Spell checker installed
Apologies to all for my spelling! - must try harder...
L3 in the 44 corresponds to L4 in the 33 and L1 in the 44 corresponds to L5 in the 33.
I have photo's and sketches to send but I can't upload them for some reason. - I'll have to try again tomorrow now - sorry!
Roy.
Apologies to all for my spelling! - must try harder...
Yes I see that.
On the 33 crossover there are 2 air-cored inductors. The smaller one is actually L5 and the larger one is L4. The L numbers are backwards to the 44.
L3 in the 44 corresponds to L4 in the 33 and L1 in the 44 corresponds to L5 in the 33.
I have photo's and sketches to send but I can't upload them for some reason. - I'll have to try again tomorrow now - sorry!
Roy.
Photo's
Hi,
Here are the actual photos of the crossover board – please note that I have reversed the ‘track’ side. This should make it easier if you wish to check through the circuit.
The large inductor in the centre is L4, and L5 is at top left. The other three inductors ( L1, L2 & L3) with yellow tape are ferrite cored.
What is interesting is the fact that on the 44 circuit, inductors L2 and L5 are the same, and on the 33 L3 and L2 are also the same. – But the large air-cored inductor in the centre of the 33 is definitely L4 which is the 2mH.
Hope this is useful
Roy
Hi,
Here are the actual photos of the crossover board – please note that I have reversed the ‘track’ side. This should make it easier if you wish to check through the circuit.
The large inductor in the centre is L4, and L5 is at top left. The other three inductors ( L1, L2 & L3) with yellow tape are ferrite cored.
What is interesting is the fact that on the 44 circuit, inductors L2 and L5 are the same, and on the 33 L3 and L2 are also the same. – But the large air-cored inductor in the centre of the 33 is definitely L4 which is the 2mH.
Hope this is useful
Roy
Attachments
Getting the hang of it now!
Hi again,
Here are a couple of photos of the Ditton 33 Mid-range driver. I measured its voice coil resistance as 3.4 ohms, but I will check it again and report back when I put a new battery in my DMM (Fluke 85).
If I can find a way, probably from the internet, I will attempt to measure the inductance of all the inductors on the crossover, - but this may take a while.
To all readers
Can anyone help in finding more information on the Ditton 33 speakers – especially the HF1000 tweeters – PLEASE!
Regards to all
Roy,
Hi again,
Here are a couple of photos of the Ditton 33 Mid-range driver. I measured its voice coil resistance as 3.4 ohms, but I will check it again and report back when I put a new battery in my DMM (Fluke 85).
If I can find a way, probably from the internet, I will attempt to measure the inductance of all the inductors on the crossover, - but this may take a while.
To all readers
Can anyone help in finding more information on the Ditton 33 speakers – especially the HF1000 tweeters – PLEASE!
Regards to all
Roy,
Attachments
Ah hah! – The penny’s dropped!
Hi Alan,
Right! - I understand what you’re saying now. So (on the 33) L4 may not be 2mH, but closer to the value of .66mH, and L2 & L3 may be the 2mH with them both being the same values, like in the 44. – Doh! - I got there in the end!
So it really is important to determine the values of those inductors.
Also, you asked me to compare sound levels between the tweeter and the woofer and ignoring the mid-range. I managed to find a small soft cushion which I placed up against the mid to kill its sound. Both I and my wife listened in this way and came to the conclusion that the woofer was slightly louder. This was with listening to voices, both male and female.
The Morel tweeter I find has a very sweet zing to it which easily draws attention to itself. I agree it’s not a bad sound but I’m hoping the seas will be more natural and integrate better with the rest of the system.
Hope this make sense
Roy.
Hi Alan,
Right! - I understand what you’re saying now. So (on the 33) L4 may not be 2mH, but closer to the value of .66mH, and L2 & L3 may be the 2mH with them both being the same values, like in the 44. – Doh! - I got there in the end!
So it really is important to determine the values of those inductors.
Also, you asked me to compare sound levels between the tweeter and the woofer and ignoring the mid-range. I managed to find a small soft cushion which I placed up against the mid to kill its sound. Both I and my wife listened in this way and came to the conclusion that the woofer was slightly louder. This was with listening to voices, both male and female.
The Morel tweeter I find has a very sweet zing to it which easily draws attention to itself. I agree it’s not a bad sound but I’m hoping the seas will be more natural and integrate better with the rest of the system.
Hope this make sense
Roy.
try first
Hi Roy,
good stuff ! - your diagrams and photos.
In size comparison to the known 0.14mH air-core coil, the larger air-core coil is not 2mH.
It will be significantly less than 2mH in inductance.
The 44 mid-cones I have seen out-of-box are definitely different to those 33 cones you have,
though I think the 44s I saw are the original large magnet versions that Lucas mentions in this thread,
thus perhaps those you have are the small magnet versions, {which Lucas also mentions},
because you have what would be equivalent of a Mark II version of the 33,
because your crossover board is of the P.C.C. type as in Mk II of 44 and 66.
I will try to get diameter measurement of the 44 cone to conclude that part.
The "sweet zing" you are hearing from the Morel tweeter ...
it could be a characteristic of the tweeter, but if you have it connected to those old black/red-end caps they are likely leaking lower frequency signals through given their age, and such could be overdriving the tweeter at its Fs which is in the midrange, thus a "zing" sound.
Even if not leaking significantly, 8uF for the input cap is too large to filter the Morel sufficiently in that circuit,
thus significant amount of mids will be getting to it.
If you have any smaller capacitances that are not faulty, try them before you consider changing the tweeter.
Any value between 3.3uF <---> 4.7uF will suffice in place of the 8uF to test the tweeter,
and if you have either of the resistor combinations I posted above, then try those at the same time,
and again with the mid-cone covered in the way you described so as to be sure you are primarily hearing the tweeter's sound.
Is there a shop near where you live that you can buy 5 watt rated resistors from, or will you have to buy resistors via Mail Order ?
{as for new capacitors}.
Yes, do re-measure the DC resistances when you have a new battery installed.
It is worth buying a +/- 1% tolerance 10 ohm resistor, {or in lower resistance},
to check your meter against when measuring unknown low resistances,
because many meters are not particually accurate for low DC resistances.
I do not know the Fluke 85, but my Fluke 87 is tolerable though not wonderful over low resistances,
and of course not when its battery is very low !
I'll comment more about the tweeter versus woofer audible level differences when I have time,
but don't rush into buying new capacitors yet ... if you really want to get the relative output levels in balance.
I hope you have seen and read my posts about the audible effects of the Dielectric Absorption that is present in all electrolytic caps,
regardless of their age.
I posted about such in this thread and in the Celestion 66 thread, and in the 66 thread there are listener reports by owners who changed from new electro caps to polypropylene caps.
Hi Roy,
good stuff ! - your diagrams and photos.
In size comparison to the known 0.14mH air-core coil, the larger air-core coil is not 2mH.
It will be significantly less than 2mH in inductance.
The 44 mid-cones I have seen out-of-box are definitely different to those 33 cones you have,
though I think the 44s I saw are the original large magnet versions that Lucas mentions in this thread,
thus perhaps those you have are the small magnet versions, {which Lucas also mentions},
because you have what would be equivalent of a Mark II version of the 33,
because your crossover board is of the P.C.C. type as in Mk II of 44 and 66.
I will try to get diameter measurement of the 44 cone to conclude that part.
The "sweet zing" you are hearing from the Morel tweeter ...
it could be a characteristic of the tweeter, but if you have it connected to those old black/red-end caps they are likely leaking lower frequency signals through given their age, and such could be overdriving the tweeter at its Fs which is in the midrange, thus a "zing" sound.
Even if not leaking significantly, 8uF for the input cap is too large to filter the Morel sufficiently in that circuit,
thus significant amount of mids will be getting to it.
If you have any smaller capacitances that are not faulty, try them before you consider changing the tweeter.
Any value between 3.3uF <---> 4.7uF will suffice in place of the 8uF to test the tweeter,
and if you have either of the resistor combinations I posted above, then try those at the same time,
and again with the mid-cone covered in the way you described so as to be sure you are primarily hearing the tweeter's sound.
Is there a shop near where you live that you can buy 5 watt rated resistors from, or will you have to buy resistors via Mail Order ?
{as for new capacitors}.
Yes, do re-measure the DC resistances when you have a new battery installed.
It is worth buying a +/- 1% tolerance 10 ohm resistor, {or in lower resistance},
to check your meter against when measuring unknown low resistances,
because many meters are not particually accurate for low DC resistances.
I do not know the Fluke 85, but my Fluke 87 is tolerable though not wonderful over low resistances,
and of course not when its battery is very low !
I'll comment more about the tweeter versus woofer audible level differences when I have time,
but don't rush into buying new capacitors yet ... if you really want to get the relative output levels in balance.
I hope you have seen and read my posts about the audible effects of the Dielectric Absorption that is present in all electrolytic caps,
regardless of their age.
I posted about such in this thread and in the Celestion 66 thread, and in the 66 thread there are listener reports by owners who changed from new electro caps to polypropylene caps.
Last edited:
ok - will do
Hi Alan,
I will probably end up buying mail order, but I do have a Maplins quite close to me. So I will go there for now and purchase some 5 watt resistors and ~ 4uF non-polarised caps to try. I will also see if they have any 1% or better tolerance resistors.
I’ll fit a new battery in my meter shortly and post the mid-range resistance, then I’ll report back once I’ve got & fitted the above components.
Thanks Alan
Roy.
Hi Alan,
I will probably end up buying mail order, but I do have a Maplins quite close to me. So I will go there for now and purchase some 5 watt resistors and ~ 4uF non-polarised caps to try. I will also see if they have any 1% or better tolerance resistors.
Yes I really would like to get the balance right and will gladly be guided by your expertise.
I’ll fit a new battery in my meter shortly and post the mid-range resistance, then I’ll report back once I’ve got & fitted the above components.
Thanks Alan
Roy.
Roy,
I'd suggest you browse Maplin, but not buy unless you see a fanatstic deal.
I use Rapid online, Farnell, Dalbani, RS, in that order.
Try to maximise single orders to get advantage of free postage deals. The postal costs mount up disproportionately if you place many small orders.
I buy Zeners, resistors & diodes by the 100 pack ( literally pence each) most others by the 10 or 25 pieces to get a small quantity discount.
I'd suggest you browse Maplin, but not buy unless you see a fanatstic deal.
I use Rapid online, Farnell, Dalbani, RS, in that order.
Try to maximise single orders to get advantage of free postage deals. The postal costs mount up disproportionately if you place many small orders.
I buy Zeners, resistors & diodes by the 100 pack ( literally pence each) most others by the 10 or 25 pieces to get a small quantity discount.
New battery fitted
Hi again,
Quick update – I’ve re-measured the coil resistance of the mid range unit and it is 3.5 ohms. This was with a new battery fitted in my DMM. Please let me know if any more measurements are required.
Hi AndrewT
Thanks for the info. I did know about RS and Farnell but not the others. I think I was ok with Maplin this time though as I got free postage.
Regards
Roy
Hi again,
Quick update – I’ve re-measured the coil resistance of the mid range unit and it is 3.5 ohms. This was with a new battery fitted in my DMM. Please let me know if any more measurements are required.
Hi AndrewT
Thanks for the info. I did know about RS and Farnell but not the others. I think I was ok with Maplin this time though as I got free postage.
Regards
Roy
Hmmm!
My components arrived. So I went about trying the different L-pad values, {15 ohms + 1.5 ohms} and {18 ohms + 1.2 ohms}, and the 8uF capacitor replacement.
I think it’s fair to say I am now little bewildered. First I tried the L-pads and I’ve settled with 15 ohm + 1.5 ohm. I thought the other combination made the tweeter louder compared to the base.
Next I replaced the 8uF cap with a 3.3uF. This made the speaker sound awful. The sound was lifeless and laid back with no ‘body’ - especially with voices. Next I tried a 4.7uF which was a little better but still not very good.
At the moment I’ve got 5.5uF (3.3 in parallel with 2.2) which is just about acceptable although but I feel inclined to put the 8uF back.
On the brighter side I have found a little more info for the HD1000 tweeter whilst surfing the net, – but its in German – so if any one can translate…
Also I saw a couple of pairs on eBay, one pair going for the extortionate price (IMO) of 68 pounds! – On the other pair it said that "both coils measured 4.2ohms DCR" on his DMM. This would confirm Its 4 ohm impedance wouldn’t it?
Hope the info is useful, but where do I go from here
Regards
Roy
My components arrived. So I went about trying the different L-pad values, {15 ohms + 1.5 ohms} and {18 ohms + 1.2 ohms}, and the 8uF capacitor replacement.
I think it’s fair to say I am now little bewildered. First I tried the L-pads and I’ve settled with 15 ohm + 1.5 ohm. I thought the other combination made the tweeter louder compared to the base.
Next I replaced the 8uF cap with a 3.3uF. This made the speaker sound awful. The sound was lifeless and laid back with no ‘body’ - especially with voices. Next I tried a 4.7uF which was a little better but still not very good.
At the moment I’ve got 5.5uF (3.3 in parallel with 2.2) which is just about acceptable although but I feel inclined to put the 8uF back.
On the brighter side I have found a little more info for the HD1000 tweeter whilst surfing the net, – but its in German – so if any one can translate…
Also I saw a couple of pairs on eBay, one pair going for the extortionate price (IMO) of 68 pounds! – On the other pair it said that "both coils measured 4.2ohms DCR" on his DMM. This would confirm Its 4 ohm impedance wouldn’t it?
Hope the info is useful, but where do I go from here
Regards
Roy
Polarity
Hi Roy,
I'll have to be brief today.
What you have been trying is good diy process.
Next to try: swap the Polarity of the connections to the tweeter and listen again, preferably with the 4.7uF cap in circuit,
and report the listening results here of one polarity versus the other,
and preferably when listening on-axis to the mid-cone, not the tweeter,
because on axis to the mids was the usual design for 3-way loudspeakers then,
and still is for some today.
I can decipher what I need to know from that German language specification.
As result of that, and your measurement of the mid-cone's DCR I now understand that unusual crossover a bit better.
I will explain more when I have time available, but in the interim try the above and report here.
Remember, you have yet to install reliable capacitors in the mids' circuit,
thus don't make final conclusions yet ... more about this next time.
Do you have the Fluke 85 meter or the 87 ?
I ask because I read Fluke 87 in an earlier post of yours, and 85 in a later one.
The meter may be able to be used with other things to estimate the inductance of the unknown air-core coil.
Hi Roy,
I'll have to be brief today.
What you have been trying is good diy process.
Next to try: swap the Polarity of the connections to the tweeter and listen again, preferably with the 4.7uF cap in circuit,
and report the listening results here of one polarity versus the other,
and preferably when listening on-axis to the mid-cone, not the tweeter,
because on axis to the mids was the usual design for 3-way loudspeakers then,
and still is for some today.
I can decipher what I need to know from that German language specification.
As result of that, and your measurement of the mid-cone's DCR I now understand that unusual crossover a bit better.
I will explain more when I have time available, but in the interim try the above and report here.
Remember, you have yet to install reliable capacitors in the mids' circuit,
thus don't make final conclusions yet ... more about this next time.
Do you have the Fluke 85 meter or the 87 ?
I ask because I read Fluke 87 in an earlier post of yours, and 85 in a later one.
The meter may be able to be used with other things to estimate the inductance of the unknown air-core coil.
Morel tweeter quality ?
Roy, I was in such a hurry last time that I forgot the primary reason I had previously recommended you try the tweeter with a capacitor between 3.3uF <---> 4.7uF,
and that is of course to decide your earlier point about changing the Morel for an SEAS H737 ...
thus, ignoring the other audible characteristics you heard after listening with either of the new capacitors, did the Morel sound cleaner or does it still have the "sweet zing" you described ?
and if it does, is that to same degree as previously or to a lesser degree partially or significantly ?
This will probably be best decided with the 4.7uF cap rather than the parallel pair of caps to 5.5uF because a single cap cannot cause a distortion of the Transient Response of the signal that unequal capacitances in parallel combination cause if one has a faster pulse rise time than the other.
This distortion is audible as a spitting sound - sibilant - though it can be very small and then mistaken for addtional treble detail.
It is less likely to be audible when electrolytic caps are paralleled than when polypropylene caps, because the significant and different ESR {resistance} of each different value electro cap slows the transient response through each cap in inverse proportion to its capacitance in such way that what would be the faster cap if no ESR slows down to greater degree than the would be slower cap with the end result that both have close to the same pulse rise time through, hence little transient distortion caused by the paralleled pair.
That does not occur with polyprop caps because they have negligible ESR.
Of course one can experiment with a different small value resistance in series with each poly cap of the pair to try to achieve equal pulse rise times,
but that is a lot of time consumed and extra components to buy.
Simpler is to use a single cap when possible, or parallel an equal capacitance pair , or three if need be, to get the exact total capacitance that is needed.
However, even if you have bought electro caps I still think it better to decide the tweeter quality via a single cap.
The 12uF output cap is in Series, not Parallel, with the input cap,
thus its different pulse rise time cannot cause distortion of the transients ... unless the cap itself is intermittantly faulty ... and it could be as it is so old, thus if you are not able to make a confident decision then replace the old 12uF with a low price 10uF or 15uF from a local shop,
or a 12uF electrolytic for 1.36 from www.wilmslow-audio.co.uk
Later, after interim matters final values for tweeter capacitances can be decided and you can then buy the better quality Supersound capacitors from Wilmslow Audio at higher price if you want to buy within the UK but not pay huge prices.
If you want to install new caps in the mids' filter now, I recommend the Supersounds in exactly the same values as in your crossover: 16uF and 30uF, unless you want to spend more for higher quality caps.
It will be a waste of money putting low price electro-caps in the mids for interim,
because electros cause smearing of the sound as result of their Dielectric Absorption,
and additionally that effect will make it harder for you to decide the optimum balance between mids and bass,
because that 2.2 ohm resistor may have to be increased ... to be decided by ear.
For new bass section caps, the choice may have to depend on how much space there is on your crossover boards,
because the Supersounds are large size.
There are smaller sized polypropylene caps available that are suitable for there and will cause better sound than electros,
but to obtain those you will have to buy via Mail-order from France or Canada or USA.
Summary: decide the tweeter quality first, because if you need to change to the SEAS, it is lower Sensitivity than that Morel thus you will have to change the L-pad resistors ... AND as we now have to simulate a nominal 4 ohm tweeter to get the new tweeter to neatly cross to the mids without changing either of the inductors I need to know which tweeter you will be using.
Next, what you stated as audible:
"I replaced the 8uF cap with a 3.3uF. This made the speaker sound awful. The sound was lifeless and laid back with no ‘body’ - especially with voices. Next I tried a 4.7uF which was a little better but still not very good.
At the moment I’ve got 5.5uF (3.3 in parallel with 2.2) which is just about acceptable although but I feel inclined to put the 8uF back."
Did you do that test with the mid-cones covered or uncovered ?
If you listened with the mid-cones covered I understand the effects you described.
If the mid-cones were uncovered I would have expected the sound to be clearer with one or other of 3u3 or 4u7 than with 8uF, because for 8uF to work the Morel tweeter's Impedance has to be lowered with a suitable value resistance in parallel with it.
I would expect the 8uF to cause significant audible colouration or resonance when connected to a higher impedance tweeter in the circuit with the 0.14mH inductor.
Whether the coloration resulted in louder or quieter sound in the upper mids/lower treble would depend on phase interference through the crossover region ...
thus why I last week advised listening with the alternate Polarity connection of the tweeter as that will change the direction of whatever phase error
For this test listen with the mid-cones audible.
The blocking mids' test is only to decide tweeter quality ...
not to decide optimum capacitance values for the crossover.
Thus, if necessary do your audio testing again,
and whatever the case is, post a report here.
The next step will follow the above two.
Roy, I was in such a hurry last time that I forgot the primary reason I had previously recommended you try the tweeter with a capacitor between 3.3uF <---> 4.7uF,
and that is of course to decide your earlier point about changing the Morel for an SEAS H737 ...
thus, ignoring the other audible characteristics you heard after listening with either of the new capacitors, did the Morel sound cleaner or does it still have the "sweet zing" you described ?
and if it does, is that to same degree as previously or to a lesser degree partially or significantly ?
This will probably be best decided with the 4.7uF cap rather than the parallel pair of caps to 5.5uF because a single cap cannot cause a distortion of the Transient Response of the signal that unequal capacitances in parallel combination cause if one has a faster pulse rise time than the other.
This distortion is audible as a spitting sound - sibilant - though it can be very small and then mistaken for addtional treble detail.
It is less likely to be audible when electrolytic caps are paralleled than when polypropylene caps, because the significant and different ESR {resistance} of each different value electro cap slows the transient response through each cap in inverse proportion to its capacitance in such way that what would be the faster cap if no ESR slows down to greater degree than the would be slower cap with the end result that both have close to the same pulse rise time through, hence little transient distortion caused by the paralleled pair.
That does not occur with polyprop caps because they have negligible ESR.
Of course one can experiment with a different small value resistance in series with each poly cap of the pair to try to achieve equal pulse rise times,
but that is a lot of time consumed and extra components to buy.
Simpler is to use a single cap when possible, or parallel an equal capacitance pair , or three if need be, to get the exact total capacitance that is needed.
However, even if you have bought electro caps I still think it better to decide the tweeter quality via a single cap.
The 12uF output cap is in Series, not Parallel, with the input cap,
thus its different pulse rise time cannot cause distortion of the transients ... unless the cap itself is intermittantly faulty ... and it could be as it is so old, thus if you are not able to make a confident decision then replace the old 12uF with a low price 10uF or 15uF from a local shop,
or a 12uF electrolytic for 1.36 from www.wilmslow-audio.co.uk
Later, after interim matters final values for tweeter capacitances can be decided and you can then buy the better quality Supersound capacitors from Wilmslow Audio at higher price if you want to buy within the UK but not pay huge prices.
If you want to install new caps in the mids' filter now, I recommend the Supersounds in exactly the same values as in your crossover: 16uF and 30uF, unless you want to spend more for higher quality caps.
It will be a waste of money putting low price electro-caps in the mids for interim,
because electros cause smearing of the sound as result of their Dielectric Absorption,
and additionally that effect will make it harder for you to decide the optimum balance between mids and bass,
because that 2.2 ohm resistor may have to be increased ... to be decided by ear.
For new bass section caps, the choice may have to depend on how much space there is on your crossover boards,
because the Supersounds are large size.
There are smaller sized polypropylene caps available that are suitable for there and will cause better sound than electros,
but to obtain those you will have to buy via Mail-order from France or Canada or USA.
Summary: decide the tweeter quality first, because if you need to change to the SEAS, it is lower Sensitivity than that Morel thus you will have to change the L-pad resistors ... AND as we now have to simulate a nominal 4 ohm tweeter to get the new tweeter to neatly cross to the mids without changing either of the inductors I need to know which tweeter you will be using.
Next, what you stated as audible:
"I replaced the 8uF cap with a 3.3uF. This made the speaker sound awful. The sound was lifeless and laid back with no ‘body’ - especially with voices. Next I tried a 4.7uF which was a little better but still not very good.
At the moment I’ve got 5.5uF (3.3 in parallel with 2.2) which is just about acceptable although but I feel inclined to put the 8uF back."
Did you do that test with the mid-cones covered or uncovered ?
If you listened with the mid-cones covered I understand the effects you described.
If the mid-cones were uncovered I would have expected the sound to be clearer with one or other of 3u3 or 4u7 than with 8uF, because for 8uF to work the Morel tweeter's Impedance has to be lowered with a suitable value resistance in parallel with it.
I would expect the 8uF to cause significant audible colouration or resonance when connected to a higher impedance tweeter in the circuit with the 0.14mH inductor.
Whether the coloration resulted in louder or quieter sound in the upper mids/lower treble would depend on phase interference through the crossover region ...
thus why I last week advised listening with the alternate Polarity connection of the tweeter as that will change the direction of whatever phase error
For this test listen with the mid-cones audible.
The blocking mids' test is only to decide tweeter quality ...
not to decide optimum capacitance values for the crossover.
Thus, if necessary do your audio testing again,
and whatever the case is, post a report here.
The next step will follow the above two.
Last edited:
Hi Alan,
Sorry I haven't been around lately, just so busy with work. Hoping for some 'hobby time' this week end.
In describing the sound of the Morel, I wasn't aware of it sounding clearer but it was definitaly less 'zingy' (or 'sparkley').
Initially, even with the L-pads in place I could hear a significant amount of mid-range information coming from the tweeter. Changing the 8uF cap removed or lessened this which had the overall effect of making the music sound rather life-less.
At this point I'd like to say that I know I'm not very good at explaining the differences in sound when components are altered - and for that I'm sorry! But I will do my best.
So, the next thing I'll do is to replace the input cap with a single 4.7uf and reverse the tweeter polarity. Then I'll listen and report back report back. Hope this is OK.
Once again, apologies for the delay.
Regards
Roy.
Sorry I haven't been around lately, just so busy with work. Hoping for some 'hobby time' this week end.
In describing the sound of the Morel, I wasn't aware of it sounding clearer but it was definitaly less 'zingy' (or 'sparkley').
I covered the mid-cone when deciding on the L-pad values so as to get the levels between the bass and treble the same.
I listened with the mid-cones uncovered, and the L-pad of 15 ohms + 1.5 ohms (decided above) in place when deciding on the cap value.
Initially, even with the L-pads in place I could hear a significant amount of mid-range information coming from the tweeter. Changing the 8uF cap removed or lessened this which had the overall effect of making the music sound rather life-less.
At this point I'd like to say that I know I'm not very good at explaining the differences in sound when components are altered - and for that I'm sorry! But I will do my best.
So, the next thing I'll do is to replace the input cap with a single 4.7uf and reverse the tweeter polarity. Then I'll listen and report back report back. Hope this is OK.
Once again, apologies for the delay.
Regards
Roy.
Hi Alan,
I have decided I will order the Seas tweeters and try again with those in place of the Morels.
For completion
I put the 4.7uf capacitor back and listened for a while, and then I reversed the tweeter connections and listened again. A definite difference was heard. With the connections reversed voices had more depth and there seemed to be more happening in the mid frequencies. The music sounded more wholesome and not so thin or lean as it was with the connections normal. However, after listening for a while the sound still became wearing and I seemed to be always aware of the tweeters, not being too loud, but somehow my attention was always being drawn to them.
I will await the arrival of the new tweeters and hopefully have better success with them. I welcome your comments on my decision.
Regards
Roy.
I have decided I will order the Seas tweeters and try again with those in place of the Morels.
For completion
I put the 4.7uf capacitor back and listened for a while, and then I reversed the tweeter connections and listened again. A definite difference was heard. With the connections reversed voices had more depth and there seemed to be more happening in the mid frequencies. The music sounded more wholesome and not so thin or lean as it was with the connections normal. However, after listening for a while the sound still became wearing and I seemed to be always aware of the tweeters, not being too loud, but somehow my attention was always being drawn to them.
I will await the arrival of the new tweeters and hopefully have better success with them. I welcome your comments on my decision.
Regards
Roy.
why the tweeter ?
Hi Roy,
the differences you describe about the sound for one polarity connections versus the other are typical of what I hear myself, but not entirely,
and I think the tweeters may be as you described as:
"I seemed to be always aware of the tweeters, not being too loud, but somehow my attention was always being drawn to them."
because the midrange drivers are being heard via deteriorated capacitors.
For the next step I would replace the midrange capacitors with the best quality types I could afford -{keeping in mind my total budget for capacitors for all sections, including that the large caps for the bass section do not need to be as expensive a brand as the mids and treble}- and listen again,
because with new mids' caps the mid drivers will be more prominent - perhaps similar to what you are hearing from the tweeters now -
simply more obvious even when suitable resistor chosen for matching the volume level of mids to bass and treble.
Why do you think it is the tweeters at fault ?
It is possible they may be, but unless comparison with reconditioned mids I would not know, unless you are hearing a zing resonance from the tweeters, or some other peculiarity {which you do not hear from tweeters in another loudspeaker that are sure is in good working condition}.
If you are certain you want the SEAS H737 you will have to change the L-pad resistors because the H737 is about 2dB less sensitive than the Morel 298.
If you are intending to buy the SEAS, then reply here and I will calculate another L-pad for you so that you can buy the resistors at the same time, because the SEAS seller will have resistors.
If you are buying the SEAS from Wilmslow Audio, I recommend you buy the mids' caps I listed in my previous post at the same time,
unless you want smaller sized caps or higher quality caps -{ for which you will have to buy from USA or Canada}- ,
and Wilmslow's 12uF cheap electro cap to try in the treble section.
Buy also a 3.3 ohm resistor, in 10 watts or close to, because when new polypropylene caps are in the mids section as those have almost zero ESR you will need to increase the external series ESR to compensate.
The 3.3 would replace the 2.2 currently in the circuit.
You can try your 1.2 ohm resistors in Series with the new poly 16uF for initial listening, and that will probably be the optimum or close to
... and can be changed later if necessary.
It won't require less than 1 ohm there, and may require a bit higher than 1.2.
Resistors are cheap compared to caps, and more resistors can be bought later when you buy new caps for the bass section.
From what I have analysed of that crossover now, I think it best to keep the midrange filter components the same values as currently and experiment with new cheap caps in the treble filter until you get an even sounding crossover.
You have sufficient new bipolar electros to use two in parallel as:
4.7 + 3.3 = 8uF ; 4.7 + 2.2 = 6.9uF ; 3.3 + 2.2 = 5.5uF
for the input treble cap, and after trying each combination you can estimate if an in-between of any two of the above is likely to be more suitable.
The optimum value for output cap is not likely to be less than 12uF, and it could require a little larger because the impedance and output versus frequency characteristics of the Morel and SEAS tweeters whilst different to each other will also be somewhat different to the old HD1000 tweeter.
Also, did you note the relative Polarity of the tweeter connection versus the midrange for each of the listening options ?
That is if the mids' +ive is connected to the top of the circuit and -ive connected to earth
-{which I think is the case in the Ditton 33 - ? - It is in the Ditton 44 and 66}.
Which of your described tweeter sounds is the tweeter +ive to top of circuit/ -ive to earth {same Polarity as mids},
and which sound is the tweeter -ive to top of circuit/ +ive to earth {reverse Polarity versus mids} ?
I ask this because I have noticed at least 2 different types amongst people for relative Polarities' hearing, and I need to know which type you are if I am to advise you well.
Hi Roy,
the differences you describe about the sound for one polarity connections versus the other are typical of what I hear myself, but not entirely,
and I think the tweeters may be as you described as:
"I seemed to be always aware of the tweeters, not being too loud, but somehow my attention was always being drawn to them."
because the midrange drivers are being heard via deteriorated capacitors.
For the next step I would replace the midrange capacitors with the best quality types I could afford -{keeping in mind my total budget for capacitors for all sections, including that the large caps for the bass section do not need to be as expensive a brand as the mids and treble}- and listen again,
because with new mids' caps the mid drivers will be more prominent - perhaps similar to what you are hearing from the tweeters now -
simply more obvious even when suitable resistor chosen for matching the volume level of mids to bass and treble.
Why do you think it is the tweeters at fault ?
It is possible they may be, but unless comparison with reconditioned mids I would not know, unless you are hearing a zing resonance from the tweeters, or some other peculiarity {which you do not hear from tweeters in another loudspeaker that are sure is in good working condition}.
If you are certain you want the SEAS H737 you will have to change the L-pad resistors because the H737 is about 2dB less sensitive than the Morel 298.
If you are intending to buy the SEAS, then reply here and I will calculate another L-pad for you so that you can buy the resistors at the same time, because the SEAS seller will have resistors.
If you are buying the SEAS from Wilmslow Audio, I recommend you buy the mids' caps I listed in my previous post at the same time,
unless you want smaller sized caps or higher quality caps -{ for which you will have to buy from USA or Canada}- ,
and Wilmslow's 12uF cheap electro cap to try in the treble section.
Buy also a 3.3 ohm resistor, in 10 watts or close to, because when new polypropylene caps are in the mids section as those have almost zero ESR you will need to increase the external series ESR to compensate.
The 3.3 would replace the 2.2 currently in the circuit.
You can try your 1.2 ohm resistors in Series with the new poly 16uF for initial listening, and that will probably be the optimum or close to
... and can be changed later if necessary.
It won't require less than 1 ohm there, and may require a bit higher than 1.2.
Resistors are cheap compared to caps, and more resistors can be bought later when you buy new caps for the bass section.
From what I have analysed of that crossover now, I think it best to keep the midrange filter components the same values as currently and experiment with new cheap caps in the treble filter until you get an even sounding crossover.
You have sufficient new bipolar electros to use two in parallel as:
4.7 + 3.3 = 8uF ; 4.7 + 2.2 = 6.9uF ; 3.3 + 2.2 = 5.5uF
for the input treble cap, and after trying each combination you can estimate if an in-between of any two of the above is likely to be more suitable.
The optimum value for output cap is not likely to be less than 12uF, and it could require a little larger because the impedance and output versus frequency characteristics of the Morel and SEAS tweeters whilst different to each other will also be somewhat different to the old HD1000 tweeter.
Also, did you note the relative Polarity of the tweeter connection versus the midrange for each of the listening options ?
That is if the mids' +ive is connected to the top of the circuit and -ive connected to earth
-{which I think is the case in the Ditton 33 - ? - It is in the Ditton 44 and 66}.
Which of your described tweeter sounds is the tweeter +ive to top of circuit/ -ive to earth {same Polarity as mids},
and which sound is the tweeter -ive to top of circuit/ +ive to earth {reverse Polarity versus mids} ?
I ask this because I have noticed at least 2 different types amongst people for relative Polarities' hearing, and I need to know which type you are if I am to advise you well.
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Resistors, and combinations to listen with
Hi Roy,
If I understand correctly from all your previous posts you have Resistors in:
1.7 ohm and 10 ohm; 1.5 ohm and 15 ohm ; 1.2 ohm and 18 ohm.
Enquire if your order/s for the SEAS tweeters and/or the caps + 3.3 ohm for the midrange have not been packed yet and if not add 1 ohm and 12 ohm, a pair of each both in 5 watt at least, and also a pair of 0.47 or 0.5 ohm which Wilmslow do not stock but I mention in case you are ordering from elsewhere.
Given there can be significant + and - tolerance errors in very low ohms' resistors it would be safer to order four of the 0.47/0.5 ohm {3 watt minimum} and four of the 1 ohm, as you will need two of 1 ohm later when you upgrade the bass filter's caps.
The SEAS tweeter is higher Impedance than the Morel, thus may require 12 ohm in Parallel, and perhaps as low as 10 ohm in Parallel
to get it down to sufficiently low effective impedance to work with your 0.14mH inductor.
As it is lower Sensitivity than the Morel, it will not likely need more than 1 ohm in Series to complete the L-pad, and probably only 0.5 ohm.
As you are starting with the Morel with the 1.5 ohm/15 ohm L-pad,
after you listen with that remove the 1.5 ohm and leave only the 15 ohm in circuit for the SEAS.
You will then be able to hear the SEAS in similar effective impedance to what the Morel effectively was in the circuit, and whether the SEAS is at suitable level
or if slightly louder than the L-padded Morel was then add the 0.5ohm for the SEAS, and if still not happy with the sound then change the 15 ohm to 12 ohm.
It may require as low as 10 ohm in parallel ... this you will have to decide by listening ... all with 12uF as the output cap and various combinations of caps for values between 4.7uF <---> 8uF for the input position.
When you get down to the lower resistances in Parallel the Input position caps summing to 8uF is more likely to be the optimum, or close to,
and if not then decrease the summed caps to the 6.9uF combination, etc ... reduce in decreasing capacitances if necessary.
I can explain the reason for the lowering of effective Impedance in more detail later when I have more time available,
and I'll include my analysis of the entire crossover then if you would like to know why I am advising as I have been recently.
I think the woofers are likely 4 ohm - ? - check them with your meter when you open up to change the crossover next.
Also, post which Polarity for tweeter connection with respect to midrange +ive is which for the two sound characteristics you previously described.
Hi Roy,
If I understand correctly from all your previous posts you have Resistors in:
1.7 ohm and 10 ohm; 1.5 ohm and 15 ohm ; 1.2 ohm and 18 ohm.
Enquire if your order/s for the SEAS tweeters and/or the caps + 3.3 ohm for the midrange have not been packed yet and if not add 1 ohm and 12 ohm, a pair of each both in 5 watt at least, and also a pair of 0.47 or 0.5 ohm which Wilmslow do not stock but I mention in case you are ordering from elsewhere.
Given there can be significant + and - tolerance errors in very low ohms' resistors it would be safer to order four of the 0.47/0.5 ohm {3 watt minimum} and four of the 1 ohm, as you will need two of 1 ohm later when you upgrade the bass filter's caps.
The SEAS tweeter is higher Impedance than the Morel, thus may require 12 ohm in Parallel, and perhaps as low as 10 ohm in Parallel
to get it down to sufficiently low effective impedance to work with your 0.14mH inductor.
As it is lower Sensitivity than the Morel, it will not likely need more than 1 ohm in Series to complete the L-pad, and probably only 0.5 ohm.
As you are starting with the Morel with the 1.5 ohm/15 ohm L-pad,
after you listen with that remove the 1.5 ohm and leave only the 15 ohm in circuit for the SEAS.
You will then be able to hear the SEAS in similar effective impedance to what the Morel effectively was in the circuit, and whether the SEAS is at suitable level
or if slightly louder than the L-padded Morel was then add the 0.5ohm for the SEAS, and if still not happy with the sound then change the 15 ohm to 12 ohm.
It may require as low as 10 ohm in parallel ... this you will have to decide by listening ... all with 12uF as the output cap and various combinations of caps for values between 4.7uF <---> 8uF for the input position.
When you get down to the lower resistances in Parallel the Input position caps summing to 8uF is more likely to be the optimum, or close to,
and if not then decrease the summed caps to the 6.9uF combination, etc ... reduce in decreasing capacitances if necessary.
I can explain the reason for the lowering of effective Impedance in more detail later when I have more time available,
and I'll include my analysis of the entire crossover then if you would like to know why I am advising as I have been recently.
I think the woofers are likely 4 ohm - ? - check them with your meter when you open up to change the crossover next.
Also, post which Polarity for tweeter connection with respect to midrange +ive is which for the two sound characteristics you previously described.
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Its Christmas! - almost
Hi Alan,
I have all my parts now but unfortunately I just haven't any spare time at the moment. When I can, I will carry on with your recommendations and report back here.
If I may Alan I would like to thank you for helping me this far, and also wish yourself and every one else
A Merry Christmas & A Happy New year.
Regards
Roy.
Hi Alan,
I have all my parts now but unfortunately I just haven't any spare time at the moment. When I can, I will carry on with your recommendations and report back here.
If I may Alan I would like to thank you for helping me this far, and also wish yourself and every one else
A Merry Christmas & A Happy New year.
Regards
Roy.
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