5 Way Crossover design *HELP!* - Page 2 - diyAudio
Go Back   Home > Forums > Loudspeakers > Multi-Way

Multi-Way Conventional loudspeakers with crossovers

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 20th June 2011, 06:47 PM   #11
T101 is offline T101  Bulgaria
diyAudio Member
 
Join Date: Mar 2010
Location: Sofia-Bulgaria
If what Cal posted is the diagram of the crossover of your speakers, what I said still applies.
And you can't make simple Butterworth crossover, because of the speakers impedance of 4 ohms. Inductances DCR plays crucial role in that crossover because if all were low DCR the amplifier would see terribly low impedance at some frequencies, particularly in the high frequencies.
And again, with that crossover are adressed both some pure acoustical issues and some driver specific issues.

For instance, have a look at the shape of the signal fed to the woofers, R1 is the woofer that goes to 125 hz and R2 is the one that is crossed at 60 hz.
I can bet on you that R1 is a kind of notch/impedance flattering device together with it's whole crossover for R2. Sorry I didn't sim the whole electrical equivalent of a driver, but the parameters of those are unknown for me.

R1 is fed with signal with a hole in it jut in the place where R2 would exhibit a peak.
Unfortunately, my competence extends only to the investigation part of it all.
Now see the second attached picture, in it there are two plots, one of a bass system without a crossover - green and one with a crossover - lilac...
The first peak you get any time you use a second order Butterworth or similar crossover and the second is the bonus that you get with 4th order crossover of any type. That or similar or one that is a relative to those you could get with low crossover of a conventional design and a soft suspension woofer.

This is the principle of it, in practice the complex behavior would lead to different frequencies of the occurrence of those anomalies and some anomalies would not be evident due to the measures taken, but that does not mean that they do not exist

Best regards!

p.s. don't mind the values of the midrange and tweeter R's, I just altered them randomly to see what happens.
The lilac line in the second picture is fourth order @ 60 hz for an 8 ohm driver that I have and with parameters that are dully entered into the software... and... Zobel circuit does not help that situation... a transformer with a center point between primary and secondary grounded through a capacitor does help to some extent... but I haven't worked that out yet...
Attached Images
File Type: jpg IRSII.JPG (118.0 KB, 73 views)
File Type: jpg IRSIIp.JPG (60.0 KB, 70 views)

Last edited by T101; 20th June 2011 at 07:06 PM.
  Reply With Quote
Old 21st June 2011, 12:02 AM   #12
AllenB is offline AllenB  Australia
diyAudio Member
 
Join Date: Oct 2008
Just re-read the thread. Beeferer, when you talked about dried caps, this is an opportunity to restore your crossover using quality parts. If you redesign it then unless you go to a large amount of effort, or have a small specific outcome in mind then you will in likelyhood make things worse.
  Reply With Quote
Old 21st June 2011, 12:18 AM   #13
diyAudio Member
 
Join Date: Jul 2008
Location: Wisconsin
At this point I think I am going to try to replace as many of the caps as I can. I am not going to try to redesign a whole new crossover using the same crossover frequencies. Thank you all for your help and suggestions.
__________________
cheesehead
  Reply With Quote
Old 21st June 2011, 04:29 AM   #14
diyAudio Member
 
paulspencer's Avatar
 
Join Date: Sep 2003
Location: Melbourne, Australia
It's not clear what speaker you actually have. A search shows up different speakers.

When I was first getting into audio, I remember lusting after one of the Infinity towers. None of them *look* like 5 way speakers that I've seen.

I'd be considering an active/passive hybrid at least with active bass, then replacing the caps making them up with multiple parts as needed. It would seem a shame to have to resort to electros to do it.

A little active conversion is a more ambitious project, but not insanely priced. MiniDSP is very cheap, measurement tools are also cheap. Perhaps more work than you had in mind, but worth considering.
  Reply With Quote
Old 21st June 2011, 07:15 AM   #15
rabbitz is offline rabbitz  Australia
diyAudio Member
 
rabbitz's Avatar
 
Join Date: Jul 2003
Location: Newcastle, Australia
Great speaker BTW. I'd just renew the parts with same values. The old Infinity did good work on their crossovers and this one is more difficult due to the OB mids and rear firing EMIT.

These would be them?
RS II

For caps, use MKP for the smaller sizes and these Mundorf bipolar are good for very high values.
Mundorf Bipolar Audio
  Reply With Quote
Old 21st June 2011, 07:35 AM   #16
rabbitz is offline rabbitz  Australia
diyAudio Member
 
rabbitz's Avatar
 
Join Date: Jul 2003
Location: Newcastle, Australia
I did a look a like a few years ago and was a failure even after several driver changes, enclosure mods, so was scrapped.... sounded good but not great.

3-ways and beyond can be a nightmare.
Attached Images
File Type: jpg RSLAL.jpg (57.6 KB, 50 views)
File Type: jpg RSLAL1.jpg (61.2 KB, 51 views)
File Type: jpg RSLAL2.jpg (55.0 KB, 43 views)
  Reply With Quote
Old 21st June 2011, 07:49 AM   #17
diyAudio Member
 
rex.johnston's Avatar
 
Join Date: Dec 2007
Metalized polyprop caps don't have electrolytes. Why don't you just measure the caps you have? They are likely fine. Electrolytics are easily recognizable and easy to replace, nor is their exact value critical.
  Reply With Quote
Old 21st June 2011, 10:16 AM   #18
diyAudio Member
 
Join Date: Sep 2007
Location: Sofia
Send a message via Skype™ to haralanov
Quote:
Originally Posted by T101 View Post
...he is a professional audio equipment seller and those were in his showroom. the components even had a price tags, but he said that he'll sell when he gets better system... five years later, he still haven't sold these
Where is that showroom?
  Reply With Quote
Old 21st June 2011, 01:39 PM   #19
diyAudio Member
 
Join Date: Jul 2008
Location: Wisconsin
Rabbitz found a good site with great pictures. Here they are:RS II
__________________
cheesehead
  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
crossover design montana Full Range 1 8th June 2006 01:34 AM
Crossover design help?? DuaneLewis Multi-Way 5 28th January 2005 03:45 AM
Need help to design crossover Mikael Abdellah Car Audio 6 11th January 2004 03:50 PM
Crossover Design ! postman Multi-Way 21 15th April 2003 07:36 PM


New To Site? Need Help?

All times are GMT. The time now is 09:13 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