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

What can I do against 'box sound' ?
What can I do against 'box sound' ?
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 19th September 2020, 07:54 AM   #211
chris661 is offline chris661  United Kingdom
diyAudio Member
 
chris661's Avatar
 
Join Date: Feb 2008
Location: Sheffield
Quote:
Originally Posted by Stal View Post
I read through this thread rather quickly but don't think this has been put forward as a suggestion. I.e. using more than one drive unit such as MTM. For a given midwoofer design, an extra midwoofer would give 6dB gain which would mean for a given spl level the cone would only need to move by 1/4 of the displacement. For a given internal box design with chosen stuffing or absorbent solution as mentioned previously, having two such boxes dealing with less energy into each box would help, would it not?
I know MTM vs 2 way has its own debate but that aside....
Your maths is out.

If you double the cones, each must move half the amount, so that the same volume of air is being shifted.


With regards to the rest of it, you'd also double the radiating area of the cabinet, so any sound passing through the cabinet walls will also increase in level. Similarly, any sound bouncing around inside the cabinet and exiting via the cone will also increase.

No net gain or loss, I'm afraid.


I do think I covered the unwanted cabinet sound portion of this quite comprehensively in an earlier post: What can I do against 'box sound' ?

Chris
__________________
Bits of information and other things I've worked on: https://www.grimshawaudio.com/lab
  Reply With Quote
Old 19th September 2020, 07:58 AM   #212
scottjoplin is offline scottjoplin  Wales
diyAudio Member
 
scottjoplin's Avatar
 
Join Date: Dec 2015
Location: Penrhyndeudraeth
Quote:
Originally Posted by scottjoplin View Post
Interesting, references please.
Anyone?
  Reply With Quote
Old 19th September 2020, 08:01 AM   #213
bansuri is offline bansuri  Italy
diyAudio Member
 
Join Date: Aug 2008
Location: Dolceacqua
Quote:
Originally Posted by Stal View Post
For a given midwoofer design, an extra midwoofer would give 6dB gain which would mean for a given spl level the cone would only need to move by 1/4 of the displacement. .
No it is linear with SPL and voltage, would move 1/2
  Reply With Quote
Old 19th September 2020, 01:54 PM   #214
scottjoplin is offline scottjoplin  Wales
diyAudio Member
 
scottjoplin's Avatar
 
Join Date: Dec 2015
Location: Penrhyndeudraeth
Quote:
Originally Posted by xrk971 View Post
Actually, compression and rarefaction (Boyle’s Law) are not symmetric - hence why sound propagation in air intrinsically has 2nd order distortion, and why we associate that with natural sounding.
I asked for references but nothing forthcoming as yet. Is this an interesting theory or conjecture?
  Reply With Quote
Old 19th September 2020, 04:25 PM   #215
krivium is offline krivium  France
diyAudio Member
 
Join Date: Oct 2009
^ It's not a reference but i remember reading about this in a Nelson Pass's article about the Aleph series amplifier ( iirc ) and then read it in books about acoustic too ( can't remember the reference ).

This is not conjecture or theory but facts to me.

Last edited by krivium; 19th September 2020 at 04:27 PM.
  Reply With Quote
Old 19th September 2020, 04:29 PM   #216
scottjoplin is offline scottjoplin  Wales
diyAudio Member
 
scottjoplin's Avatar
 
Join Date: Dec 2015
Location: Penrhyndeudraeth
Thanks, I'd like to know more, how and why this is the case. Nelson says:

"Simplicity is not the only reason for the use of the single-ended topology. The characteristic of a single-ended gain stage is the most musically natural. Its asymmetry is similar to the compression / rarefaction characteristic of air, where for a given displacement slightly higher pressure is observed on a positive (compression) than on a negative (rarefaction). Air itself is observed to be a single-ended medium, where the pressure can become very high, but never go below 0. The harmonic distortion of such a medium is second harmonic, the least offensive variety."

Which is probably what X is paraphrasing.
  Reply With Quote
Old 19th September 2020, 04:36 PM   #217
scottjoplin is offline scottjoplin  Wales
diyAudio Member
 
scottjoplin's Avatar
 
Join Date: Dec 2015
Location: Penrhyndeudraeth
Quote:
Originally Posted by krivium View Post

This is not conjecture or theory but facts to me.
Which bit? As far as I know hearing sound that travels through air is the usual natural way to hear it.

Also I can't find where Boyle mentions asymmetry

Last edited by scottjoplin; 19th September 2020 at 04:39 PM.
  Reply With Quote
Old 19th September 2020, 04:37 PM   #218
phase is offline phase  United States
diyAudio Member
 
Join Date: Oct 2004
Some of the best packing material that I’ve found to help boxes (sealed/ported) sound better is bubble wrap, and lots of it. Usually fill the upper half of the cabinets with a not-too-tight roll of the small (3/16”bubbles) stuff in ported arrangements, and even more in a sealed.
  Reply With Quote
Old 19th September 2020, 05:45 PM   #219
andy19191 is offline andy19191  Europe
diyAudio Member
 
Join Date: Apr 2005
Location: -
Quote:
Originally Posted by scottjoplin View Post
Also I can't find where Boyle mentions asymmetry
Are you winding up the chap you are asking or do you want to know?
  Reply With Quote
Old 19th September 2020, 05:50 PM   #220
scottjoplin is offline scottjoplin  Wales
diyAudio Member
 
scottjoplin's Avatar
 
Join Date: Dec 2015
Location: Penrhyndeudraeth
I said it was interesting and asked for a reference, do you have one?
  Reply With Quote

Reply


What can I do against 'box sound' ?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
Lets collect: Tips on Sound-Design (How to make speaker sound like...) qQxSzbwqYW Multi-Way 0 12th February 2018 10:15 PM
how to mix sound from notebook and external sound card and get headphones output burence73 Headphone Systems 17 29th December 2012 07:58 PM
Kicker zx700.5 sub channel has humming sound and amp2 has echo like sound ivkata Car Audio 3 10th April 2012 09:23 PM
The Ultimate Sound Improving for Compact Disc's through Patent-Pend.CD Sound Improver tiefbassuebertr Digital Source 145 25th April 2011 07:39 PM
Eighteen Sound (18 Sound) NSD 1095N Compression Drivers and XT1086 Horns opc Swap Meet 6 1st May 2009 03:48 AM


New To Site? Need Help?

All times are GMT. The time now is 04:47 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
Copyright ©1999-2020 diyAudio
Wiki