Small horn in 1955 - 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 19th August 2006, 11:24 PM   #1
Jaime is offline Jaime  Uruguay
diyAudio Member
 
Jaime's Avatar
 
Join Date: Apr 2004
Location: Montevideo
Default Small horn in 1955

The grandfathers of the Fostex small horns in 1955.
And an nice amplifier with triodes also (6SL7, 6SN7, 6BX7, 6X5)

......The construction principles that are explained here are those that are used in expensive cabinets of loudspeakers of great size. Although this same design applied to enclosures of small loudspeakers improvement extraordinarily these systems, the certain thing is that until now it seems to be ignored completely.....

http://www.mimecanicapopular.com/vernota.php?n=615

Mecanica Popular is the Spanish version of Popular Mechanics
__________________
I write in English worse than Tarzan
  Reply With Quote
Old 20th August 2006, 01:48 AM   #2
diyAudio Member
 
Join Date: Apr 2004
Location: Costa Rica
Send a message via AIM to johninCR Send a message via MSN to johninCR Send a message via Yahoo to johninCR
Jaime,

As far as the speaker is concerned, it looks more like the grandfather of Bose hype, because it doesn't look like much of a rear horn. The added bass output of the unit may be resonance of those huge voids.
__________________
Everyone has a photographic memory. It's just that most are out of film.
  Reply With Quote
Old 21st August 2006, 02:29 AM   #3
Nanook is offline Nanook  Canada
diyAudio Member
 
Nanook's Avatar
 
Join Date: Feb 2004
Location: Chinook Country.Alberta
Default small horns..

well I translated the isometric drawing to a 2d side view in Autocad. The horn length is approximately 58", So=4.25", Sx =21.85" (or so, I took a little poetic licence). The ratio is 5.1388

Fill the cavities with sand (providing you have a way to ensure they don't topple over). I end up with a 1/4 wave frequency of 58.6Hz for a 58" horn length.

The material is 3/8", so use Baltic birch, finish the interior exactly as the exterior (ie, paint if exterior is to be painted, etc., )

I wonder if there is an English print of these out there:-). I guess somewhat similar to the Frugal Horn, other than Dave has em firing rearward..
__________________
stew -"A sane man in an insane world appears insane."
  Reply With Quote
Old 21st August 2006, 11:34 AM   #4
diyAudio Member
 
Scottmoose's Avatar
 
Join Date: Mar 2005
Location: UK
I'd call that an expanding TL rather than a BLH. MathCad predicted response attached, using above dims and the FE83E, which is probably going to be roughly similar to the original driver specs. (And the magnet might just about fit).

I've seen worse, though it'll need damping out, and as it's a straightforward expansion as far as I can see, no filter chamber, with the mouth effectively on-axis to the listener, I suspect you'll run into problems with mids coming out of the vent. Note the classic expanding TL nulls at the odd harmonics.

It might go a touch lower due to the reflectinal boundary condition of the floor nominally doubling the mouth size, but I wouldn't bet on it -Fs of most any driver that'll fit this thing will be well over 100Hz, and you won't want to try pushing them too hard. Nothing to stop you from scaling it up though.
Attached Images
File Type: gif small.gif (6.0 KB, 364 views)
__________________
Community sites www.frugal-horn.com http://frugal-phile.com/
  Reply With Quote
Old 21st August 2006, 05:11 PM   #5
Dumbass is offline Dumbass  British Antarctic Territory
diyAudio Member
 
Join Date: Mar 2003
Location: British Antarctic Territory
I dig old articles like that. Check out the styling record changer and amp de tubos.
  Reply With Quote
Old 21st August 2006, 06:16 PM   #6
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 Dumbass
I dig old articles like that.
Me too. I had a stack of late 40s (and some early40s & early 50s) Radio Craft & Radio magazines. I sold them all on eBay but not before scanning all the articles i found interesting. A treasure trove of info.

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 21st August 2006, 07:35 PM   #7
diyAudio Member
 
Scottmoose's Avatar
 
Join Date: Mar 2005
Location: UK
Likewise. Some creative stuff that's been forgotten, and can be re-used, with a modern twist. The BIB for example. Be interesting to look at multiple tuned pipes described in Voigt's patent at some point too.
__________________
Community sites www.frugal-horn.com http://frugal-phile.com/
  Reply With Quote
Old 21st August 2006, 07:36 PM   #8
chrisb is offline chrisb  Canada
diyAudio Member
 
Join Date: Aug 2002
Location: victoria BC
Default Re: small horns..

Quote:
Originally posted by Nanook
... I guess somewhat similar to the Frugal Horn, other than Dave has em firing rearward..

Having built several pairs of the latter, I'd respectfully suggest : No, I don't think so. I can also attest that Dave's inspiration was of more recent vintage.

  Reply With Quote
Old 21st August 2006, 07:45 PM   #9
Dumbass is offline Dumbass  British Antarctic Territory
diyAudio Member
 
Join Date: Mar 2003
Location: British Antarctic Territory
Quote:
Originally posted by planet10
Me too. I had a stack of late 40s (and some early40s & early 50s) Radio Craft & Radio magazines. I sold them all on eBay but not before scanning all the articles i found interesting. A treasure trove of info.
The engineering library here at UCLA has Audios going back to the magazine's inception (late 1940s?). When I'm bored I sometimes just flip through them in the stacks, as much for the ads as the articles. Great stuff.
  Reply With Quote
Old 21st August 2006, 08:21 PM   #10
Nanook is offline Nanook  Canada
diyAudio Member
 
Nanook's Avatar
 
Join Date: Feb 2004
Location: Chinook Country.Alberta
Default similar to Frugal Horns..

only in basic overall dimensions, and compact design.

Having redrawn the above horn in Autocad and playing with the internal dimensions only,it's easy to see just how inspired Dave was/is with Frugal Horn Project--kudos to dave (and u 2 chris for building em), Ed form the Horn shop, etc.

Dave's line length of 82 1/2" in the super compact Frugal Horn is , what I believe, one of the most efficient packaging of a line of this length in such a small overall envelope possible (If it is possible to make the length larger within the confines of this envelope, I don't see how).

The best I could do with the "1955" was a line length of 83 2/3" without a compression chamber, Sx/So= 5.14. Maybe my terminology is incorrect regarding the 1955 as a horn
__________________
stew -"A sane man in an insane world appears insane."
  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
DAC 1955 paralleled fabiodord Digital Source 9 25th September 2008 11:20 PM
Small-ish BLH horn? trvale Multi-Way 12 15th November 2005 06:04 AM
looking for 6.5inch woofers suitable for a 30 - 35Hz horn... and a small horn too :P SkinnyBoy Multi-Way 24 13th February 2004 06:06 AM


New To Site? Need Help?

All times are GMT. The time now is 05:25 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