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

Introduction to designing crossovers without measurement
Introduction to designing crossovers without measurement
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 30th July 2017, 01:15 PM   #551
nareshseep is offline nareshseep  Trinidad and Tobago
diyAudio Member
 
Join Date: May 2010
Great post, learnt alot .. Now to build my first crossover!
  Reply With Quote
Old 1st August 2017, 10:10 PM   #552
evershumi is offline evershumi  Portugal
diyAudio Member
 
Join Date: Mar 2014
good evening

I need help to make a crossover for 2x eminence beta 15, connected in parallel in a H-frame, 125hz, second order.

thanks in advance
  Reply With Quote
Old 2nd August 2017, 10:59 AM   #553
AllenB is offline AllenB  Australia
diyAudio Member
 
Join Date: Oct 2008
If all goes well with your dipole you may end up with a region of falling response with a flat response above this. I've attached a random dipole response plot from S. Linkwitz's site.

You might want to use the speaker in the sloping region (otherwise why make a dipole ) and one way to compensate for this is to begin your crossover in this region. This can bring it back to flat... then where the response is already flat higher up, it will pull it down and roll it off. This way, the crossover is set by the baffle dimensions.

If this is a woofer, then the lower you begin this low-pass crossover, the more low bass you'll get. On the other hand sensitivity will be lower and so will power handling.
Attached Images
File Type: gif mideq1.gif (15.0 KB, 168 views)
  Reply With Quote
Old 2nd August 2017, 09:18 PM   #554
evershumi is offline evershumi  Portugal
diyAudio Member
 
Join Date: Mar 2014
Thanks for the quick response.

I am following this article http://www.quarter-wave.com/OBs/U_and_H_Frames.pdf. At the bottom of page 8 is the graph of a woofer eminence alpha15 but the graph of beta 15a is very similar, but with more 4Dbs. Taking the advice on using the crossover at 125hz, by my calculations the reel will be 5mh am I right?
  Reply With Quote
Old 4th August 2017, 01:11 PM   #555
AllenB is offline AllenB  Australia
diyAudio Member
 
Join Date: Oct 2008
I'm thinking 18mH and 90uF. This is based on Martin suggesting 125Hz 2nd order Linkwitz/Riley (ie Q=0.5), and around 7 ohms at the woofer... Since this determination has already been made, a crossover calculator script (app) can give these values.
  Reply With Quote
Old 4th August 2017, 11:12 PM   #556
evershumi is offline evershumi  Portugal
diyAudio Member
 
Join Date: Mar 2014
Quote:
Originally Posted by AllenB View Post
I'm thinking 18mH and 90uF. This is based on Martin suggesting 125Hz 2nd order Linkwitz/Riley (ie Q=0.5), and around 7 ohms at the woofer... Since this determination has already been made, a crossover calculator script (app) can give these values.

this values work with 2 woofers 8ohms beta 15 in paralel ?
  Reply With Quote
Old 5th August 2017, 01:43 PM   #557
AllenB is offline AllenB  Australia
diyAudio Member
 
Join Date: Oct 2008
No, sorry. Double the capacitance and halve the inductance
  Reply With Quote
Old 15th August 2017, 12:25 AM   #558
Quard is offline Quard  United States
diyAudio Member
 
Join Date: Nov 2012
sorry if this is ot.
pbr and laziness are in charge over here, apologies.

looking for an online calculator for single xover circuit elements,
this would be for what I think would be called parallel xovers, correct me if I'm wrong


hopefully, it would have x spaces for me to enter

first entry: choice of series element or shunt, highpass or lowpass
second: desired "knee" frequency, for dropoff of 6db/octave
above/below this single circuit element
(highpass for cap-series or inductor-shunt,
lowpass for inductor-series or cap-shunt)
third: impedence of "target" speaker, bare (no other xover elements), at that frequency

yes, something so simple would leave an absolute vaccuum,
despite nature's "abhorrent!" cry,
of how any other shunts/series elements would work together.


but it would be enough to give numbskulls like me a start at guessing rough magnitudes
of parts involved, and going to Digi-Key or some such & pricing such rough ideas out
(in at least a little tighter fashion than simply acknowledging
lower=more expensive, eventually nutso)

my lukewarm pabst thanks you for your patience
(and diligence if you got this far),
I'm just along for the ride, but thanks! for any reliable refs at all
  Reply With Quote
Old 15th August 2017, 08:47 AM   #559
AllenB is offline AllenB  Australia
diyAudio Member
 
Join Date: Oct 2008
There are many online calculators available. You can confirm that they should give the same result for a first order filter into a fixed resistance.

This is where the response is at -3dB, which is the half power point. Speakers are often crossed at -6dB which is the half pressure point. For this and other reasons the desired values may vary.

First order filters can be difficult to work with, especially where the speakers don't have a smooth/gradual natural response.
  Reply With Quote
Old 5th September 2017, 04:14 PM   #560
Tom1957 is offline Tom1957
diyAudio Member
 
Join Date: Sep 2017
I have a pair of DIY loudspeakers with Dynaudio drivers. They were built in mid 80's. Recently my tweeter got fried and I finally managed to get a replacement. However, I think it would be good time to replace the capacitors. These boxes were custom built by a guy who is unfortunately no longer with us. I took out the crossover from one of the boxes, but I have hard time determining the values of two capacitors. I'm no electronic wiz, so if the value is not specifically stated in μF, I am not sure what they are. The only thing on one of them is:

MKT 1.60
10 K 160V-

It's a bigger thing, inch x inch x half an inch. I'd really appreciate any help.
  Reply With Quote

Reply


Introduction to designing crossovers without measurementHide 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
WinSpeakerz vs others for measurement & crossovers rick57 Multi-Way 8 12th December 2010 10:20 PM
Designing crossovers using Vidsonix Virtual Crossover triode4 Multi-Way 0 28th October 2007 01:22 AM
A brief introduction WayneM Introductions 7 30th April 2005 01:23 AM
Designing passive tri-mode crossovers? Datoyminaytah Multi-Way 9 4th September 2004 12:33 PM
Designing for guys who like designing Sch3mat1c Tubes / Valves 14 31st August 2003 11:46 AM


New To Site? Need Help?

All times are GMT. The time now is 05:26 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright ©1999-2017 diyAudio
Wiki