Cab vibration vs amp electronics

[Cage]

Just have your old lady ( or your date) sit on top of your cab and hold the amp. .
That way , she gets ready for the show after the show and your amp stays safe

And plus all that vibration you might get lucky lol

 

[Cazman]

Thanks for the discussion y’all. This was only a passing thought that ran through my head and in my almost 40 years of playing through multiple rigs, I can’t say I’ve had a failure that I can specifically attribute to cab vibration (but maybe?). Never have I experienced what I would deem premature failure. I just assumed that after a long period of usage, something wore out and it was time to move into something else.
Some terrific input here on the subject....for my own peace of mind though, a isolating pad of some sort will find its way under my amp going forward.
Cheerios!

 

[TubeDood]

Good point, there are so many inexpensive (and good too) testing tools available these days assuming you understand the principles behind the measurements.

My old engineering partner who retired about 5 years ago was a senior engineering technician for one of the big testing labs that did the vibrational analysis on several of the Apollo landing craft. They had a large test chamber with enough mechanical energy available to shred sheet aluminum. They used shaped acoustic energy to simulate the rockets at launch as well as the buffeting by the atmosphere. They also were able to test for the reentry forces including the effects of deceleration. I learned a lot about such mechanics and respect the potential for damage very well.

That makes sense , since vibrational energy is strong enough to lift objects.
I bet that guys brain was fun to pick.

 

[BogeyBass]

Equipment in bouncing trailers is always fun. Good idea to put heads and mixers in the tow vehicle.

Even more fun as a drummer on short little tours. Trailer will rattle every head to some unbelievable weird tuning. Sometimes loose. Sometimes tight.
It never makes sense

 

[Jesuguru]

If anybody wants to test vibration of their cab there are sensitive seismograph apps on IOS and android.

They can log and plot results. Put it on the cab, in front of the cab, on the head, ... and it will measure the shake. I have seen scientific use of this and it can be a solid field test comparable to lab equipment from years back.

Keep in mind that IOS devices like iPhones/iPad and any Adriod device are chocked full of surface mount devices and can handle the shaking.

Good tip, I wonder if it would be worth compiling a public table of results so owners could post their various brand/model cab vibrations. It may or may not be of value, not so much in measuring potential damage to amps on top, but the quality of bracing which is one factor affecting quality of tone.

 

[bucephylus]

Good tip, I wonder if it would be worth compiling a public table of results so owners could post their various brand/model cab vibrations. It may or may not be of value, not so much in measuring potential damage to amps on top, but the quality of bracing which is one factor affecting quality of tone.

Unfortunately, the real situation is a little too complicated to allow what you are suggesting. The vibration amplitude on the cabinet top surfaces has strong variation, depending on position and on factors like internal bracing, porting, and other construction details. In my measurements, I always tried to locate the sensor, an accelerometer, in the position of maximum vibration; and then I fastened it in place while changing any variables I wanted to look at. But, trying to compare cabinets that way would be unreliable, due to the complex distribution profiles.

 

[Giffro]

Thanks for the discussion y’all. This was only a passing thought that ran through my head and in my almost 40 years of playing through multiple rigs, I can’t say I’ve had a failure that I can specifically attribute to cab vibration (but maybe?). Never have I experienced what I would deem premature failure. I just assumed that after a long period of usage, something wore out and it was time to move into something else.
Some terrific input here on the subject....for my own peace of mind though, a isolating pad of some sort will find its way under my amp going forward.
Cheerios!

I ran my Peavey MKIV head on top of my 1820 Peavey cab for 30 years without an issue but as we all know Peavey gear is indestructable anyway and if it fell out the trailer you could still gig with it that night loll
EDIT: It still works well enough to blow ya pants leg bottoms into the crowd.

 

[Bill Whitehurst]

I think a lot has to do with the cab and the head.
Some cabinets will vibrate more.
Some amps will have components that can vibrate and might be damaged over time.

I can say, for a fact, that Fender, or other tube amps with the tubes hanging down
from the chassis do need tube clamps of some sort to keep them from working their way out.
Dropping a 6L6 mid set sucks!

If in any doubt, you can pad the amp on top of the cabinet or
there is no law that it even has to be on top of it.
The Fender PS400 comes to mind.
If you want to have the option of changing anything on the amp quickly,
you can use a long speaker cord and a keyboard stand to have it closer to you as you play.
That will isolate it pretty well.