Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Multi-Way Conventional loudspeakers with crossovers

Foil inductors, stray capacitance?
Foil inductors, stray capacitance?
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Thread Tools Search this Thread
Old 14th October 2011, 03:44 PM   #11
Mark.Clappers is offline Mark.Clappers  Netherlands
diyAudio Member
Mark.Clappers's Avatar
Join Date: Jan 2010
Location: The Netherlands, near the German border
Originally Posted by Conrad Hoffman View Post
IMO, you won't find any great difference in practical performance between a cheap hand wound 0.15 mH inductor made of wire and a boutique foil component. Also, I'd never buy a foil inductor from anybody that wouldn't tell me the Q and the self-resonant frequency up front without having to buy the thing and measure it.
Professionally I wouldn't either, but as this is a hobby and I like experimenting with these kinds of things it's not a problem. Especially the very low DCR of this coil is interesting for me. I want to use it to make a notch to control the resonance of a mid bass driver, the rest of the system is fully active (Samson 3 way x-over 24dB LR + modified Behringer DEQ2496 and a bunch of LM3886 based amps).

This setup is already working very nicely with a Seas U18RNX/P woofer which doesn't require a notch. (tweeter is a ScanSpeak version of the XT25) I know I can also make the notch part of the active circuitry but this would require (a lot) more effort.

I have experience in designing filters for TV applications (mainly IF filters) so a notch filter for audio frequencies shouldn't be a problem. That is, if all the data is available...

Anyway I am rambling, thank you all for your input!
Music is art - Audio is psychoacoustics & engineering
  Reply With Quote
Old 14th October 2011, 03:54 PM   #12
Conrad Hoffman is offline Conrad Hoffman  United States
diyAudio Member
Join Date: Mar 2007
Location: Canandaigua, NY USA
A man after my own heart- after all, measurement is fun! FWIW, I've also seen improvements at certain values and frequencies by winding coils with the right Litz wire.
I may be barking up the wrong tree, but at least I'm barking!
  Reply With Quote
Old 14th October 2011, 10:16 PM   #13
AllenB is online now AllenB  Australia
diyAudio Member
Join Date: Oct 2008
Originally Posted by Mark.Clappers View Post
I have experience in designing filters for TV applications (mainly IF filters)
Speaker inductors are practically close to the ideal component. If you are curious, put some resistance (0k1 -10k?) in series with the winding and sweep it (maybe into the low MHz range) watching for the peak, preferrably on a scope. I wouldn't bother with the smaller values like this one.... mains transformer primaries usually show this peak, often near the upper audio band. This is where I usually use this test either when damping the windings of a power transformer or finding suitable output transformers.

You can then back calculate an approximation of the capacitance...I'd be reluctant to rely on a meter due to the nature of the lumped strays.
  Reply With Quote


Foil inductors, stray capacitance?Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Shunt/Stray Capacitance starz00700 Planars & Exotics 3 3rd July 2010 11:32 AM
Stray capacitance of CCS zigzagflux Tubes / Valves 1 29th April 2008 12:59 PM
Stray capacitance in audio circuit ? gaetan8888 Solid State 8 10th June 2007 05:38 AM
Foil inductors in Australia? xephon Parts 3 30th September 2006 02:58 PM
Connecting foil inductors dublin78 Multi-Way 2 29th June 2006 07:53 PM

New To Site? Need Help?

All times are GMT. The time now is 12:58 PM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio