Closed back 15" cabs with JBLs for bass?

Re: Closed back 15" cabs with JBLs for bass?

Postby moonliner » Tue Jan 14, 2014 2:15 pm

I'm interested as well.....
moonliner
tiger
tiger
 
Posts: 23
Joined: Mon Oct 01, 2012 1:24 pm

Re: Closed back 15" cabs with JBLs for bass?

Postby Rusty the Scoob » Wed Jan 15, 2014 8:14 am

zambiland wrote:
Rusty the Scoob wrote:Count me in as curious, I'd be very interested in a sealed-back cab designed around something like a Weber Neomag 15" with the ribbed cone and aluminum dome, even if it never turned out as practical for stage use as my current cabs. I just don't really have the motivation to do the carpentry or especially the design myself.



It would be interesting to try it out with construction techniques such as those used in the fEARful designs, where they used carefully braced 1/2" plywood, resulting in a very lightweight cabinet.


Yeah, 3/4" would be weigh a ton. I'd even consider doing unbraced 1/2" as an experiment in tone, since I doubt I'd be moving it as much as my more conventional cabs.
User avatar
Rusty the Scoob
Senior Member
 
Posts: 2296
Joined: Mon Mar 03, 2008 5:28 am
Location: Concord, MA

Re: Closed back 15" cabs with JBLs for bass?

Postby ugly rumor » Wed Jan 15, 2014 5:58 pm

The problem with unbraced 1/2' bass cabinets is the resonance of the cabinet. bracing keeps the resonance to a minimum, letting the sound of the speaker be uncolored. 1/2" MDF would work unbraced, but then you have a heavy and unstable cabinet.
Gone are the days we stopped to decide where we should go, we just ride...
ugly rumor
Bobby
Bobby
 
Posts: 369
Joined: Thu Aug 13, 2009 6:33 am
Location: Virginia

Re: Closed back 15" cabs with JBLs for bass?

Postby zambiland » Wed Jan 15, 2014 6:05 pm

ugly rumor wrote:The problem with unbraced 1/2' bass cabinets is the resonance of the cabinet. bracing keeps the resonance to a minimum, letting the sound of the speaker be uncolored. 1/2" MDF would work unbraced, but then you have a heavy and unstable cabinet.


One interesting method of bracing is to use cross pieces in the middle of each panel, i.e., side to side, up and down and front to back, which force each wall to its maximum excursion, instead of a bracing system that just tries to keep them from moving.
zambiland
Senior Member
 
Posts: 526
Joined: Fri Nov 24, 2006 12:13 pm
Location: Boulder CO

Re: Closed back 15" cabs with JBLs for bass?

Postby ugly rumor » Wed Jan 15, 2014 11:15 pm

Anything that stiffens the walls. The purpose of bracing is not strength, but removing the tendency of the cabinet to carry sound waves in an organized manner. I might be a little suspicious of bracing that forces too much pressure on the sides, as I would feel that eventually it would fail at the points of pressure. I could be very wrong, but I wouldn't build one that way. I would almost think that that might create its own resonance problem.
Gone are the days we stopped to decide where we should go, we just ride...
ugly rumor
Bobby
Bobby
 
Posts: 369
Joined: Thu Aug 13, 2009 6:33 am
Location: Virginia

Re: Closed back 15" cabs with JBLs for bass?

Postby Rusty the Scoob » Thu Jan 16, 2014 7:07 am

I could see that type of bracing acting like the soundpost on an upright bass and causing resonance due to the tension. But I'm far from an expert!
User avatar
Rusty the Scoob
Senior Member
 
Posts: 2296
Joined: Mon Mar 03, 2008 5:28 am
Location: Concord, MA

Re: Closed back 15" cabs with JBLs for bass?

Postby zambiland » Thu Jan 16, 2014 12:04 pm

Rusty the Scoob wrote:I could see that type of bracing acting like the soundpost on an upright bass and causing resonance due to the tension. But I'm far from an expert!


I guess that's a potential, but I haven't heard any of the Acme cabinets have any problems like that.
zambiland
Senior Member
 
Posts: 526
Joined: Fri Nov 24, 2006 12:13 pm
Location: Boulder CO

Re: Closed back 15" cabs with JBLs for bass?

Postby ugly rumor » Thu Jan 16, 2014 5:35 pm

That's because Andy is a professional, and I am a jackleg!
Gone are the days we stopped to decide where we should go, we just ride...
ugly rumor
Bobby
Bobby
 
Posts: 369
Joined: Thu Aug 13, 2009 6:33 am
Location: Virginia

Re: Closed back 15" cabs with JBLs for bass?

Postby Rusty the Scoob » Fri Jan 17, 2014 8:06 am

zambiland wrote:
Rusty the Scoob wrote:I could see that type of bracing acting like the soundpost on an upright bass and causing resonance due to the tension. But I'm far from an expert!


I guess that's a potential, but I haven't heard any of the Acme cabinets have any problems like that.


That's how Acmes are built? Then I'm sold. I used to drool over those in college, with a Walter Woods head. Never owned either one.
User avatar
Rusty the Scoob
Senior Member
 
Posts: 2296
Joined: Mon Mar 03, 2008 5:28 am
Location: Concord, MA

Previous

Return to Cabinets

Who is online

Users browsing this forum: No registered users and 0 guests