XO help wanted.
Hi. I've been reading here a while but not posting so much. It's mostly
above me but I'm trying to learn....
I have a problem, forgive me if this is the wrong forum in which to ask for
help. However I feel that I'm quite a way away from being able to sort it
out myself (although I do have a budget LCR meter that just arrived from
Hong Kong).
I have some small two-way speakers that I'm quite partial to. I don't run
them full range however, having a Jamo 4th-order isobarik passive sub, 8 ohm
nominal (with a large inductor in series with each driver and a 72uF / 50V
capacitor in series with the 'satellites out' terminals. I guesstimate that
it's passing around 210Hz and above? From the sound of it it's going down to
a bit below 100Hz, perhaps as low as 80Hz. I have a 12" Klipsch powered sub
set to 70Hz and lower, after experiementing, that seems about right. (I
don't like the Klipsch running much higher as I find it sounds a bit 'boomy'
approaching 100Hz, and above.)
The 2-ways have always sounded a bit 'confused' at the high-mid to low high
range (if you'll excuse the terminology). I don't notice it often but when I
do it bugs me. Recently I had cause to pull the XOs out (connected to the
terminal block) and I see that the 4" 'woofer' is being run full-range.
There was a 3.3uF electro cap in series with the tweeter (which I replaced
with a polyprop unit, the XO PCB was stenciled and drilled for both) there
is also a fine-wired, air-core inductor in parallel with it.
I would very much like to put a simple low-pass filter on the woofer, with
the cut-off point the same (or as close as possible) as that of the
high-pass circuit on the tweeter. However, other than the woofer being 3.6
Ohm and the tweeter being 8 Ohm (boxes rated at 4 Ohm) I know nothing about
them. They're small Philips units, quasi-ribbon tweeters, well finished with
a good rose-wood veneer and I bought them at auction.
Any and all help appreciated. TIA,
--
Shaun.
"Humans will have advanced a long, long, way when religious belief has a
cozy little classification in the DSM."
David Melville (in r.a.s.f1)
|