Golden Box Ratio - Important or not?

Ornlu

Member
2005-05-20 11:06 pm
MA
How much will the "golden box ratio" change the sound of a sub as opposed to a standard cube with good internal bracing. The concept behind the golden box ratio is to reduce equi-distant walls to reduce resonance/standing wave frequency. But does this really play a role in subwoofer design?

I'd much rather do a cube as I could have much better internal bracing and the option of having it down firing at the same time.


Also, down firing vs front firing? Is the only benefit of down firing that you don't see the drivers. And is there any accoustical downfall of down firing subwoofers?

Thanks
 

Vikash

diyAudio Moderator Emeritus
2003-05-17 9:08 pm
UK
www.vikash.info
Ornlu said:
The concept behind the golden box ratio is to reduce equi-distant walls to reduce resonance/standing wave frequency. But does this really play a role in subwoofer design?
No.


Ornlu said:

Also, down firing vs front firing? Is the only benefit of down firing that you don't see the drivers. And is there any accoustical downfall of down firing subwoofers?
Aesthetics is main reason. Other factors are how low you cross over, how much space is underneath, and if the driver will sag overtime.

You'll find loads of answers to such questions with a quick search;)
 
With a subwoofer the frequency range is usually below 100hz. The wavelength of 100hz is ~11ft which makes a half wavelength ~5.5 feet. As long as no internal dimension enclosure exceeds a half wavelength of the frequencys being reproduced there will be no standing waves. For most sub boxes this is no problem at all. Bracing is most important.

There are many who say that downfiring will gain you ~3db due to boundry loading, but I've never seen any testing or confirmation of that. Downfiring will however cause the cone to sag slightly due to the weight of the cone and gravity pulling it down. Adire has a nice cone sag calculator on their website in the "technical" section under "woofer orientation" which will be able to tell you if a certian speaker is suitable for downfiring or not. Here's a link http://www.adireaudio.com/TechInfo.htm
 

Ornlu

Member
2005-05-20 11:06 pm
MA
Ok, thanks. It didn't seem logical, but every subwoofer box designer I tried suggested this "golden ratio" which seemed like a bad idea because it'd need more bracing than a cube, would need more materials than a cube, and would take up more space than a cube...

Sorry about the question mark?