And you are quite at liberty to tweak capacitor values before settling back in your armchair to listen to the music! 😎
The LS4a/2 bi-wire speaker has a 4 uF capacitor following the 1.5 ohm resistor and that's well worth auditioning in comparison to the 8 uF in the same position in your single-wire LS4a speaker.
I'm simply making this extra remark to clarify the situation for members. I look forward to your promised report on the outcome of your tweaking.
EDIT: Looking more closely at the LS4a/2 HP filter, C1 is actually 4.7 uF. Plus, one little fly in the ointment, the value of C2 in that filter is not visible!
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After considering my above EDIT, I must agree with your above assumption.
I now regard the bi-wire LS4a/2 crossover as a red herring.
Ha! I certainly might have caught the bug. I do see why people enjoy doing modifications and fall down the proverbial rabbit hole.
My goal is to first get these speakers up and running again. They were my first splurge purchase when I was working as a stock boy at a stereo store in NYC in my teens.
I do have a pair of Celestion 9's sitting around that I found at a thrift store for not much money at all that I never loved. Punchy but not very balanced to my ears -- if I recall correctly. They might become my "experiment."
I did find another example of an LS4a crossover online that I am attaching. It does look like a 4uF cap with an 8 uF one.
Here is the link to that thread on another forum:
https://www-audioplanet-biz.transla...l=auto&_x_tr_tl=en&_x_tr_hl=en&_x_tr_pto=wapp
What difference should I expect between a 4/8 setup and an 8/8 one?
My goal is to first get these speakers up and running again. They were my first splurge purchase when I was working as a stock boy at a stereo store in NYC in my teens.
I do have a pair of Celestion 9's sitting around that I found at a thrift store for not much money at all that I never loved. Punchy but not very balanced to my ears -- if I recall correctly. They might become my "experiment."
I did find another example of an LS4a crossover online that I am attaching. It does look like a 4uF cap with an 8 uF one.
Here is the link to that thread on another forum:
https://www-audioplanet-biz.transla...l=auto&_x_tr_tl=en&_x_tr_hl=en&_x_tr_pto=wapp
What difference should I expect between a 4/8 setup and an 8/8 one?
Attachments
Ah! The plot thickens. My, this IS turning out to be fun!
Which colour is for the 4/8 combination AllenB?
The red trace looks nice!
The crossover frequency for the LS4a is 3,000 Hz. Have you any further comment?
The crossover frequency for the LS4a is 3,000 Hz. Have you any further comment?
What I think I'd glean from this is the difference between the two. If one is supposed to be correct then it's likely you'd hear it. The plot shows the frequency of interest but the damping may not show accurately since the tweeter impedance and response would vary.
Two 8uF capacitors could be made to give 4uF for testing if that helps.
Two 8uF capacitors could be made to give 4uF for testing if that helps.
Ok, reporting back as promised.
I successfully rebuilt the crossovers with all your help using the 4uF caps along with an 8uF one on the tweeter circuit
I played them for a few days and although they sounded ok, I felt some of the midrange was missing.
I had previously been alternating between a pair of vintage KLH and Klispch KSB 3.1's.
Had hoped to be finished with the project but decided to disassemble the crossover replacing the 4uF caps with 8uF ones.
What a difference! The sound is so much more "complete." They aren't nearly as loud as the Klipsch but much more balanced as the KLH's are.
All the other caps I replaced measure within the tolerance +/- according to my cheap DMM, however the eights all measure on the high side -- 9+.
Not sure if a lower tolerance would result in better sound but I am pretty happy as they are now configured.
I successfully rebuilt the crossovers with all your help using the 4uF caps along with an 8uF one on the tweeter circuit
I played them for a few days and although they sounded ok, I felt some of the midrange was missing.
I had previously been alternating between a pair of vintage KLH and Klispch KSB 3.1's.
Had hoped to be finished with the project but decided to disassemble the crossover replacing the 4uF caps with 8uF ones.
What a difference! The sound is so much more "complete." They aren't nearly as loud as the Klipsch but much more balanced as the KLH's are.
All the other caps I replaced measure within the tolerance +/- according to my cheap DMM, however the eights all measure on the high side -- 9+.
Not sure if a lower tolerance would result in better sound but I am pretty happy as they are now configured.