Archived from groups: rec.audio.pro (More info?
Gareth Magennis <firstname.lastname@example.org> wrote:
>what would be the likely effect of someone having replaced a 4 ohm bass
>driver with an 8 ohm one in a 2 way 4 ohm passive crossover speaker?
The crossover point changes by a whole octave, totally screwing things up.
Also the efficiency of the driver will be different which will also totally
screw the response up.
>Specifically, this is a Peavey (sorry about that) 1 x 15 plus compression
>driver box where the original Black Widow 4 ohm is now an Eminence Kappa 8
>ohm. I'm most concerned about what happens to the compression driver
You can think of most crossovers as being independant low pass and high
pass filter that (with a perfect amp and cable) don't interact much. So
putting the wrong load on the low end will screw up the low pass point but
it won't change the high pass point much.
BUT, you also have problems in that the T-S parameters for those drivers
are very different, so the box interactions will not be right either and
your low end will just generally be wrong in addition to the hole at the
crossover region from the wrong impedance.
I don't think you'll damage anything operating the speaker like this, but
it must sound really horrible. Change the driver.
"C'est un Nagra. C'est suisse, et tres, tres precis."