Here I am trying to mod the speaker with better cap. Hope someone can help to share some steps to avoid the mistake.

Here is the KEF cresta 10 crossover



I have change the cap to all Elko Glatt (Mundorf oem). sounds quite good except the bass is restricted. After I put back original 10uF cap (which is Likon) it is ok and sound surprisingly smooth and revealing.

However When I measure the 7uF (old unit), I found the capacitance is 18uF. Normally the old cap the capacitance will drop after time, but why is it the value higher than what is stated. I measure the other unit and found the same high value.

Then I try put in the 10uF (which is measured to be 12uF) and now do the testing.

Some hints for your capacitance measurements, unless your test equipment is at 'K' pricing, otherwise the cheap regular multimeter won't give you the accurate reading.

So my advice is no need to care about the reading, just use it.

This post has been edited by coolkwc: Jan 4 2009, 01:49 PM

I meausred the old unit and new unit of the same capacitance.

I found all matches well (6uF and 10uF) except the 7uF. The 7uF gone to 20uF. So I dont think my meter has got problem.

Anyway, I tried replacing the 7uF with 10uF M-cap (elko oem) and found the treble is blur. The music is no more natural. So I put back the 6.8uF M-cap (Elko )

I am also told to use lower cap to replace the new cap. e.g. 7uf with new 6.8uF cos the new cap the capacitance is always higher. true ?

for the best result is to try
variant types of capacitor likewise : metal-film, polyproprene, oil capacitor

M-cap 10uF ? its very big !
affordable ones you can tryout Solen capacitor.

i recommend obbligatto premium cap i using for my Mordaunt Short really nice warm n thick sounding
i use for my tweeter and mundorf copper foil inductor for mid

This post has been edited by abel: Jan 4 2009, 10:27 PM

but the first question you have to ask yrself ~

1. You merely change the crossover due to aging ? if not
2. Insufficient deep bass ? mid bass ? mid ? high frequency ?
3. What types of sound do you want to achieve in this modification ?

my advise is stick to the original value of capacitor ~ but higher grade of capacitor likewise mentioned polypropylene/silver-oil or etc.

i believe Kef did many research, measurements & countless hour of listening session to built the crossover.
unless you trust yr own ears..

yeah i agree with that is not easy to built ur own because crossover got few type of network
butterworth , linkwitz and etc and from 1st order up to 4th order some are more hehehehe

i also stick with same value for my speaker

This post has been edited by abel: Jan 4 2009, 10:29 PM

Haha chua, I got 2 10uF and 2 8uF taiwan caps, will send it to u along with your parcel 2moro, let u try try If "ngam" your taste, sell it cheap cheap to you These caps' sound are no cheapskate compare to premium one

apa brand i know china famous obbligatto i very recommend this for budget user i tested it can compared with Mundorf Supreme

This post has been edited by abel: Jan 4 2009, 10:41 PM

serious ? really curious to know ~ what type of material is the capacitor made from ?

Obbligato capacitors are premium polypropylene film in a non-magnetic case. Values are laser etched into the surface. Pure copper soldered lead out wires.

Below is tested the old Obbligato not Premium

I refer from this page at first i not believe i buy n try on my speaker is sound warm n thick sound but also wont lack of detail ... now i got use in my tube amp as well .....
http://www.humblehomemadehifi.com/Cap.html

Obbligato aluminium-foil MKP 630VDC – 5% tolerance

Technical Specifications: Chinese built, extra tight winding, no voids and thick-coated aluminium film imported from Germany. Very low inductance. Lead-outs are soldered copper, solid core.

Sound: Analogue is the word that keeps popping-up in my head when trying to describe these capacitors. They have a rich texture and produce and open and smooth image with realistic dynamics and good retrieval of ambient information. They have slightly less depth than a Clarity Cap DTAC but are also very detailed and never get harsh. They seem to have a sort of “detailed warmth” about them. Very nice especially when you look at their price!

Verdict: 10

Obbligato Film Oil MKP 630VDC – 5% tolerance

Technical Specifications: Chinese built, extra tight winding, no voids and thick-coated aluminium film imported from Germany. Very low inductance. Lead-outs are soldered copper, solid core.

Sound: pleasant “analogue” approach to music with a nice clear, smooth presentation and good separation. Left to right imaging and front to back sound stage is realistic but not as open as the dry type Obbligato. Also the overall balance is a little more forward than the Obbligato aluminium foil type, especially fresh out of the box. So give them some time to burn-in.

Verdict: 9,5

Mundorf Supreme Cap MKP 800VDC – 2% tolerance

Technical Specifications: 1. Special induction-free winding technology: Two capacitor windings are interleaved so that their inductances effectively cancel each other out. These two windings are connected in series. This means that it takes two 2µF windings to make a single 1µF M-CAP SUPREME capacitor - the same amount that it would take to produce a full 4µF of capacity using conventional technology! 2.Best available materials: The polypropylene film used for the M-CAP SUPREME has exceptionally low loss characteristics. 3. Sturdy plastic and aluminium cases:This prevents microphone effect feedback, thus protecting important signal details.

Sound: The M-CAP SUPREME delivers a very spatial sound with lots of depth. Good reproduction of the musical nuances. Detail and depth from the high treble right down into the low mid-range. Furthermore, this effect is not only achieved with very expensive high-end components. It delivers a significant enhancement in more price-conscious configurations, making it a very worthwhile upgrade. Clear and transparent sounding cap with a good sound stage. They provide a good improvement in clarity, focus and dynamics compared to standard quality MKP’s. The degree of improvement is comparable to upgrading to high-end cables and interconnects. I must say I was impressed when I first auditioned them. The Mundorf M-Cap Supreme mix very nicely with Clarity Cap SA type capacitors, so blend the two to make your own personal taste.

Verdict: 9



This post has been edited by abel: Jan 4 2009, 10:56 PM

I put that obligatto into my soundstage 1.5.

After that, I find it very interesting.

but now we are talking about speaker crossover. modifying the cap does not mean it will get out of its tune but more to suit my ear.

the designer ear is not my ear.

polypropylene cap & pure copper ? good stuff .. worth a try.
what is the sound characteristic of this capacitor ?

the housing is make by copper although price are not very cheap
i buy 3.3uf 600vdc about RM 70 per pc if compare to Mundorf Supreme i think more than RM 100
malaysia got ppl sell u go to octave they got sell

that expensive now ?
previously i bought my Mundorf silver oil 4.7uf/600Vdc <rm100 , it was like 5 years ago.

5 years ago hhehe now silver oil for 3.3uf is more than RM 250

my fren just recently buy silver/gold/oil new one 0.47uf is RM 600 hehehehe
very huge different compare old Silver Gold good seperation n depth are like long highway

This post has been edited by abel: Jan 4 2009, 11:08 PM

250 each ??? err... i've about 6 mundorf silver oil & gold coupling cap residing in my power amp ~
if i remember correctly the value is 0.22uF/ 0.33uF/ 0.47uF

This post has been edited by bose00: Jan 4 2009, 11:11 PM

rm600 ? as for me i'll rather order Lundahl Interstage Transformer as coupling and take away those Mundorf coupling cap.

yeah my fren put for his car speaker but his speaker cost few thousand soo ok loh rich man
some more got V-CAP

This post has been edited by abel: Jan 4 2009, 11:16 PM

not to mention i've V-Cap inside my DAC. the V-Cap does deliver the clarity and detail.
but seriously the price you mention is sky rocket high compared to what i have purchased previously.. if its true then i don't feels its
worth investing in these audiophiles cap.

This post has been edited by bose00: Jan 4 2009, 11:30 PM

Obbligatto sounds more analogue. Its vocal is more warm yet with detail. The vocal is also more forward, smooth and clear. quite good for value.

ccschua got picture of the cap to share? really curious to know.

I didnt take photo. may be abel can help.

check this out.

http://www.humblehomemadehifi.com/Cap.html

this the cap
actually it got marking .... something like V-CAP got direction but anyt side can use just give different sound
u can check the price from
http://www.diyhifisupply.com/?q=catalog/21/capacitors



This post has been edited by abel: Jan 4 2009, 11:38 PM

It is huge. I only use 0.47uF for my soundstage 1.5, and it is huge and heavy.

the outlook looks like Audio Note/Jensen Coupling Cap w/o lettering

ccschua u got put the right direction or not ... the red mark is output ... if i not mistaken



This post has been edited by abel: Jan 4 2009, 11:46 PM

I am waiting for Jantzen cross cap to arrive. Then I can mod again loh. This time I will reduce the capacitance at 7uF to 5.6uF.

Does anyone know if I can test out the freq response of the X O network.

The so called audio cap damn expensive due to its voltage rating, lol, 630VDC, i would say even 50Vdc is more than enough...

why would the voltage be so high? and at weird figures of 630V?

you want>? joking.. I don't have these...

I can't imagine which Amp can generate voltage even higher than the power supplied to the amp itself...

I hope someone give a reason for using those damn high voltage cap, no choice or what?

This post has been edited by coolkwc: Jan 5 2009, 12:50 AM

not at this point of time

Nothing weird. They're made to suit and suitable for signal coupling or bypass capacitors in tube amplifiers where the anode voltage potential may be in 3 figures.

Okay.. that make sense thanx bsl!

e.g. 6SN7 tube coupling cap 0.1 uF is 333V.

It make sense for Tube coupling cap but for X.O...

Somehow I don't fancy paper in oil caps for speaker crossover, as it may veil the sonics, takes time to break in, reduce some sparkle in the highs and slow down the pace. Polypropylene caps are usually a more popular choice, but for the modder, anything can fit in because you're altering the sound to your personal taste, even if it means altering the response curve of the loudspeaker.
By reducing the cap value from 7uf to smaller value, you're actually narrowing the high frequency range to the tweeter. Less mids to the tweeter, and you may find a roll off in the midrange. The smaller the capacitance in series to the tweeter results in blocking more low frequencies whilst allowing high frequencies to pass through. A bypass capacitor to ground encourages high frequencies to bypass to ground, and thats usually at the woofer or LF driver to block any high frequencies outputting to the LF driver. Thats where the high freqencies are "crossover" to the HF driver. In other words the woofer takes care of low frequencies and the highs are passed on to the HF driver. The RC network determines the point it crossover, minimal overlap for flattest frequency response and match the tonal character of the speaker drivers.

This post has been edited by bsl555: Jan 5 2009, 01:21 AM

I havent learned up the network yet. the 7uF cap is normally not there. I increase the cap value and found the vocal flatter. I was thinking lowering that 7uF will bring in more higher treble ? the 6uF works on high pass. is the 7uF works on high pass as well ?

I was refering to your diagram in the 1st page and thinking thats the actual crossover in the Kef. If the 7uf is "normally not there", what's the actual circuit?
The manufacturer selected values are likely best matched to the characteristics of the speaker drivers. You're rolling about the cap values are likely to result in adding something somewhere and deprive something somewhere else.

even 50uf can works on high pass. The value of high pass cap determine how much mid range down to bass send to the tweeter, not to make more higher treble.

A speaker crossover is actually a frequency divider and doing a balancing act. However you mod it will NOT extend the frequency range beyond the extent of the speaker design and potential. In practice you're altering its tone.

clarity, dynamics, bass response. 1st order, 2nd order , 3rd order filter. the circuit diagram is a 3 rd order XO.

i think i am going to have to convince you to do a series crossover, you can tweak easily by ear. thats how all my speakers have been done without any measuring equipment and software. but to a degree it is important to have the thiel/small parametres of the drivers themself to find out all the important things like the voice coil inductance, resistance, Vas, xmas, total Q this is when you can do the crossovers with calculations, and my philosophy! your ear is the best judge on what YOU like to hear, so dont let anybody persuade you differently from that, because of so called RULES of speaker making. yes the basics have to be adhered to but theres no fun if you can't break the rules sometimes.

i still think you need a higher value in your tweeter cap after the inductor as I suggested a while back. try a 14 uf as it is quite pointless having a C1 @6uf and then the third order cap @7uf after the inductor as the C2 cap is designed to lower the crossover slope either faster or slower. but having one nearly identical is just a waste of a cap in the signal path as far as i am concerned.if you dont have the 14uf to replace the 7uf just take it out and use the 2nd order electrical slope crossover, this will give you a lot better vocals as the slope is less and your tweeter will be taking up some of the work with the woofer around the 2khz to 5 khz range this will give some clarity and a more forward presentation in the vocals

let me know how you go.

My 6.8uF Jantzen cross cap is on the way. will try

1. parallel 2x6.8uF cap.
2. bypass 7uF i.e. 2nd order. (isnt that -12dB/octave and a much gentler slope than 3rd order which is -18dB/octave). All this while, my tweeter survice the -18dB slope.

The sifu of series crossover is cooking now. will get to it around the corner.

This post has been edited by ccschua: Jan 5 2009, 11:29 PM

thats correct the 2nd order is a much gentler slope giving the tweeter a little bit more work to do, but if you listen at sensible musical levels I would be surprised that anything would happen to the tweeter.
try it and see how it brings the vocals forward a bit more. start with the 14uf and you can decrease gradually. the other thing is Phase allignment which once you have found the correct value of the cap you can swap the positve and negative input to your tweeter to see which one is phase alligning with the woofer. and it is always good to sit your speakers back on an angle to get time allignment between the two drivers , i am sure it was designed in the original crossover but since we are playing with your new crossover you can try lots of different things to get them singing as you want.

regards

series crossover i tried it in my car before, quite interesting but abit harsh on the highs for me, didnt continue researching tho...

I also tried a series on my car, but unless you have really high quality drivers like scanspeak vifa i think it probably would sound a little harsh.

I tried it on my focals in my car and it sounded ok but i believe that an ordinary series crossover used in a car environment doesnt take into account the natural brightness of some car tweeters. So you probably needed to put a lcr network in there or Zoebel as I believe most car tweeters are fairly eratic on their natural frequency curve.
but realistically the series crossover is and should be used at home as they are renowned for there clear defined soundstage and imaging. where in a closed environment such as a car it would not be benificial as the sound stage collapses because of the limited space for the speakers to breathe.

my two sens worth.....

---

Added on January 6, 2009, 6:55 pmI am going to send you a series crossover with the solen caps i have for you also i have included some other caps for you to try including a brazilian made 8uf one. have no idea on how it sounds but it looks quite impressive.

If you like the series crossover then you can either keep it with a bartering of items or copy it and send it back to me when your ready.
of course not knowing the parametres of the drivers you have it will be a little bit of a guess as to how it will incorpaorate but i can guide you through the changing of values for the caps and the resistor between the + and - leg of the crossover.

I will get wifey to send in the next couple of days to the address you gave me before.

cheers


This post has been edited by chefsinc67: Jan 6 2009, 06:55 PM

That would be great. Now I am pampered with too many items. I just received some white sausage too.

Enjoy the Taiwan made white sausage

This post has been edited by GodLuvSxS: Jan 7 2009, 12:27 AM

Hi Chua

series crossover and solen caps on the way!

oh sorry i sent them before you got back to me regarding the 0.470uf caps so i did not send them but i did send some other solen caps including 2x 4.7uf and 2 x 6.8uf as well as the brazilian made 8uf caps. hope you enjoy the series crossover. when you hook it up let me know what it sounds like and i can guide you through any adjustments that you may need on the caps and the resistors.

let me know when our Jantzen crosscaps arrive from australia.


ps I will be in Kuching Next week for the opening of Sheraton four points, helping out so probabaly wont be online but if you need anything my handphone number is on the bottom of my email signature.

cheers

The cap just received. Again the Malaysia posmen is too lazy to wait for people to answer their call.

Dunno how to complain about my problem.

By tomorrow I would be able to receive the parcel.

---

Added on January 8, 2009, 11:48 pmoh nice.

got all the cap now.
the Jantzen and the solen.
plus the taiwan unknown cap.

---

Added on January 8, 2009, 11:55 pm

This post has been edited by ccschua: Jan 8 2009, 11:55 PM

To all the sifu here,

I've just bought a pair of used speakers; unfortunately, I didn't have chance to test it due to the seller sold off his amp when I bought the speakers.

The previous owner had left the speakers in store room over 1 year.
The speakers exterior looks perfect, including the woofer/ tweeter condition.

When I hooked it up at home, my God! The sound was so dull !!

No mid and high, only bass!

After re-run in about 30 hours now, the high is coming out now, but the mid (especially vocal part) still sound dull!

My question to all the sifu here is:

If there're any capacitors in the crossover circuit fails, what would be the possible consequence to the speaker sound?

In my case, could it be something wrong with the speakers' crossover?

Both speakers sounded the same! But I've heard the same model of this speaker before (Castle Severn II), it shouldn't sound so dull.

Help Sifus!

What I normally do is to bypass the crossover to see is there any different or not. To do that you need to locate where the crossover located, some on speaker box connector, some beside the box. You can unscrew the speaker to see the location clearly.

Another easy way to take out the speaker and connect direct using cable from your amp...

@ccschua,
you quote your own post lor....

This post has been edited by nordingh: Jan 9 2009, 02:36 PM

castle seven should not sound dull, they are regarded as some pretty good kit, as for possible issues we need to see them front back and inside with the crossover if possible.

once you have taken the pics post them on here and I can have a look at all areas that would be detrimental to the usual sound. it maybe as simple as some crossed wires or a crappy resistor/ capacitor in them, but as they are both the same maybe your source and amp are not up to running these speakers. please list all your equipment you are using also so it maybe the amp cd player etc.
I am happy to help after building so many speakers now i can share my thoughts and experience.

regards

i think you just need to run in >300 hours for amplifier and speaker which is much longer.
the speaker cone has hardened a little due to being idle so long as you describe 1 year or maybe longer.

give it some time..

For me, it is better to describe what is the setup. matching is always the first thing to check.

Thanks for all the sifu here

My setup as below:

1) CD Player : a) Denon DCD-S10 b) Primare D20
2) Pre-Amp: Musical Fidelity F22
3) Power Amp : Adcom GFA-555
4) Interconnect : VDH D102 MK III, Taralab Prism , Chords Cobra 3
5) Speaker cable: Chords Odyssey 4

Currently, I've another 3 pairs of speakers : Castle Harlech S2, Castle Richmond , Tannoy 705 Anniversary . All these 3 pairs of speakers don't sound dull at all in my system. My system even though is not extremely bright, but it definitely not mellow in sound.

The thing is, my Tannoy 705 had been sitting in my brother storeroom for 7 years , but when I tried it today, it had no such problem (dull sound).

Only the Castle Severn II got this problem. I really don't believe Castle Severn II is so dull in sound (in UK was listed at 599 or 699 pounds); for such a dull sound, nobody is going to buy it

I'll try to take some picture of the crossover tomorrow when I got the tools to open up the woofer / speaker terminals.

This post has been edited by billyngcam: Jan 10 2009, 11:34 PM

Open it and trace the circuit.

u should see the connection from input to output, tweeter and woofer. Normally more symtoms can be found if u check the cross over.

---

Added on January 11, 2009, 11:34 pmJust tested the Jantzen Cross Cap. I am surprise at how clean the sound is and very detail presentation. It is definitely good cap.

This post has been edited by ccschua: Jan 11 2009, 11:34 PM

All the Sifus,

I finally got time to open the speaker terminals to see the crossover.

Photos as below.

I tested it by connecting the bass unit directly to speaker cable , bypassing the crossover, and the speakers do sound bright enough!

So, now almost 90% confirm the problem is with the crossover. Either the factory pre-set it like that, or something not working correctly. But the strange thing is, both side of the speakers sounded the same.... can both speaker crossover spoil at the same time kah? So lucky?

Now, my headache start..... Sifus, how to check which component fail?

At the end of the day, if, just if, nothing is wrong with the crossover, how or where can I modify the crossover to make it sound brighter?

thanks in advance bro!





This post has been edited by billyngcam: Jan 13 2009, 06:06 PM

Yours look very similar to mine, except u have 1 resistor less than mine. Again I do not want to speculate what is the cross over network. can u trace the circuit from input to the output and put in a sketch like mine in the 1st post.

I dont like the wire connection using clip on. prefer solder.

I would start by taking out the capacitor near the leads to the woofer, this is your second order cap to roll off the woofer faster. if you take this out this will roll off the bass slower bringing it more into the vocal region and should at least give you a better midrange.

try this and let me know if it is enough as then we can adjust the tweeter crossover a bit as well but it seems that it is a third order on the tweeter and a 2nd order on the woofer, so it is probably a low crossover already. but as I said start with the removal of the 10.0j capacitor. and report back the result.

cheers

Hi Chef,

welcome back. take it out as shorting it with some lead wire?

I have also come across the Vishay Roederstein MKP1837. What do you think of this little sweetener ?

The Jantzen really opens up the soundstage, become clearer and the bass more punchy.

Hi Chua,

no what i mean is simply just take it out and do not put anything else such as a shorting wire.


vishay i have not come across so cannot comment, hows your mods on the crossover.

yes the jantzens are a very good cap for the money and probably better than the solens. i will let you know about the dac as i have just got back and have too much work to do this week.

cheers

Can anyone teach me what value of component and connection should be for:
- 4ohm tweeter to High pass at 2kHz
- 4ohm mid bass band pass at 50Hz to 2kHz

Thanks.

This post has been edited by kww: Jan 21 2009, 07:55 PM

hi there,

well i wish it was that easy, BUT you have to calculate the values based on thiel/small parametres.

eg, if your 4 ohm tweeter has a sensitivity of 92db and the woofer had a sensitivity of 89db you need to pad your tweeter 3db to have a nice even output. padding is where you need a resistor either in series or an L pad (2 resistors to bring your tweeter level down to match the woofer).

then you need to take into consideration the on axis response, 30 degrees off axis response 60 degrees off axis response as well.etc. etc.

then with the woofer you need to know the response curve ie break up nodes in the response and where best to cross it over, the fs, the qts, the x-mas, the VAS, the voice coil inductance at selected crossover point, how to add a zoebel network, the actual application of the woofer has to take into even more considerations. as well as designing a volumus cabinet best suited to the woofers parametres.

all these things add up into the crossover and ulimatley the full speaker design.

but if you wanted to just do a calculation that would not take all these into the design then you use this for simple crossovers.

Crossover Component Selection Guide

High Pass
Crossover
Frequency
6 dB/octave 12 dB/octave
4 ohm 8 ohm 4 ohm 8 ohm
C1 in uF C1 in uF L1 in mH C1 in uF L1 in mH C1 in uF
500Hz 79.60 39.80 1.801 56.270 3.601 28.135
700Hz 56.86 28.43 1.286 40.193 2.572 20.096
1,000Hz 39.80 19.90 0.900 28.135 1.801 14.067
1,500Hz 26.53 13.27 0.600 18.757 1.200 9.378
2,000Hz 19.90 9.95 0.450 14.067 0.900 7.034
2,500Hz 15.92 7.96 0.360 11.254 0.720 5.627
3,000Hz 13.27 6.63 0.300 9.378 0.600 4.689
3,500Hz 11.37 5.68 0.257 8.039 0.514 4.019
4,000Hz 9.85 4.98 0.225 7.034 0.450 3.517
4,500Hz 8.84 4.42 0.200 6.252 0.400 3.126
5,000Hz 7.96 3.98 0.180 5.627 0.360 2.813

Low Pass
Crossover
Frequency
6 dB/octave 12 dB/octave
4 ohm 8 ohm 4 ohm 8 ohm
L1 in mH L1 in mH L2 in mH C2 in uF L2 in mH C2 in uF
75Hz 8.49 16.99 12.00 375.132 24.00 187.566
100Hz 6.37 12.74 9.00 281.349 18.00 140.674
150Hz 4.25 8.49 6.00 187.566 12.00 93.783
200Hz 3.19 6.37 4.50 140.674 9.00 70.337
250Hz 2.55 5.09 3.60 112.540 7.20 56.27
300Hz 2.12 4.25 3.00 93.783 6.00 46.891
350Hz 1.82 3.64 2.572 80.385 5.145 40.193
400Hz 1.59 3.19 2.251 70.337 4.502 35.169
450Hz 1.42 2.83 2.00 62.522 4.00 31.261
500Hz 1.27 2.55 1.80 56.270 3.60 28.135
700Hz .91 1.82 1.286 40.193 2.572 20.096
1,000Hz .637 1.27 0.900 28.485 1.804 14.067
1,100Hz .579 1.16 0.818 25.577 1.637 12.789





Explanation
Using the charts

The chart above is for calculating 6dB and 12dB crossovers. For higher crossover points than those shown, simply move the decimal point to the right one place to match the new frequency, find the capacitor and inductor values and move their decimal point one place to the left. For example: If you desire a high-pass crossover frequency of 50 Hz for a 12 dB crossover for 8 ohms, find the 500 Hz listing. Locate capacitor and inductor values and move their decimal one place to the right. The correct values would then be 36.01 mH and 281.35 µF. Example 2: if you desire a low-pass crossover frequency of 50 for a 6 dB crossover for 4 ohms, find the 500 Hz listing. Locate the inductor value and move it's decimal to the right, making it 12.7 mH.

Tolerances

When looking for capacitors and inductors, keep in mind that the tolerances of the components can help simplify your search. For example: The calculation chart finds 281.35 to be the exact capacitor value for the above crossover. If you're looking through the Non-Polarized Crossover Capacitors, their tolerance is 10%. This means that the actual measured value of each capacitor is within 10% of the listed value, in this case ±28 µF. So, adding 250 µF and 33 µF in parallel to achieve 283 µF, considering the tolerance, will put them somewhere between 255 and 311 µF, which is suitable for the application. For example 2, if you're looking in the 18 gauge, Perfect Layer Wound Air Core Inductors, their tolerance is ±2%. The calculated value of 12.7 mH could be suitably achieved using a 12.00 mH inductor, whose 2% tolerance puts its actual value between 11.76 and 12.24.

Combining Components To Achieve Needed Values

If you are unable to find larger component values, components may be added together to yield the desired values. To add capacitor values, they can be connected to each other in parallel. For example, if a value of 500 µf is needed, two 250 µf caps can be connected such that both sets of leads are connected.

so good luck but dont waste expensive drivers if your not going to integrate them with all the considerations of a full speaker design.

Chef, that is very details explanation. But I am still not very sure of the how to consider all the small parameters. Here the links where you will find all the small details including the off axis graph:
tweeter: http://www.tymphany.com/d2904_600000
mid bass: http://www.tymphany.com/18w_4531g00

Do you have extra components that can sell to me?
Thanks for all the help. Really appreciate it.

I need to know whether this is for a car or home system, as it will definatley change quite a lot for car systems.

once i know this I will design a crossover for you, but the best way to finish a crossover is to listen and listen. as your ears will be doing the listening you need to be very exact on what your ears are telling you.

It is for car. Thanks.

here is an estimate crossover for you using the information you gave me.


Second Order (12db/octave) Two-Way Crossover

High Pass Impedance: 4 Ohms ( 5 ohms at crossover point)
Low Pass Impedance: 4 Ohms ( 6 ohms at crossover point)

Frequency crossover point Hz 2000


high pass
C1 = 12 µF
L1 = 0.400mH


low pass
C2 = 10 µF
L2 = .680mH


zoebel on low pass 8 uf + 5 ohm resistor







some interesting reading

Second order low pass filters consist of a coil in series followed by a capacitor in parallel to a loudspeaker. The coil must come before the capacitor. For a 100 Hz second order low pass filter for a 4 ohm load, L2 = 9.00 mHy and C2 = 281 µfd. For a 50 Hz low pass filter for a 4 ohm load, L2 = 18.00 mHy and C2 = 562 µfd. For a 100 Hz second order low pass filter for a 2 ohm load, a 4.5 mHy coil and a 562 µfd capacitor are needed. To calculate values, use this calculator or the appropriate chart.


Using a 100 Hz second order low pass filter on a woofer or woofers, at 200 Hz or one octave above the crossover frequency, power to the woofer(s) will be reduced by 93.75.% or 12 dB.


Second Order High Pass Filters
Second order high pass filters consist of a capacitor in series followed by a parallel coil to a loudspeaker. The capacitor must come before the coil. For a 5000 Hz second order high pass filter for a 4 ohm load, C2 = 5.62 µfd and L2 = .18 mHy. For a 4000 Hz high pass filter for a 4 ohm load, C2 = 7.03 µfd and L2 = .23 mHy. For a 5000 Hz second order high pass filter for a 6 ohm load, an 11.25 µfd capacitor and a .09 mHy coil are needed. To calculate values, use this calculator or the appropriate chart.

Using a 5000 Hz second order high pass filter on a tweeter or tweeters, at 2500 Hz or one octave below the crossover frequency, power to the tweeter(s) will be reduced by 93.75.% or 12 dB.


here is an example of a crossover schematic for you to understand

This post has been edited by chefsinc67: Jan 25 2009, 07:35 AM


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ccschua


may i know how's the white sausage caps sound in your system ???

Hi chefsinc67,
Here is a scratch i made:

I want to do band pass for the mid woofer at 100Hz that's why I put in 190uF and 14mH but I doubt I can find such value also not sure is this correct way to do it.

Please comment. Thanks.


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hi there,

can i ask whats the purpose of doing a band pass when the speaker driver you are using is great down to 30hz, even if you u use a subwoofer, i have through trial and error used the sub woofers in my car as a reinforcement of the woofers in the doors, not rely soley on the sub to give me lower bass but to assist in the spl only, besides a 14mh inductor will cost you about RM 200++ for one so it could become a very expensive attempt.
also with a large cap value like that it would also be expensive for a decent sounding one.

as i said before I gave you a crossover that will be suited to your drivers worked out properly and should give you a nice sound without the need for a huge subwoofer.

I use 2x 8 inch woofers in the back tray of my Myvi SE just to add to some low hz to what i am getting from my focals in the doors. it doesnt dominate and gives you a nice amphitheatre affect in the car. anyway try my suggsestion if you want but I would not advise that you use crossover you have put forward.

hope my 2 sens worth assits...

also i just noticed you put the zobel in the tweeter high pass as well, you dont need to do that, as this is for the woofer only.

This post has been edited by chefsinc67: Jan 30 2009, 07:21 PM

Sorry I didnt notice your post. The white cap is polypropylene cap from Taiwan. The sound is towards clear and transparent. The weird part is when I use it, the bass is very restricted. I guess need time to run in. that;s the trouble with new poly cap.

Hi chefsinc67,
Ok, I have changed it to something like the attachment.

My reason for the band pass is because of the huge jump in impedance from 100Hz (4ohm) to 30Hz (35ohm), I think that is the reason you suggested zobel filter. And also i am worry it will vibrate the door panel if play too low.

Next task will be the parts, any suggestion what to use?
Thanks.


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tough poly sounds good in xover....!!! have you try to bypass it with some caps? i heard it works for most...

yeah. the MKP 1837 Roederstein. It doesnt seem to work on my speaker. funny. Will in future try again.

go for some russian pio. i use k42-y and it works like a charm....

I have that too and i use a lot of them for the zero franken mod. Also i use that for my shigaraki clone cd transport. I found it good.

Any recommendation on inductor to use? My budget is below rm50 per pcs.
Thanks.

for a car crossover and a paralell crossover the resistance value isnt as important in the inductors so any half decent inductor with a wire diametre of up to 16 gauge would be fine i am in langkawi so dont have a clue where to get speaker parts in KL, unless another member can enlighten us?
dont worry about door shaking bass from the scan speak this crossover has no baffle step circuit in it so it will be smooth bass , not overly powerful, but please make sure you put a good amount of padding or bitumen pads behind them on the inside panel of the door. this helps a lot as you dont get panel vibration as much.


good luck and let us know the results.

actually depends on the value n thickness i bought Mundorf copper foil 0.51mh 14gauge for RM 120 per pc

I try look for inductor in Farnell, there are 2 type of inductor material: mainly ferrite and iron. To get one that can support 1A and above the tolerance will be more than 10%. Some are call "coke" like:
http://my.farnell.com/bourns-jw-miller/571...ctor/dp/1189597
or
http://my.farnell.com/bourns-jw-miller/525...hoke/dp/1103553
Can I use this?

Abel, copper foil = CFC? Better than air core? Where you get it?
Thanks.

This post has been edited by kww: Feb 5 2009, 11:58 AM

if you want to waste money and get foil type inductor then abel has the place to go to, i would settle for an aircore in the car and use the foil inductors for my home hifi in which i have done to my reference speakers.

aircore inductors u should be able to get at any good car hifi store in kl i guess.

anyone can help this Lad out with some local knowledge?

cheers

if want Mundorf copper foil can get from Octave or order from internet i use copper foil for my home hifi
if u want cheaper try to find Alpha or Solo

this my passive crossover for my car speaker


This post has been edited by abel: Feb 6 2009, 10:35 AM

abel,

ask chua for a lend of my series crossover and try it in your car mate, give that a go and see how it sounds...

nice to see you have a zoebel in there also, makes a huge difference to the woofer control. nice caps as well, bit pricey though...what drivers you using abel in the car?

now i no longer into car hifi sold everything off
now iam into home hifi previous i using Nakamichi speaker (OEM by Vifa) MG17WK001 mid and D26NC05 tweeter
for the passive actually iam follow the original factory passive design

i got try Linkwitz 12db at 3000hz for the tweeter and 6db 3000hz for the mid that time didnt use any attenuation just borrow from fren sound not that nice

This post has been edited by abel: Feb 6 2009, 05:51 PM

mg17's are what i use for my centre speaker in langkawi, the one i made! not bad with the right crossover. the tweeter is a vifa also.

true i am more into home hi fi then car speakers as you dont get out what you put into the cars, where as sitting down in front of the hi fi with a nice cold can of beer and some funky vibes, is as sweet as pie to me!!

Oh yes. let me know who is interested in the Series Cross Over board. I will post some photo on it later.

yeah car alot of noise very irritating soo i go into home hifi i can infront of the home hifi have some coffee iam not into beer

is tat a kimawe carbon film resistor (green one) ?

nobody game enough to try my creation? anyway Chua i hope you tried it and was different from what you expected.

by the way my zero is completley rosak and if no one sells me the board then thats that! I will try and use some pieces out of it but I cannot eevn get power to the headphone amp now as i was thinking of turning it into a buffer amp for my mini disc player as I had bypassed the crappy opamps in the mini disc and now the sound db is a lot less, so if I can fabricate a buffer in line with this to the pre amp it could be ok.

i made a new case for the zero so I may have to either do a pre-amp or maybe try a dac kit this time.any suggestions which is worth trying?

anybody want to get rid of their broken zero I am interested...-