X-over Comments & Help

[GOWA]

I am trying to match the Seas L18RNXP / 1224 to the North Creek D25S-06 tweeter. Any comments or especially help would be most appreciated. I have posted what I have done so far here: http://s197.photobucket.com/albums/aa7/linggowa/

Thanks

 

[Inductor]

Do you want to change the L-pad on the tweeter? What are your impressions.

 

[GOWA]

Right now they sound like cheap bargain basement speakers.

 

[PeteMcK]

Getting tweeter attenuation right & BSC are probably the place to start tweaking.
How have you dealt with BSC?
are your cabinets vented or are you using subs?

 

[GOWA]

GETTING CLOSER

I made a few changes and they are sounding much better.
http://s197.photobucket.com/albums/aa7/linggowa/

 

[jnb]

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]

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]

The impedance EQ won't hurt at this stage.

Did you take your phase measurements yourself?

 

[GOWA]

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.

 

[jnb]

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.

 

[Inductor]

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.

 

[Inductor]

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.

GOWA,
Any news?... I hope you got it right.

 

[GOWA]

L18RNXP

I haven't had much time to work on it lately. I am working on two other projects that I need first.
With the L18, I keep coming back to the idea that a point of 1750Hz or so seems to be the best sounding and I will be revisiting this again soon.

 

[Dave Bullet]

GOWA,

From memory, Zaph said in hindsight for his L18/TBFCG design he would lower the xo point from 2KHz. I don't know how the North Creek tweeter will handle it but that I believe was to get as far away as practicable from the L18 breakup and higher order odd HD as possible.

David.

 

[jupiterjune]

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]

L18RNXP / 1224 + D25S-06

I will be testing again this weekend and I hope with better results.
I am also putting together a set containing the 6-1/2'' Dynavox with the North tweeter.
http://s197.photobucket.com/albums/aa7/linggowa/

 

[GOWA]

Hey JJ,
What type of 3-ways have you been working on? I have one in the mix as well.

 

[jupiterjune]

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]

That's a lot of work. Nice going.


I am working on a design which has:

TWEETER = Seas - 27TFFNC/G (H1396-04) http://www.seas.no/index.php?option=com_content&task=view&id=186&Itemid=182

MIDRANGE = Vifa - PL11MH09 (8Ohm) http://www.madisound.com/catalog/index.php?cPath=45_234_265

WOOFER = Aurum Cantus - AC-200MK2 http://www.aurumcantus.com/aurumcantus-midwoofer/index_midwoofer.htm

 

[GOWA]

So far I'm here with the 3-way