I think I blew out a 15 through over-excursion

Tractorr · #1 11-14-2011, 08:22 AM

I have a Peavey VB2 head and a Peavey 2X15D cabinet. During practice the cab goes dead. I look at the top woofer and the voice coil has ripped right through the cone.

I play a 4 string in standard tuning. EQ is flat on bass. I usually have the pre gain dimed, the bass set to 8, the mid set to 6, the treble set 2, and the master around 6 or 7. I don't think I play overly hard (in fact I may even play a bit on the softer side).

Does it seem like it was my fault that this speaker went or was it just the speaker's time?

BurningSkies · #2 11-14-2011, 08:28 AM

No, it was your fault.

You had a lot of bass boost, which moves the driver more and gives more power to the drive. Like many bass cabs, the thermal limits of the speaker is higher than the excursion limits. Not only did you exceed xmax (the point of distortion, aka 'the fart zone'), you also exceeded the mechanical limits of the speaker and punched the voice coil out through the cone.

Joe Louvar · #3 11-14-2011, 08:31 AM

I don’t know who’s fault it was but if the diaphragm is ripped you need to repair the cone or replace the driver.

DonKartofflo · #4 11-14-2011, 08:32 AM

BassmanPaul · #5 11-14-2011, 08:49 AM

There may be replacement baskets available for your damaged drivers. I use the plural because if you have damaged the one so severely your other driver will be damaged also. You will have to identify just what your drivers are and see if they do have replacement baskets for that model.

Fault lies in too much bass boost and playing too loudly in that state.

I hope you switched the amp off immediately because a tube amp can be damaged quite quickly with no load on the output.

hdracer · #6 11-14-2011, 08:58 AM

The VB-2 needs the bass turned up. I am not sure but I think 5 is flat on this amp. It sounds like it to me. The owners manual shows recommended settings for different styles of music and all of them show the bass at 8 or above. I always run mine in the 8-9 range.

cchorney · #7 11-14-2011, 09:12 AM

Burningskies is right. Drivers don't fail all on their own. The OP pushed the driver too hard. So, in addition to repairing his cab, it seems he needs to cut his volume, cut his bass frequencies, or find some other way of not driving his cab so hard. Maybe a second 215 cab? Seems overkill to me but something in this equation needs to change for the result to be different. Also, not to pile on but the OP should also listen to what's coming out of his cab. I'm sure that driver complained (in the form of farting out) a fair bit before it failed in a permanent manner.

gimp · #8 11-14-2011, 09:35 AM

If your cab isn't a BW cab, I've got some drivers from my Peavey 2x15 I'm not using. I'm not too far from you as well.

1958Bassman · #9 11-14-2011, 09:41 AM

Quote:

Originally Posted by Tractorr

I have a Peavey VB2 head and a Peavey 2X15D cabinet. During practice the cab goes dead. I look at the top woofer and the voice coil has ripped right through the cone.

I play a 4 string in standard tuning. EQ is flat on bass. I usually have the pre gain dimed, the bass set to 8, the mid set to 6, the treble set 2, and the master around 6 or 7. I don't think I play overly hard (in fact I may even play a bit on the softer side).

Does it seem like it was my fault that this speaker went or was it just the speaker's time?

What, specifically, makes you think that setting the input at 10 is a good idea when the instrument isn't producing low output? Then, you set the bass to 8 with the master at 6 or 7. You didn't mention effects and if you use them and set them so the output is higher with them on, they're adding gain.

This is like mashing your gas pedal to the floor and waiting for parts to fly through the hood- You need more speakers. More power through one or two speakers isn't the best way to reach maximum output. If you want CLEAN sound, set the input lower and raise the output until it's noise-free. If it's not loud enough, you need more power and/or speakers.

Why the H do you need it that loud when you practice?

BurningSkies · #10 11-14-2011, 09:42 AM

It all really depends on the cabinet and what speakers are in it. Peavey has been making 2x15 cabs for about 40 years now. I'm not sure that Peavey speakers are known for having an extended excursion, and I'm guessing that many from the 70's up until recently have extremely limited excursion...

If the user is a fan of distortion or pushing their preamp for some kind of overdrive/clipping, you have to be REALLY careful. Often its hard to differentiate the sound of a speaker going non-linear through your intended level of distortion...it masks your speaker's signs of pain.

BurningSkies · #11 11-14-2011, 09:47 AM

Quote:

Originally Posted by 1958Bassman

What, specifically, makes you think that setting the input at 10 is a good idea when the instrument isn't producing low output? Then, you set the bass to 8 with the master at 6 or 7. You didn't mention effects and if you use them and set them so the output is higher with them on, they're adding gain.

This is like mashing your gas pedal to the floor and waiting for parts to fly through the hood- You need more speakers. More power through one or two speakers isn't the best way to reach maximum output. If you want CLEAN sound, set the input lower and raise the output until it's noise-free. If it's not loud enough, you need more power and/or speakers.

Why the H do you need it that loud when you practice?

A quick look at the OP's posting shows that he's probably working from the 'harder' side of things...Heavy, distorted, loud. I see postings about doom, metal, etc. I'm guessing that he's using the Pre in the VB-2, to generate distortion with a fair amount of low end boost to get a big sludgy heavy sound. What a lot of those guys do to get that sound is to add speakers. You have to be really careful with that kind of sound not to rip through drivers, because you can't hear when they scream for mercy.

cchorney · #12 11-14-2011, 09:51 AM

Quote:

Originally Posted by BurningSkies

If the user is a fan of distortion or pushing their preamp for some kind of overdrive/clipping, you have to be REALLY careful. Often its hard to differentiate the sound of a speaker going non-linear through your intended level of distortion...it masks your speaker's signs of pain.

Reading this caused me to reread the OP's post, and I've realized I misread something. I thought he had the pre-gain DIMMED which I took to mean the light doesn't come on. But he actually wrote DIMED, meaning it's at 10 out of 10. And he has the bass turned up. And the mids turned up. And the volume turned up. And he asks if its him? Dude let me help you out - yes it's you! To quote the great Frank Zappa, "TURN IT DOWN!"

Joe Louvar · #13 11-14-2011, 09:55 AM

The OP needed more volume so they turned up. However had they matched both the amp impedance and power this should not have happened. This is a good example of why it’s important to match both the amp ohms and watts. The OP, needs more speaker to utilize the amps full potential.

someparts · #14 11-14-2011, 09:57 AM

I've had a couple 215D cabs over the years. They made a shallow and a deep version I think and the shallow version is quite bright for a 2x15 cab. Maybe that's some of the issue here if it's a shallow cab. Not the best cab for the style and possibly forcing those EQ settings.

BurningSkies · #15 11-14-2011, 10:05 AM

Quote:

Originally Posted by Joe Louvar

The OP needed more volume so they turned up. However had they matched both the amp impedance and power this should not have happened. This is a good example of why it’s important to match both the amp ohms and watts. The OP, needs more speaker to utilize the amps full potential.

Well...not quite. Remember, that cabinets are rated for thermal handling, not excursion limitations. Most if not all cabs are rated this way, and a very broad but usually correct generalization says that production bass cabs reach their excursion limits well before they hit the point of thermal meltdown.

I agree that the user either needs more speakers or 'better' speakers to make this work. I'm not sure what this has to do with him 'matching ohms and watts' though. It doesn't sound like he had an impedance mismatch or that necessarily that the VB2 was too powerful. Its a 225w amp at 2, 4, or 8ohms.

hdracer · #16 11-14-2011, 10:10 AM

I know that if I set my pre gain at 10 and master at 7 with my 2 3015's you would never be able to hear the rest of the band!
I have never gone over 5-6 pre & 5 master and my band plays loud, 2 gp's with tube heads & 412's

billfitzmaurice · #17 11-14-2011, 10:11 AM

Quote:

Originally Posted by BurningSkies

Well...not quite. Remember, that cabinets are rated for thermal handling, not excursion limitations.

+1. Power ratings are meaningless, driver excursion capacity is what counts, with respect to both output and the potential for mechanical damage.

**bassman314** · #18 11-14-2011, 10:20 AM

Quote:

Originally Posted by Joe Louvar

I don’t know who’s fault it was but if the diaphragm is ripped you need to repair the cone or replace the driver.

If the diaphram is ripped, you might want to start saving for child support payments..

Tractorr · #19 11-14-2011, 10:23 AM

Lets see,

No effects.

We practice this loud to keep up with my guitarist 4X12 with a JCM800 head. That thing is ridic loud. He has the master on 1 and it is painfully loud.

At the settings listed the rig is really not that loud.

It seems to me that a 15 inch speaker should be able to handle 112.5 watts pretty easily (half of the amps power).

It is the deep cabinet but it is not very bassy. My 200 Hartke 1X15 combo can easily generate more low end.

All this being said I bought this cab used (recently) and have no idea what the previous owner did to it.

Once I replace the cones I am going to practice without the grill cloth on for awhile to make sure I am not overworking the speakers.

BurningSkies · #20 11-14-2011, 10:29 AM

Quote:

Originally Posted by Tractorr

Lets see,

No effects.

We practice this loud to keep up with my guitarist 4X12 with a JCM800 head. That thing is ridic loud. He has the master on 1 and it is painfully loud.

At the settings listed the rig is really not that loud.

It seems to me that a 15 inch speaker should be able to handle 112.5 watts pretty easily (half of the amps power).

It is the deep cabinet but it is not very bassy. My 200 Hartke 1X15 combo can easily generate more low end.

All this being said I bought this cab used (recently) and have no idea what the previous owner did to it.

Once I replace the cones I am going to practice without the grill cloth on for awhile to make sure I am not overworking the speakers.

Watching the drivers isn't the best way to see if they're overworking. Its by hearing them and if they're distorting. Unless you can figure out how many millimeters the speaker can take and can eyeball how far out the speaker is traveling.

Of course, your 225w amp may be putting out more than 225w, that's the nature of things, especially if you like things less than clean. And for the record, those speakers could very easily have an excursion limit well below 112.5w, especially if you're trying to push a lot of low. Just because you're not hearing lows doesn't mean that you're not feeding it to the cab. It just means that the cab is unable to reproduce it.