Future woofer production - Page 10 - diyAudio
Go Back   Home > Forums > Commercial Sector > Manufacturers > Markaudio

Markaudio Designers and builders of audiophile grade drivers

Reply
 
Thread Tools Search this Thread
Old 17th January 2013, 09:48 AM   #91
diyAudio Member
 
markaudio's Avatar
 
Join Date: Nov 2008
OK Folks,
Thinking of woofs, (mid-bass units) we should continue to address the issue of power handling. Sadly as the industry as a whole has no universally agreed standard on this issue, I'm happy to throw the whole thing open and ask for comment. This issue can be a hot-potatoe so please expect and respect wide variations of opinion.

I've received allot of requests to talk more about how actually cones work in relation to issues of power and its application. I'll do what I can so here goes. Possibly a way is to talk about the issue of simple and complex emittance in the LF band and how it relates to issues of compliance and power-handling in driver power-trains. I'll try to keep this brief and to the point as its a challenging design issue.

Please take a look at the first graph "simple wave form". For design/mechanical engineers like me, we love this form of output. Its regular, linear and therefore easy to design an emitting power-train for this primary oscillatory form. However, its not representative of most sounds we could readily identify, especially anything recognisably musical. The second graph, "complex wave form" better illustrates the more typical output that a driver's power train will need to emit. Its more complex, likely requiring the driver's power-train to mechanically move back un forth (oscillate) and also statically resonate. These more complex form better represent typical musical output. Nearly all drivers to be effective, need to emit both mechanical oscillation and resonant output simultaneously. Looking at the "drum- 2 seconds" graph, it helps illustrate this requirement while the "combined output" graph help to show how various wave forms combine.

Possibly an interesting way to think about emittance, is that to be representative of sounds that are familiar to us, e.g a jazz double-bass, while it plays low (LF), within the oscillatory component, there will be a set of smaller micro-resonant components that are included in its output. This is important as we can think of a set of sounds forming a particular recognisable sound signature. Its a prime method by which humans can distinguish between one sound signature and another e.g between a double-bass and bass guitar. While both instruments might operate in a similar LF region, most listeners can easily distinguish between the 2 due to their near unique signatures.

For a driver neigh cone designer, its hell of a challenge. On one hand, the bigger wave forms are LF, some requiring strength and rigidity for reliable oscillation, the other hand, the mid and high band forms have very little energy within them, requiring the minimum mass possible to reduce losses across the cone's substrate surface. Something of a design "catch 22". Do we design/build more for oscillation (power) and sacrifice detail, or do we err towards musical definition (original High-Fidelity) and give up some of the LF?

I'll talk more about driver design and relative application in the next post. For now, at least I hope this post gives a flavour of the competing challenges from the technical/design and production perspective.

Cheers
Mark.
Attached Images
File Type: jpg simple-wave.jpg (11.2 KB, 257 views)
File Type: jpg complex-wave.jpg (13.3 KB, 253 views)
File Type: jpg drum-2sec.jpg (11.9 KB, 242 views)
File Type: jpg combined-output.jpg (29.7 KB, 683 views)

Last edited by markaudio; 17th January 2013 at 10:38 AM.
  Reply With Quote
Old 17th January 2013, 02:25 PM   #92
wron is offline wron  Canada
diyAudio Member
 
wron's Avatar
 
Join Date: Nov 2004
Location: canada
Wink Both please...

Quote:
Originally Posted by markaudio View Post
OK Folks,

For a driver neigh cone designer, its hell of a challenge. On one hand, the bigger wave forms are LF, some requiring strength and rigidity for reliable oscillation, the other hand, the mid and high band forms have very little energy within them, requiring the minimum mass possible to reduce losses across the cone's substrate surface. Something of a design "catch 22". Do we design/build more for oscillation (power) and sacrifice detail, or do we err towards musical definition (original High-Fidelity) and give up some of the LF?

Cheers
Mark.
Of course, as a speaker builder I want both and not being a fan of subwoofers, this means that some sort of compromise is required. I suppose that varying the thickness of the cone might play some role, i.e. thinner near the centre of the cone for superior high frequencies and thicker near the surround to prevent cone flex at lower frequencies. Perhaps Mark can enlighten us more on his thinking regarding cone construction and the trade offs involved. For myself, I'd prefer a design that erred on the side mid-range performance, though a high impedance design (above 7 ohm Re) might facilitate 2 1/2 type designs which would help increase bass headroom.
  Reply With Quote
Old 17th January 2013, 09:42 PM   #93
TiMBoZ is offline TiMBoZ  Australia
diyAudio Member
 
Join Date: Aug 2012
Location: Sydney
Thanks for the info/lesson Mark. Thanks also to Dave Planet 10 for the Downwards Dynamic Range idea/info in previous post. It's all very educational/very interesting. I can't really respond to this constructively until we had an outcome, a definition of driver/outcome in mind. Just to clarify: Are you interested 'polling' us; taking votes as to what type of driver/category the driver should be? Sub-woofer, woofer, mid/bass? Or what characteristics/specifications we/I would want to see in an MA 'mid/woofer' for use with a tweeter?
  Reply With Quote
Old 17th January 2013, 09:58 PM   #94
TiMBoZ is offline TiMBoZ  Australia
diyAudio Member
 
Join Date: Aug 2012
Location: Sydney
Quote:
OK Folks, Thinking of woofs, (mid-bass units)
Ooops, sorry folks - there it is! MID BASS UNITS
  Reply With Quote
Old 17th January 2013, 10:48 PM   #95
diyAudio Member
 
Join Date: Jan 2008
Quote:
Originally Posted by planet10 View Post
Flat FR is all and good,but it is the surface of the body of water. A really good loudspeaker also has a wide transmission bandwidth orthogonally, going down (ie deep into the water using that analogy) -- termed DDR (downward dynamic range) and described in poetic fashion with many terms.

I have yet to see anyone measure DDR but the ear/brain can quickly zoom in on it. How flat is the response way down there? Lots more unanswered questions.

dave
I can't measure it, and can't get description of how to reproduce the conditions so that I may learn how to quickly zoom in on it. Can you help me with this, or do I need to buy a specific speaker to get my mind around DDR. I google this and find nothing relevant.
  Reply With Quote
Old 17th January 2013, 11:03 PM   #96
frugal-phile(tm)
diyAudio Moderator
 
planet10's Avatar
 
Join Date: Oct 2001
Location: Victoria, BC, NA, Sol III
Blog Entries: 5
The ability to objectively measure DDR in anything is still a major research task. And then it needs to be correlated to what the ear/brain perceives (for which there is already far too little for existing test regimes).

At this point the nly tool we have is a well-trained listener, paying attention to the right parts of the musical stream (and a good musical stream) -- just like jitter, ear/brains discovered the issue, and it took many years/decades to make tools to measure it.

For loudspeakers the 1st requirement would be a very good anechic chamber. I have a feeling that if one looks for existing kit, this might be useful, Microflown

And one would need to have good facility to extract data & present it in graphically useful way.

In terms of trying to search out information, look for Allen Wright (RIP, an incredible loss to the audio community). His pre-amp cookbook is a good read and has some good background.

http://www.vacuumstate.com/index.dna...251.4445726420

dave
__________________
community sites t-linespeakers.org, frugal-horn.com, frugal-phile.com ........ commercial site planet10-HiFi
p10-hifi forum here at diyA
  Reply With Quote
Old 17th January 2013, 11:38 PM   #97
TiMBoZ is offline TiMBoZ  Australia
diyAudio Member
 
Join Date: Aug 2012
Location: Sydney
I'm can't really describe or define DDR either. Maybe it has something to do with 'Q' stuff? I think that it may be a more technical term for what non technical listeners (I) might refer to as 'slam, shove, drive, authority, command' A sense of power and control to the sound. Say if sound has 4 dimensions; frequency is like height and width, then there's time, dynamics are like depth. the deep water? Not soundstage. I mean all sound has to have amplitude. So dynamics is control of variations in amplitude of any given set of frequencies. This is how I'm trying to understand it. But control of variations in amplitude is not just a function of a speaker; the amp plays a major role in this also; damping factor, output impedance characteristics etc. Sorry if this is a bit broad of topic or whistle 'ethereal'
Some of it relates to Sd, cone material, but you can hear that voice coils/driver motors all have their 'flavours' as well. One driver will present the sound of a saxophone, drums and bass really well, while another presents the sound of a voice, flute, clarinet really well. Neither driver can ever quite match each other at both. That's why we have multi way. I think DDR may have something to do with drivers that are really good at sax, drums, bass. The 'oscillation' side of things. But I am just speculating.
  Reply With Quote
Old 17th January 2013, 11:58 PM   #98
frugal-phile(tm)
diyAudio Moderator
 
planet10's Avatar
 
Join Date: Oct 2001
Location: Victoria, BC, NA, Sol III
Blog Entries: 5
Quote:
Originally Posted by TiMBoZ View Post
I'
a more technical term for what non technical listeners (I) might refer to as 'slam, shove, drive, authority, command' A sense of power and control to the sound.
Wrong axis. A technical term that blankets more nebulous terms like detail, nuance, finesse, noise floor (even thou that last is a technical term, it has a different connotation. It most definitely has an impact on imaging. For instance, given source material with it, i use the ability of an EnABLed driver (because of greater DDR) to throw a more robust & 3D images to be able to pick them out when challenged to a blind test. Something with good DDR is capable of transmitting this low level information even in the face of a much louder signal... as Mark explains more & more what he means by micro-resonance, the more i think that AW's DDR & Mark's microresonance are closely related. Mark's attention to this is lilely a large contributing factor to how well Mark's drivers are at throwing an image.

dave
__________________
community sites t-linespeakers.org, frugal-horn.com, frugal-phile.com ........ commercial site planet10-HiFi
p10-hifi forum here at diyA
  Reply With Quote
Old 18th January 2013, 12:00 AM   #99
diyAudio Member
 
buzzforb's Avatar
 
Join Date: Oct 2010
Location: Burlington, NC
Quote:
Originally Posted by planet10 View Post
Something with good DDR is capable of transmitting this low level information even in the face of a much louder signal...
dave
You could argue that this is the very thing that sets good amps apart from great amps, speakers notwithstanding.
__________________
...Shape the sound , Man!
  Reply With Quote
Old 18th January 2013, 12:13 AM   #100
frugal-phile(tm)
diyAudio Moderator
 
planet10's Avatar
 
Join Date: Oct 2001
Location: Victoria, BC, NA, Sol III
Blog Entries: 5
Quote:
Originally Posted by buzzforb View Post
You could argue that this is the very thing that sets good amps apart from great amps, speakers notwithstanding.
As it was originally couched to me, long before i had the term DDR to attach to it, "the difference between good hifi and great hifi is what is happening 40 dB down".

It is applicable to all kit, and limited by the bit with the least DDR.

dave
__________________
community sites t-linespeakers.org, frugal-horn.com, frugal-phile.com ........ commercial site planet10-HiFi
p10-hifi forum here at diyA
  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
Woofer-Fullrange-Woofer vs Tweeter-Midrange-Woofer fakeout Multi-Way 5 11th August 2012 07:17 PM
VAM1202 out of production ? ashok Chip Amps 5 12th January 2010 09:01 PM
Tubes currently in production Nevod Tubes / Valves 4 3rd August 2008 11:47 AM
Best production EL34? Pyre Tubes / Valves 39 26th December 2007 01:32 AM
Is piezosource in production yet? Mikael Abdellah Planars & Exotics 0 7th January 2007 07:58 PM


New To Site? Need Help?

All times are GMT. The time now is 11:47 AM.


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