. We do not know their precise ESR, and this shifts the effective crossover frequency and (slightly) the slope.
My experience after replacing with poly caps (Solen) was that the balance was out, much too much midrange. I am not sure that padding resistors are succeeding for me.
Modern polys are more transparent, especially as one goes up in quality from Dayton, Solen... If these had been available at the time, the crossover chosen by Celestion would look different, for sure.
I will let you know how it goes.
Hi Harnfield, Alan
This was my experience too, that the midrange was very aggressive when I first changed the caps to polypropylenes of equivalent value, but I found that with resistors, in the value range that Alan estimated and suggested to me in another thread compensated for ESR and brought things into line admirably. The result is quite sublime, actually.
What values of resistor are you currently employing? Perhaps you could draw us a schematic of your current crossover configuration.
I would be very interested to see what all the latest technology would determine was the "perfect" crossover for the 66s. I'd also be surprised if it were to blow the originals away, but maybe...
All the best
Lucas
Perfect crossover?
Any adjustment is crutial
Size and place matters
Quality is second, or doesnt matter at all
But to determine whether one adjustment is right can be VERY difficult
At first it doesnt sound like right at all
Its dependable on other adjustment as well
Mostly, one single adjustment simply doesnt work until other adjustment are made
And to find those you may need yet other adjustment in other places, or several
Its back and forth
Many many options, and most of them wrong ones
It surely doesnt come easy
Commercial people have no time to do such
They have to make the decision "good enough"
And sales department think "better sooner than later"
Perfect, I dont think so
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