[powerdoc]

I have an EV aristocrat enclosure and I want to add a horn tweeter but
the woofer is 16 ohms and the choice of tweeters in 16 ohms is
limited. I don't want to go to the expense of finding a 16 ohm EV
horn driver as this is a "basement" unit. I've looked at a lot of
posts regarding x-overs and haven't found a "formula" for mixing
impedances. Suggestions?

[[email protected]]

On Jan 3, 1:55 pm, powerdoc wrote:
I have an EV aristocrat enclosure and I want to
add a horn tweeter but the woofer is 16 ohms and
the choice of tweeters in 16 ohms is limited.
I don't want to go to the expense of finding a
16 ohm EV horn driver as this is a "basement"
unit. I've looked at a lot of posts regarding
x-overs and haven't found a "formula" for mixing
impedances.

That's because none is necessary.

Especially in the case of parallel passive ladder
networks (which the vast majority of crossovers
are), each driver's impedance is relevant ONLY for
the portion of that crossover feeding that driver.
This is true assuming the you're going to be
driving the entire system from the typical amplifier,
ie.e, one whose output impedance is substantially
lower than any of the impedances presented by the
drivers and their respective crossovers.

The technique is simple and straightforward:
Use the load impedance of the woofer to select
the woofer crossover component values, and use
the impedance of the tweeter to select the tweeter
crossover component values.

Now, having said that, regardless of whether the
"rated" impedance of each is 4 ohms, 8 ohms, 16
ohms or a bazillion ohms, be aware of the fact
that the REAL impedance of each driver is likely
to be something else entirely. Adjusting the
crossover for different tweeter and woofer
impedances is easy. The hard part is because
the actual impedance of ANY driver, for the
purposes of crossover design, is very different
than the rated impedance.

[powerdoc]

Well, I basically solved my own problem: I found a 16 ohm horn and
driver on the 'bay. Now I don't have to build my own x-over and can
use a commercially built one. Appreciate the help; may still use a
program I found which calculates x-over values based on impedance.

[Kalman Rubinson[_3_]]

On 4 Jan 2009 15:56:47 GMT, powerdoc wrote:

Well, I basically solved my own problem: I found a 16 ohm horn and
driver on the 'bay. Now I don't have to build my own x-over and can
use a commercially built one. Appreciate the help; may still use a
program I found which calculates x-over values based on impedance.

Of course, you realize that all commercial crossovers, unless built
specifically for the exact drivers you have, are based on assumptions
that the drivers are purely resistive and linear. Thus, no
off-the-shelf crossover will give as good performance as a custom
built one.

Kal