# Simple crossover help



## Steak (Mar 16, 2006)

I'm going to build a pair of small monitors, running a 4" mid
http://www.madisound.com/catalog/pr...d=101&osCsid=c0a6a6cb439b834d7a45648d4cad3a50

and a tweeter
http://www.madisound.com/catalog/product_info.php?manufacturers_id=121&products_id=1767


What is the simplest crossover that I can do here? Where can I get it from?
Any help is appreciated


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## solacedagony (May 18, 2006)

Steak said:


> I'm going to build a pair of small monitors, running a 4" mid
> http://www.madisound.com/catalog/pr...d=101&osCsid=c0a6a6cb439b834d7a45648d4cad3a50
> 
> and a tweeter
> ...


You could build your own for the price of 4 caps and 4 coils  But it's certainly not guaranteed to sound very good.


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## Arc (Aug 25, 2006)

Is this your first attempt? If so, I would recommend something a little easier, like copying an existing design. 

Zaph has a 4" monitor that uses the same tweeter that you have picked out.

http://zaphaudio.com/ZBM4.html

It has everything you need there, including crossover schematic. 

If you don't want to do that, go to parts express and look under their crossover FAQs. There you will find the values for 6 and 12dB slope crossovers. Then look at the FR of each driver you selected, and select the most appropriate points. 

If I were you, and doing my own. I would buy a range of value for different slopes and crossover points and experiment with an external crossover first. Then find the one that suits your needs.


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## Steak (Mar 16, 2006)

Thanks for the replies.

Arc: Can't do Zaphs design because I already have the Audax mids, and want to put them to use. Not set on the tweets yet though.

I emailed madisound and they quoted me $25 for the crossover design, + $30 for each crossover. Do you think it is worth it? I mean, $85 worth of passive, simple 2 way crossovers seems kinda steep to me...


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## Arc (Aug 25, 2006)

Personally I think it is steep. You could have them design and you build them if you are comfortable doing it yourself.

Or go over to DIYA and see what the guys over there say. I am not too good with crossovers.


Have a look through these links:

http://www.partsexpress.com/resources/crossover-component-selection-guide.cfm

http://www.partsexpress.com/resources/building-a-crossover.cfm

http://www.partsexpress.com/resources/crossover-faqs.cfm

http://www.lalena.com/Audio/Calculator/XOver/

http://www.passivecrossovers.com/


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## solacedagony (May 18, 2006)

Arc said:


> Personally I think it is steep. You could have them design and you build them if you are comfortable doing it yourself.


That's what I'd do. It's not hard at all. And if you do screw it up, you can always fix it and there's always support here on the forum.


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## Steak (Mar 16, 2006)

solacedagony said:


> That's what I'd do. It's not hard at all. And if you do screw it up, you can always fix it and there's always support here on the forum.


well I think I'll give it a shot building my own crossovers, hope I don't blow something up!
Thanks!

-- On another note, I plan on adding a sub later on, to help with the lower freqs
I have two options:
1. use a 10" PG rsd10 car sub (need a 4 ohm home amp)
2. wire 2 dayton rs180-4 for an 8 ohm load, in a ported enclosure.

These are my two only options because I already have the speakers and would like to put them for use. Which one would you do and why?


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## solacedagony (May 18, 2006)

Steak said:


> well I think I'll give it a shot building my own crossovers, hope I don't blow something up!
> Thanks!
> 
> -- On another note, I plan on adding a sub later on, to help with the lower freqs
> ...


I'd use the PG because it's designed to be a sub.

Second, I'd use neither and just grab a pair of the eD EHQS 12s since they're so damn cheap.


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## seagrasser (Feb 6, 2007)

Steak said:


> Thanks for the replies.
> 
> Arc: Can't do Zaphs design because I already have the Audax mids, and want to put them to use. Not set on the tweets yet though.
> 
> I emailed madisound and they quoted me $25 for the crossover design, + $30 for each crossover. Do you think it is worth it? I mean, $85 worth of passive, simple 2 way crossovers seems kinda steep to me...


I would venture that the crossover design would probably do alright with the audax mids.

The woofer side is very simple (2nd order with no notch) with minimal BSC. The more complex side of it is the tweeter which I would retian if you wanted to use this design.

Of course I say this without seeing the spectrum ofthe audax woofer. I assume it is well behaved.

Jason


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## MiniVanMan (Jun 28, 2005)

The Zaph mini-monitor design is a good building block for what you're wanting to do. 

The Audax mid you have has noticeably less cone breakup in the 10khz region than the MCM mid Zaph uses in his design. What does that mean? Well, there are really two things that you're most concerned with when designing a crossover network. First is baffle step. This is a function of the baffle itself, and not necessarily the driver. Loudspeaker placement plays a big role in how baffle step will react. The further from the wall the better (at least 24"). Second is the top end roll off (for mids). Your top end roll off is pretty simple to predict unless you have cone breakup to deal with. Breakup can complicate your crossover network.

So, that all being said, if you copy the baffle Zaph uses, you could probably copy his crossover design as well, and get adequate results. Optimal? Not sure about that, but since both drivers behave relatively similar, it wouldn't be horrible. 

The only thing to take into consideration is the L-Pad on the tweeter. I didn't compare sensitivities between the MCM and Audax mid. If they're similar then that makes it easy, if not, you'd have to recalculate your L-Pad to accomodate for the different sensitivities.

Hope this helps. Of course paying Madisound for a design isn't a bad idea either, and will yield a bit better results.


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## seagrasser (Feb 6, 2007)

^^^^
Forgot about the relative sensitivities. 

He is wise and very right.


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## Steak (Mar 16, 2006)

solacedagony said:


> I'd use the PG because it's designed to be a sub.
> 
> Second, I'd use neither and just grab a pair of the eD EHQS 12s since they're so damn cheap.


Thanks for the recommendation on the sub. Those EHQS might be cheap to you, but shipping and taxes to costa rica would kill me. I would much rather use something I already have in my closet.


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## Steak (Mar 16, 2006)

seagrasser said:


> I would venture that the crossover design would probably do alright with the audax mids.
> 
> The woofer side is very simple (2nd order with no notch) with minimal BSC. The more complex side of it is the tweeter which I would retian if you wanted to use this design.
> 
> ...


Here is the mid I'm using: http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Product_ID=7783&CATID=49

And here is its specs: http://www.partsexpress.com/pdf/296-053.pdf

From what I can gather, it seems to have a pretty natural top end roll off at around 10K. Zaphs crossover design starts to roll off @ around 3000 Hz.


==> How about running this driver full range, and let it roll off naturally? And then just high pass the tweet at say, 8-10 K range?

MinivanMan: Thanks for the help. These speakers will be at least 4 feet from a wall, in a terrace facing an open pool area, if that matters. 
The sensitivity for the Audax mid is listed as 89. The sensitivity for the Aura Tweet is listed as 88.5. Is that close enough for it not to be a problem??

I am also concerned about highpassing the mid. What do you think?

oh and lastly, I kinda need to make a final decision today and start building something, 'cause I need them for Christmas as a gift


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## solacedagony (May 18, 2006)

Steak said:


> Thanks for the recommendation on the sub. Those EHQS might be cheap to you, but shipping and taxes to costa rica would kill me. I would much rather use something I already have in my closet.


Oops, didn't notice you were from Costa Rica. Yea, go for the PG in a nice big box and call it a day


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## Arc (Aug 25, 2006)

ANother option to throw in here. If Parts Express carries both drivers call the Tech support and ask for Eric. He will design a crossover for you. He did for me for a Dayton RS 3 way. He will email you a pdf of it and a expected response curve. 

He did that for free last year, he said it was his side hobby. I don't know if he will now, but its worth a shot for free.


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## MiniVanMan (Jun 28, 2005)

Steak said:


> Here is the mid I'm using: http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Product_ID=7783&CATID=49
> 
> And here is its specs: http://www.partsexpress.com/pdf/296-053.pdf
> 
> ...


Because you lose any off-axis response that the those monitors would have. 3000 hz will yield a very good off-axis response. Which if they're going in an open area, which you are saying they will, that will be critical. 

I'd definitely go with the Zaph design now. Outside you won't really hear any slight differences a non-optimized crossover would have. 

As for the tweeter, I have a hard time believing the Audax mid is that sensitive. However, you could start by putting a 1 ohm padding resistor on the tweeter (in series with the tweeter), instead of a full L-Pad, and see how that sounds.

If you're really worried about high passing the mid, then just use a sealed enclosure. You lose bottom end, but outside, that's not much of a big deal anyway.


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