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

Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum

Balanced active crossover advice
Balanced active crossover advice
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
Reply
 
Thread Tools Search this Thread
Old 9th April 2007, 03:38 PM   #1
zigzagflux is offline zigzagflux  United States
diyAudio Member
 
zigzagflux's Avatar
 
Join Date: Oct 2006
Location: Charlotte, NC
Default Balanced active crossover advice

I am in process of building my next amplifier, and was heading towards a Lynn Olson Amity/Karna type. I currently run a set of ME-2 Ariels with a ST-70 and powered subwoofer.

I do not get enough midbass (100-500Hz) out of the ME-2's, and have read a number of articles (some written by Lynn) about what to do about this. Alas, not a simple solution.

My first preference is a passive linestage 6 dB filter for the ME-2's, with a separate midbass/bass driver. Attached is a possible attempt for the amplifier input.

It seems to me frequency-wise the filter would work, but if the components are not perfectly matched, which they won't be, the benefits of balanced topology are lost.

Is this a waste of time, or is it possible to get good performance if I attempt to match components? Like buy 10-20 capacitors and pick the best matches.

Better solutions?
Attached Files
File Type: pdf xover.pdf (7.7 KB, 161 views)
  Reply With Quote
Old 9th April 2007, 04:47 PM   #2
EC8010 is offline EC8010  United Kingdom
diyAudio Moderator Emeritus
 
EC8010's Avatar
 
Join Date: Jan 2003
Location: Near London. UK
Why not move the 0.01uF capacitors to the primary, and combine them into one single series capacitor?
__________________
The loudspeaker: The only commercial Hi-Fi item where a disproportionate part of the budget isn't spent on the box. And the one where it would make a difference...
  Reply With Quote
Old 9th April 2007, 04:57 PM   #3
zigzagflux is offline zigzagflux  United States
diyAudio Member
 
zigzagflux's Avatar
 
Join Date: Oct 2006
Location: Charlotte, NC
Could certainly try that, but I have read a number of cautions about attempting to cap couple to transformers. Don't have any links to those cautions in front of me, but I do remember reading it.

Maybe it was at K&K, don't know. If it's really that simple why all the fuss about the difficulties in using active crossovers? Not talking 12/18/24 dB, of course.

http://www.clarisonus.com/blog/?p=17
  Reply With Quote
Old 9th April 2007, 08:51 PM   #4
EC8010 is offline EC8010  United Kingdom
diyAudio Moderator Emeritus
 
EC8010's Avatar
 
Join Date: Jan 2003
Location: Near London. UK
Yes, there's a possibility of an LF resonance between the capacitors and the primary inductance of the transformer. The only way to be certain of how a transformer is going to behave is to set it up and measure it.
__________________
The loudspeaker: The only commercial Hi-Fi item where a disproportionate part of the budget isn't spent on the box. And the one where it would make a difference...
  Reply With Quote
Old 10th April 2007, 12:22 PM   #5
zigzagflux is offline zigzagflux  United States
diyAudio Member
 
zigzagflux's Avatar
 
Join Date: Oct 2006
Location: Charlotte, NC
So sweep the input from 1Hz to 40kHz, and check the output?

What if I find a resonant peak? Do I try damping with resistance, or return to the secondary balanced filter?

Is this considered the best approach for a passive HP filter?
  Reply With Quote
Old 10th April 2007, 12:27 PM   #6
EC8010 is offline EC8010  United Kingdom
diyAudio Moderator Emeritus
 
EC8010's Avatar
 
Join Date: Jan 2003
Location: Near London. UK
Sweep it and see what you find. I've never done this before, so I really don't know what to expect. It may be feasible, it may not. Only experiment will prove it either way.
__________________
The loudspeaker: The only commercial Hi-Fi item where a disproportionate part of the budget isn't spent on the box. And the one where it would make a difference...
  Reply With Quote
Old 10th April 2007, 06:07 PM   #7
planet10 is offline planet10  Canada
frugal-phile(tm)
diyAudio Moderator
 
planet10's Avatar
 
Join Date: Oct 2001
Location: Victoria, BC, NA, Sol III
Balanced active crossover advice
Default Re: Balanced active crossover advice

Quote:
Originally posted by zigzagflux
I do not get enough midbass (100-500Hz) out of the ME-2's
With an 8" baffle width, that is likely baffle step loss... lots of ways to deal with that http://www.t-linespeakers.org/tech/b...intro-bds.html

Given my dislike for MTM... i'd look at building a bipole...

dave
__________________
community sites t-linespeakers.org, frugal-horn.com, frugal-phile.com ........ commercial site planet10-HiFi
p10-hifi forum here at diyA
  Reply With Quote

Reply


Balanced active crossover adviceHide 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
Moving to triamp, need decent cheap 3-way active crossover and poweramp advice bikehorn Solid State 5 23rd November 2006 04:28 AM
Need advice on this active crossover(please) ostie01 Multi-Way 0 13th February 2006 01:58 AM
Advice on active 6 dB crossover ostie01 Multi-Way 0 17th December 2005 11:45 PM
Active crossover advice Duck-Twacy Multi-Way 16 18th May 2003 06:07 PM
XVR1 active crossover, discrete active stage promitheus Pass Labs 18 22nd July 2002 01:29 AM


New To Site? Need Help?

All times are GMT. The time now is 05:14 AM.


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
Wiki