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crossover confusion
http://diyaudioprojects.com/Forum/viewtopic.php?f=11&t=4971
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Author:  Dared [ 12 Oct 2014, 15:10 ]
Post subject:  crossover confusion

Good day to you all,
As I'm working and temp. living in Brazil I wanted to build my own speaker boxes as none is available here (except Sao Paulo which is 10 hours away).
Buying at home and importing it is asking for trouble in this country, either you lose it and if you get it it will see at least 100% extra costs involved for duties, freight etc. So I ordered in Europe for some relative to take it over. Ordering at 2 different online stores did not go good. I screwed up on the crossover bits and pieces.
Thought to be clever and bypass all that by getting somebody else involved and ended up for my speakers 2x visaton crossovers, Checking the online calculators it does not make sense at all.
Visaton gives me for bass: inductor of 1.0mH and capacitor 10µF, for high 3.3 and 0.3 as values.
On the net it reads like this
C1=4.69 µF high pass
L1=0.6 mH
C2=4.69 µF low pass
L2=0.6 mH

In actual fact it should be
C1=6.25 µF
L1=0.45 mH
C2=4.69 µF
L2=0.6 mH
As the tweeter is 6Ohm and the online shop sold it as an 8Ohm but never mind,
Why would a simple crossover have different values assuming we have 2nd order Butterworth in place?
Would the frequency still be 3000hz to crossover this way? I fiddled with the figures (online)to get closer to the Visaton values but can't get even close to it.
This country is terrible for finding out something or getting help, they can fix a TV but sound is only for cars and Hi-Fi gives funny faces only.

Ok, how bad is this situation:? I'm just getting the box material done (sealed) by the carpentar so not able to check/hear what is happening yet.

Appreciate some guidance or reassurance.
Thanks,
Ed

Author:  Dared [ 24 Oct 2014, 19:12 ]
Post subject:  Re: crossover confusion

Well, I assume that everybody that has read this is confused too.
See nothing to appreciate.
Regards,
Ed

Author:  turk 182 [ 27 Oct 2014, 11:33 ]
Post subject:  Re: crossover confusion

is the difference in values the result of using the dc resistance rather than the impedance with whatever online calculator your using?

Author:  Dared [ 02 Nov 2014, 18:48 ]
Post subject:  Re: crossover confusion

Hi Turk182, no it was the Imp that I used as was asked for. Most, I think all, calculators come up with the same (huge) difference.
I've asked Visaton for clarification but to no avail.

Author:  turk 182 [ 02 Nov 2014, 20:05 ]
Post subject:  Re: crossover confusion

if your telling me you think you'll hear the difference or shift in the crossover point because you somehow think they built the crossover wrong i don't know maybe you can but looking at the change in values you reported it still puts you in the ball park as far as turnover frequency. come on it's a passive crossover and unless you want a specific alignment i don't think difference in the values is going to make any of this un-listenable.
can you list the model # of the crossover's and the speakers or kit #

Author:  turk 182 [ 02 Nov 2014, 20:12 ]
Post subject:  Re: crossover confusion

and when comparing x-over's the actual arrangement of components (series or parallel with respect to driver) has to be the same.
beware what circuit that an online calculator is using and insure that the filter types are the same

Author:  Dared [ 03 Nov 2014, 07:19 ]
Post subject:  Re: crossover confusion

The crossover specs are from the Visaton catalogue:
Hauptkatalog 2006/2007 Visaton.
Model nr. 5402 and specifications
Slope steepness 12 dB/oct.
Rated power 100W
Cross-over frequency 3000 Hz
Impedance 8Ω
Dimensions 100 x 150 mm

Drivers are: Visaton W 170 S 8 Ohm and SEAS H1283 22TAF/G

Author:  turk 182 [ 03 Nov 2014, 08:12 ]
Post subject:  Re: crossover confusion

well i wish i had the visaton catalogue your looking at because i can't find any current product listings with the 5402 model number attached on Visaton's website

ok are you concerned that the seas tweeter impedance is going to shift the crossover frequency and want it to stay at 3k for a specific reason?

have you loaded all this stuff into a box, hooked it all up, listened to it to and come to the conclusion that it's all a crossover problem? :up:

Author:  Dared [ 04 Nov 2014, 08:24 ]
Post subject:  Re: crossover confusion

No none of that, I'm in a village in a country where they repair electonics with a hammer, I'm in line waiting at the carpenter to get me the wood I need to build the boxes, haven't heard a tone yet. The concern I have is the difference in the Visaton filter and the ones I get from online calculators. If they say to keep the filter as simple as possible why is difference between the two so big?
Attached the Visaton filter, I'm just trying to understand, is this a huge difference or are there more ways to come to the same solution?

Author:  turk 182 [ 04 Nov 2014, 10:19 ]
Post subject:  Re: crossover confusion

there's a difference between designing a filter with published data and one that is designed from actual measurements made with drivers in their boxes.
it seems that your overly concerned with something that may not even be an issue.
the differences in value aren't as large as you seem to think we are talking about micro farads and milli henry's and have you tried to source/ purchase these components with those exact values?(as an exercise: the values you reported earlier deviate by 2.5 micro farads and .2 millihenry's i can't say that i or you could hear the actual difference between the two)
now the cross-over you linked to and the values you mentioned earlier don't seem to match up so i still can't tell what your after seems like you want someone to teach you about designing filters...

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