Risk of blowing out a combo amp?

oniman7 · #1 01-15-2011, 06:46 PM

I've got an Acoustic B200 combo amp. It's 200 watts and has a 15 inch speaker. I use it for full band practices (to keep up with drums and very loud guitarists) but at the last practice I got a little nervous about the volume. We got very loud and I ended up turning up to about 6 volume and slightly higher gain. I'm curious what the risk is of blowing out the speaker or otherwise damaging it at loud volumes. I'm sure it's always at some slight risk, but when does it become a concern?

Also, if it matters, I have an active bass, but I use the active input.

martyman5000 · #2 01-15-2011, 06:51 PM

You and the drummer play together and then ask the guitarist to set his volume to suit. You should find a nice volume and tone and then bring the guitarist in, learn to accompany each other not a battle of volumes.

oniman7 · #3 01-15-2011, 06:53 PM

Sounds like a good idea. It wasn't really a battle yet -- we all just wanted it loud.

For future reference, though, I'd still like to know what the risk is for blowing one of these out.

SurferJoe46 · #4 01-15-2011, 08:42 PM

I've pushed my Acoustic B-115 pretty hard and it will tell you when it's in distress.

I don't really care who thinks so or not - the cone in a 15" isn't as compliant as the smaller-less massive cones in 10s or 8s or anything smaller than a 15" cone.

That's where the trouble usually starts - the sheer mass of the 15" cone is putting a lot of stress on the linear motor that drives the cone back and forth.

Some high dollar 15s are better at handling extreme power than others, and that's totally understandable. So far I haven't smoked my 15, but I can see where it can happen if I get crazy and just push it when I should be using multiple 10s instead.

The rule I follow is: lots of volume requires lots of 10-inchers.

oniman7 · #5 01-15-2011, 09:02 PM

That's good to know. I'm thinking about adding a 4X10 or something later on down the road.

how far have you pushed your B115, and when did you start seeing trouble?

SurferJoe46 · #6 01-15-2011, 09:15 PM

Quote:

Originally Posted by oniman7

That's good to know. I'm thinking about adding a 4X10 or something later on down the road.

how far have you pushed your B115, and when did you start seeing trouble?

Well --- on the B-450 combo with it's 2-10s, I have slightly heard it start to fart. I backed off instantly and pulled it off line and ran my B-410. That was at a little over the '8' position on the output (VOL) and about 50% Gain.

On a B-600H, I would never run it alone - or in combo with a B-410 - or the B-810.

I use the B-115 under my B-450 in those quieter venues like the Blue-Haired Wine Tasting And Cheese Gumming Tours in 'The Wine Country Cafes' in Temecula.

It's mellow, deep and resonant and just has a presence with enough overhead to cover a loud drunken blue hair who's had too much wine and not enough cheese.

To guess : I'd say anything over 200 Watts is gonna get it a little distressed, but that's just a guess on the low side as I don't like to mistreat any of my gear.

If I had a B-200 with the 15", I'd add another 15" driver in the B-115 cab to make a better acoustic/sound match.

Hopkins · #7 01-15-2011, 09:18 PM

I think I blew the speaker in my B100 combo at practice yesterday, and I've never pushed it very hard. So I wouldn't push your B200 very hard. Mine can't handle an open E at low volume with a flat EQ.
Im probably going to get a 210 cab and leave it at the practice space and just take my head. I don't have much faith in the new acoustic junk, I've had problems with the combo and their B410 cabs.

oniman7 · #8 01-15-2011, 09:20 PM

It's a combo, so it's a 15 inch speaker with a 200 Watt head. So, that should be good, right? I don't see myself pushing this to max any time.

oniman7 · #9 01-15-2011, 09:21 PM

Quote:

Originally Posted by Hopkins

I think I blew the speaker in my B100 combo at practice yesterday, and I've never pushed it very hard. So I wouldn't push your B200 very hard. Mine can't handle an open E at low volume with a flat EQ.
Im probably going to get a 210 cab and leave it at the practice space and just take my head. I don't have much faith in the new acoustic junk, I've had problems with the combo and their B410 cabs.

That's odd.

I've played a low D with a full bass EQ (on my instrument, not the amp) at around 6, and it played fine. I only did that for a little bit, but I've seen no problems with it.

JimmyM · #10 01-15-2011, 09:24 PM

Quote:

Originally Posted by oniman7

It's a combo, so it's a 15 inch speaker with a 200 Watt head. So, that should be good, right? I don't see myself pushing this to max any time.

you would think so, but it's not always the case, especially with cheaper stuff. you could easily blow that cab if you're not careful. one of my big pet peeves is companies lying about power handling to get more impressive looking numbers. it's pretty widespread, and it answers a lot of questions from people who blow cabs as to why it happens. rule of thumb...if it starts to make noises like it ate too many burritos, back it down.

oniman7 · #11 01-15-2011, 09:26 PM

Sounds like a plan. What's the average cost to get a speaker replaced/fixed if something like this happens? I know a guy who does amp repairs pretty cheap, but I'd like to avoid that altogether.

SurferJoe46 · #12 01-15-2011, 09:29 PM

The only problem I've ever had was a bad set of spade connectors on one of my 10-inch drivers in my B-450.

I solved it with soldering pigtails on the drivers and eliminated a potential disaster with the load changing according to the vibrations inside the cab, making and breaking electrical contact.

It sounded like I had shattered the drivers and smoke the amp until I out-thunk'd it and made the repair.

The B-410s are hard to destroy and I've had mine to very high volumes and for long periods of time and no problems at all.

The amps are pretty much bullet-proof, and although the drivers may not be the best, they are more than sufficient for what I need.

The B-450 has a B-600H in it and of course, the B-600H is a very powerful amp with lots of EQ and solid low-B capacity.

SurferJoe46 · #13 01-15-2011, 09:32 PM

Quote:

Originally Posted by oniman7

Sounds like a plan. What's the average cost to get a speaker replaced/fixed if something like this happens? I know a guy who does amp repairs pretty cheap, but I'd like to avoid that altogether.

The nicest part of the Acoustic/GC/MF guarantee is that if you take it back, you get another one instantly - if they have one that is. So far, I've not had to exercise that option.

Did you buy the Pro-Coverage? It's golden.

I play Acoustic pretty much exclusively, and although I'd not go on a world tour with it, it travels well enuff and has just the right 'Olde School' sound I love.

Hopkins · #14 01-15-2011, 09:43 PM

Quote:

Originally Posted by oniman7

That's odd.

I've played a low D with a full bass EQ (on my instrument, not the amp) at around 6, and it played fine. I only did that for a little bit, but I've seen no problems with it.

It was fine for a while, then it started farting out at very low volumes.

Like I said, I've had nothing but problems out of Acoustic gear, you get what you pay for I guess. On the other hand some people have had good luck with them.

JimmyM · #15 01-16-2011, 12:23 PM

especially where cabs are concerned, you get what you pay for. there are good deals out there that sound really nice for the money, but at least stay away from the super budget stuff.

Gero · #16 01-16-2011, 12:55 PM

I've had very little trouble with my acoustic gear (b200h w/ matching 15). The button on the cab to turn on/off the horn (always leave off) releases air at higher volumes/bass levels. Seal it up and there's no problem. Another thing, though not really a serious problem yet, is the delay the amp has turning on sometimes.

SurferJoe46 · #17 01-16-2011, 01:05 PM

Quote:

Originally Posted by Gero

I've had very little trouble with my acoustic gear (b200h w/ matching 15). The button on the cab to turn on/off the horn (always leave off) releases air at higher volumes/bass levels. Seal it up and there's no problem. Another thing, though not really a serious problem yet, is the delay the amp has turning on sometimes.

I had the blowing problem on my B-115, and just silicon'd a small, flat Tupperware container over the whole control panel and INPUT jacks area inside of the cab and never heard another peep outta it.

I've done that for all my Acoustic gear by now - although none of the others have had the same noise.

They wouldn't DARE!

oniman7 · #18 01-16-2011, 10:52 PM

Quote:

Originally Posted by Gero

I've had very little trouble with my acoustic gear (b200h w/ matching 15). The button on the cab to turn on/off the horn (always leave off) releases air at higher volumes/bass levels. Seal it up and there's no problem. Another thing, though not really a serious problem yet, is the delay the amp has turning on sometimes.

My amp's always taken about 5 seconds to turn on. I assumed it was loading up power or something. Is this a problem?

JimmyM · #19 01-16-2011, 11:29 PM

a lot of amps have a power up delay just to make sure everything's powered up inside so you don't get loud pops. and if they have tubes, those delays will be longer to give the tube enough time to warm up because you can damage them if you play before they're warmed up.

SurferJoe46 · #20 01-17-2011, 10:12 AM

Quote:

Originally Posted by JimmyM

a lot of amps have a power up delay just to make sure everything's powered up inside so you don't get loud pops. and if they have tubes, those delays will be longer to give the tube enough time to warm up because you can damage them if you play before they're warmed up.

Never though of it that way.

I always surmised that they wouldn't work until they were up to a threshold minimum of heat or ability to work and they weren't subject to damage since they couldn't work anyway.

Hmmm - interesting.