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[Rafi Singer]

Hey all,

The background on the rig in the big room in the club I work at: In a 700 cap room, there are only 4 EV Deltamax 18" subs for the entire room being powered by a MA3600vz. When I first got in there, the drivers were being blown about every year. Two years in, we replaced the drivers with Peavey Lowmax (2400W program, 1200W continuous rated) to help get a bit more life out of them. About 1.75 years later, we've blown them again. What was interesting to me is that first the two left 18"s blew, and about two shows later, the right two 18"s went. Perhaps it doesn't mean anything, though.

I wasn't terribly surprised about this, figuring that this is just another case of "not enough rig for the gig." The Macrotech was recently serviced, so I would presume that they would have tested it for issues of DC offset before letting it leave the bench. Is there any possible reason you see that may have evaded me?

[Paul G. OBrien]

In a 700 cap room, there are only 4 EV Deltamax 18" subs for the entire room being powered by a MA3600vz.

The obvious question is what processing does the system have?

[Rafi Singer]

The obvious question is what processing does the system have?

A BSS FDS-355.

[Tim McCulloch]

Hey all,

The background on the rig in the big room in the club I work at: In a 700 cap room, there are only 4 EV Deltamax 18" subs for the entire room being powered by a MA3600vz. When I first got in there, the drivers were being blown about every year. Two years in, we replaced the drivers with Peavey Lowmax (2400W program, 1200W continuous rated) to help get a bit more life out of them. About 1.75 years later, we've blown them again. What was interesting to me is that first the two left 18"s blew, and about two shows later, the right two 18"s went. Perhaps it doesn't mean anything, though.

I wasn't terribly surprised about this, figuring that this is just another case of "not enough rig for the gig." The Macrotech was recently serviced, so I would presume that they would have tested it for issues of DC offset before letting it leave the bench. Is there any possible reason you see that may have evaded me?

Thermal failure (what kind?) or mechanical failure?

And yep, it would appear that this is Not Enough Rig for the Gig®.  Perhaps not by a lot as the failures aren't closer together, but still not up to the results the operators desire.  How old is the design/gear, and what, if anything, has changed in the program material or typical operating level?

Inquiring mind....

Tim Mc

[Ivan Beaver]

A BSS FDS-355.

I think he meant-what are the high and low pass filters, eq etc.

[David Parker]

Hey all,

The background on the rig in the big room in the club I work at: In a 700 cap room, there are only 4 EV Deltamax 18" subs for the entire room being powered by a MA3600vz. When I first got in there, the drivers were being blown about every year. Two years in, we replaced the drivers with Peavey Lowmax (2400W program, 1200W continuous rated) to help get a bit more life out of them. About 1.75 years later, we've blown them again. What was interesting to me is that first the two left 18"s blew, and about two shows later, the right two 18"s went. Perhaps it doesn't mean anything, though.

I wasn't terribly surprised about this, figuring that this is just another case of "not enough rig for the gig." The Macrotech was recently serviced, so I would presume that they would have tested it for issues of DC offset before letting it leave the bench. Is there any possible reason you see that may have evaded me?

If you check the manual on that 3600 you'll find that the 3600 watt rating is at .05% thd, in other words, long before audible clipping. You'll also see that the beast reaches 6000 watts very easily at I think 1% thd. It's been a long time, I just remember the amp is under rated. Also, that amp has no built in limiting as other amps do, it just keeps going like the energizer bunny. AS others have said, you need to know if you are melting voice coils or tearing them up from overexcursion, as the remedy would be different depending on that. You may have enough rig, just not setting your hi pass correctly.

[Dave Bigelow]

I see a few red flags here.

1) Not enough rig for the gig unless you are doing acoustic and bluegrass (which doesn't even need subs), Most 700 seaters I see have at least twice that for low end.

2) Cabinet and driver combo. Did anybody do the research to see what demands the Peaveys have for cabinet size, porting, and all that or did somebody just say "they are rated higher, use those."?

3) Blowing up half the low end and then probably running the dogshit out of the other half and not expecting it to follow.

None of those on their own leads to good results, combine them all and I'm surprised anything works. I understand that in club land sometimes you gotta do what you gotta do due to cheap bar owners so I'm not ripping you personally here. Please don't take it that way, it's early and I'm not a very PC kind of person.


What exactly happened to the drivers? Overexcursion? Burnt up VCs? It would be nice to see what the processor is doing as well and what (if any) limiting is being used.

[Brad Weber]

The background on the rig in the big room in the club I work at: In a 700 cap room, there are only 4 EV Deltamax 18" subs for the entire room being powered by a MA3600vz. When I first got in there, the drivers were being blown about every year. Two years in, we replaced the drivers with Peavey Lowmax (2400W program, 1200W continuous rated) to help get a bit more life out of them. About 1.75 years later, we've blown them again. What was interesting to me is that first the two left 18"s blew, and about two shows later, the right two 18"s went. Perhaps it doesn't mean anything, though.

Whether the DMS-1181, DML-2181 or DMS-2181, I don't think any of those came loaded with Peavey drivers so when you replaced the drivers did you consider factors other than the power rating of the speaker?  This is especially relevant as the power rating may not be as much of a factor as you think.

Assuming you mean the single 18" DMS-1181, it was rated at 600W long term, 8 Ohms nominal and 6.5 Ohms minimum.  One potentially relevant fact here is that although the DMS-1181 is rated at 600W long term, the EVX-180A driver used in it is actually rated at 1,000W long term, which makes one wonder if a similar factor may effect the 1,200W drivers you used and if you really gained anything.

The recommended amp for the DMS-1181 is 600-1,200W into an 8 Ohm load, so two boxes per channel would equate to a recommended 1,200-2,400W into 4 Ohms per channel amp.  The MA-3600VX is rated at 1,565W per channel into 4 Ohms and that is a 1kHz rating, expect less for sub use.  So the amp being too much for the drivers should not be or have been an issue, in fact a little more amplification might help reduce any clipping.

I wasn't terribly surprised about this, figuring that this is just another case of "not enough rig for the gig."

You haven't really said what the gig is as far as type of music, how hard you run the system, who operates the system, etc., but it sounds like you've been focusing on the speakers when based on the above you maybe should be looking at the operation and perhaps the processing.

If you check the manual on that 3600 you'll find that the 3600 watt rating is at .05% thd, in other words, long before audible clipping. You'll also see that the beast reaches 6000 watts very easily at I think 1% thd. It's been a long time, I just remember the amp is under rated. Also, that amp has no built in limiting as other amps do, it just keeps going like the energizer bunny. AS others have said, you need to know if you are melting voice coils or tearing them up from overexcursion, as the remedy would be different depending on that. You may have enough rig, just not setting your hi pass correctly.

Since they mentioned the two right and two left subs it seems reasonable to assume that the system is run with two boxes per channel, thus 4 Ohms per channel.  Looking at the manual, the MA-3600VZ ratings for stereo, 4 Ohm per channel operation are 1,565W/ch (1kHz, 0.1% THD+N), 1,555W/ch (1kHz, 0.05% THD+N), 1,860W/ch (40ms tone burst, 50Hz, 0.05% THD+N) and 2,230W (single cycle tone burst, 50Hz, 0.05% THD+N).  Even the single cycle rating is under the 1,200 to 2,400W per channel amplification recommended for the speakers.

[Rafi Singer]

Thermal failure (what kind?) or mechanical failure?  How old is the design/gear, and what, if anything, has changed in the program material or typical operating level?

Inquiring mind....

Tim Mc

I didn't smell anything, nor did I see anything that looked charred. The drivers measured open when we metered them.

The age of the actual enclosures themselves must be at least ten years. I would have to check with the company that installed them. The age of the drivers that we put in there are about 1.75 years upon death.

I suppose you could point to having a moderate increase in electronic acts, but by the same token, this place used to be a haven for the MA hardcore scene before I ever got there. To answer a similar question, the club sees a wide range of acts, including electronic, hiphop, straight-ahead rock, and metal. I've been harping the owner for years that we would need at least four 2X18"'s to begin to be adequately covering the room.

I see a few red flags here. 

2) Cabinet and driver combo. Did anybody do the research to see what demands the Peaveys have for cabinet size, porting, and all that or did somebody just say "they are rated higher, use those."?

The idea came at the suggestion of the company that had previously installed them. It wouldn't surprise me if they had researched it, but part of how it was sold was higher rating and fitting in the box. To be fair, once we installed them, the low end tightened up considerably. Instead of hearing an ill-defined rumble when a bassist played, we started hearing actual notes.

3) Blowing up half the low end and then probably running the dogshit out of the other half and not expecting it to follow.

I'm actually not that surprised. I did dial back the amp considerably after half went out, but figuring that they all had been abused equally, it was probably just a matter of time. To answer the related, after the first side blew, I checked cross, and it seemed that the previous person had set it to start at 22Hz with a slope of 18LR. To play it safe, I dialed up to about 65hz and increased the slope dramatically. I don't recall the limiter settings offhand, but I always seem to be seeing it kick in before there is enough in the room, pointing back to the inadequate amount of rig.

What exactly happened to the drivers? Overexcursion? Burnt up VCs? It would be nice to see what the processor is doing as well and what (if any) limiting is being used.

To be honest, we've been crazy busy, so I didn't get to look too far into it before I dropped them off at the shop. From what I saw, the VC wasn't rubbing when I moved the cone, it metered as open, and I didn't smell or see any charring. I just called the shop though, so I should have an answer soon.

[David Parker]

several years ago on this forum, when the MA3600 amps were popular, a lot of folks had problems blowing subs with them. Some said that they moved up to the MA5000 with the same subs and stopped having problems.

[Doug Fowler]

several years ago on this forum, when the MA3600 amps were popular, a lot of folks had problems blowing subs with them. Some said that they moved up to the MA5000 with the same subs and stopped having problems.

That is correct. I looked for old posts but could not find them.

[duane massey]

Simple answer, which you already know: not enough rig for the gig, although I know of several local sound guys (kinda) that think it is standard procedure to toast subs twice a year. I find any regularly occurring failure unacceptable.

[Mark Oakley]

Are the subs spread out (2 boxes per side)? Is it possible to group them together in front of the stage for some low freqency coupling?

-Mark

www.oakleyaudio.ca

[Marty McCann]

When there are no signs of mechanical failure, no unraveling of voice coil turns, and no discoloration of copper, the usual culprit is due to transient clipping that actually hits the Peak DC voltage rails of the amplifier.  At this point a turn in the coil opens like a fuse, thus no continuity.

[Stu McDoniel]

Hey all,

The background on the rig in the big room in the club I work at: In a 700 cap room, there are only 4 EV Deltamax 18" subs for the entire room being powered by a MA3600vz. When I first got in there, the drivers were being blown about every year. Two years in, we replaced the drivers with Peavey Lowmax (2400W program, 1200W continuous rated) to help get a bit more life out of them. About 1.75 years later, we've blown them again. What was interesting to me is that first the two left 18"s blew, and about two shows later, the right two 18"s went. Perhaps it doesn't mean anything, though.

I wasn't terribly surprised about this, figuring that this is just another case of "not enough rig for the gig." The Macrotech was recently serviced, so I would presume that they would have tested it for issues of DC offset before letting it leave the bench. Is there any possible reason you see that may have evaded me?

This is really a pretty simple fix...get more subs.   Turn it down

[Tim Padrick]

I recall at least a couple of posts (from back when I started here) from folks who solved their sub blowing problems by replacing their MA3600 with an MA5000.

[Stu McDoniel]

Hey all,

The background on the rig in the big room in the club I work at: In a 700 cap room, there are only 4 EV Deltamax 18" subs for the entire room being powered by a MA3600vz. When I first got in there, the drivers were being blown about every year. Two years in, we replaced the drivers with Peavey Lowmax (2400W program, 1200W continuous rated) to help get a bit more life out of them. About 1.75 years later, we've blown them again. What was interesting to me is that first the two left 18"s blew, and about two shows later, the right two 18"s went. Perhaps it doesn't mean anything, though.

I wasn't terribly surprised about this, figuring that this is just another case of "not enough rig for the gig." The Macrotech was recently serviced, so I would presume that they would have tested it for issues of DC offset before letting it leave the bench. Is there any possible reason you see that may have evaded me?

Make sure you have your input sensitivity switch set properly.. go to page
15 of this pdf document and follow the directions.  I am not claiming this to be your answer but I am saying follow the directions.

http://www.crownaudio.com/pdf/amps/125113.pdf

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