Simple 2-way Crossover Rebuild... Help Please?

[SONDEKNZ]

Hi Guys

I've inherited someone else's project: Nice 2-way speakers that were never actually rebuilt.

I've got everything sorted except the crossovers. I have the originals which had never failed, but they have been ruthlessly extracted. So, I'm unsure how to wire them, as I don't really understand them at all.

Nevertheless, I have built amp kits and the like and can follow instructions.

Whilst I don't want to waste money, through this rebuild, I'm hoping to apply as good components as possible. I figure I might as well while they are open.

In essence, in each speaker I've got two wires coming from the tweeter; and two wires coming from the woofer.

I'm hoping some of you kind souls might be prepared to: -

• Take a look and tell me if the Capacitor is a really good one for the job, and worth keeping?
• Instruct me (Pics?) which wire goes to which point on the crossover

[MUCH APPRECIATION IN ADVANCE!]

Here's some pics of one of the crossovers. I've got two of 'em, identical!
(Hopefully, you can open these pics for a closer look...)

 

[Lojzek]

There is a high probability of my assumption being correct. Capacitor is a keeper. Tinned wires of ferrite inductor and a cap ( points 1 and 2), are to be tied together for single wiring.

 

[SONDEKNZ]

Just to clarify…

Many thanks LOJZEK, for this fantastic diagram. Such a fast reply. Appreciated.

Just to clarify, the Ferrite Core Inductor is the one with the metal can in the centre. Correct?

 

[Lojzek]

You are welcome. Correct, this is the one, the other one is an air core. I was able to draw the diagram quickly only because of our good man Mr.Waslo, who wrote a terrific piece of software XSim.

 

[SONDEKNZ]

A picture paints a thousand words...

Hey LOJZEK

Here's my translation of your picture - into my real world.
Do you agree with my conclusions?
Have I got this right?

 

[Lojzek]

Yes, you got it right. Thanks for the sharp photos.

 

[SONDEKNZ]

There's a problem...

Thanks LOJZEK

Sadly, I see a problem.
It seems one of the legs of each capacitor has been torn off, right down to the body of the cap itself.
I guess this means new caps after all?
Am I right in saying that these caps are: -

• 4.7uF / 100v / Polyester
• Any high performance recommendations?

Or is there a way to salvage these caps?

 

[Lojzek]

Any xo parts can be checked with a multimeter, lcr meter or similar. There is plenty of caps manufacturers, pick one. You need a non polarized 4.7 uF, 100V or greater cap. Perhaps it would be best to make a new board. You can use whatever you like, pertinax, vitroplast, plywood...etc.


edit: salvaging could be done, although not everone's cup of tea.

 

[SONDEKNZ]

Just trying to determine the type of cap...

Capacitors come in many formats. I have used (Black Gate, Panasonic) Electrolytic and (Low-ESR) Polypropylene caps - to great improvements - in my amp projects. But not sure about the unique needs of crossovers...

Am I right in saying that the current caps are POLYESTER caps???
(Not sure...)

If so, I assume the designer picked this type for a reason, perhaps for its superior high frequency performance?
Anyways, if you could help me identify the cap type, I will order a couple of new ones.

You need a non polarized 4.7 uF, 100V or greater cap

When you say "...or greater cap" are you referring to greater voltage handling or greater uF; or both? What would increasing these values achieve sound-wise?
(I'm concerned that moving to a different uF value will mess with the frequency filtering...)

 

[David Morison]

MKT means metallised PET (Polyethylene terephthalate, Polyester) is used as the main material - so it would be best to stick with something as similar as possible.
Definitely keep the Capacitance value the same - Voltage is the one where you may go higher if you want.

 

[Lojzek]

I was reffering to a greater voltage. Rated voltage spec means a capacitor can handle voltages up to that value. For example this:

 

[SONDEKNZ]

Thanks for the clarity...

Thanks DAVID MORISON and LOJZEK

In keeping with the original designers original choice of capacitor format, I was considering the following: -

 

[SONDEKNZ]

These look nice too...

I guess you just have to read the reviews, pay your money and take your chances?

 

[SONDEKNZ]

BYPASS CAPS for High Pass Filter?

I'm wondering if anyone has successfully experimented with BYPASS CAPS for a simple High Pass Filter application - like this one?

I'm thinking of adding a .o1uF (say) Polystyrene BYPASS CAP in addition to the base 4.7uF cap that I am replacing...

Any feedback on this line of thought?

 

[SONDEKNZ]

Well, the parts are on their way...

For us newbies, this is lambs to the slaughter!

I mean, I have read as much as possible about the sound of different capacitors in speaker crossovers - but there are really no guarantees.

It was just a case of making a decision and giving it a go! So, I made some choices and the parts are now on their way.

To replace the old (totally buggered, getting them out!) KONEK 4.7uF 100 V-MKT, I have chosen the following: -

• [*]CLARITYCAP 4.70uF 250Vdc PX Series Metalized Polypropylene

Just to experiment a bit, I have also ordered a small handful of the following capacitors, which I intend to use to "Bypass" the ClarityCap: -

• [*]MOJOTONE Dijon 0.001uF 630Vdc, Polypropylene Film & Foil caps
  [*]ISHAY-ROEDERSTEIN MKP-1837 Series, 0.01uF 100Vac-160Vdc caps ; and
  [*]CORNELL-DUBILIER 940C Series, .01uF 3kV, Polypropylene caps

I'm eagerly awaiting their arrival so I can get busy!

Meanwhile, I'm giving a bit of love to the old speaker cabinets...

 

[SONDEKNZ]

Doubt sets in...!!!

I just thought I would double-check everything.

Earlier-on, it was made clear that the capacitors being replaced had a value of 4.7uF /100V

After a quick last look at the outgoing capacitors again, I noticed it actually reads: -

4,7u-K
100 V-MKT

Can I ask someone more learned to just double-check that I have ordered the correct cap values here, please?

Does 4,7u-K mean the same thing as 4.7uF???

(It's that "-K" that bothers me...)

 

[rabbitz]

K is the tolerance code ±10%.

 

[SONDEKNZ]

Phew!

Thanks RABBITZ!

It seems that I can relax now, certain that the 4.7uF ClarityCaps that I've ordered are the right value.


Cheers!

 

[SONDEKNZ]

REGA KYTE: Front Baffle Colour Choice... OPINIONS???

Meanwhile, as I wait for crossover parts to arrive, I've restored the cabinet (rear timber) veneer. It's really looking great!

But I'm wrestling with the colour choice of the front baffle.

These classic REGA KYTES that belong to these crossovers this thread is about, originally came in real wood veneer with a black front baffle.

I think the black baffle looks a bit dreary and was thinking about going for a fresh look charcoal grey, just to spruce things up a bit. I know it moves away from the all original REGA look, but it's the same speaker with the same great (cult following) sound - but perhaps I can make it look a bit better?

Here's a few pics.

The REGA KYTE with (Original) black baffle.

A second option, where someone (not me) has opted for the MISSION 770 Freedom-looking silver baffle.

A third option - which I prefer - is basing the new look on the very stylish looking DALI CONCEPT 2, in charcoal baffe. (Those clever Danes...)

Before I make a decision, I was hoping for a bit of feedback.

What do others think?

 

[SONDEKNZ]

Crossover Progress!

The parts finally arrived and I found a bit of time... Progress!

I rebuilt the crossovers using CLARITY CAPS PX Series and bypassed them with MOJO DIJON.

I would like to have sampled the speakers before and after the application of the MOJOs, but the way this little speaker is put together - with the incredibly tough Hylomar Liquid Gasket clamping the drivers to the cabinets, I knew that I couldn't afford to wrestle them open again. So it was a case of do it once and get it right!

Once the first crossover was complete - with genuine Naim Crystal II Oxygen-free Copper Solid Core cable for most of the wiring - I chose to test the crossover outside of the cabinet. It worked!!!

Note the much thinner gauge solid-core wire for the tweeter wiring. When it comes to tweeters, I reckon the thinner the better - which probably explains why the last few inches of all tweeter voice coil feed wires look like they're made of hair. It's all about extending the top-end...

Note too, that the new speaker binding posts are actually hard-wired (soldered) to provide an unbroken circuit that (hopefully) won't degrade over time.