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.