Help me get rid of distortion

[/\/\3phist0]

Good ideas! Never thought putting different sides on the floor.
Maybe try on carpeting to isolate?

Sit it on a couch?

The objective here it to put pressure on a different side panel, to ferret out a possible weak point in the panel joinery, or a "flapping" corner protectors.
In addition, open her up and check the wiring and connection to the cabinet of any subcircuit board such as crossover .
Sometimes the jack panel has a printed circuit board, to which the Jack's themselves are soldered to. This is fastened to the jack plate by one or two screws.
The horn may also be a suspect.

 

[basscooker]

Does it happen on E string E to A? Seems to me if something were rattling in the room it would do it on those notes too.

 

[Iristone]

Half the people here use distortion pedals, the other half want to eliminate it...

I understand though, cab distortion usually sounds unmusical and indicates something wrong.
I suppose maybe there are loose parts inside the cabinet?

 

[bozha]

Lot of ideas here, thanks guys.

So far I can confirm that nothing seems loose or prone to shake and rattle except wiring inside. I'm thinking about placing it into foam tube or something.

But first, I will probably try to take a test with the friquency generator, and than to take out the speaker and check how it will behave alone outside of enclosure, connected to amp and guitar.

One thing you've been mentioning, all my pickups are set high at max. Maybe first to try lowering them...

 

[jj.833]

I think that if it were a rattle, inside or outside the box, it would happen mostly on one certain frequency = tone. If it rattles on E on A string, it should also rattle on E on E string, E on D string, perhaps even on octave higher E on G string, or on partials.
If it rattles on many tones on a string, but doesn't on the same tones on other string, it might quite likely be a pickup problem. If it were a pickup problem, even on headphones (or plugged directly to PC audio card) you should hear it.
If lowering pickups doesn't help, try the same bass and amp with another box. If you use another box of similar quality, you should hear the same distortion if it originates in bass or amp. If you find out it's a problem of the box, I can also imagine this could be a problem of the horn speaker or cross over (I haven't checked if there are any). My old EBS Gorm has a volume knob to take the horn volume up or down. My EBS has a plenty of highs, that's why I think of this. Perhaps yours too, try to turn the horn down or turn it off.

 

[micguy]

Your assumption that you’re within the power ratings of your cabinet means it shouldn’t be power related is something you should question.

Powee ratings are typically related to thermal capacity - many cabinets can be driven to distortion at less than their power ratings by low notes.

 

[Sixgunn]

An often overlooked cause of distortion is a dying battery in an active bass. Definitely worth checking if you're using an active bass.

 

[Rolling Thunder]

It certainly sounds like that, bit like a snare drum when you hit its frequency, but it is definitely coming from the box and it hapends in a couple of different rooms. I will try to record it next time.

I got the same thing one day....a sitar sound. It was a banjo near my cabs.

 

[Loring]

I had a similar problem wit a trace Elliot cab - driver was bad. Likely the coil was out of round - had a scraping sound at all volumes but only certain frequencies. It sounded kind of like distortion but not. Changed the driver for a couple hundred and it sounded like new. I tried everything else first though as should you. Otherwise you’ll spend the money and still have the problem - good luck. Hopefully it’s an air leak!

 

[Loring]

I got the same thing one day....a sitar sound. It was a banjo near my cabs.

i had that too at one time - both suspended ceiling and a metal art piece minted to the wall

 

[OogieWaWa]

Think outside the box! Literally! I had a cab start doing that, a LOUD buzz at a certain note only, and of course anything small buzzing is amplified tremendously, that's the cabinet's job, right?!!!

So I tried "everything". Opened it up, checked all the bracing, unseated and reinstalled the driver, checked all the wires routing, removed/reinstalled the connector/crossover board, tapped all the surfaces, everything I could think of.

Then I put it all back together, sat it down one more time, played, got the buzz going; and just happened to rest my foot on one of the plastic (interlocking type) corner pieces. It stopped!!!!!!! What the heck???

Here I pulled off the corner and found that a tiny piece of the plywood had split down along the grain on one of the edges, with the split ending at where one of the screws went into the wood; probably from bumping the corner, leaving a short 1/4 inch by 1/2 inch "reed" hanging off of the edge that would sympathetically buzz at just one frequency! There was just enough room between the rest of the wood and the corner piece to let it get going maybe 1/16" or so. That was it! That little thing buzzing was getting blown way louder than you could imagine. Glued the sucker down and haven't heard a squawk out of it since!!!

 

[basscooker]

OP I was thinking that a teeny bit of coil rub could be the issue, but you said youd had it reconed. Have you checked for rub?

 

[Loring]

OP I was thinking that a teeny bit of coil rub could be the issue, but you said youd had it reconed. Have you checked for rub?

That’s what mine was. Even at low volume sounds kinda like dist.

most expensive fix though...

 

[bumperbass]

Sit it on a couch?

Maybe SIT on each side?

 

[6thplanet]

I'm just thinking isolated from the floor. Turning it on each side is a good suggestion. Sit on it is also worth trying.

 

[bozha]

Half the people here use distortion pedals, the other half want to eliminate it...

(please accept this lousy joke until i get in chance to continue testing at right volume outside my quiet neighbourhood)