Walkabout Scout distorting

BBQV · #1 06-05-2011, 04:45 AM

I've encountered a problem with my Mesa/Boogie Walkabout Scout 1x12". When I turn the master volume about halfway up it's distorting. I don't think it should distort the internal speaker at that level...

It's not the amp, I've tried it with other cabs. I've also tried other amps through the Scout combo and the problem occurs when the volume reaches a certain level. As far as I can tell there's nothing wrong with the speaker, no visible damage and no noise when the cone moves.

How do I find the problem?
Anyone else experienced the same thing?
What's the most likely component to fail? Speaker? Tweeter? Passive radiator?

lomo · #2 06-05-2011, 05:33 AM

The passive radiator is just a port, so I doubt this is a problem. Try turning down the tweeter to see help differentiate tweet from woofer. Remove the speaker and check inside for loose things rattling. Try with grill off to check for rattle. If you can borrow another woofer to try, that'd be great as well. Otherwise, bring it to an expert.

BBQV · #3 06-05-2011, 06:20 AM

Good ideas! Thanks.

A friend said it sounds like the box isn't air-tight. Could that be an issue?

Sorry for all the strange questions. I'm quite good with basses but I'm a total tool when it comes to amps...

lomo · #4 06-05-2011, 06:32 AM

[quote=BBQV;10997331]Good ideas! Thanks.

A friend said it sounds like the box isn't air-tight. Could that be an issue?

QUOTE]

Possibly. If there are unused holes in the jackplate (like for a 1/4" cable), try plugging them.

TomB · #5 06-05-2011, 06:39 AM

Is it a subtle sound? I've heard of the little braided leads (I forget their proper name) that go from the speaker wire connections to the voice coil rubbing against the back of the cone, making a rattling noise. Sounds crazy, but it's common and easy to fix.

BBQV · #6 06-05-2011, 06:49 AM

Thanks guys, I'll look into those things!

RickenBoogie · #7 06-05-2011, 07:11 AM

You know, it just may be that you're pushing the little box beyond it's limit. The 4 ohm 12" Scout cannot handle all 300 watts of the amp, and neither can most any single 12. It's the reason I got rid of my Scout cab- not enough useable volume from it. Depending on how the amp's eq is set, halfway on the gain and volume is about max (or beyond) for the Scout.

BBQV · #8 06-05-2011, 08:59 AM

Hmm... It is pretty loud at 50% so I wouldn't rule it out, but still, halfway up?

Anyone else had this problem with a Walkabout?

lomo · #9 06-05-2011, 09:05 AM

Quote:

Originally Posted by RickenBoogie

You know, it just may be that you're pushing the little box beyond it's limit. The 4 ohm 12" Scout cannot handle all 300 watts of the amp, and neither can most any single 12. It's the reason I got rid of my Scout cab- not enough useable volume from it. Depending on how the amp's eq is set, halfway on the gain and volume is about max (or beyond) for the Scout.

This is spot on. With an average bass with good output, beyond master and gain at noon, you're beyond the 12's useaable limit (in the passive input!). If the other cabs you're testing it with are larger, that test is faulty. No normal off the shelf 12 can handle a full 3oo watts without compression/distortion.

Crabby · #10 06-05-2011, 10:52 AM

I find that RickenBoogie's comments are spot on. My Scout12 starts to fart and complain when taking the master up around noon with the gain at halfway. The Scout cab really impresses if the amp is sitting on a hardwood floor but if its up off the ground or on a carpeted surface, you wont get the same performance. A 112 can only do so much.

The best setup I have tried so far with my Walkabout head is with a pair of Powerhouse 115 cabs. This combo had more volume and authority then even with my 4 ohm PH412!

billfitzmaurice · #11 06-05-2011, 11:14 AM

Quote:

Originally Posted by BBQV

Hmm... It is pretty loud at 50% so I wouldn't rule it out, but still, halfway up?

The position of the volume knob has no relationship to the power being produced. Depending on the gain structure of the amp and the instrument used that could be 200 watts or more, which few twelves are capable of handling without distorting, and certainly not the twelve in this rig.

R Baer · #12 06-05-2011, 02:16 PM

Quote:

Originally Posted by billfitzmaurice

The position of the volume knob has no relationship to the power being produced...

+1 An amp using a log taper pot, it will usually deliver most of its output in the 1/2 to 2/3 of the knobs rotation. A linear pot will deliver very little in the first half of the knobs rotation and get much louder towards the end.

GregC · #13 06-07-2011, 01:43 PM

Quote:

Originally Posted by RickenBoogie

You know, it just may be that you're pushing the little box beyond it's limit. The 4 ohm 12" Scout cannot handle all 300 watts of the amp, and neither can most any single 12. It's the reason I got rid of my Scout cab- not enough useable volume from it. Depending on how the amp's eq is set, halfway on the gain and volume is about max (or beyond) for the Scout.

I'm chiming in late here, but Rickenboogie is right on. I love my Scout combo, but like anything else, it has limits. I've also found that noon on the gain and volume knobs is close to the max, and the 4 ohm 12" Scout cab can't take quite that much. If you love the tone at lower volumes, get a second 12" Scout cab to get louder. (Just don't run the amp *too* hard at 2 ohms.)

BBQV · #14 06-07-2011, 02:01 PM

If it's a fact that the cab can't take more than that, maybe I should swap the woofer and get the 8 ohm version instead. I wouldn't have to worry about pushing it too hard and I could add another cab if I need to be louder.

Or I just get a 2x15" or a 4x12" and use the head with that on larger venues.

Crabby · #15 06-07-2011, 04:16 PM

I thought about putting an 8 ohm driver in my Scout and then ordering an 8 ohm extension cab but its an expensive way to go as the Scout cabs are quite pricey new.

lomo · #16 06-07-2011, 05:27 PM

Quote:

Originally Posted by BBQV

If it's a fact that the cab can't take more than that, maybe I should swap the woofer and get the 8 ohm version instead. I wouldn't have to worry about pushing it too hard and I could add another cab if I need to be louder.

Or I just get a 2x15" or a 4x12" and use the head with that on larger venues.

Either is a good option. IME if you want big gig volume from the WA, a much larger cab is the best way to go (the Avatar TB153 works great, but isn't an option for your location), like an efficient 410......a 412 would be positively luxurious

rodl2005 · #17 06-07-2011, 06:02 PM

I've got the 8 ohm 12" WA Scout & even IT will not handle ALL the power the amp will put out. It'll start to over excurse (is that right?? ) or 'fart out' when the volume is pushed.

Up around the 12-1 o'clock mark - even with the 8 ohm. It IS a 1 x 12"!!

Add another 12" & U got a lot more volume on tap or use the amp with a BIG cab & Whooosh!!! Smacks of vintage lovely-ness!

mb94952 · #18 06-07-2011, 06:07 PM

I had the EXACT same issue with mine. I live across the street from Mesa (Lucky, huh !) and I took it to Rich. He put it through the ringer and found nothing wrong with it.

I DID check for rattles, loose grill, etc first.

My solution was to sell the 112 Scout cab and keep the head.

I LOVE the Walkabout and it's been my main head for over two years now. I go through an SWR Goliath 610 and I couldn't be happier. I have tried EVERY amp and cab out there (just about) and besides my SWR Henry 8x8, I think I have the dream set up now...

lomo · #19 06-07-2011, 07:06 PM

Yup, a single 12 is a single 12, unless it's a fEarful, nEarful or TC12 based on a superior 12" driver.

JimmyM · #20 06-07-2011, 11:14 PM

Sure it's not the amp?

Just kidding...