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, 08:25 PM   #221
andy19191 is offline andy19191  Europe
diyAudio Member
 
Join Date: Apr 2005
Location: -
Quote:
Originally Posted by scottjoplin View Post
I said it was interesting and asked for a reference, do you have one?
A reference to what? I can discuss the science but you will have to ask audiophiles directly about their alternative notions about what is going on.

Sound is defined as a small/linear perturbation about a mean. If the perturbation is large enough for linearity to break down then we become unable to uniquely identify a part of the fluid motion as sound. This doesn't mean engineers can't kludge things a bit to handle distortion in specific limited circumstances but what is to be considered "sound" will be clear.

Boyles law is for an isothermal process but the sound waves in our rooms are much closer to adiabatic.

Last edited by andy19191; 19th September 2020 at 08:35 PM.
  Reply With Quote
Old 19th September 2020, 09:31 PM   #222
scottjoplin is offline scottjoplin  Wales
diyAudio Member
 
scottjoplin's Avatar
 
Join Date: Dec 2015
Location: Penrhyndeudraeth
Quote:
Originally Posted by andy19191 View Post
Boyles law is for an isothermal process but the sound waves in our rooms are much closer to adiabatic.
That's what I thought
  Reply With Quote
Old 19th September 2020, 09:52 PM   #223
Pharos is offline Pharos  United Kingdom
diyAudio Member
 
Join Date: Feb 2020
Location: Seaford
Quote:
Originally Posted by AllenB View Post
The backEMF is AC and works both ways. So does ringing. One part of what you seem to be describing is a phase difference between voltage and current, which isn't in itself asymmetrical.

The other part, if I understand you, would be the asymmetry of the envelope of the waveform, which is a different thing.
I need to think some more when not so tired.

Agree with the andy19191 point, but how significant is it?

Last edited by Pharos; 19th September 2020 at 09:55 PM.
  Reply With Quote
Old 20th September 2020, 12:35 PM   #224
andy19191 is offline andy19191  Europe
diyAudio Member
 
Join Date: Apr 2005
Location: -
Quote:
Originally Posted by Pharos View Post
Agree with the andy19191 point, but how significant is it?
A good question and I think the answer lies with the role played by scientific/engineering knowledge in how one reasons and goes about the hobby. Most posters on the forum don't possess the considerable amount of background technical knowledge that a competent trained engineer would use to reason about how to design speakers. When someone posts how to go about something using reasoning based on fundamental engineering knowledge it will carry significant weight for an engineer that possesses this knowledge but it won't for those without. They will have to check and test the likely truth in other less efficient ways and against other competing ideas that may lack a scientific basis but may be closer to what seems to be true among peers.

My experience has been that most don't welcome scientific/engineering reasoning when it conflicts with what they want from the hobby. It is hard to see much wrong with this if it enables one to have fun and achieve success on what one might perhaps think of as audiophile terms rather than scientific ones. It is a hobby after all and not an engineering job with success being measured by pleasure performing DIY and interacting with peers.
  Reply With Quote
Old 20th September 2020, 01:38 PM   #225
scottjoplin is offline scottjoplin  Wales
diyAudio Member
 
scottjoplin's Avatar
 
Join Date: Dec 2015
Location: Penrhyndeudraeth
Quote:
Originally Posted by Pharos View Post

Agree with the andy19191 point, but how significant is it?
If you are referring to the sound waves inside the box (how the conversation started) then isn't it reasonable to conclude it's totally insignificant? If you are referring to sound waves in a room, then it seems irrelevant. I just wondered if there was something I'd missed about Boyle's law.
  Reply With Quote
Old 20th September 2020, 02:26 PM   #226
hifijim is offline hifijim  United States
diyAudio Member
 
hifijim's Avatar
 
Join Date: Sep 2019
Location: St Louis, MO
Quote:
Originally Posted by xrk971 View Post
Actually, compression and rarefaction (Boyle’s Law) are not symmetric -.
True at high variations of compression. But sound propagation is tiny variations in pressure. For these tiny variations in pressure, the process is adiabatic, and the air behaves as if it is linearly elastic.

Quote:
...hence why sound propagation in air intrinsically has 2nd order distortion, and why we associate that with natural sounding
Atmospheric pressure is 101,000 Pa. A variation of 1 Pa (0.001% variation) equates to about 90 dB.

Perhaps the non-linearities begin to matter at the diaphragm face of a very high output compression driver. But I can't imagine a direct radiator driver producing an SPL high enough for this to be a concern.
  Reply With Quote
Old 20th September 2020, 02:55 PM   #227
hifijim is offline hifijim  United States
diyAudio Member
 
hifijim's Avatar
 
Join Date: Sep 2019
Location: St Louis, MO
To further my point: A pressure variation of 0.1% (i.e. 101 Pa) would equate to an SPL of 130 dB. There is just no way that volumetric non-linearity is of any significance when the pressure is oscillating around 0.1%.

A 0.1% pressure oscillation will produce a 0.1% volume oscillation, for any practical or measurable purposes.

I refreshed my memory with this useful web page - - Sound Intensity and Sound Level | Physics
  Reply With Quote
Old 20th September 2020, 03:23 PM   #228
puppet is offline puppet  United States
diyAudio Member
 
Join Date: Dec 2011
Location: The Dells, WI
What can I do against 'box sound' ?
Quote:
Originally Posted by andy19191 View Post
A good question and I think the answer lies with the role played by scientific/engineering knowledge in how one reasons and goes about the hobby. Most posters on the forum don't possess the considerable amount of background technical knowledge that a competent trained engineer would use to reason about how to design speakers. When someone posts how to go about something using reasoning based on fundamental engineering knowledge it will carry significant weight for an engineer that possesses this knowledge but it won't for those without. They will have to check and test the likely truth in other less efficient ways and against other competing ideas that may lack a scientific basis but may be closer to what seems to be true among peers.

My experience has been that most don't welcome scientific/engineering reasoning when it conflicts with what they want from the hobby. It is hard to see much wrong with this if it enables one to have fun and achieve success on what one might perhaps think of as audiophile terms rather than scientific ones. It is a hobby after all and not an engineering job with success being measured by pleasure performing DIY and interacting with peers.
One of the smartest observations I've seen posted here.
  Reply With Quote
Old 20th September 2020, 04:13 PM   #229
chris661 is online now chris661  United Kingdom
diyAudio Member
 
chris661's Avatar
 
Join Date: Feb 2008
Location: Sheffield
Quote:
Originally Posted by hifijim View Post
To further my point: A pressure variation of 0.1% (i.e. 101 Pa) would equate to an SPL of 130 dB. There is just no way that volumetric non-linearity is of any significance when the pressure is oscillating around 0.1%.
While true for most speakers, consider what's going on with a compression driver or inside a small sealed subwoofer.

Chris
__________________
Bits of information and other things I've worked on: https://www.grimshawaudio.com/lab
  Reply With Quote
Old 20th September 2020, 04:14 PM   #230
oldspkrguy is offline oldspkrguy  United States
diyAudio Member
 
Join Date: Dec 2019
As I have shared many times; I am a retired Engineer and Technician and former musician all. I understand the math and science; I also trust my own ears. Sometimes; the minor yet significant differences to me are likely to NOT be measurable to anyone with just home based equipment or technology. The human brain is an amazing thing; can't be outdone by technology IMO when it comes to music and audio (for what it is I'm after anyway). And so it goes; on and on...
  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 11:45 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