Handling a rising response - 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 12th March 2003, 05:37 AM   #1
diyAudio Member
 
Join Date: Dec 2002
Location: dry ol Melbourne Australia
Default Handling a rising response

I'm intending to do a speaker using PHL drivers, due to all the raves, and I'm attracted to the high efficiency. They don't publish FR graphs ("mostly sell to pro companies, who get test samples"), but I've heard that many of them have a rising response, that's "easily handled in the crossover".

I'd have to get some and test them to see by how much they rise, but I want to be confident that it's reasonably easily dealt with.

I was going to use them in an open baffle, driven actively.

Suggestions?
  Reply With Quote
Old 12th March 2003, 10:32 AM   #2
diyAudio Member
 
Join Date: Dec 2002
Location: dry ol Melbourne Australia
Default Open baffles

Open baffles cause a rise 6 db/ octave. Perhaps that's the phenomenon I've heard reference to.

How to calculate the parts/ values deal with it?

TIA
  Reply With Quote
Old 12th March 2003, 01:33 PM   #3
SY is offline SY  United States
diyAudio Moderator
 
SY's Avatar
 
Join Date: Oct 2002
Location: Chicagoland
Blog Entries: 1
Stick 'em in the open baffle, measure 'em, and then design the crossover to incorporate whatever EQ you think is appropriate. EQ will make ANYTHING flat on axis; the tough job is to control off axis response.
__________________
You might be screaming "No, no, no" and all they hear is "Who wants cake?" Let me tell you something: They all do. They all want cake.- Wilford Brimley
  Reply With Quote
Old 12th March 2003, 08:56 PM   #4
diyAudio Member
 
Join Date: Dec 2002
Location: dry ol Melbourne Australia
Default off axis response

ok, so any suggestions to control off axis response?
  Reply With Quote
Old 12th March 2003, 09:07 PM   #5
SY is offline SY  United States
diyAudio Moderator
 
SY's Avatar
 
Join Date: Oct 2002
Location: Chicagoland
Blog Entries: 1
That's a little like asking, "How do I get to the grocery store from my house?" when I don't know where you live or where the grocery store is!

Decide what you want the off-axis response to look like (there are several schools of thought). Get the on axis response of your drivers. Get the responses at 10, 20, 30, 40, and 50 degrees off axis. Then you can make an intelligent choice about how and where to crossover. If you post your measurements, there won't be any shortage of opinions.
__________________
You might be screaming "No, no, no" and all they hear is "Who wants cake?" Let me tell you something: They all do. They all want cake.- Wilford Brimley
  Reply With Quote
Old 12th March 2003, 09:29 PM   #6
diyAudio Member
 
Join Date: Dec 2002
Location: dry ol Melbourne Australia
Default off-axis response schools of thought

Sure it's a sweeping question. (I'm a newbie) - I thought that, leaving aside dipole vs bipole vs monopole, there were only basically only two schools of thought - make it as linear as possible for multiple listeners or positions, or assume a single sweet spot, and don't worry about off-axis response.

What other views are you thinking of, or are there threads or sites that you suggest?

Thanks again.
  Reply With Quote
Old 12th March 2003, 09:46 PM   #7
SY is offline SY  United States
diyAudio Moderator
 
SY's Avatar
 
Join Date: Oct 2002
Location: Chicagoland
Blog Entries: 1
No, it's (unfortunately) a LOT more complicated than that. For example, should the off-axis response be uniform (i.e. close to omnidirectional?) Or should it be uniform in the midrange and slowly roll off in the high end? Should the crossover response be all-pass or constant power? Or both? And then there's the vertical response...

The best way to start is Dickason's "Loudspeaker Design Cookbook." I've recommended it so many times, he oughta start sending me commission checks. There are also a wide range of speaker cad programs which will let you simulate the effect of the crossover on polar response.

For my own philosophy (and let me be clear that this isn't Received Divine Wisdom!), I think it's ok to let highs roll off at increasing horizontal angles, but you need to look carefully at the directivity of the drivers so that you pick a crossover point and slopes where there are no "horns" or "holes" off-axis. These can cause a lot of problems with tonal balance and imaging, at least in real-world semireverberant rooms.
__________________
You might be screaming "No, no, no" and all they hear is "Who wants cake?" Let me tell you something: They all do. They all want cake.- Wilford Brimley
  Reply With Quote
Old 12th March 2003, 09:53 PM   #8
diyAudio Member
 
Join Date: Dec 2002
Location: dry ol Melbourne Australia
Default Dickason's

Thanks, Some interesting food for thought.
(Only started getting into diy 6 months ago).
I'll read again my new copy of Dickason's.
  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
Why Scanspeak rising frequency response in woofers?? Daveis Multi-Way 5 3rd December 2011 06:54 PM
beta 8a rising response? AudioGeek Full Range 1 27th April 2009 08:45 PM
Taming rising frequency response 'naturally'... Taperwood Full Range 31 12th May 2006 02:50 AM
How would you aproach this rising frequency response? swak Full Range 6 4th November 2004 08:30 PM


New To Site? Need Help?

All times are GMT. The time now is 03:09 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