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Infinity Crossover mod?

RickeyM said:
That 10uf is the shunt cap on the woofer section of the X-O. It's not directly in the signal path so changing it won't improve the tweeter. Now for the fun part. It may be easier/simpler to mount the tweeter X-O parts on a separate little board and use a couple of short wires to connect that to the present X-O circuit board.
Click to expand...
Yeah I get that the 10uf is for the woofer, but would a poly there improve woofer sound quality in any way?
 
Renegade said:
Yeah I get that the 10uf is for the woofer, but would a poly there improve woofer sound quality in any way?
Click to expand...

The "shunt capacitor" of the woofer X-O is to "bleed off" high frequencies from the woofer. The consensus is it doesn't have much effect (if any) on the sound. If you're OCD like me, you replace it because it's not liable to go out of spec and change the woofer response for a long, long, long time.
 
Renegade said:
...would a poly there improve woofer sound quality in any way?
Click to expand...
Some people believe that some of the components in a crossover (or any type of filter) are "in the signal path" and others aren't, and the ones that aren't don't matter. This is entirely wrong and betrays a misunderstanding of how a filter works.
Take as an example the simple RC filter shown below:
220px-RC_Series_Filter_%28with_V%26I_Labels%29.svg.png

The capacitor is obviously entirely essential to the operation of the circuit. If the capacitor has parasitic elements such as inductance, they can be added to the circuit to make a more accurate picture of reality and clearly those parasitic elements affect the circuit.
There's really no hierarchy of significance in crossover components and the idea that some are in the signal path and some aren't is plain wrong.
 
RickeyM said:
The "shunt capacitor" of the woofer X-O is to "bleed off" high frequencies from the woofer. The consensus is it doesn't have much effect (if any) on the sound. If you're OCD like me, you replace it because it's not liable to go out of spec and change the woofer response for a long, long, long time.
Click to expand...
OCD is why I asked, and also why I will replace the 10 as well.

Thank you for your insight.
 
rothwellaudio said:
Some people believe that some of the components in a crossover (or any type of filter) are "in the signal path" and others aren't, and the ones that aren't don't matter. This is entirely wrong and betrays a misunderstanding of how a filter works.
Take as an example the simple RC filter shown below:
220px-RC_Series_Filter_%28with_V%26I_Labels%29.svg.png

The capacitor is obviously entirely essential to the operation of the circuit. If the capacitor has parasitic elements such as inductance, they can be added to the circuit to make a more accurate picture of reality and clearly those parasitic elements affect the circuit.
There's really no hierarchy of significance in crossover components and the idea that some are in the signal path and some aren't is plain wrong.
Click to expand...
Now who in their right mind would argue with this?
Thank you as well.
 
One way to think about shunt caps is that they are subtracting a certain portion of the waveform from the total, and the remainder is going through the woofer. If there is distortion or artifacts in what is subtracted, one might conclude that the remaining waveform is also not what it should be. In other words, if you take a bite out of a pancake, the shape and size of what is left behind might be different depending on whether you are a small fastidious dog or a snaggle-toothed hyena.
 
UPDATE

I finally received the new Poly caps and got them in today. Huge difference in sound, bigger and brighter and still bass.

However, After a few minutes of playing them I noticed a light static sound, only from the left speaker, and only when playing files from my PC though a DAC. But I did that before without noticing any static.

Confusing to me, not sure where to start here, maybe a better DAC, or maybe I have a bad polycell in that speaker.

Thoughts?
 
PCs and USB cables can cause noises. I'd try to discard the PC or the USB cable as the source of the noise, playing from a different source. At home, playing music with a different Operative System in the same computer, creates noises (I guess related to CPU usage and Power Supply not up to the task). Also, a cheap USB cable created noises. A good quality USB cable solved that (not a fancy "audio" wire, just a good one from an USB printer I had around)
 
Wiggle your RCA cable connections. Well, all connections really, and see if it changes. Could be a bad cable or a corroded/dirty connection.

Also could be a dirty source selector switch.
 
elnaldo said:
PCs and USB cables can cause noises. I'd try to discard the PC or the USB cable as the source of the noise, playing from a different source. At home, playing music with a different Operative System in the same computer, creates noises (I guess related to CPU usage and Power Supply not up to the task). Also, a cheap USB cable created noises. A good quality USB cable solved that (not a fancy "audio" wire, just a good one from an USB printer I had around)
Click to expand...
Yeah I played it initially for maybe twenty minutes through my cd player and was very clean and sounded very good. Switched over to the PC/DAC connection and after a few minutes at moderate volume is when I noticed the static. Later in the evening I switched back and forth between the 2 sources at much lower volume and never heard the static again, Is it possible the new caps just needed time to properly saturate? Once I get a chance I will crank it a little and try again to see how it does but it's rare that I'm home alone where I can crank it for an extended period of time to properly test it.
 
toxcrusadr said:
Wiggle your RCA cable connections. Well, all connections really, and see if it changes. Could be a bad cable or a corroded/dirty connection.

Also could be a dirty source selector switch.
Click to expand...
Thanks, I did try this but noticed no difference. Honestly the only change I made was the new poly caps in the Infinities.
 
I don't think the capacitors needed that time to work. I think the problem is at the PC-DAC source, probably the PC or the wire from PC to DAC. Happened to me something similar, listening as usual, and suddendy a very little "sstt" in the middle of the song, repeating time to time. I thought it was a damaged audio file, but the problem was the longer USB cable I was using. Installed back my old cable, and everything works fine since then.

In other computer, if I load the CPU too much (Windows OS playing youtube videos, or playing music while other tasks take the CPU), static noises start to appear at the audio signal. If I change to a light weight linux live CD (puppy linux, my main OS since 2007), everything is silent.
 
elnaldo said:
I don't think the capacitors needed that time to work. I think the problem is at the PC-DAC source, probably the PC or the wire from PC to DAC. Happened to me something similar, listening as usual, and suddendy a very little "sstt" in the middle of the song, repeating time to time. I thought it was a damaged audio file, but the problem was the longer USB cable I was using. Installed back my old cable, and everything works fine since then.

In other computer, if I load the CPU too much (Windows OS playing youtube videos, or playing music while other tasks take the CPU), static noises start to appear at the audio signal. If I change to a light weight linux live CD (puppy linux, my main OS since 2007), everything is silent.
Click to expand...
Come to think of it, both
cables to and from the DAC are 6' long.
Shorten them up?
 
In my setup, the problem was not the length, the problem was the poor quality of the USB cable. A better one made a difference (as said, not fancy audiophile cables, just a good quality USB cable that came from an old USB printer)
 
Capacitors should work right out of the box. Even if you believe in capacitor break-in, it never involves staticy sounds, only tonal balance and such.
 
I pulled the crossover in the nasty speaker last night and found a very ugly solder that was bridged at a tiny spot it should not be. Pulled the cap, cleaned the sloppy soldering up and soldered the cap back in and it sounds clear as a bell now.

Thanks for the help fellas.
 
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