golden ratio. I dont get it
 User Name Stay logged in? Password
 Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read Search

 Multi-Way Conventional loudspeakers with crossovers

 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
 4th December 2012, 03:58 AM #1 murphythecat8   Account disabled at member's request   Join Date: Mar 2011 Location: Somewhere in Quebec golden ratio. I dont get it hi my dimension for my bass (30 to 300hz) enclosure requirement is that the box is no more then 38cm wide and 82 heigt. I want to have around 110 liter. I dont know I to make the golden ratio, can anyone help thanks
 4th December 2012, 04:10 AM #2 planet10   frugal-phile(tm) diyAudio Moderator     Join Date: Oct 2001 Location: Victoria, BC, NA, Sol III 38 x 61.5 x 99.5 is golden ratio. If 18 mm ply, gross volume would be 191 litres, If we start with 110 litre add 5 litre for bracing and back of driver then: 115 litre = 115,000 cm^3. Take the cube root = 48.6 48.6 x 1.618 = 78.7 48.6 / 1.618 = 30 So interior dimensions of 30 x 48.6 x 78.7 cm dave __________________ community sites t-linespeakers.org, frugal-horn.com, frugal-phile.com ........ commercial site planet10-HiFi p10-hifi forum here at diyA
 4th December 2012, 11:27 AM #3 speaker dave   diyAudio Member     Join Date: Nov 2009 Location: The Mountain, Framingham I don't get it either. The golden ratio was originally for visually pleasing proportions. Put proper absorption in the cabinet (fiberglass) and don't worry about the dimension ratios. David
DeonC
diyAudio Member

Join Date: May 2002
Location: Kimberley, South-Africa
Quote:
 Originally Posted by planet10 38 x 61.5 x 99.5 is golden ratio. If 18 mm ply, gross volume would be 191 litres, If we start with 110 litre add 5 litre for bracing and back of driver then: 115 litre = 115,000 cm^3. Take the cube root = 48.6 48.6 x 1.618 = 78.7 48.6 / 1.618 = 30 So interior dimensions of 30 x 48.6 x 78.7 cm dave
Thanks, Dave. I did not start this thread, but find the info very useful. That method is so simple I wish I had thought about it.

Deon
__________________
I don't suffer from insanity. I enjoy every minute of it.

 4th December 2012, 11:35 AM #5 Mark.Clappers   diyAudio Member     Join Date: Jan 2010 Location: The Netherlands, near the German border The golden ratio spreads the internal standing waves in the frequency domain (ie they don't overlap, both the base and the harmonics). This is useful for mid-range but not so much for bass as the wavelengths involved are usually much larger then the enclosure size. __________________ Music is art - Audio is psychoacoustics & engineering
balerit
diyAudio Member

Join Date: Apr 2011
Location: South Africa
Quote:
 Originally Posted by speaker dave I don't get it either. The golden ratio was originally for visually pleasing proportions. Put proper absorption in the cabinet (fiberglass) and don't worry about the dimension ratios. David
I agree, it's for looks only, just another myth. I use Square root of 2 to propertion my bass reflex boxes. Also remember when you calculate a boxes volume it is the ideal volume and therefor everything that goes inside the box takes away from this ideal volume and you have to compensate for this by making the box larger, my free software does this for you.

Sample - The Book Worm

puppet
diyAudio Member

Join Date: Dec 2011
Location: The Dells, WI
Quote:
 Originally Posted by speaker dave I don't get it either. The golden ratio was originally for visually pleasing proportions. Put proper absorption in the cabinet (fiberglass) and don't worry about the dimension ratios. David
I've wondered about this, too. If you're just modeling a flat baffle for diffraction purposes (say for an OB), seems like the "golden ratio" doesn't produce an optimal response in sim. Might be fine to start there though.

 4th December 2012, 03:21 PM #8 speakerdoctor   R.I.P.   Join Date: Sep 2006 Location: New England When it comes to room acoustics, use of the GR to position speakers can be helpful. __________________ "It's all about the music!"
awkwardbydesign
diyAudio Member

Join Date: Dec 2005
Location: Plymouth
Quote:
 Originally Posted by speaker dave I don't get it either. The golden ratio was originally for visually pleasing proportions. Put proper absorption in the cabinet (fiberglass) and don't worry about the dimension ratios. David
Wasn't it for concert halls? Unlike Victorian structures, such as the Albert Hall.

 4th December 2012, 06:23 PM #10 mondogenerator   diyAudio Member     Join Date: Sep 2009 Location: City Of Villans I always thought it was observed in ancient egyptian design, adopted by the greeks, and used visually to proportion windows, paintings etc. Ive never tested if it really works in acoustics. My favourite adaptation of GL is to halve the longest length, calculating for twice the volume. Its a nice way to get a more cube-like shape. Of course standing waves would be more bunched up, but i never heard a problem. GL is better than guesswork, or breaking the 'rules' i.e. W equally a third H for example. __________________ Balancing the things I must do, with the things I'd like to do...This is a skill (or a luxury) amongst many that I do not possess.

 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 Rules
 Forum Jump User Control Panel Private Messages Subscriptions Who's Online Search Forums Forums Home Site     Site Announcements     Forum Problems Amplifiers     Solid State     Pass Labs     Tubes / Valves     Chip Amps     Class D     Power Supplies     Headphone Systems Source & Line     Analogue Source     Analog Line Level     Digital Source     Digital Line Level     PC Based Loudspeakers     Multi-Way     Full Range     Subwoofers     Planars & Exotics Live Sound     PA Systems     Instruments and Amps Design & Build     Parts     Equipment & Tools     Construction Tips     Software Tools General Interest     Car Audio     diyAudio.com Articles     Music     Everything Else Member Areas     Introductions     The Lounge     Clubs & Events     In Memoriam The Moving Image Commercial Sector     Swap Meet     Group Buys     The diyAudio Store     Vendor Forums         Vendor's Bazaar         Sonic Craft         Apex Jr         Audio Sector         Acoustic Fun         Chipamp         DIY HiFi Supply         Elekit         Elektor         Mains Cables R Us         Parts Connexion         Planet 10 hifi         Quanghao Audio Design         Siliconray Online Electronics Store         Tubelab     Manufacturers         AKSA         Audio Poutine         Musicaltech         Aussie Amplifiers         CSS         exaDevices         Feastrex         GedLee         Head 'n' HiFi - Walter         Heatsink USA         miniDSP         SITO Audio         Twin Audio         Twisted Pear         Wild Burro Audio

 Similar Threads Thread Thread Starter Forum Replies Last Post PrecisionAudio Multi-Way 43 11th October 2012 04:15 PM Stee Solid State 7 22nd February 2009 09:46 PM edjosh23 Full Range 13 3rd February 2009 10:52 PM Ornlu Subwoofers 5 27th May 2005 07:52 AM icebear Multi-Way 5 17th April 2004 09:40 PM

 New To Site? Need Help?

All times are GMT. The time now is 11:54 PM.