Cab vibrations & movement...

[BurningSkies]

You can take the stuffing out of an old ply filled bed pillow if money is an issue. You can buy new poly filled pillows for a few dollars. If they fit, don't even take them out of the cotton cover. Keep it neat.

Again, you don't want 'fill' you want quilt batting material. Rather than buying pillows, you can get rolls of the stuff for about 5 bucks. then a can of spray glue and a pair of scissors later, you're all set.

 

[NKBassman]

1/2x1 strips won't do diddly.

Just to make sure we are on the same page, I'm talking 1/2" thick, 1" tall, cut to length, and glued on edge so that they sit tall off each wall panel. Like the "girdle", "pillar", and "spine" braces on a fearful.

Money is an issue.

 

[zachoff]

Would something like this work for a rear loading cab for bracing (blue would be 3/4" dowels)? I know it's probably not "optimal" but would it make a difference? I just don't want to lock the speakers in bracing jail, ya know?

 

[NKBassman]

1.5" would be enough to notice a difference, but plan on lining the cab rather than stuffing. Stuffing tends to work for sealed cabs, not ported cabs. And on the bracing, some kind is better than no kind right? Take a look a the plans on the 15/6 or 1515/66 to see the way it works in the fEARfuls and work a scheme for your cab.

Thanks BurningSkies! Didnt see your post before.

I'm actually going to be working on a 15/6 this weekend. Hopefully once I have that under my belt I'll be able to come up with a better idea of what to do with my Emperor.

And yes, I meant lining, as opposed to stuffing.

 

[will33]

Would something like this work for a rear loading cab for bracing (blue would be 3/4" dowels)? I know it's probably not "optimal" but would it make a difference? I just don't want to lock the speakers in bracing jail, ya know?

Not good enough, the braces need to tie together opposite walls. Lock them in jail and leave an escape route or make a grillcloth frame so it attaches from the front and front load the drivers. That's what you should do because that cab will always have leaks with the grillcloth wrapped around the baffle like it is now.

 

[rpsands]

1/2 ply in 2-3" wide strips have worked well for me--a la the fEarful model.

Similarly, 3/4" dowels have worked very well.

Emperor cabs are just pathetic. I'd rather buy vintage fender cabs and retrofit them with modern drivers. Just as crappy and quite a bit lighter and cheaper.

 

[will33]

Yeah, you can build ribcages onto the inside walls, I've done a few like that and they're solid. It is more work and isn't better than the dowels but it will leave the middle of the cab open.

 

[billfitzmaurice]

Just to make sure we are on the same page, I'm talking 1/2" thick, 1" tall, cut to length, and glued on edge so that they sit tall off each wall panel. Like the "girdle", "pillar", and "spine" braces on a fearful.

Same page. They'd have little effect. Cross bracing would be at least four times as effective and would cost not a penny more. Spine braces need to be at least 1/2" x 4" to work as well.

 

[NKBassman]

Same page. They'd have little effect. Cross bracing would be at least four times as effective and would cost not a penny more. Spine braces need to be at least 1/2" x 4" to work as well.

Thumbs up for one of the most helpful people on talkbass.
That's exactly what I needed to know. Thanks a bunch.

 

[jmlee]

We've been looking at the same issues here as in another thread where my Ampeg SVT-15E speaker is vibrating like crazy. Opened up, there's no cross-bracing at all, although there are cardboard port ducts and a good battening of the interior (see pictures). I'm going to do some of Bill's dowel cross-bracing later this month. Stay tuned for results.

 

[billfitzmaurice]

We've been looking at the same issues here as in another thread where my Ampeg SVT-15E speaker is vibrating like crazy. Opened up, there's no cross-bracing at all

They should rename that cab the Beancounter Special.

 

[MikeBass]

No matter how much bracing you do, it will vibrate.
I don't design cabs, I actually go out and gig with them, so use my opinion to balance what the brain trust tells you.
I've owned (and own) cabs by some of the best our industry has to offer.
With plastic corners that are in contact with a tile of other slick floor/stage. You cab will move a bit. If it's walking a few feet....well, I don't know what to tell ya other than turn the hell down!
But they vibrate. Period.
Seen it happen with all kinds/types.
Never had it be bad enough to vibrate my amp off, but I can't tell you how many times my tuner has dumped off the top of my cab. And a drink or 4 as well. I could totally see how it would happen with a non carpet covered cab.
And I'm sure the guys a BagEnd, Jim Bergantino and Nick Epifani know a thing or two about designing a decient cab- and my tuner and or other trinkets have tried to commit suicide off those cabs more than a few times.

 

[masonsjax]

Same page. They'd have little effect. Cross bracing would be at least four times as effective and would cost not a penny more. Spine braces need to be at least 1/2" x 4" to work as well.

So, are you saying the bracing used in fEARful cabs is not effective?

 

[billfitzmaurice]

So, are you saying the bracing used in fEARful cabs is not effective?

Not as effective as panel to panel. I used to use spine bracing on my Omni series, with the last revision changed it to panel to panel, there's no question that panel to panel is better.