X-over Comments & Help

jnb

Member
2006-12-30 11:55 pm
You might try shaving the bump off at 250Hz. Try increasing the value of L2, then adjusting C2 to bring the upper mid response back into line. If Req and Ce are correct then don't change them. If you can't match well enough to the tweeter, you may have to tweak it there as well.
 

GOWA

Member
2007-01-08 2:31 am
Ontario
GETTING CLOSER

I am using the PE .5 cu. cabs. http://s197.photobucket.com/albums/aa7/linggowa/?action=view&current=CABS.jpg
They are sealed for the moment and sound quite good that way but I will be using a port. It's not the woofer where I am having the trouble, it's lining up the tweeter. I think it is crossed where I want to be but I am experiencing some sibalence. From first impressions, this has the potential to be a very dynamic sounding speaker. I wish I knew how to use better software but I am lumbering along in X-Over Pro.
I'm not sure if I should get rid of the EQ on the woofer and just go with a notch. You can't see the effect of notch filters on the design in X-Over Pro, so I'm sort of working in the dark.
John Krutke has both of these units on his website. I have used the North tweeter before and still maintain that $ for $ it is the best buy out there.
 

jnb

Member
2006-12-30 11:55 pm
After you mentioned the sibiance, I thought there may be some integration issue between the drivers and it is much easier to get this right with the right measurements. Pehaps you could change the polarity of one of the drivers and see whether it sounds "right versus wrong" or just different and still not right.

If you use one half (just the woofer's part) of a well designed crossover (assuming your box resembles Zaph's), then leave the woofer there and tweak the tweeter till it sounds right. I would start by choosing an L and C that give a rolloff at the same frequency and slope as the woofer is supposed to be at, then tweak the L-pad down, being careful to keep it at the right total impedance, till the tweeter just disappears from being the focus of attention, then tweak the L and C a little more.
 
GOWA said:
If you are speaking of the graph, no.
I removed the EQ, implemented Zalph's notch and there is a difference. (for the better) Still needs some work up top.

Please report your status and post your xover implementation components as is, and results you expect to see again, for clarification, unless you are still testing.

Again phase is important as was mencioned by jnb and it didn't look as it belongs to this xover but to a corrected phase alignment (xover) with inverted polarity on the tweeter, and this doesn't show on picture # 2 of the "2-Way Crossover Network".

Thanks. Good Listenings.
 
Wow-

You design crossovers the way I do. It looks like you are getting your BSC using the George Short philosophy. I like to bring the tweeter level to 6db below the woofer level, so in theory everything will be flat when the speaker is placed well into the room. (I use xover pro as well.)

Now the bad news. I think the sibilence is due to cone breakup, and I never was able to get rid of it with any crossover tricks. The only thing that works reasonably well is to set your crossover point at less than 1/3 of the breakup frequency.

I messed around with my Odin's for months trying to get rid of the metal sound from the speakers. I finally glued lightweight damping material to the backs of the woofer cones. This worked reasonably well, but my very sensitive ears could still hear a bit of cone breakup when listening to certain female vocalists.

I finally started building three ways.

JJ
 
GOWA-

Tweeter: one Tang Band 25-1372SC (1" ti)
Mid: one Tang Band W3 1335SB (3" ti)
Woofers: four Dayton RS 150-4 in series parallel

The tweeter and woofers I would do differently, but the midrange is very natural sounding -- no sibilence. Not quite as detailed as some metal coned speakers, but that might not be entirely due to the midrange. I can post more info if you are interested.

JJ
 

GOWA

Member
2007-01-08 2:31 am
Ontario
So far I'm here with the 3-way
 

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