Walkabout Scout - blown speaker - main or the radiator?

[mrpackerguy]

I've got bad buzzing coming from my Walkabout Scout from the third fret on the A string on down.

How do I tell if it's the main or the radiator speaker that's blown?

[Interceptor]

Snarky answer - whichever one costs more.

Try a stethescope. Or a the tube from a roll of paper towel.

I really would be shocked if it was the passive.

[Chef]

Pull the front grill off.
Press on the main speaker's cone, out by the edges, and gently push it thru it's motion.
It should move freely and smoothly.
If it feels all gritty and such, that's bad news.

I doubt it's the radiator.

[Chef]

Another thing to check is to make sure the back panel that holds the head in is secure.
Sometimes the foam strip under there sacks out, and lets that panel vibrate a tad.

[greenboy]

It's not always a driver though, even when it happens only in a certain range. I had one corner on a cab that was rattling when I played certain notes. Fixed with a little hot glue. Grills can be that way too. Solution: another standoff or two in the right places, if tightening down fully hasn't solved the problem.

[mrpackerguy]

OK, thanks guys for the advice.

[rekesbass]

the radiator is not actually a speaker...so it can't be the radiator

[mrpackerguy]

Originally Posted by Chef

Pull the front grill off.
Press on the main speaker's cone, out by the edges, and gently push it thru it's motion.
It should move freely and smoothly.

Alright, did that and removed the head. Actually removed the speaker too and looked inside. (I actually learned what I thought was a 4ohm Walkabout is an 8ohm from the stamp on one of the metal boxes inside the cab)

Still buzzing, but I'd more describe it like a subtle fuzz pedal on notes starting at the "C" on the "A" string on down. At full volume is't not really noticeable (maybe that's why the Mesa repair center at Guzzardo's Music in Rockford said "Unit plays perectly" = fail).

So I'm still at a loss, but I'm thinking if I send it to Mesa for repair, they could possibly add the player network, fix the speaker and maybe even convert it to 4ohm for me.

[Chef]

So moving the speaker by hand does not feel gritty?
Have you tried the head thru another speaker?

[Alex1984]

Originally Posted by mrpackerguy

Alright, did that and removed the head. Actually removed the speaker too and looked inside. (I actually learned what I thought was a 4ohm Walkabout is an 8ohm from the stamp on one of the metal boxes inside the cab)

Still buzzing, but I'd more describe it like a subtle fuzz pedal on notes starting at the "C" on the "A" string on down. At full volume is't not really noticeable (maybe that's why the Mesa repair center at Guzzardo's Music in Rockford said "Unit plays perectly" = fail).

So I'm still at a loss, but I'm thinking if I send it to Mesa for repair, they could possibly add the player network, fix the speaker and maybe even convert it to 4ohm for me.

If you wanted all these things done at the same time, I think they'd probably just sell you a replacement cab. Are there any things in the room that might be vibrating? Does the vibration happen at all volume levels?

[mrpackerguy]

Originally Posted by Chef

So moving the speaker by hand does not feel gritty?
Have you tried the head thru another speaker?

Nope, no grittiness. Did not try the head through another speaker, but did plug in the Mpulse600 and got the same fuzz. WIll stry the Walkabout head into my 1212BMF tonight. I should try my F500 into the Walkabout cab, just to make sure I don't have some loose or bad tubes.

[mrpackerguy]

Originally Posted by Alex1984

If you wanted all these things done at the same time, I think they'd probably just sell you a replacement cab. Are there any things in the room that might be vibrating? Does the vibration happen at all volume levels?

Possibly, there is a lot of metal duct work. But getting down on the floor right next to the speaker, I'm sure it's coming from the speaker. And, no, only happens at moderate to loud volumes. The higher the volume, the worse and the louder the fuzz.

[rkingly]

I recently replaced a blown 4ohm WA speaker, the sound you describe is the sound mine was making. Replaced & everything was AOK.
The same day another WA cab purchased here on TB sounded strange & I couldn't believe I had another blown Cab.
Opened her up & 1 of the passive radiator screws had come loose, that and a piece of a packing peanut was trapped in the main speaker giving a rattle sound. After addressing issues, problem solved.

[Strat-Mangler]

I tried a WA Scout a week ago with a Jazz bass (passive) and it was farty with the volume dial on 4. It was the 1x12 model I was testing.

That alone was enough to convince me to not consider it. The tone was OK, but if it's already farty at 4 with a passive bass, I can't imagine the speaker taking more abuse. And let's not even talk about an active bass.

Good luck!

[greenboy]

Unless the input pregain section is deficient, there should be no difference between using a passive bass or using an active bass.

[Chef]

On older ones, there are active and passive inputs.
on newer ones, there's a selector switch.

i've never had to use the active pad with an active bass on any of my 3 walkabouts.

Strat, I don't know how you had the eq set, but that doesn't sound like a normal walkabout experience.

[pfschim]

Originally Posted by rekesbass

the radiator is not actually a speaker...so it can't be the radiator

well, its not an active driver, but it does have a cone, and it does move in concert with the active driver, so that part could conceivably get blown out if the cab was way over driven.

[sunbeast]

Originally Posted by Chef

On older ones, there are active and passive inputs.
on newer ones, there's a selector switch.

i've never had to use the active pad with an active bass on any of my 3 walkabouts.

Strat, I don't know how you had the eq set, but that doesn't sound like a normal walkabout experience.

+1. I've only experienced that if I boosted the lows through the 112. But there's no way a single 12" speaker can handle that much low end signal without bottoming out (and with the voicing of the Walkabout Scout I usually have the Bass turned down to about 25% anyway!)- especially with the 4 ohm cab, where you have the potential to be putting 300 watts into a speaker that probably can only handle 100-150 watts of full-range signal without hitting its limits.

Also- the Gain/Volume level you see on the knobs is pretty arbitrary, as it depends on all sorts of different variables like input volume, pot taper, internal gain structure, etcetera. Mesa amps tend to max out on clean Volume around halfway on the knob if you have the Gain around 12 oclock with a decent input signal, though that can vary widely based on your EQ. If it is farty at "4" on the volume, I would guess either the EQ or Gain were boosted pretty significantly (the combo can sound farty if the mid knob and gain are both cranked).

[rekesbass]

Originally Posted by pfschim

well, its not an active driver, but it does have a cone, and it does move in concert with the active driver, so that part could conceivably get blown out if the cab was way over driven.

the radiator is a big port with a cone..the cone is moved by the air inside the cab produced by the real speaker...you would have to move a ton of air to "blow" it...not sayin it cant happen but,its highly unlikely..

[mrpackerguy]

Well, thanks to all the suggestions. All of them were tried. I called Mesa & they gave me a couple other things to check including the tubes.

Looks like I'll be ordering a new speaker.