Bracing More Important than Thickness?

[Cardboardcat15]

Originally the title of this thread had "stiffness" instead of "bracing", but, you know.

 

So here's something that I've been mulling around in my head the past few weeks, but I can't seem to find a definitive answer to. Maybe someone more knowledgeable than me can chime in.

 

Is wall stiffness more important than wall thickness when building a box? In other words, when we build enclosures for larger sized sub stages, are the multi-layered walls adding to some type of acoustic characteristic aside from stiffness, or is it just solely for the purpose of stiffness? Obviously a box needs to be as stiff as possible to detract from panel flex which ultimately leads to colored sound/loss of output/damaged equipment, but is wall thickness improving another acoustic area of enclosure performance?

 

TL;DR: Here's a scenario to help clarify what I'm talking about: 

Let's say, hypothetically, a user wanted a set up with something like 4 hefty 18's in a flat wall. Could they, given proper bracing that eliminates all panel flex, build an entirely single layered enclosure? Would this enclosure be as acoustically sound as a counterpart with the same stiffness, but thicker walls in lieu of bracing? 

 

Let's hear what you guys have to say. I'm in not a box builder in any way, and this question has been bugging me for a while now.

[slowfkncar]

You might be surprised how different two identical enclosures can sound from one another regardless of having the same air space & port area.

Baffle thickness > bracing , its good to have both though.

[Cardboardcat15]

16 minutes ago, slowfkncar said:

You might be surprised how different two identical enclosures can sound from one another regardless of having the same air space & port area.

Baffle thickness > bracing , its good to have both though.

That's another point. Barring it being a functional part of the port, does baffle thickness serve a purpose other than stiffening the mounting surface? Normally, from what I've seen in my 8+years of being on here and going to shows, it seems like baffle thickness (again, when it's not a functioning part of the port) is usually built thicker to supplement rigidity and stiffness for mounting very heavy woofers. I've seen baskets come apart and split due to baffle flex in conjuction with a 70lb motor mounted on a vertical surface. So again, if one could adequately brace a box, baffle included, to reduce panel flex to nothing, would the super thick baffles be necessary?

 

My intuition tells me that thickness is important to some degree of the acoustic integrity of the box BUT that's a completely unfounded thought; I don't have an engineering/acoustics/physics background to base it off of.

 

Does anyone here know of someone who's tried building a box with single layers but more bracing?

[Skullz]

Depends on how you want the box to sound.

I personally prefer to dampen the box with a layer of dacron batting inside on all the walls, this will give a deeper and richer sound to the sub sound. The reason you want to either brace or dampen a box are the same though, they will prevent the box from ringing. Ringing is where the box makes more noise than the sub and adds an off sound to it that is disturbing to say the least.

[Kyblack76]

Thickness on the baffle, for me is needed. You ever try and hang 6 18s, that weight 130lbs a go, on a single anything? ya, fuck that.  Also, in ALL our testing, bracing brought our score DOWN. Took all of our vertical bracing out.  Just what we saw.

 

 

Good thing the back baffle is 18" thick, with a 9" loading wall, 5 sheets on the sides, with metal, same on roof and floor. 

[Cardboardcat15]

10 hours ago, Skullz said:

Depends on how you want the box to sound.

I personally prefer to dampen the box with a layer of dacron batting inside on all the walls, this will give a deeper and richer sound to the sub sound. The reason you want to either brace or dampen a box are the same though, they will prevent the box from ringing. Ringing is where the box makes more noise than the sub and adds an off sound to it that is disturbing to say the least.

Interesting. This makes me think that maybe resonant frequency of the panels of the box could also have something to do with this.. If the panels are thin, wouldn't that technically have a higher res. freq. and cause some nasty sounds?

 

3 hours ago, Kyblack76 said:

Thickness on the baffle, for me is needed. You ever try and hang 6 18s, that weight 130lbs a go, on a single anything? ya, fuck that.  Also, in ALL our testing, bracing brought our score DOWN. Took all of our vertical bracing out.  Just what we saw.

 

 

Good thing the back baffle is 18" thick, with a 9" loading wall, 5 sheets on the sides, with metal, same on roof and floor. 

That's really odd. Only the vertical bracing removal saw an increase in scores. I wonder if that could possibly do with air flow within the box. Was it a flat wall? Or was it an internally baffled box like a 4th/6th?

[Triticum Agricolam]

12 hours ago, Cardboardcat15 said:

Does anyone here know of someone who's tried building a box with single layers but more bracing?

For the boxes I build, I much prefer bracing over adding layers, but bracing has to be well thought out and implemented to be effective.  Adding layers requires much less mental effort.  

The reason I prefer bracing is it takes up less space, uses less material, adds less weight and often results in a stronger/stiffer box than just adding layers will.  With that being said, having a sufficiently thick baffle to support the weight of the subs being used is important, as others have described.  I pretty much alway use a double baffle, and will add additional support to the baffle if I think it is warranted.  

Here is an example of a large, relatively high-powered enclosure I did that was single layer except for the baffle: https://www.facebook.com/pg/triticumaudio/photos/?tab=album&album_id=884735451572941

If I were to build that box again, I'd probably do the bracing a little differently, but you get the idea.  

[Karkov]

Both.

 

^^ JEEBUS I like that box Mr.Farmer

[DiBo]

I knew I shouldn't have posted pictures of my box... Triticum don't be playing fair! 

[Triticum Agricolam]

2 hours ago, DiBo said:

I knew I shouldn't have posted pictures of my box... Triticum don't be playing fair! 

I saw your pics and I thought you did a great job!