vibrating marshall combo

[mpdd]

need some advice, have a marshall 5522 ibs 200 watt combo with a new 4 0hm black widow 1x15 speaker that vibrates really noticably when i play around the 5th frets on the D and G strings using my new fender highway one precision bass when i turn the amp to about 2 and i turn the bass all the way up

(the front of the amp is missing one of the 4 large screws that attaches the head inside the cabinet)

here are the things i tried so far that didn't work:

1. i took the head out and tightened every screw i could
2. i took the back of of the cab off
3. i tie wrapped the gold metal bracket that doesn't have a screw to the
black metal so it wouldn't vibrate
4. used about a thousand different eq settings
5. used my blue tube 903 with the output turned all of the way up and the drive turned all of the way down

[JimB52]

I have a 5520 that vibrates on the low F, F# and G. I think it's the handles making the noise.

[beans-on-toast]

Sometimes these sort of problems are difficult to track down. I would try removing the amp from the cabinet and play the notes that cause the vibrations. This will allow you to determine if the problem is within the cabinet or the amp. If you hear no buzzing from the cabinet, they you have eliminated the possibility of a loose speaker, handle, panel or the cabinet itself. It is still possible that the weight of the amp is warping the cabinet and this is resulting in a buzz. The chances of this are slim though.

If the cabinet is ok, look for something rattling on the amp such as a transformer, loose circuit board, etc.

More than likely, it is caused by the missing chassis screw.

The last thing to check out is anything that might be vibrating near the amp. Move the amp to a different room and see if it still vibrates.

[Din Of Win]

I get strange vibrations on some of my amps/cabs as well.

One of the most universal reasons for it has been the room i was playing in. I'm no physics whiz, but if i move to a larger room, about 90% of the time the vibrating stops.

Try playing in another room.

[LesS]

"(the front of the amp is missing one of the 4 large screws that attaches the head inside the cabinet)"

Are you going to replace the missing screw?

If the amp chassis is rattling, putting something rubber between the amp and the cabinet might help.

I would try putting rubber (or something else than could dampen) under the feet or casters.

Also when it is making the vibration, try to see if you can stop it with your hand - to try to identify the source.

Re-glue all internal braces and joints. I had a cabinet once that rattled because one of the internal supports was loose.

If it does not have much internal bracing, add a front to rear brace. You could use screws to attach the rear part of the brace to the cabinet back.

Remove the speaker and check for anything in front of the cone that could be rattling. Also sometimes the wires from the terminals to the voice coil can rattle.

Also if you didn't do this already, tighten the speaker mounting bolts.

[carlos840]

I would say replace the missing screw and mainly WHY would you turn the bass all the way up?????

Im sure most amps would start to vibrate and sound like crap with the bass all the way up!!!!

[mpdd]

thanks for the input everybody, next week i am getting the replacement mounting screw from vst in pasadena, california
but in the meantime here is what i did to improve things

shoved latice wood or foam board/cardboard in all of the gaps between the head and the cab, removed plastic handles, put weather stripping around the edge of the back panel of the cab

and just to clarify i turned my precision all of the way up not the amp bass volume or low frequency settings

when i used to play in punk bands in kent, ohio i played an early gibson grabber through a sunn 2000s with a marshal 1x15, so i was hoping i could get a similiar sound with my new gear (loud, vintage, warm)
fender highway one pbass, marshall 5522, blue tube 903