Head keeps rolling off my cab?

creis2 · #1 01-28-2013, 12:36 PM

I never had this problem before until I started using this specific cab.

It's a custom LDS 410 with duratex finish. I have my heavy SVT tube head on top. Tried with my Ashdown ABM head, same thing.

When I play most notes, it doesn't move. When I play C#‎, even at low volumes, the head starts floating off the cab.

Does anyone think there's maybe an issue with the cab?

I tried doing this without the casters on, put the cab on thick carpet, tried a friend's gamma pad. Nothing seems to help.

It not a slight movement, that happens over a set. As soon as I hit that one note, it looks like the head turns into a hovercraft and starts to fly right off.

I-play-bass · #2 01-28-2013, 12:40 PM

I kinda want to see this on video, while it sounds terrifying, it also sounds awesome.

wcriley · #3 01-28-2013, 12:41 PM

The cab seems to have a resonance at that frequency.
Maybe some additional bracing inside the cab would help?

creis2 · #4 01-28-2013, 12:43 PM

Quote:

Originally Posted by wcriley

The cab seems to have a resonance at that frequency.
Maybe some additional bracing inside the cab would help?

I had Don build the cab with 1/2 ply, so there is a ton of bracing inside.

BassmanPaul · #5 01-28-2013, 12:45 PM

We GTA bass players have something in common. I too would love to see an SVT floating above a speaker cabinet!!!

Aside from that I would have to say that if sounds like the cabinet could do with more bracing. Don at LDS knows his stuff so I would talk to him about the problem.

creis2 · #6 01-28-2013, 12:47 PM

Quote:

Originally Posted by BassmanPaul

We GTA bass players have something in common. I too would love to see an SVT floating above a speaker cabinet!!!

Aside from that I would have to say that if sounds like the cabinet could do with more bracing. Don at LDS knows his stuff so I would talk to him about the problem.

Yeah, I've blasted this cab before with no odd noises coming out of it. So I don't think it's bracing.

**CL400Peavey** · #7 01-28-2013, 12:48 PM

Quote:

Originally Posted by wcriley

The cab seems to have a resonance at that frequency.
Maybe some additional bracing inside the cab would help?

Quote:

Originally Posted by creis2

I had Don build the cab with 1/2 ply, so there is a ton of bracing inside.

Have you opened it up and seen what kind of bracing is on the top? There might be something to add that could stop the vibration.

Lazarus.Bird · #8 01-28-2013, 12:50 PM

Yeah, sounds like you're definitely running into a resonant frequency issue. My Dually shakes my Orange Terror Bass around, but it is only 15 lbs. An SVT should definitely not be moving around!

creis2 · #9 01-28-2013, 12:52 PM

Quote:

Originally Posted by Lazarus.Bird

Yeah, sounds like you're definitely running into a resonant frequency issue. My Dually shakes my Orange Terror Bass around, but it is only 15 lbs. An SVT should definitely not be moving around!

Well the SVT doesn't move as violently as the Ashdown, but the head is a tank.

The Ashdown (which isn't a feather at all), glides like butter.

ev rodriguez · #10 01-28-2013, 12:56 PM

Dude how loud are you playing that it vibrates an svt head off of the cab? Are al of the pets in nearby establishments catching fire too?

bassgod0dmw · #11 01-28-2013, 12:56 PM

That's some serious stuff if it's moving an 80lb head! In for video too

lokikallas · #12 01-28-2013, 01:01 PM

Get a slice of dynamat to put under the head.

creis2 · #13 01-28-2013, 01:01 PM

Quote:

Originally Posted by ev rodriguez

Dude how loud are you playing that it vibrates an svt head off of the cab? Are al of the pets in nearby establishments catching fire too?

Not loud at all. It was happening at practice with my band, that doesn't play loud at all.

I'll try to take a video.

enjoi1018 · #14 01-28-2013, 01:06 PM

Soft adhesive rubber feet. I have some on the bottom of my power supply, amp, EQ, and small speakers... even on the bottom of this computer.

They're so sticky that I kinda have to pull up on the above objects to release friction to pic it up. If your amp's still moving after that, you've got an angry cab

skychief · #15 01-28-2013, 01:06 PM

Quote:

Originally Posted by creis2

...

It not a slight movement, that happens over a set. As soon as I hit that one note, it looks like the head turns into a hovercraft and starts to fly right off.

This I gotta see!

creis2 · #16 01-28-2013, 01:10 PM

Quote:

Originally Posted by skychief

This I gotta see!

I'm def going to post. Since I don;t have any practices or gigs, I have to find time to do it from home. Didn't think this was that unusual.

bassgod0dmw · #17 01-28-2013, 01:21 PM

Quote:

Originally Posted by creis2

Didn't think this was that unusual.

An SVT bouncing around on top of a cab? I'd say that it is!

lowphatbass · #18 01-28-2013, 02:35 PM

Get the type of liner that's designed for the inside of tool boxes, it's pretty grippy and gives a little cushion as well. I'd give this try.

hover · #19 01-28-2013, 02:42 PM

A properly braced cab should not display this behavior (granted, only so much you can do with that thin material, but a tensionned t-b brace should be in the equation somewhere, imo)...the box should not be that "live". That said, expect when all sorted out, that the cab will sound a bit different in the end for it. How thick is the baffle?

Also, that amount of vibration is doing none of your heads any favors (including the one on your shoulders), so you need to address this soon.
Also, is the Duratex glossy? That might be part of the issue.

I too really want to see video. But only with a spotter for the head...

**Chef** · #20 01-28-2013, 02:55 PM

This is -exactly- right.
Call Don, pronto.
He would want to know about this, and correct it.

[quote=BassmanPaul

Aside from that I would have to say that if sounds like the cabinet could do with more bracing. Don at LDS knows his stuff so I would talk to him about the problem.[/QUOTE]