Xover components.... what to get?

[rebojorge]

Hi all....

I have finally decided what to build as my first speaker project.... I will go with a proven design the Eros MKII.

Now I am in the process of buying everything and have some doubts about the xover components. Which are best? Which are worst?

I know that for inductors the lower the awg the better... since it has less resistance, other than that I don´t know the difference from air core or others.

The same goes for Caps (electrolityc, polypropilene, etc.) and Resistors (metal fillm, cemented, etc.).

Can anyone advice on the different types, (brands) vs. performance, as well as where to buy them (websites).

I don´t want to get a bargain that turns out to be crap, or spend a fortune on something that would be overkill!

Thanks in advance....

 

[Paradise_Ice]

Experiment,

Spend at least 10% on your cross over parts, dont go crazy, but good quality caps and coils can make or break a speaker.
ICI make good quality caps rated at 630 volts! look at parts express for, even if you dont buy from them, they can help with your needs!
My teacher told me cross over making is a Black Art!
he was not wrong.

 

[geewhizbang]

If you have found an existing design, you should try to buy the same parts as specified in the design, within reason.

It may not be actually better to use a lower DC resistance inductor than the one specified in the design, since the DC resistance of the particular inductor specified is part of the overall design.

With caps, the problem is less, but you certainly shouldn't substitute electrolytics for some more expensive type.

Some really golden ears claim all sorts of benefits for various types of capacitors, but if you buy the same type as specified in the design (even if it is a different brand), you won't notice as much of a difference than what you would if you substituted an electrolytic for a mylar cap.

Resistors are not that big of a deal. You just need ones with the same values, capacity and tolerance specified in the design.

I know I will get some flames from the golden ears on this. But even if there are diffrences between various resistors, they are subtle.

I would recommend starting out with good quality components, but don't believe everything some people say about "X" being better than "Y" especially when X is dramatically more expensive but is just a different brand than Y.

There is a huge difference between drivers. But expensive is not always the best thing for you first project. You will be amazed at how even affordable drivers sound if you put them in a good box with a good crossover made from acceptable quality components.

You can get expensive later when you figure out the best places to spend the dough to get a better result.

For me that is part of the fun, anyway. Spend a little more here and there upgrading until you tweak your system into something really impressive.

 

[rebojorge]

Ok... .this helps to some point, but my question was more in the lines of what is out there, (mylar, polypropylene, metalized polypropylene... etc.) and what is considered to be best in performance. I will then look at the different options and make a compromise between quality/price.

In the Eros design it states that all Caps should be metallized polypropylene, or better. What is better?

For the inductors it stats... 12 awg CFAC...
What does CFAC stands for?

Inductors.... Air core or something else.... what is better?

thanks for the replies!

 

[sreten]

Parts Express sell very good value crossover components.

Going better than metalised polypropylene is an expensive business.

Film and foil types are regarded as being better.

http://www.partsexpress.com/webpage.cfm?&DID=7&WebPage_ID=61

Note that making up a capacitor value by combining types
in parallel is also an option, e.g. C4 could be :

http://www.partsexpress.com/pe/pshowdetl.cfm?&PartNumber=027-440&DID=7
+
http://www.partsexpress.com/pe/pshowdetl.cfm?&PartNumber=027-426&DID=7
+
http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=027-724


Inductors :

http://www.partsexpress.com/aircoreinductorpage.html

CFAC is copper foil air cored :

http://www.partsexpress.com/copperfoil.html

The higher gauges are better as they have less DCR.

non inductive resistors are better than standard :

http://www.partsexpress.com/webpage.cfm?webpage_id=3&SO=2&&DID=7&CATID=48&ObjectGroup_ID=345

Also see :
http://home.hetnet.nl/~geenius/CAP.html

sreten.

 

[rebojorge]

Sreten!

Thanks a lot!!!

That is more in the line of what I wanted to know!... one more thing What about cemented resistors?... I have not seen any of those.

 

[klitgt]

Speaker x-over components can not be good enough! Everything you put before the drivers will influence the way the drivers behave, that is logic, is it not??

In series with a tweeter any resistor must be carbon composite or graphite. Capacitors should be paper/oil copperfoil or aluminium if copperfoil seems too expensive. Polypropylenes are not as good as paper/oil types with copper foil. Inductors must be as low DCR as possible and air core.

If you stick to these rules of thumb you are on the right track. But remember: this only applies if your gear is high-end. If not less expensive components are OK.

 

[geewhizbang]

If you want to label your speaker as high end or even "esoteric" go ahead and buy the most spendy esoteric components. But you can save a lot of money by careful component selection, wiithout affecting the sound in a significant way.

If you have a total budget of X dollars, you need to pick the best set of components you can buy for your money and time. It only makes sense that a combination of good choices will sound much better than spending way too much on some "high-end" capacitor, at the expense of spending $20 more on better drivers.

At most budget levels, I would say that you can probably steer clear of iron core inductors and electrolytic capacitors.

Electrolytic capacitors are cheap, but the electrolyte eventually dries out 10-20 years later, and they don't sound quite as good on the very high frequencies. The difference, however, is fairly subtle compared to the difference between a good tweeter and an excellent tweeter.

But I would recomment avoiding them, since Partsexpress.com has a wide selection of generic "Dayton" brand metallized film polyester (mylar) and polypropylene capacitors at reasonable prices. They also have perfectly adequate ceramic resistors and air coil inductors.

The elitists here buy several-times more expensive esoteric capacitors and resistors, and claim all sorts of audible improvements for them. In my opinion, the difference between the esoteric stuff and the good quality components is much smaller (or even is non-existent) compared to the difference between electrolytic caps and the Dayton metalized film caps.

So it usually isn't worth spending $40 on a capacitor when a very good one costs $5.50 and I doubt if a double blind listening test could hear the difference.

As for inductors, it is a good idea to avoid iron core inductors. Air coils are not much more expensive and have less problems with hysteresis. The fancy, somewhat pricier foil inductors have a small advantage over air coils as they have less resistance, but very often you are adding small amounts of resistance in the circuit anyway to shape the sound, and you can usually work around the small difference between air coils and foils coils fairly well when designing crossovers.