large value capacitors for chr 70 high pass - diyAudio
Go Back   Home > Forums > Commercial Sector > Manufacturers > Markaudio

Markaudio Designers and builders of audiophile grade drivers

Reply
 
Thread Tools Search this Thread
Old 1st May 2011, 05:54 PM   #1
diyAudio Member
 
Bill poster's Avatar
 
Join Date: Jun 2008
Location: London/Bangkok
Default large value capacitors for chr 70 high pass

Chr 70 crossed at 350-400 hz.. can't find much at those values! What would you recommend?
  Reply With Quote
Old 1st May 2011, 06:01 PM   #2
diyAudio Member
 
Join Date: Nov 2005
This might be useful:

Passive Crossover Design Equations Formulas Calculator - Two Way First Order Network Butterworth
  Reply With Quote
Old 1st May 2011, 11:21 PM   #3
diyAudio Member
 
Bill poster's Avatar
 
Join Date: Jun 2008
Location: London/Bangkok
Quote:
Originally Posted by Andrew Eckhardt View Post
Thanks. I've got this result.
C1 = 5.3E-5 farads (so I need a cap value of 5.3?)
L1 = 0.0033970276008493 henries



Excuse my ignorance but with the butterworth diagram that means no bi wiring?
  Reply With Quote
Old 2nd May 2011, 12:08 AM   #4
diyAudio Member
 
Join Date: Nov 2005
5.3e-5=53e-6= 56uF.

You can bi-wire, not that it will make a difference anything like a well tuned crossover. The diagram just shows the high and low pass tapped on to the usual single feed.

For tuning pick off the driver impedance from the published or measured curves at the crossover frequency. Buy some slightly undersized caps for the main unit and a few smaller values to parallel on if needed. Same for the inductor, only series to increase value. You can rerun calculations at different turnover points to get a smarter idea about what values to buy..
  Reply With Quote
Old 2nd May 2011, 01:00 AM   #5
diyAudio Member
 
Bill poster's Avatar
 
Join Date: Jun 2008
Location: London/Bangkok
Thanks for the sensible advice.
Yes, thats the figure I got on the Erse site, I thought I'd made a mistake. I'm assuming the ohm inputs are the overall driver rating and not the ohm level at point of crossover?

so that value is going to be expensive if i choose a decent cap..

Last edited by Bill poster; 2nd May 2011 at 01:03 AM.
  Reply With Quote
Old 2nd May 2011, 09:26 PM   #6
chrisb is online now chrisb  Canada
diyAudio Member
 
Join Date: Aug 2002
Location: victoria BC
Quote:
Originally Posted by Bill poster View Post
Thanks for the sensible advice.
Yes, thats the figure I got on the Erse site, I thought I'd made a mistake. I'm assuming the ohm inputs are the overall driver rating and not the ohm level at point of crossover?

so that value is going to be expensive if i choose a decent cap..

Passive line level XO and active start to look really attractive when parts for speaker level XO cost more than the drivers

TLS.org | Passive Line-Level Crossover
__________________
you don't really believe everything you think, do you?
community sites t-linespeakers.org, frugal-horn.com commercial site planet10-HiFi
  Reply With Quote
Old 2nd May 2011, 10:34 PM   #7
diyAudio Member
 
Bill poster's Avatar
 
Join Date: Jun 2008
Location: London/Bangkok
Quote:
Originally Posted by chrisb View Post
Passive line level XO and active start to look really attractive when parts for speaker level XO cost more than the drivers

TLS.org | Passive Line-Level Crossover
chris, I'm looking at the link .. for me anything like this is..well, its a bit like the swedish chef making a pastilla

could you explain it in very simple terms?

btw I was thinking to either go for pulse x's (true film and foil 50uf caps are crazy prices)or try a big fat industrial oil type capacitor. both are inexpensive and it might be interesting to see which is preferable with the alpair. cd I bypass with a nice low value cap if needed?

Last edited by Bill poster; 2nd May 2011 at 10:38 PM.
  Reply With Quote
Old 3rd May 2011, 04:59 PM   #8
chrisb is online now chrisb  Canada
diyAudio Member
 
Join Date: Aug 2002
Location: victoria BC
Quote:
Originally Posted by Bill poster View Post
chris, I'm looking at the link .. for me anything like this is..well, its a bit like the swedish chef making a pastilla

could you explain it in very simple terms?

btw I was thinking to either go for pulse x's (true film and foil 50uf caps are crazy prices)or try a big fat industrial oil type capacitor. both are inexpensive and it might be interesting to see which is preferable with the alpair. cd I bypass with a nice low value cap if needed?

well if you're anything like me, even an explanation in simple enough terms that I fool myself that I understand it will soon evaporate from my memory

this type of filter uses the amplifiers' input impedance as one of the formula's operands, any changes in amps might require new parts values

however, there is a calculator included - you enter the amp's input impedance and desired XO frequency, and it does the rest



http://homepage.mac.com/planet10/TLS...ulator.xls.zip

FWIW, the calculated parts are small enough that they can easily be installed at the amp's input jacks - I did exactly that about 10 years ago during some mods to a pair of Decware Zen C amps for a simple 2 way active system - one was filtered LP and the other HP

This particular model had 2 pairs of RCAs and a toggle switch for adjusting the bias of driver tube by adding cathode load resistors. It was easy to re-purpose these parts to allow for bypass of the input filters to run full range.

Worked like a charm, and without getting silly exotic, the cost of parts for the 2 amps was under $50.
__________________
you don't really believe everything you think, do you?
community sites t-linespeakers.org, frugal-horn.com commercial site planet10-HiFi
  Reply With Quote
Old 18th May 2011, 03:38 PM   #9
diyAudio Member
 
kipman725's Avatar
 
Join Date: Jun 2007
Location: London/N.lincs
Send a message via MSN to kipman725
Just use 4*56uf Electrolitics in non polarised confiiguration. Make sure they are low esr >0.5ohm and >50V rating. Works fine don't belive that just because a signal is an audio waveform capacitors stop working corectly. Total cost <2$ so worth trying.
__________________
CHR-70+Subs
  Reply With Quote
Old 18th May 2011, 05:08 PM   #10
chrisb is online now chrisb  Canada
diyAudio Member
 
Join Date: Aug 2002
Location: victoria BC
Quote:
Originally Posted by kipman725 View Post
Just use 4*56uf Electrolitics in non polarised confiiguration. Make sure they are low esr >0.5ohm and >50V rating. Works fine don't belive that just because a signal is an audio waveform capacitors stop working corectly. Total cost <2$ so worth trying.


respectfully - certainly valid to test for optimal C value, but I don't believe the difference wouldn't be audible between cheap ELs and decent film types when used at speaker level
__________________
you don't really believe everything you think, do you?
community sites t-linespeakers.org, frugal-horn.com commercial site planet10-HiFi
  Reply With Quote

Reply


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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
chr-70 vs. chp-70? Sonogasm Full Range 10 26th November 2011 05:02 PM
CHR-70, CHP-70, Alpair 7 Desktops - Japan markaudio Full Range 4 1st February 2010 01:42 AM
F.A.S.T. Project: Tangband W3-315 vs. MARK AUDIO CHR-70, CSS EL-70 or Alpair jockel77 Full Range 13 11th January 2010 11:20 PM
Large capacitors low and high voltage rkc7 Swap Meet 0 24th March 2006 02:17 PM


New To Site? Need Help?

All times are GMT. The time now is 02:41 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2