8" Hall of Fame - Page 3 - diyAudio
Go Back   Home > Forums > Loudspeakers > Full Range

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 13th November 2013, 11:37 PM   #21
diyAudio Member
 
Join Date: Apr 2010
How loud a given driver can go is a function of its diameter, its Xmax (physical) and its power handling (thermal) limits. At lower frequencies, it is generally the physical constraint is binding. I am using a subwoofer and want to be able to cross at a relatively low frequency, so the displacement-limited output of the FR unit becomes a critical design element. That is why I asked about 8" drivers. Perhaps I should have made the criterion more explicit, like "100 dB @ 100 hz" - I hadn't thought it through to that level of detail when I posed the question.

Last edited by Doppler9000; 13th November 2013 at 11:49 PM.
  Reply With Quote
Old 14th November 2013, 12:23 AM   #22
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 Doppler9000 View Post
How loud a given driver can go is a function of its diameter, its Xmax (physical) and its power handling (thermal) limits.
Given that there are NO standards for measuring or specifying power handling, not something you can use to directly compare different makes of drivers.

And to mean anything you would also need to factor in the (real) efficiency of the driver

How loud do you intend on playing?

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 14th November 2013, 12:29 AM   #23
diyAudio Member
 
Join Date: Apr 2010
Can you explain how efficiency affects the displacement-limited output? (Are you talking about room gain?) Are you saying that Sd and Xmax specifications are fudged so much that we can't use them to evaluate a driver?

I would like to be able to go to the 102 - 105 dB range.

John

Last edited by Doppler9000; 14th November 2013 at 12:34 AM.
  Reply With Quote
Old 14th November 2013, 12:39 AM   #24
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 Doppler9000 View Post
Can you explain how efficiency affects the displacement-limited output?
John,

It is needed to know how loud things are at the power limit.

ie without the efficiency you are observing a number which is meaningless (AFAIS) in the context of sitting down and listening.

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 14th November 2013, 12:46 AM   #25
diyAudio Member
 
Join Date: Apr 2010
Dave,

Efficiency, other than room gain, has no effect on displacement-limited output - it just tells you how much power it takes to get there, as I understand it.

John
  Reply With Quote
Old 14th November 2013, 12:54 AM   #26
frugal-phile(tm)
diyAudio Moderator
 
planet10's Avatar
 
Join Date: Oct 2001
Location: Victoria, BC, NA, Sol III
Blog Entries: 5
If you don't know how loud it is, what meaning does it give you?

The context of this is that my A12.2p play pretty loud (in my large room)

A12.2p not really designed for a sealed box, is what you are really saying is that in a sealed box it doesn't go low enuff?

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 14th November 2013, 12:56 AM   #27
diyAudio Member
 
LineSource's Avatar
 
Join Date: Sep 2003
Location: SiliconValley
I am happy with my Tang Band W8-1808. It started as a sealed HDTV speaker, and is now in a 4cuft MLTL with a good bedroom relaxing sound.

WinISD
Tang Band W8-1808 in sealed box.
Woofer Peavey 560600 LoRider 18 in ported box.
Each is ~$210.
Attached Images
File Type: jpg TB1808Peavey18.JPG (303.0 KB, 313 views)
  Reply With Quote
Old 14th November 2013, 12:58 AM   #28
diyAudio Member
 
vinylkid58's Avatar
 
Join Date: May 2005
Location: Victoria, B.C.
Quote:
Originally Posted by Doppler9000 View Post
I would like to be able to go to the 102 - 105 dB range.
Peaks of 105 dB are not a problem for a pair of 12p's in vented boxes (Planet_10 MarKenT's). This was at approx. 2.5m listening position, with an 18W/Ch amp, and no signs of distress from either, just my ears.

FWIW, in an 8L closed box, WinISD predicts an SPL of 105dB @100Hz (106dB @ 120Hz) with an input of 25 watts, and a cone excursion of 4.67mm @93Hz. This is with a parametric EQ of 3dB centered @100Hz.

Max. input for the 12p is 30W, with a max. cone excursion of 5.4mm, as per MA.

jeff
  Reply With Quote
Old 14th November 2013, 01:06 AM   #29
diyAudio Member
 
Join Date: Apr 2010
Quote:
Originally Posted by planet10 View Post
If you don't know how loud it is, what meaning does it give you?

The context of this is that my A12.2p play pretty loud (in my large room)

A12.2p not really designed for a sealed box, is what you are really saying is that in a sealed box it doesn't go low enuff?

dave
The displacement-limited output is (can be) calculated in dB SPL - it is an objective measure of loudness.

John
  Reply With Quote
Old 14th November 2013, 01:10 AM   #30
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 Doppler9000 View Post
The displacement-limited output is (can be) calculated in dB SPL - it is an objective measure of loudness.
Can you point me to the math?

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
Any Hall Effect gurus out there? peace brainerd Everything Else 39 7th April 2013 10:26 AM
best speakers for hall ia9 PA Systems 8 29th June 2012 06:05 PM
fikham hall cookie monster Everything Else 0 30th July 2010 04:34 PM
Sad News about Don Moses of Wadia Fame Zero Cool Digital Source 0 29th November 2008 11:10 PM
Music Hall CD25 help. robertwstephens Digital Source 1 29th April 2007 04:23 AM


New To Site? Need Help?

All times are GMT. The time now is 02:08 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