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Multi-Way Conventional loudspeakers with crossovers

Kef 104 Crossover help.
Kef 104 Crossover help.
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Old 2nd January 2011, 09:12 PM   #11
Mattias l is offline Mattias l  Sweden
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Quote:
Originally Posted by speaker dave View Post
KEF tended to sort capacitors and pick non-standard values for drivers that needed a different particular vlaue. I would replace with 4.7 if that is what your unit had.

Its not worth getting too fussy over the values as the drivers can drift a little over time. It is also possible that KEF sorted through wide tolerance parts for a particular value: for example, 4.5 actual value, although marked as 4.7. You would have no way of knowing.

Get 4.7s and don't worry about it.

David S.

Thanks mate I will order 4.7 ones then.

/Mattias
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Old 4th January 2011, 11:58 AM   #12
alan-1-b is offline alan-1-b  United Kingdom
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Default options for the capacitors

Quote:
Originally Posted by Mattias l View Post
I bought this 5.0uF AuriCap for the Mid/bas Capacitor change: AuriCap 5 0uF 10 400V AUR505K400VA

And some cheaper capacitors from ClarityCap for the tweeter:
https://www.madisound.com/store/prod...oducts_id=8148

https://www.madisound.com/store/prod...oducts_id=8147

What is really wierd is that the blue capacitor on my crossover is a 4.7uF capacitor and according to the schematic it should be a 4.2 so have not ordered the last capacitor yet, is it better to pick a 3.9uF?

/Mattias
Hi Mattias,

you have done things in the reverse of the usual audible priorities with the capacitors you have bought.
Usually one would would use any better audio quality caps in the tweeter filter, as any advantages would be more audible there than in the bass filter,
because the treble caps are in direct Series connection with the tweeter,
but in the bass filter that particular capacitor is a shunt bypass,
from in between two inductors to ground,
thus its audio signature is modified by the inductors to greater degree than will be the case for the caps in the treble circuit.

A modern low Dielectric Absorption capacitor, which Polypropylene caps are,
and that is otherwise well designed and not faulty in assembly will be quite adequate in the bass filter.
I would install the ClarityCap PX 5.0uF there.

That 5.0uF Auricap is ridiculously expensive for a +/- 10% Tolerance component !
With +/- 10% tolerance variations, you may get 4.5uF or 5.5uF, and worse is that you may get one of each !
... and that will cause an audible difference between the two loudspeakers.

As you have ordered 4.7uF in a +/- 5% Tolerance cap for the treble, I recommend that you send the 5.0uF Auricap back and ask for exchange for a 5.6uF polypropylene cap that is AT LEAST in +/-5% Tolerance,
plus include two 27 ohm/10 watt resistors in the order.

A 27 ohm resistor connected in Parallel with the Kef tweeter will reduce its mid-band Impedance sufficiently to allow 4.7uF and 5.6uF to work with it,
AND, the resistor will in-part reduce the effect of the tweeter's resonant frequency -{ Fs }- on the circuit.
"in-part" - it will NOT completely remove the effect of the tweeter's Fs, which is what the ab T-network does,
but it will produce a response that is towards that and better than without any resistor.

Ideally the inductor in the treble filter should be reduced a little in mH also, after the 27 ohm resistor is installed,
but for initial listening try with simply the caps changed, then Post here about the audible change.

After that you can buy a slightly smaller mH inductor for the treble circuit at the same time as you buy new inductors for the bass circuit after you have decided which of the Tap settings you and your girlfriend prefer from the large inductor.
If you like aspects of two adjacent settings of the tapped inductor, then an in-between mH inductor can be put in there, as there are plenty of options available currently.

ClarityCap PX are quite good audio quality. The Auricap may cause better sound in the treble circuit, but ONLY if it is close to its Nominal Specified capacitance, and not 4.5uF !
If both the Auricaps measure 5.5uF, or very near to that, then they will be suitable in the treble filter instead of a 5.6uF cap there,
but if they aren't near 5.5uF, or if you can't measure them, then I advise you exchange them unused, as I described above.

You do not need Auricap price components with Kef 104.
What does the seller have in 5.6uF at +/-5% Tolerance or better, at reasonable price ?

You can then obtain the 27 ohm resistors to fill your Credit balance.

If that does not entirely fill the Credit balance, then request two 2.2 ohm resistors in at least 5 watt rating
{though higher power is better to ensure they stay cool during high signal levels}.
These I will advise where to install when you buy the new inductors.
__________________
Alan

Last edited by alan-1-b; 4th January 2011 at 11:59 AM. Reason: to move a phrase
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Old 4th January 2011, 12:16 PM   #13
Mattias l is offline Mattias l  Sweden
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Quote:
Originally Posted by alan-1-b View Post
Hi Mattias,

you have done things in the reverse of the usual audible priorities with the capacitors you have bought.
Usually one would would use any better audio quality caps in the tweeter filter, as any advantages would be more audible there than in the bass filter,
because the treble caps are in direct Series connection with the tweeter,
but in the bass filter that particular capacitor is a shunt bypass,
from in between two inductors to ground,
thus its audio signature is modified by the inductors to greater degree than will be the case for the caps in the treble circuit.

A modern low Dielectric Absorption capacitor, which Polypropylene caps are,
and that is otherwise well designed and not faulty in assembly will be quite adequate in the bass filter.
I would install the ClarityCap PX 5.0uF there.

That 5.0uF Auricap is ridiculously expensive for a +/- 10% Tolerance component !
With +/- 10% tolerance variations, you may get 4.5uF or 5.5uF, and worse is that you may get one of each !
... and that will cause an audible difference between the two loudspeakers.

As you have ordered 4.7uF in a +/- 5% Tolerance cap for the treble, I recommend that you send the 5.0uF Auricap back and ask for exchange for a 5.6uF polypropylene cap that is AT LEAST in +/-5% Tolerance,
plus include two 27 ohm/10 watt resistors in the order.

A 27 ohm resistor connected in Parallel with the Kef tweeter will reduce its mid-band Impedance sufficiently to allow 4.7uF and 5.6uF to work with it,
AND, the resistor will in-part reduce the effect of the tweeter's resonant frequency -{ Fs }- on the circuit.
"in-part" - it will NOT completely remove the effect of the tweeter's Fs, which is what the ab T-network does,
but it will produce a response that is towards that and better than without any resistor.

Ideally the inductor in the treble filter should be reduced a little in mH also, after the 27 ohm resistor is installed,
but for initial listening try with simply the caps changed, then Post here about the audible change.

After that you can buy a slightly smaller mH inductor for the treble circuit at the same time as you buy new inductors for the bass circuit after you have decided which of the Tap settings you and your girlfriend prefer from the large inductor.
If you like aspects of two adjacent settings of the tapped inductor, then an in-between mH inductor can be put in there, as there are plenty of options available currently.

ClarityCap PX are quite good audio quality. The Auricap may cause better sound in the treble circuit, but ONLY if it is close to its Nominal Specified capacitance, and not 4.5uF !
If both the Auricaps measure 5.5uF, or very near to that, then they will be suitable in the treble filter instead of a 5.6uF cap there,
but if they aren't near 5.5uF, or if you can't measure them, then I advise you exchange them unused, as I described above.

You do not need Auricap price components with Kef 104.
What does the seller have in 5.6uF at +/-5% Tolerance or better, at reasonable price ?

You can then obtain the 27 ohm resistors to fill your Credit balance.

If that does not entirely fill the Credit balance, then request two 2.2 ohm resistors in at least 5 watt rating
{though higher power is better to ensure they stay cool during high signal levels}.
These I will advise where to install when you buy the new inductors.

Ok I was told it is better to have a better capacitor in the mid/bas that's why I bought the Auricaps for the mid/bas, they are factory matched pairs if that's helps? should I put the Auricaps in the tweeter instead and go for the ClarityCaps int the mid/bas?
Is this a better choice instead of tha Auricap? http://www.audiocap.co.uk/47uf-630v-...itor-110-p.asp

Mattias

Last edited by Mattias l; 4th January 2011 at 12:19 PM.
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Old 4th January 2011, 06:38 PM   #14
Mattias l is offline Mattias l  Sweden
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Hi guys I'm confused and this is getting complicated for me and I'm not so good at this

I want to in a simple and not to expensive way change the capacitors in my crossover to get a better sound, I don't want to add things just change the capacitors so what should I buy?

I'm still confused about the 4.2uF caps that is connected to the tweeter on the schematic and on my crossover it's 4,7uF caps, some people say it's not that big issue and some do So should I try yo get caps that is near 4.2?

Tweeter: 4.2uF
4.3uF Claritycap ESA Range polypropylene Tolerance:..............................+/- 3%

4.4uF Claritycap SA Range polypropylene
Tolerance:..............................+/- 5%
Or 4.7uF from same make?

I could change my Auricaps to these ones from Ampohm if I wanted.

4.7uF 630V Ampohm Metallized Polypropylene Audio Capacitor

+/- 5%

Tweeter: 5.0uF
ClarityCap 5.0 mfd PX Range Polypropylene Caps
Tolerance +/-5%


Bas/mid: 5.0uF

ClarityCap 5.0 mfd PX Range Polypropylene Caps
Tolerance +/-5%

Is it possible to use 4.7caps where it should be 5.0uF ones? It's hard to find 5.0uF caps, or 4.7uF + 0.33uF?

Please help me out guys and I'm sorry if I'm a pain in the*** now

/Mattias

Last edited by Mattias l; 4th January 2011 at 06:59 PM.
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Old 4th January 2011, 08:02 PM   #15
Mattias l is offline Mattias l  Sweden
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I found these capacitors with +/-1% tolerance
Dayton Precision 1% Metallized Polypropylene Capacitors at Parts Express

I can get them in 2.2uf + 2.0uF and 3.0uF + 2.0uF how about that?

/Mattias
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Old 4th January 2011, 08:42 PM   #16
speaker dave is offline speaker dave  United States
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Quote:
Originally Posted by Mattias l View Post
Hi guys I'm confused and this is getting complicated for me and I'm not so good at this

I want to in a simple and not to expensive way change the capacitors in my crossover to get a better sound, I don't want to add things just change the capacitors so what should I buy?

I'm still confused about the 4.2uF caps that is connected to the tweeter on the schematic and on my crossover it's 4,7uF caps, some people say it's not that big issue and some do So should I try yo get caps that is near 4.2?

/Mattias
Well, now you have to decide whether spending a lot of money to get some exact value, overpriced capacitor to replace the caps in a 30 year old speaker (probably still good caps, by the way) will give you sonic nirvana, or whether it is sort of silly.

Hmmm?

David S.
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Old 4th January 2011, 09:02 PM   #17
Mattias l is offline Mattias l  Sweden
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Quote:
Originally Posted by speaker dave View Post
Well, now you have to decide whether spending a lot of money to get some exact value, overpriced capacitor to replace the caps in a 30 year old speaker (probably still good caps, by the way) will give you sonic nirvana, or whether it is sort of silly.

Hmmm?

David S.

Is there a middle ground?
I can spend $90/58 on the capacitors

/Mattias
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Old 5th January 2011, 05:59 AM   #18
alan-1-b is offline alan-1-b  United Kingdom
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Default Apology and Correction - not 27 ohms !

Quote:
Originally Posted by alan-1-b View Post

plus include two 27 ohm/10 watt resistors in the order.

A 27 ohm resistor connected in Parallel with the Kef tweeter will reduce its mid-band Impedance sufficiently to allow 4.7uF and 5.6uF to work with it,
AND, the resistor will in-part reduce the effect of the tweeter's resonant frequency -{ Fs }- on the circuit.
"in-part" - it will NOT completely remove the effect of the tweeter's Fs, which is what the ab T-network does,
but it will produce a response that is towards that and better than without any resistor.

Ideally the inductor in the treble filter should be reduced a little in mH also, after the 27 ohm resistor is installed,
but for initial listening try with simply the caps changed, then Post here about the audible change.
Mattias,

I apologise, there is a mistake in my Post #12 of yesterday.
I recommended a 27 ohm resistor - [as in the Quote I have pasted above] .
That is the incorrect resistance.
The correct resistance is 56 ohms.

This came into my mind later, but I was not able to get access to a computer again till now.
{27 ohm is the compensation resistor for a project I am working on, thus why 27 ohms was in my mind.}

For 56 ohms in Parallel with the Kef tweeter there will be little current through the resistor,
thus less power dissipated in that resistor,
thus a 5 watt rated resistor will be sufficient, but if the seller has only in higher powers that is OK.

If no 56 ohms, then buy the nearest resistance larger, such as 62 ohms,
but not as high as 68 ohms because that will be too high for there to be sufficient compensation effect.
56 ohms in 5 watts or larger power is quite common. One simply has to look for sellers.

***************

I will now read the new posts since my last here, and reply when I have time available.
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Last edited by alan-1-b; 5th January 2011 at 06:03 AM. Reason: to add a sentance
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Old 5th January 2011, 06:38 AM   #19
alan-1-b is offline alan-1-b  United Kingdom
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Default What measured capacitance ?

Quote:
Originally Posted by Mattias l View Post

, they are factory matched pairs if that's helps?


Is this a better choice instead of tha Auricap? 4 7uF 630V Ampohm Metallized Polypropylene Audio Capacitor

Mattias
Hi again Mattias,

they may be a factory matched pair, BUT what is the measured capacitance ?

They could be a matched 4.5uF pair, or a matched 5.5uF pair,
or any matched pair of numbers that is within +/- 10% of 5uF.

You need to know their measured capacitance to be able to decide now where is best to use them,
and if other modifications may be necessary.

You paid for a matched pair, therefore you are entitled to know what their measured value is.
If the seller will not tell you the measured value then send them back and ask for a Refund,
because a +/- 10% Tolerance capacitor is of little use in a crossover that has to work in the midrange,
which is what the 104 crossover is.


Whether Ampohm is better or not than Auricap, or than any other brand of well-made metallized polypropylene capacitor, one will have to decide by listening.

It is more important to use the optimum values of measured capacitance, than to be concerned about some of the brand names.

A few brands seem to have batch variations with some samples poorly assembled, and results with those can be audibly unpleasant.

"Solen" and "Bennic" brands are reported by a lot of users to be not as good in midrange and treble sounds as the other brands that have been mentioned in this thread.
"Dayton" is made by Bennic, and for the Dayton Precision range the price is for the +/- 1% Tolerance.

I think that ClarityCap PX series is quite good enough for Kef 104 and good in general.
I use them, and have no problems with them.
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Last edited by alan-1-b; 5th January 2011 at 06:40 AM. Reason: to better space the paragraphs
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Old 5th January 2011, 07:03 AM   #20
alan-1-b is offline alan-1-b  United Kingdom
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Default confused, and why ...

Quote:
Originally Posted by Mattias l View Post

Hi guys I'm confused and this is getting complicated for me and I'm not so good at this


I want to in a simple and not to expensive way change the capacitors in my crossover to get a better sound, I don't want to add things just change the capacitors so what should I buy?



I'm still confused about the 4.2uF caps that is connected to the tweeter on the schematic and on my crossover it's 4,7uF caps, some people say it's not that big issue and some do So should I try yo get caps that is near 4.2?


It's hard to find 5.0uF caps, or 4.7uF + 0.33uF?


Please help me out guys and I'm sorry if I'm a pain in the*** now

/Mattias
Hi again Mattias,

I am not surprised that you are confused, and you are correct in saying that you are not good at this.
I think you have been lead by too many opinions about differences in sound between brands of capacitors being able to improve the sound of loudspeaker systems for which another matter has to be addressed to actually cause a real improvement.
Kef addressed the other matter when trying to improve the original 104, and their result is the 104ab.

If you like the sound of the original 104, then copy EXACTLY the capacitances that are in the Specification
for it, OR, as close as you can buy to those.
Closest available now is 4.3uF and 5.0uF, or 5.1uF in some brands.
Those will work.

Buy in +/- 5% Tolerance- that will get you close enough.

I recommend that you do not use 4.7uF unless you intall the 56 ohm resistor I described.
If you use the 56 ohm Parallel connected resistor, then use 4.7uF and 5.6uF in the treble filter, and 5uF in the bass filter.
This will give you an improvement in midrange coherence over the old 104 design and towards the 104ab design.
This will cause a more significant audible result than any expensive capacitor priced higher than ClarityCap PX series.

I recommend that you do NOT use 4.7uF + 0.33uF in Parallel to create the 5uF cap.
This is a complicated topic, and may confuse you more.

Save the remainder of your money to use for better inductors later,
for after you have listened with the new capacitors installed,
and decided about the switched/tapped bass-mid inductor position.

That is the best "middle ground" I can think of.
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Last edited by alan-1-b; 5th January 2011 at 07:07 AM. Reason: to better space a paragraph
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