Sound Quality Vs. Measurements - Page 1014 - diyAudio
Go Back   Home > Forums > Member Areas > The Lounge

The Lounge A place to talk about almost anything but politics and religion.

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 29th July 2013, 08:26 PM   #10131
diyAudio Member
 
Join Date: Mar 2007
Location: Oxfordshire
Click the image to open in full size.

For Dvv . The late Jim Bongiorno's 1985 circuit for bridged bridge . If I understand L to R bridge is also a further possibility . My bass amp would be a simplified version along these lines using MJ11015/16 . It might work on strip board if kept simple .
  Reply With Quote
Old 29th July 2013, 11:13 PM   #10132
fas42 is online now fas42  Australia
diyAudio Member
 
fas42's Avatar
 
Join Date: Jun 2012
Location: NSW, Australia
Blog Entries: 11
Quote:
Originally Posted by nigel pearson View Post
Click the image to open in full size.
I don't like the lack of anything minimising back and forth rocking. Personally, I would extend the concrete base far enough to the rear so that 2 rigid members could form truss shapes with the centres of each driver being at an apex. This means that the vibrational energy of the drivers is transferred to and dissipated in the floor.
__________________
Frank the truth is, I just like a bit of ASMR ...
  Reply With Quote
Old 30th July 2013, 06:00 AM   #10133
dvv is offline dvv  Serbia
diyAudio Member
 
Join Date: Sep 2004
Location: Belgrade, Serbia
Quote:
Originally Posted by nigel pearson View Post
Click the image to open in full size.

For Dvv . The late Jim Bongiorno's 1985 circuit for bridged bridge . If I understand L to R bridge is also a further possibility . My bass amp would be a simplified version along these lines using MJ11015/16 . It might work on strip board if kept simple .
Never saw this before, Nige, so I'll have to think about it a bit. It does look interesting.

And, as you of all peole know, I had and have much respect for the grumpy James, as I have come to know him only via corresnpondence, most unfortunately, I never had the chance of meeting him in person. I am in his debt insofar that over the 10 years or so that we exchanged occasional messages, mostly my question for him, he never once failed to answer in full, on time and most accurately. A true Grand Master.
__________________
Per Aspera Ad Astra.
  Reply With Quote
Old 30th July 2013, 08:17 AM   #10134
diyAudio Member
 
Join Date: Mar 2007
Location: Oxfordshire
Click the image to open in full size.

This would kill two birds with one stone . It makes bracing it easier and offers front support . If an attractive hoop was made the diffraction should be minimal . The next step is to make it more practical . The advantage I see is if two supports they could be adjustable . For initial tests even cardboard will be giving an idea for the baffle . A front support also if you like . The bolts could have wood dampers around them ( or whatever ) . Concrete slab from the builders merchant . Slate when perfected perhaps ?

Dvv . The amp is said to date to 1974 if the industrial Crown M600. I have doubts about that . The one shown is GAS , wish I had the biasing . If I build it I will do an Op amp fudge and use 3 diodes ( approximately 2.1 V bias when 2.4 is required ) . At LF I see no reason to give it proper biasing . As I have a bunch of given to me TO3 Darlingtons I will risk strip board layout . I have a blown up / disgusting PA amp as the PSU and fan and box . I hope to run it without fan most of the time . I will do as I have before and configure the amp as an active filter . I might capacitor couple it . Crude first order subsonic filter and DC protection in one .

One thing is possible here . The true magic of the high end ( goose bumps ) using ideas so crude as to say don't do it . All rules should be challenged . Look at Soviet weapons . No one told them it couldn't work . I wouldn't risk thinking they don't . A piece of leather as the return device in a machine gun running at high speed ! Lets list some of mine . Under biased class B using feedback to correct ( 180 Hz bandwidth ) . 12 inch speaker as mid range . No box . > 12 dB EQ . Nothing above 8 kHz ( at first ) . Paper cones . 8 watt valve amp with big input pentode and UL pentode . Capacitor coupled . BTW , the lowest grade capacitors out measure most valve output transformers . High grade caps are very cheap and do protect speakers . Put multiple 220 uF 35 V non polars in your kids speakers . Celestion did ( 500 uF only !!!! Qts was matched ) . These will work without any modifications . 8 = enough for 100 watts ( 0.4 x 8 = 3.2 A ) .

http://www.rapidonline.com/Electroni...acitor-11-3078


One thing I can do with the valve amp is to EQ the mid via the cathode capacitor . They are necessities of my design . I might get a double free lunch !!! The smaller cap will be nicer . Many say better to filter the signal . Options to try or mixes .

Last edited by nigel pearson; 30th July 2013 at 08:39 AM.
  Reply With Quote
Old 30th July 2013, 09:32 AM   #10135
diyAudio Member
 
PlasticIsGood's Avatar
 
Join Date: Mar 2012
Location: Bradford
The top of the "support", previously labelled "bracket", wasn't a good idea in the first place, and is superfluous now. If the cantilever "support" should be stiff, triangulate to the bottom, as Frank suggested. Attaching speakers front and back to the same support is problematic, too, unless the aim is to stress the basket.
  Reply With Quote
Old 30th July 2013, 12:44 PM   #10136
Pano is online now Pano  United States
diyAudio Moderator
 
Pano's Avatar
 
Join Date: Oct 2004
Location: Milliways
Blog Entries: 4
Jamo does a rear support on their OB, but it doesn't touch the drivers
Click the image to open in full size.
  Reply With Quote
Old 30th July 2013, 02:46 PM   #10137
diyAudio Member
 
PlasticIsGood's Avatar
 
Join Date: Mar 2012
Location: Bradford
Interesting. Is the baffle intended to be a sounding board, or rigid? Curvy triangulation reminds me of a bike frame...slightly springy. Top support is much stiffer than in Nigel's original floppy parallelogram. Looks quite musical, rather like a harp.
  Reply With Quote
Old 30th July 2013, 05:07 PM   #10138
bcarso is offline bcarso  United States
diyAudio Member
 
Join Date: May 2005
Location: Canoga Park, California
Default DNA speaker

DNA Sequence Speakers dipole open baffle woofer high efficiency point source array midrange tweeter treble loudspeaker

Here's Don's approach. By the way, I didn't authorize the adjectives about me, although it helped a maths friend in locating me. On the site, the products for headphone listening are entirely his own development.
  Reply With Quote
Old 30th July 2013, 05:09 PM   #10139
diyAudio Member
 
Join Date: Mar 2007
Location: Oxfordshire
News from my travels . Matthew Farly known as Fatmarley at DIY has measured my units and the 12LTa 's I got from him . I am lucky he lives 37 miles from me .
Very big thanks Matt . Love your speakers .

Eminence Beta 12 LTA
Click the image to open in full size.
As said before this is probably it at best UK price ? .
BETA 12LT - EMINENCE - EMINENCE BETA-12LT 12" 225W TWIN | CPC

QTC 15 " 95 dB /W 902.539
Click the image to open in full size.
MW 15" Replacement Driver 902.539 - Music Warehouse
  Reply With Quote
Old 30th July 2013, 05:38 PM   #10140
diyAudio Member
 
Join Date: Aug 2003
Location: Cheltenham
Quote:
Originally Posted by nigel pearson View Post
Very big thanks Matt .
No problem. Always happy to help a fellow diyer




Quote:
Originally Posted by nigel pearson View Post
Love your speakers .
They're not bad - Lets hope my next design is even better.


I'll be watching this thread with interest...
  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
Quality Control differences = variations in sound quality? KT Class D 3 4th June 2014 12:02 AM
Sound Card for Measurements Marik Solid State 2 2nd January 2012 08:59 PM
Sound Card Recommendations (For Audio Measurements) dchisholm Equipment & Tools 5 16th July 2011 09:40 AM
How to protect sound card during amp measurements? okapi Everything Else 13 2nd September 2008 03:06 PM
Sound cards - test and measurements jackinnj Everything Else 2 5th July 2003 03:02 PM


New To Site? Need Help?

All times are GMT. The time now is 10:44 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