Topic: Passive Crossover

[netken]

approximately how much the silver coil ?

download the pricing catalogue below :

http://www.mundorf.com/downloads/info-news/english/070812/MUNDORF-components_range_RRP.pdf

tell us what's ur take?

[built]

octave also becoming Angkasa-One soon also ... kekeke ...

number two is in queue already.
he'll probably be number three.

[abel]

ermm not bad 2 member got chance to go to Space not bad 

[Audiophiliac]

we all just talking about silver coil; check this Audi A8; actually made out of silver

[netken]

phwwettt!! yellow card ....

[Audiophiliac]

sorry out of topic

[abel]

we all just talking about silver coil; check this Audi A8; actually made out of silver

wahh its Dubai ..... Dubai ppl too rich liow haha silver for them is nothing 

[Zenn]

thats not silver la, thats chrome, and its photoshoped, last time volvo launch also did a chrome version...

[built]

kwelll... can photoshop the reflection as well.

[louisl]

am not sifu but i have some tips for u guys and dont ask me how to designing or what cap do u need. the answer is i dont know 

First time experiment creating passive xo u need as bellow :-

*100 capacitor 1,1.5,2.2,3.3,4.7,5.6,6.8,8.2,10,22 uf each 10 pieces (made in china)
*resistor 1,1.5,2.2,3.3,4.7,5.6,6.8,8.2,10 Ohm each 10 pieces 5 watt (made in malaysia)
*lilitan/coil 40 coil @0.125mH. (made in malaysia)
*good hearing especially for staging and imaging
*prefer RTA or measurement device.

after the experiment been successful only u go for true high components.
designing passive is not as easy as thought, as for left and right components are not of the same value.
worth to invest if u get the right components for your system. 

wish you guys good luck

[SMP]

Noted that many icers start to use DIY passive.

Research on the net told that determining a intended crossover point is depend on the actual speaker impedence at that point. The speaker nominal impedence can not be used for calculation. The actual impedence for a tweeter & mid at 3000 Hz can be differently, so if assume same impedence for both driver (said 4 ohm, but actual may be 3.3 & 4) in the calculation, the result come out can be queit far out.

Some told me that can use elec. x-over to find the most appropriate crossover point then use this point for designing a passive crossover, but this still require the knowledge of the actual impedence.

Wondering how others do it? by trial and error? by actually measuring it (using equipment)? Mind to share.

Also any icer use impedence equalization net work?

[Audiophiliac]

just trying to go the easier way; by sampling the passive xover that already comes together with the speaker system using the same value of the components in it just upgrade it to a better type of components, do not have a problem doing this on my mid range because could take sampling from the already available passive xover upgrade, tune and improve from there. But have problem with tweets and Mid Bass because speaker originally do not come with the xover.

[netken]

i dun actually have a definite answer on this ... but i believe this could be a problem faced by speaker / audio manufacturers as well ?

there's an interesting readup on bcae1.com :

Advantages of Electronic Crossovers vs Passive Crossovers

Setting Crossover Frequency:
    As you already know, a passive crossover's crossover frequency is determined, in part, by the impedance of the speaker. From the 'resistance vs impedance' page, you know that a speaker's impedance is not constant. This (among other things) makes a passive crossover difficult to get exactly right. Even if you do the math right and use the right components for the speaker's nominal impedance, you could actually be quite a ways off (depending on the speaker's impedance curve and the desired crossover point). The frequency response may also have all sort of dips and peaks due to the impedance changes across the audio spectrum. Most of the time, these deviations from a flat response (in the pass band especially) are quite undesirable. Electronic crossovers don't suffer from these problems. Since the speakers are driven directly by the amplifier, it doesn't matter how much the impedance of the speaker changes. The crossover frequency and frequency response will stay rock solid. A passive crossover must be designed (and tested) for each speaker to assure the crossover point is where it's supposed to be.

any more thoughts?

[mnkh27]

I'd say heck it, let the ears be the judge. Come to think about it electronic crossovers available out there are not accurate as well, where it is arguable that measuring and testing is still required regardless.

In many cases where people compare one crossover to the other, either in-built with the hu, amp or an external electronic crossover set at the same slope (i.e 12dB) and same crossover point (i.e. 50Hz) the results can differ quite significantly. Why? Possibly QC, different quality of parts etc. who knows.... A low pass of the same settings on one crossover may cut down the highs and midrange/vocals significantly while the other crossover still allows some midrange to pass.

Anyway, do not fret! I've once attended a car audio seminar by Scott Buwalda and it is highly emphasized that the ear is undoubtedly the most powerful tuning tool available and we should actually close our eyes to tune rather than use our eyes to tune. So guys, if you cannot trust the electronics out there, I'm sure you can train your trusty ole' ears to do the job. It's cheaper and it doesn't lie to you.

[SMP]

Ageed that ear is the most accurate measuring tools provided you heard enough reference system or you have one to refer to.

I think designing a proper crossover still have to accurately deal with the varies impedence of the driver. For example to LP a SEAS W18NX at the following crossover points, interporate from the impedence graph the resulted crossover point can be very different if calculation is based on 8 ohm (the nominal impedence):

1) 2000Hz - 8ohm
2) 3000Hz - 9.5ohm
3) 4000Hz - 11ohm
4) 5000Hz - 12.5ohm

If can not measure the actual impedence, a Zobel network may be worth consideration. It make amp see constant load from the driver. So it make nominal impedence quite safe to be used for calculation.