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

Why not cardioid midrange?
Why not cardioid midrange?
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 8th August 2019, 09:57 AM   #11
Juhazi is offline Juhazi  Finland
diyAudio Member
 
Juhazi's Avatar
 
Join Date: Mar 2007
Location: Jyväskylä, Finland
Simulations of backside radiation and total directivity pattern are far from reality with midrange. With those wavelengths very small details of the baffle, driver's spider, frame and motor structure - interferences that they make - mess up ideal radiation pattern. Simulations suppose that radiator is a planar, symmetrical disc.

Dipoles and cardioids must be prototyped and meassured in 3-D. By doing those you gain experience for "an educated guess" of what will happen.
__________________
Radikal aktivist AINOgradient speaker project
  Reply With Quote
Old 8th August 2019, 12:23 PM   #12
andy19191 is offline andy19191  Europe
diyAudio Member
 
Join Date: Apr 2005
Location: -
Quote:
Originally Posted by ScottG View Post
It's MUCH cheaper to do the absorptive panel on-wall than trying to integrate it into the loudspeaker design.
Except it requires about a quarter of a wavelength depth to effectively absorb and the first cancellation dip occurs at...

A cardioid radiation pattern not only greatly reduces the interaction with the wall behind the speakers it also puts a bit less energy into transverse room modes at frequencies above what can be treated by distributed subwoofers. These benefits come at the price of more cone area and complexity.

Quote:
Originally Posted by ScottG View Post
IF you are truly concerned with back-wall reflections then an in-wall design is MUCH better.
Agreed but it is simply not an option for many.

A simple but less common option is to place the woofer/s close to the wall, the midrange a significant distance from the wall and the crossover frequency so that the frequency of the cancellation dip for the woofer is in the midrange passband and the cancellation dip for the midrange is in the woofer passband.
  Reply With Quote
Old 8th August 2019, 12:54 PM   #13
AllenB is offline AllenB  Australia
diyAudio Member
 
Join Date: Oct 2008
There's a whole lot in between. Practically in wall doesn't necessarily mean cutting into a wall. The result can be superior.
  Reply With Quote
Old 8th August 2019, 01:09 PM   #14
andy19191 is offline andy19191  Europe
diyAudio Member
 
Join Date: Apr 2005
Location: -
Quote:
Originally Posted by AllenB View Post
There's a whole lot in between. Practically in wall doesn't necessarily mean cutting into a wall. The result can be superior.
Not too sure what you mean by in between. Something like a speaker in cupboard in an alcove? Or on a wall with a wide baffle and big chamfers? Or perhaps something else?

It is an interesting problem designing a speaker to work well on or near a wall which is where many speakers end up getting placed.
  Reply With Quote
Old 8th August 2019, 01:38 PM   #15
dc655321 is offline dc655321  United States
diyAudio Member
 
Join Date: Jul 2018
Quote:
Originally Posted by ScottG View Post
-well my post did have context, no?
Sure. But I was asking for the facts/science that produced your opinion, which your response was very light on.

Quote:
Originally Posted by ScottG View Post
It's MUCH cheaper to do the absorptive panel on-wall than trying to integrate it into the loudspeaker design. IF you are truly concerned with back-wall reflections then an in-wall design is MUCH better.
Practical thicknesses of rockwool on the wall will have decreasing effectiveness as frequency decreases. Below a few hundred Hz, it may as well not be there.

Agreed that in-wall can be effective. But practical in most instances? Nope.

Quote:
Originally Posted by ScottG View Post
Plus, there are (typically) significant detriments to having it in a design:

..substantial pressure loss creating: lower sensitivity (all-else-equal), higher resulting non-linear distortion,

..and added mechanical resistance (that tend's to reduce depth, design dependent).
Again, interested to learn what basis these very vague statements arise from.
Not criticizing (yet ), just trying to learn.
  Reply With Quote
Old 8th August 2019, 02:20 PM   #16
AllenB is offline AllenB  Australia
diyAudio Member
 
Join Date: Oct 2008
Quote:
Originally Posted by andy19191 View Post
It is an interesting problem designing a speaker to work well on or near a wall
Yes, it is.
  Reply With Quote
Old 8th August 2019, 09:12 PM   #17
ScottG is offline ScottG  United States
diyAudio Member
 
Join Date: Feb 2003
Location: US
Quote:
Originally Posted by andy19191 View Post
Except it requires about a quarter of a wavelength depth to effectively absorb and the first cancellation dip occurs at...
-please note the title:

Why not cardioid midrange?


In this instance I'm treating "midrange" in the context of cardioid midrange loudspeakers.. which typically doesn't extend much lower than 400 Hz. (..of course if you need to go a bit lower then 4" instead of 3".. and if I remember correctly it starts running-out of effectiveness fast.)
Attached Images
File Type: jpg mineral_wool_graph.jpg (81.5 KB, 157 views)
__________________
perspective is everything

Last edited by ScottG; 8th August 2019 at 09:27 PM.
  Reply With Quote
Old 8th August 2019, 09:26 PM   #18
ScottG is offline ScottG  United States
diyAudio Member
 
Join Date: Feb 2003
Location: US
Quote:
Originally Posted by dc655321 View Post
Again, interested to learn what basis these very vague statements arise from.
Not criticizing (yet ), just trying to learn.
-you'll have to do a LOT of searching on that to get something more than "vague" then. ..and even then, you'll likely have to use common sense to extrapolate (..where you can find posts on real cardioid mid.s, but rarely with an equalized response and non-linear distortion results - so you'll just have to see what pressure drop (from the cardioid) and a resulting "boost" with eq. will do to non-linear distortion.)

Really, the only thing not proven is the subjective effect of adding resistance to a driver like this in the midrange. Subjective results are in general difficult to really "prove" at all.
__________________
perspective is everything
  Reply With Quote
Old 8th August 2019, 09:59 PM   #19
dc655321 is offline dc655321  United States
diyAudio Member
 
Join Date: Jul 2018
Quote:
Originally Posted by ScottG View Post
In this instance I'm treating "midrange" in the context of cardioid midrange loudspeakers.. which typically doesn't extend much lower than 400 Hz.
Have you checked out the design and measurements of the Dutch & Dutch 8c?
I guess the definition of mid-range I had in mind (and D&D use) differs from yours: 100-1200Hz.

Quote:
Originally Posted by ScottG View Post
-you'll have to do a LOT of searching on that to get something more than "vague" then. ..and even then, you'll likely have to use common sense to extrapolate
I have done lots of searching with good results, thanks. My only difficulty here is trying to understand what you're talking about - pressure drops, eq boosts, and non-linear-distortion - and how that relates topically.

I get the sense we have very different ideas in mind on how a cardioid is generated and what advantages/compromises they present.
  Reply With Quote
Old 9th August 2019, 03:28 AM   #20
ScottG is offline ScottG  United States
diyAudio Member
 
Join Date: Feb 2003
Location: US
Did you look at the measurements for the 8C?

If so, what did the non-linear graph represent? Why is it like that? What is different about that design from most, and why? (..connect the "loop" there and you'll have that answer on why the non-linear graph looks the way it does.)


-as far as understanding me, that's OK - Keyser didn't have a good time with it either (..even if he did go-on to create the 8C). ..and yes, you can search for that as well.
__________________
perspective is everything
  Reply With Quote

Reply


Why not cardioid midrange?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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
2-way: Waveguide + Cardioid-like keyser Multi-Way 210 1st August 2019 10:47 AM
Adventures in cardioid MBK Multi-Way 123 2nd January 2017 03:53 AM
DSP midrange directivity control aka kinda cardioid natehansen66 Multi-Way 104 26th January 2016 11:54 AM
Cardioid midrange Audiodidakt Multi-Way 9 17th June 2013 04:55 PM
Cardioid with a TH sub FlipC Subwoofers 23 4th February 2012 08:03 PM


New To Site? Need Help?

All times are GMT. The time now is 06:21 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright ©1999-2019 diyAudio
Wiki