Brick wall schematic wanted! - diyAudio
Go Back   Home > Forums > Source & Line > Analogue Source

Analogue Source Turntables, Tonearms, Cartridges, Phono Stages, Tuners, Tape Recorders, etc.

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 3rd November 2002, 12:15 PM   #1
e96mlo is offline e96mlo  Sweden
diyAudio Member
 
Join Date: Apr 2002
Location: Helsingborg, Sweden
Default Brick wall schematic wanted!

Does anyone know where to find it? I've tried searching the web and this site without any results. I also would like to know how the phase of the filter is behaving.

/Marcus
  Reply With Quote
Old 3rd November 2002, 07:54 PM   #2
diyAudio Member
 
Join Date: Feb 2002
Location: Belgium
A brickwall is a theoretical concept. It means that it will pass everything up to a certain frequency and then without a transitionband, pass absolutely nothing. (or the inverse if a highpass) Its filter slope is infinitly steep. Its phase is perfect.

So the only things you will find are at best approximations. In general, the higher order filters with a steep slope have more phase deviation and ripple in the passband. Unless you go digital, but then you would not be on this part of the forum.

Why do you need it for? That way we could give you some ideas of what to look for and what to avoid.
  Reply With Quote
Old 5th November 2002, 05:32 AM   #3
sangram is offline sangram  India
diyAudio Member
 
Join Date: Sep 2002
Location: India
Look for the filter design program on the TI website.

You'll be able to design 4-pole and 8-pole filters that will approximate a brickwall, and will also give you the phase response accross the frequency band. There was a link to the page on the forums, dang if I can find it. I have the file on my machine, but it's about 4 MB so I can't attach it here.
  Reply With Quote
Old 5th November 2002, 05:37 AM   #4
diyAudio Member
 
Join Date: Oct 2001
Location: .
Search for elliptic filters.

ray.
  Reply With Quote
Old 5th November 2002, 08:30 AM   #5
diyAudio Retiree
 
Join Date: Oct 2002
Location: Spain or the pueblo of Los Angeles
Default Brick wall schematic wanted!

I'll do even better than that!

http://doityourself.com/brick/retainingwall.htm
Attached Images
File Type: jpg retainingwall1.jpg (5.0 KB, 616 views)
  Reply With Quote
Old 5th November 2002, 03:32 PM   #6
e96mlo is offline e96mlo  Sweden
diyAudio Member
 
Join Date: Apr 2002
Location: Helsingborg, Sweden
I thought that the filter used in the first generation of CD-players was called "brick wall" filters. But I think I got that wrong.

Anyway, I'm interested in the filters used in those early CD-players, since they had quite steep slopes etc.

Anyone got a link or two?

/Marcus
  Reply With Quote
Old 5th November 2002, 03:44 PM   #7
diyAudio Member
 
Jiiim's Avatar
 
Join Date: Aug 2002
Location: England
Default Dang!

Dang!

Fred got there before me!

Nice to see a sense of humour round here once in a while.


Jim.
  Reply With Quote
Old 5th November 2002, 04:52 PM   #8
Banned
 
Join Date: Dec 2001
Location: Zamboanga, City of Flowers, Mindanao
Send a message via Yahoo to Elso Kwak
Lightbulb Low-pass Filterdesign Program

Hi e96mlo,
Links to the FilterPro lowpass filterdesign program can be found in this link. The program also gives a picture of the amplitude and the phase vs frequency.
CD square wave pre-ringing a filter problem?

A 8th order Chebyshev will be pretty close to a "brickwall" filter.
<B><I>Don't throw any bricks Fred!!!</B></I> (My avatar will protect me)
  Reply With Quote
Old 7th November 2002, 06:59 AM   #9
Electrons are yellow and more is better!
diyAudio Member
 
peranders's Avatar
 
Join Date: Apr 2002
Location: Göteborg, Sweden
Blog Entries: 4
Quote:
Originally posted by e96mlo
I thought that the filter used in the first generation of CD-players was called "brick wall" filters. But I think I got that wrong.

Anyway, I'm interested in the filters used in those early CD-players, since they had quite steep slopes etc.

Anyone got a link or two?

/Marcus
Hi!

My old Denon DCD-1000 had a 7th order LC-filter (20 kHz) and my other one DCD-1500 had a 9th order LC-filter at 35 kHz. Neither the DCD-1000 nor the DCD-1500 sounded very well. Was the LC-filters the cause? I don't know.

But what are going to use this filter for? It's much better to use a digital filter if it's possible.
__________________
/Per-Anders (my first name) or P-A as my friends call me
Super Regulator SSR03 Group buy
  Reply With Quote
Old 7th March 2003, 07:02 PM   #10
diyAudio Member
 
Tieftoener's Avatar
 
Join Date: Nov 2002
Location: Coastal AL
I don't know about a schematic that's already made for you - normally, you just have to pull out the 'ol TI-85 and make some calculations for some standard opamp filters. And because no design equation actually works in real life filter applications, you get to build it and test it.

But to make it easy on you, TI does have an application program for designing filters... not the greatest in my opinion though. Filter Wiz has a freeware version of their program and I like that much better than the TI program.

And to make it even easier... Linear Technology makes a variety of filter ICs already predesigned. The LTC1562 seems to have some good possibilities for an antialiasing filter or to rid your system of high frequency (above A-weighted values) noise in a post-DAC filter. My team looked into the LTC filters for our senior design project (DD, DPL, DTS, and stereo digital decoder) as additional antialiasing filters prior to our Burr Brown ADCs, but as it turns out the LTC filters are waaaaay to expensive for any realistic production cost. But for a DIYer, they're pretty fun to play with. And we really didn't need antialiasing filter because the BB ADC had one built in. I did some distortion analysis on Audio Precision with and without a modular filter I made with BB OPA2134 opamps, and it made no major improvement in distortion... so we just omitted the extra filter circuitry.

Hope this helps,
__________________
Tieftoener -- You're ears can sense a movement in air that causes your eardrum to move less than 1/10th of the diameter of a Hydrogen atom! Don't abuse the one of the most amazing organs your Creator gave you!
  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
Designing for on-wall/near-wall speaker placement morbo Multi-Way 4 27th November 2010 04:52 PM
Wanted Mordaunt-short MSW20 Schematic Wanted simon dart Subwoofers 0 22nd May 2009 08:19 AM
Another brick in the wall Supersasha Introductions 6 16th February 2008 07:53 PM
in-wall/on-wall speaker? (axiom w-22 clone?) Scott_fx Multi-Way 0 22nd February 2007 02:08 AM
Opinions on wall to wall subwoofer array jmiyake Subwoofers 35 19th July 2003 11:26 PM


New To Site? Need Help?

All times are GMT. The time now is 06:02 PM.


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