 
|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
|
|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
91.7.63.211
In Reply to: RE: You are welcome and Alan was right... posted by cdc on August 26, 2007 at 12:36:36
Give the network a good week to adjust to the magnetic field created by the earth ground.
Alan
Follow Ups:
nt
The R-C networks provide damping for the normal mode ringing on the line. This is the mode where the ringing wave voltage is from the (+) to the (-) wire within the speaker cable.
The common-mode is where both wires act together as a single wire and the wave voltage is from both wires to the outside world, which is close to the AC safety-earth potential. The R-C networks do not provide any damping for this mode, and are carried along with it at the cable ends.
A grounded, isolated material with some resistance is able to provide common-mode damping without adding the circuit complications that would arise if one were to connect R-C networks from the speaker terminals to the AC safety-earth (DO NOT DO THIS!!!).
Another material that might work is carbon fiber cloth. TI Shield is easier to make a solid connection to safety-earth, but be careful of any acoustic resonances in it.
In reading some of your other posts on commmon mode ringing, you mention that wrapping the speaker cable in carbon fiber cloth and securing with Teflon tape, particularly near each end (but better for the entire length) addresses common mode issues. But I don't recall mention of grounding the fiber cloth. Is that an "extra step" one could take, or is this entirely different; here we are talking about TI shield or Carbon Fiber betw *only* the RC network and speaker?
TI Shield is conductive, and the reports here from others are that grounding a piece of it wrapped around the R-C networks provides a benefit. I thought about what advantage the grounding could have, and concluded that doing so should improve the common-mode damping. However, I have not yet done something like this myself (too many other projects).
My cables have carbon fiber sleeve on them as you described. Since the sleeve covers both conductors, it is relatively ineffective for normal-mode waves. However, it would be effective for common-mode waves. It would be difficult to make a secure and permanent ground connection to it, as it cannot be soldered. It seems to help just used as an ungrounded wrap. I can't say whether grounding it would make it work better.
Carbon fiber is conductive, but much more resistive than TI Shield material. I use it along most or all of the cable to improve the damping. Using TI Shield in the same way would be like adding a conventional shield, and increase the cable capacitance with little series resistance. This might upset the tonal balance or create problems for the power amp.
Another caution is that I believe the AC safety-earth wiring ("ground") is a carrier of RF noise. Adding another connection to the AC safety-earth may increase the amount of RF noise that gets into the audio system.
Microsorb backing will take care of any ringing concerns.
Alan
TI Shield is helpful in all electrical applications. In this one, the TI Shield is helping to damp the ringing character of the network....this is a very good thing. Becareful not to add too much ringing into the circuit.
Alan
So I will know how many to modify, what do you guestimate the change will be? Will it tilt more to the warmer side, more toward neutral or?
Thanks bro,
Chris
| FAQ |
Post a Message! |
Forgot Password? |
|
||||||||||||||
|
||||||||||||||
This post is made possible by the generous support of people like you and our sponsors:
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2025, Audio Asylum, all rights reserved ]
