GK 1001RB II Blowing out Speakers?

[shutupdonnie]

Back in June, I blew out of of the 10"s on my 1000W avatar b410neo cabinet. As I was leaving for tour in a matter of days, I went out and purchased an 800W Gallien Krueger 410neo cabinet. Just the other day at practice, I blew out one of those 10"s. I both cases, I had at least 100W of speaker head room, so I'm wondering what went wrong here. I'm playing an Ibanez BTB400 and running a sansamp BDDI (set to unity gain) into the front end of the head. In the effects loop i have a DBX 166XL compressor and then a BBE482i sonic maximizer. With both cabinets, I am using a genuine GK 4-conductor speakon cable (I removed the crossover of the avatar cabinet, and rewired the speakon jack) to make it work just like a GK cabinet.

Here are my settings:
IMG_20110711_210416 | Flickr - Photo Sharing!

Does anyone have any idea what is going on here? Neodymium speakers aren't cheap. Any help is appreciated.

-- Donovan

 

[BurningSkies]

Speaker headroom is questionable...amp companies usually list thermal limits not excursion limits, and it sounds like you're exceeding those.

 

[GrinningMouth88]

My 700rbII goes through speakers like it's nobodies business. Not sure if it's a problem inherent to gk or not but it's enough to make me want to switch brands. whether it's aluminum, 15's, brand new neodyminium 12's from a neo 412. I'm just going to switch brands, prob the best advice I can give you. I've tried different settings, using pads, different pedals, repairing my amp, cables, different cabs, etc. It's almost as if they make these amps that have tons of balls, and no cabinet that can handle it. Maybe it's part of the whole consumer cycle, they expect us to just keep replacing speakers.

 

[Bass_Pounder]

both cases, I had at least 100W of speaker head room, so I'm wondering what went wrong here.

-- Donovan

I don't know how you can state that you had at least 100w of speaker headroom unless you have output measuring equipment.

As already stated - the wattage ratings of cabs are thermal ratings only. The mechanical limits are far less (around 50-60%).

Looking at your pic, the first thing that jumps out to me is how high you have the "low contour" setting on the BBE.

That is adding lots of low end content, and most likely helped your speakers reach their mechanical displacement limits.

 

[RickenBoogie]

+1 to posts #2 and #4.

 

[runmikeyrun]

turn down the bass. If you need more low end get another cab, like a 1x15.

 

[Bass_Pounder]

turn down the bass. If you need more low end get another cab, like a 1x15.

Yeah..........because single 15's do so well at keeping up with the output of a 4X10


Matching cabs FTW

 

[AwkwardLoudness]

Yeah, wattage (thermal) ratings on speakers cabs are generally meaningless. Your speakers were likely being pounded to the point of maximum excursion. One must adjust volume and/or EQ to avoid that. If the speakers start making 'pop' or 'fart' sounds, then you know you're in the danger zone generally speaking.

 

[shutupdonnie]

That being said, at 8ohm my head is only capable of pushing 450W at full power, or 45% of the 1000W cabinet's thermal rating. When I also run my 8ohm 18" cabinet concurrently with the 4x10, the max output drops to 350W (700W divided by 2). Could the BBE still be the culprit? I had begun to notice a decrease in volume just prior to the speaker fizzling out. I had previously thought that possibly I had some sort of short in the power section.

 

[AwkwardLoudness]

That being said, at 8ohm my head is only capable of pushing 450W at full power, or 45% of the 1000W cabinet's thermal rating.

Thermal ratings are bulls**** in most cases for bass cabs. Liberate yourself from thinking otherwise, and your life will be easier in the long run.

 

[shutupdonnie]

I can get down with that. Thermal ratings have done nothing for me thus far. Since I'm going to be buying a cabinet in the very near future, what rating should I look for? Do I want speakers with a higher xMax?

 

[Bass_Pounder]

2). Could the BBE still be the culprit? I had begun to notice a decrease in volume just prior to the speaker fizzling out. I had previously thought that possibly I had some sort of short in the power section.

The BBE could be the culprit.

From the 482i manual:

Lo Contour +12dBu adjustment at 50Hz

You have the low contour control almost maxed out - there are hardly ANY speakers out there that work well in the 50hz range, and pumping +10db or more at them is probably causing alot of cone movement.

I use a BBE 482, and keep the low contour around the 1 o'clock position. Anything more just makes it mud IMO

 

[singlemalt]

Check the GK manual, the OHM math works the other way round. When you add that 18 @ 8 ohms to the 410 @ 8 ohms you cut the resistance (OHMS) in HALF, amp now good for 700w at 4 ohm.

I looked at your settings and I notice you are driving the crap out of the low mids.
I've got the same amp, the GK 1001 rb 2. I hope you are wearing ear plugs with the master volume (woofer) knob buried at the stun setting. My master only makes it past 12 oclock when I'm really pissed at my guitard. But hey, I'm getting old! Seriously, my volume for a small club, bar type gig is maybe 10 oclock on the main.

Here's the other thing with the GK's eq: the contour knob basically scoops at 500, so when you turn that up you are taking out in the same area that you are pushing the main eq. Try turning the contour off, and unless you want lots of super highs in the main cabs, turn off the precence as well. Let the horn handle the super high content 5K and up with the tweeter control. Put the rest of the main eq knobs at 12 oclock and start from there.

As for the other, stuff: the Sans amp pre is a good idea, it gives you some other flavors from the GK's normal stuff. I run a MXR M80, same thing, pretty much. (the MXR replaced the Sans Amp). If you aren't pushing it too hard (if the input clipping light isn't on) that should be okay. I never liked the effects loop on the GK so I don't use it, any compression or effects goes in the front of the amp. You could be spiking things with the stuff in your effects loop if you kick things in and out.

The Gk 1001 is a kind of cold sounding amp until you turn it up, so having a little warmth like the sans amp or M-80 is nice at lower volumes. (Not that you seem to need lower volumes)

For cabs I run one or two fEarfuls, a 15/6/1 with the horn on the GK's high circuit and/or a 12/6. The LF drivers give me all the lows I need with out any problems.

I don't put much stock in speaker ratings, they don't really mean much. Looking at your volume level I'd say you are just pushing the speaks too hard. Minimum ohm load for the GK is 4 so you can't add more boxes, so you need some tougher cabs. Or maybe turn down just a bit.

 

[BurningSkies]

I don't know how you can state that you had at least 100w of speaker headroom unless you have output measuring equipment.

As already stated - the wattage ratings of cabs are thermal ratings only. The mechanical limits are far less (around 50-60%).

Looking at your pic, the first thing that jumps out to me is how high you have the "low contour" setting on the BBE.

That is adding lots of low end content, and most likely helped your speakers reach their mechanical displacement limits.

That being said, at 8ohm my head is only capable of pushing 450W at full power, or 45% of the 1000W cabinet's thermal rating. When I also run my 8ohm 18" cabinet concurrently with the 4x10, the max output drops to 350W (700W divided by 2). Could the BBE still be the culprit? I had begun to notice a decrease in volume just prior to the speaker fizzling out. I had previously thought that possibly I had some sort of short in the power section.

Whelp... there are a few things going on here. First off, your amp IS able to put out wattage greater than its rated for very short periods of time. Those short periods of time tend to be damaging to speakers if you’re not careful. On top of that your BBE (Which I wasn’t even looking at) has its low contour maxed, meaning you’re CRANKING your lows. Using a lot of lows does a few things. First off, it uses up any headroom your actual amp might have…lows take more wattage to reproduce than highs do. A lot more wattage. Now, on top of that…speaker excursion (that movement of your speakers) is much more extreme with lows…it takes more movement of the speaker to reproduce those low waves. Sub-sonic waves can be even more damaging. So…your speakers distort once they reach their excursion limit (the point the voice coil leaves the magnetic gap and becomes non-linear called X-MAX). The next step is reaching what’s called X-LIM, which is the mechanical limit of your speaker, or roughly the point of your speaker committing suicide and spitting its guts all over you.

 

[shutupdonnie]

The BBE could be the culprit.

From the 482i manual:

Lo Contour +12dBu adjustment at 50Hz

You have the low contour control almost maxed out - there are hardly ANY speakers out there that work well in the 50hz range, and pumping +10db or more at them is probably causing alot of cone movement.

I use a BBE 482, and keep the low contour around the 1 o'clock position. Anything more just makes it mud IMO

I usually keep it at about 1 o'clock, not quite sure why it was like that in the picture. A friend suggested putting a 31 band eq in the loop and cutting everything below 50hz to eliminate standing waves.

 

[BurningSkies]

I usually keep it at about 1 o'clock, not quite sure why it was like that in the picture. A friend suggested putting a 31 band eq in the loop and cutting everything below 50hz to eliminate standing waves.

If you're going that route, get a dedicated high pass filter for it and not a 31 band eq which is like getting a bazooka to shoot a chipmunk in this case.

 

[AwkwardLoudness]

I usually keep it at about 1 o'clock, not quite sure why it was like that in the picture. A friend suggested putting a 31 band eq in the loop and cutting everything below 50hz to eliminate standing waves.

Cutting the frequencies below 50 hZ is a good idea to lessen the stress on speakers, but it has nothing to do with standing waves. Lower frequencies cause greater mechanical movement of the speakers relative to higher frequencies. You don't really need 31 bands of adjustment for that.

 

[jeff7bass]

"Heads don’t kill speakers, people do".

This public service announcement has been brought to you by the NSA, National Speaker Association.

 

[Bass_Pounder]

I looked at your settings and I notice you are driving the crap out of the low mids.
I've got the same amp, the GK 1001 rb 2. I hope you are wearing ear plugs with the master volume (woofer) knob buried at the stun setting. My master only makes it past 12 oclock when I'm really pissed at my guitard. But hey, I'm getting old! Seriously, my volume for a small club, bar type gig is maybe 10 oclock on the main.

Here's the other thing with the GK's eq: the contour knob basically scoops at 500, so when you turn that up you are taking out in the same area that you are pushing the main eq. Try turning the contour off, and unless you want lots of super highs in the main cabs, turn off the precence as well. Let the horn handle the super high content 5K and up with the tweeter control. Put the rest of the main eq knobs at 12 oclock and start from there.

Good info here................


Also, I remember from another thread you were talking about your Avatar cab losing low end, and starting to "fart out" as you turned up.

I had suggested then that you take a close look at your speakers.

You should do that again (to both cabs if you still have them) - and pay attention to the cone area closest to the accordian surround. If you see any lines in the cone around the outer area, then you are driving them way past there mechanical limits and creasing them (especially with boosted low end EQ).

Creased cones will still sound OK at moderate volumes, but will fart out like crazy when played louder.

 

[shutupdonnie]

Check the GK manual, the OHM math works the other way round. When you add that 18 @ 8 ohms to the 410 @ 8 ohms you cut the resistance (OHMS) in HALF, amp now good for 700w at 4 ohm.

I looked at your settings and I notice you are driving the crap out of the low mids.
I've got the same amp, the GK 1001 rb 2. I hope you are wearing ear plugs with the master volume (woofer) knob buried at the stun setting. My master only makes it past 12 oclock when I'm really pissed at my guitard. But hey, I'm getting old! Seriously, my volume for a small club, bar type gig is maybe 10 oclock on the main.

Here's the other thing with the GK's eq: the contour knob basically scoops at 500, so when you turn that up you are taking out in the same area that you are pushing the main eq. Try turning the contour off, and unless you want lots of super highs in the main cabs, turn off the precence as well. Let the horn handle the super high content 5K and up with the tweeter control. Put the rest of the main eq knobs at 12 oclock and start from there.

As for the other, stuff: the Sans amp pre is a good idea, it gives you some other flavors from the GK's normal stuff. I run a MXR M80, same thing, pretty much. (the MXR replaced the Sans Amp). If you aren't pushing it too hard (if the input clipping light isn't on) that should be okay. I never liked the effects loop on the GK so I don't use it, any compression or effects goes in the front of the amp. You could be spiking things with the stuff in your effects loop if you kick things in and out.

The Gk 1001 is a kind of cold sounding amp until you turn it up, so having a little warmth like the sans amp or M-80 is nice at lower volumes. (Not that you seem to need lower volumes)

For cabs I run one or two fEarfuls, a 15/6/1 with the horn on the GK's high circuit and/or a 12/6. The LF drivers give me all the lows I need with out any problems.

I don't put much stock in speaker ratings, they don't really mean much. Looking at your volume level I'd say you are just pushing the speaks too hard. Minimum ohm load for the GK is 4 so you can't add more boxes, so you need some tougher cabs. Or maybe turn down just a bit.

No, I understand how the resistance works but I think it came out wrong. What I meant was that the 700W @ 4ohms would be distributed between the 2 cabinets, 350W per cabinet.

As it stands now, I need the volume to compete with 2 guitar players with 120W tube heads running full stacks, so I need a ridiculous amount of volume to be heard.

Thanks for the tips on the contour/presence though. I will give those a try tonight.