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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => LAB Subwoofer Forum => Topic started by: Mike Steines on April 17, 2012, 04:49:08 AM
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I have 2 peavey sp118s, I bought used, when tested off of a 300 watt amp they sounded fine. After I bought them and hooked them up to my AB international 1100a, they make a loud pop when barely pushing them. I unhooked all of my EQ's and Bass exciters, still had same problem. So I hooked them up to my mackie fr2500 to see if it was an amp issue, still same problem. Checked all cords, everything is fine. No popping thru my main speakers. I took one of the drivers out because I was afraid that I had been jipped and they werent black widows, but the are. I took off the magnet and it looked okay other then a thin black circle about 3/4 inch diameter. The black line seemed to be bubbly. Other than that I cant seem to find a problem. Are the bad voice coils? or another problem? Please help!!! I dont wanna spend 350 bucks on new baskets if thats not the problem. Thanks!
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What source signal are you driving these with?
Do you have a low cut filter engaged somewhere in the signal chain to eliminate everything below 40hz or so?
Do you have a multimeter to test the drivers continuity?
The bubbly black line you mentioned was that on the voice coil? If so that's bad and indicates the drivers are blown or were overdriven for an extended period of time and don't have much life left in them. A picture would really help here.
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I will be going to get them tonight and will send pics. The black circle IS on voice coil. And I have a crossover and eq that I have cutoff set at 40hz, But they pop at higher notes, id say 75-85hz range. I do have a multimeter and will test them.
What source signal are you driving these with?
Do you have a low cut filter engaged somewhere in the signal chain to eliminate everything below 40hz or so?
Do you have a multimeter to test the drivers continuity?
The bubbly black line you mentioned was that on the voice coil? If so that's bad and indicates the drivers are blown or were overdriven for an extended period of time and don't have much life left in them. A picture would really help here.
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I have 2 peavey sp118s, I bought used, when tested off of a 300 watt amp they sounded fine. After I bought them and hooked them up to my AB international 1100a, they make a loud pop when barely pushing them. I unhooked all of my EQ's and Bass exciters, still had same problem. So I hooked them up to my mackie fr2500 to see if it was an amp issue, still same problem. Checked all cords, everything is fine. No popping thru my main speakers. I took one of the drivers out because I was afraid that I had been jipped and they werent black widows, but the are. I took off the magnet and it looked okay other then a thin black circle about 3/4 inch diameter. The black line seemed to be bubbly. Other than that I cant seem to find a problem. Are the bad voice coils? or another problem? Please help!!! I dont wanna spend 350 bucks on new baskets if thats not the problem. Thanks!
Try slowly pushing the driver in with your hand, does it make a scratching noise? Also, have you looked thoroughly in the cabinet for anything that may be loose and rattling around? Try to narrow down if your sound is coming from the driver, or the box.
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Try slowly pushing the driver in with your hand, does it make a scratching noise? Also, have you looked thoroughly in the cabinet for anything that may be loose and rattling around? Try to narrow down if your sound is coming from the driver, or the box.
I actually took the driver out and took it to a peavey retailer. We did the push test and no scratching. He told me there was no issue with the driver. But I checked the cabinent and saw nothing loose. I even put the driver into a PV118 cabinent I had laying around and it still pops. Im 100% sure it is coming from the driver. Im leaving here in a few minutes to go get it and take pics of the coil.
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I actually took the driver out and took it to a peavey retailer. We did the push test and no scratching. He told me there was no issue with the driver. But I checked the cabinent and saw nothing loose. I even put the driver into a PV118 cabinent I had laying around and it still pops. Im 100% sure it is coming from the driver. Im leaving here in a few minutes to go get it and take pics of the coil.
While you're doing that, look down into the gap with a flashlight for debris.
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While you're doing that, look down into the gap with a flashlight for debris.
Took them apart, Tested both coils, Read 3.8Ohm. Here are the pics. Also any idea why the 2 coils look completely different but are both the same model number?
<a href="http://s889.photobucket.com/albums/ac94/djspreewell/?action=view&current=coil2.jpg" target="_blank"><img src="http://i889.photobucket.com/albums/ac94/djspreewell/coil2.jpg" border="0" alt="Photobucket"></a>
<a href="http://s889.photobucket.com/albums/ac94/djspreewell/?action=view&current=coil1.jpg" target="_blank"><img src="http://i889.photobucket.com/albums/ac94/djspreewell/coil1.jpg" border="0" alt="Photobucket"></a>
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(http://i889.photobucket.com/albums/ac94/djspreewell/coil1.jpg)
(http://i889.photobucket.com/albums/ac94/djspreewell/coil2.jpg)
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Hard to get a good look with those pictures(too dark and too close) but the coils definitely look a little cooked so you're probably going to need replacements soon. The difference in coils is probably because one or both drivers were reconed at some point and who knows but maybe one of those recones isn't correct or maybe it's just from a different supplier.
You say you have tested both drivers and they behave the same? Have you tested the amp with other speakers just to rule it out as the source of the problem? Are you using a single channel of the amp to power each speaker or is it setup for bridged operation? If bridged set it for normal 2ch operation and try again.
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(http://i889.photobucket.com/albums/ac94/djspreewell/coil1.jpg)
(http://i889.photobucket.com/albums/ac94/djspreewell/coil2.jpg)
Hi Mike;
That is something I've never seen before on a voice coil. It looks like something caused overheating in a small circular area, like debris or something in the gap .
Hard to see much detail on colors...
I am assuming the one with the small circle is the trouble driver.
Did the dealer SEE THIS?
This might be beyond my pay grade, but ...
Can you give a more detailed description of the noise that the driver makes, when it makes it, with what material through it, and at what volumes. Is it a pop, or more of a scratching sound?
A series of quick pops? Any distortion at low volumes?-Low bass tones at low volumes?
Is this just the one driver, is the other one OK?
As always, more info leads to better help.
Different looking voice coils, might indicate one has been replaced already.
If these are black widows, and one is driving OK, you might try swapping voice coil/magnets with baskets/cone assemblies, and see what happens. It is also possible that one coil might be a odd/wrong recone or some such, I'm not that familiar with the black widows to tell you what the coils are supposed to look like.
Also, are these rated 4 ohms?
Keep us updated,
Taylor
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Those baskets are toast, replace them. They should not be black in color, anywhere on the voice coil.
When replacing, fold over some masking tape (sticky sides out) and run the tape in the magnet gap to fish out any debris that may be in there.
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Hi Mike;
That is something I've never seen before on a voice coil. It looks like something caused overheating in a small circular area, like debris or something in the gap .
Hard to see much detail on colors...
I am assuming the one with the small circle is the trouble driver.
Did the dealer SEE THIS?
This might be beyond my pay grade, but ...
Can you give a more detailed description of the noise that the driver makes, when it makes it, with what material through it, and at what volumes. Is it a pop, or more of a scratching sound?
A series of quick pops? Any distortion at low volumes?-Low bass tones at low volumes?
Is this just the one driver, is the other one OK?
As always, more info leads to better help.
Different looking voice coils, might indicate one has been replaced already.
If these are black widows, and one is driving OK, you might try swapping voice coil/magnets with baskets/cone assemblies, and see what happens. It is also possible that one coil might be a odd/wrong recone or some such, I'm not that familiar with the black widows to tell you what the coils are supposed to look like.
Also, are these rated 4 ohms?
Keep us updated,
Taylor
The peavey dealer did not look at the coils. He's one of those guys that if you didn't buy from him he don't wanna help you. Both drivers do the same thing. A loud pop is heard when bearly powered. Have hooked it up every different way to 2 different amps. My mains don't pop at all. No clip lights come on when the subs pop. They are 4ohm subs. They're the 1808-4 sws black widows. The coil with the black circle doesn't seem to be bad anywhere else. I'm going to try to take better pics with an actual camera insted of my phone. Thanks again everyone.
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Here are some new better pics.
(http://i889.photobucket.com/albums/ac94/djspreewell/GEDC2102.jpg)
(http://i889.photobucket.com/albums/ac94/djspreewell/GEDC2101.jpg)
(http://i889.photobucket.com/albums/ac94/djspreewell/GEDC2100.jpg)
(http://i889.photobucket.com/albums/ac94/djspreewell/GEDC2099.jpg)
(http://i889.photobucket.com/albums/ac94/djspreewell/GEDC2098.jpg)
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They're toast, especially the one that has the black voice coil. I'm not sure what happened with the one that has a circular burn mark on it, but, that gray colored goop on it isn't right either. Don't know where that gray colored stuff came from, but it's not factory.
I'm a huge Peavey user with many systems (Versarray, QW, SP) and I can tell you that they should not look like that.
Time for some baskets my friend.
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It also looks like one of those baskets has more windings on it as compared to the other.
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00560450 1808-8 AL CP Pro Rider RB
This is the P/N for a SP118 replacement basket.
Are you sure you don't have a SP118X sub? They made two different version of those. One was 4 ohms and the other was 8 ohms.
I can clearly see 1808-4 SPS BWX RB label on the one basket with the toasted coil. If you in fact have the non "X" SP118 subs, the wrong basket has been installed.
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00560450 1808-8 AL CP Pro Rider RB
This is the P/N for a SP118 replacement basket.
Are you sure you don't have a SP118X sub? They made two different version of those. One was 4 ohms and the other was 8 ohms.
I can clearly see 1808-4 SPS BWX RB label on the one basket with the toasted coil. If you in fact have the non "X" SP118 subs, the wrong basket has been installed.
Sorry they are the sp118x subwoofers. Also the one with more windings and the circular mark has actual insulated wire from the leads to the coil and the other does not. So the coils being fried can cause them to work but pop? Sorry I'm just trying to figure this out. Anyone know the best place to get baskets?
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You can call PV parts department and order them yourself, or contact a local dealer and see if they have in stock.
You just need to know 4 or 8 ohm.
00560650 = 1808-4 SPS BWX RB
00560590 = 1808-8 SPS BWX RB
Here's the basket P/N for both the 4 and 8 ohm, the first one being the 4 ohm version.
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Sorry they are the sp118x subwoofers. Also the one with more windings and the circular mark has actual insulated wire from the leads to the coil and the other does not. So the coils being fried can cause them to work but pop? Sorry I'm just trying to figure this out. Anyone know the best place to get baskets?
Hi Mike:
As others have said, yep, toasted coils. They can be overheated, even severely overheated, and still pass current, which is why they still produce sound(and read resistance). The motor still functions, although poorly. This type of failure is most likely caused by long term over-powering, which results in long term overheating. The coil(s) will not be able to dissipate heat as fast as it's being produced, and that's why the enamel, or other materials insulating the thin wire darkens - just like toast. You can often tell how severe the overheating is by the color of the coil- the darker, the more burnt. Eventually, they will die, and stop altogether, if they are continued to be used.
You can see on the one coil, most of the windings are a shiny copper color, that's what they are supposed to look like, all over(still puzzling on that small burnt circle... a coil crop circle ??? )
Be sure to closely inspect the magnet assembly that that particular coil came out of, especially
In the gap where the coil slides into.
There's the possibility that there's either debris in the gap, or some other oddity that caused that small burnt circle, or, just could be the result of the wrong coil installed as well.
A good, though costly lesson, on using the proper limiting. Some one most likely did not know when to back off on volume, and over time, you have the result.
If you want to find out more on limiting voltage to a driver, Check out some searches on 'setting a limiter for speaker protection' and 'limiting voltage to a driver'
I'm fairly sure the archives have a schlew of threads on this.
Good that Tom is familiar with the proper replacement basket/coil, as I also think some one may have installed a wrong one in the one driver.
Best luck in getting them up and going soon,
Taylor
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You mentioned "bass exciter" in you first post. I would go easy on using that or better yet not at all. Keep in mind you only have two single 18 cabinets, they'll give you some nice thump and bump but don't expect them or make them try to do chest collapsing, pant leg blowing large room or outdoors low end. You'll need more cabinets and power to do that not a "bass exciter". Make sure you use a high pass filter and watch for clip lights.
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Hey guys, I cleaned that gray crap off the coil with the "crop circle" and cleaned the gap out on the mag. Tried it out last night at a gig and it did pretty well, still couldnt push a lot of power to it with out it popping though. The other one I threw in the trash and ordered a new basket. Should be here this week. Im going to compair the 2 and if the new one works ALOT better then the one I still have, Im going to buy another basket. I have 2 amps and im not sure which I should run them off of. I want to get the most out of them but not smoke them haha. I have a Mackie FR2500 and an AB International 1100A. Any input??
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I have 2 amps and im not sure which I should run them off of. I want to get the most out of them but not smoke them haha. I have a Mackie FR2500 and an AB International 1100A. Any input??
If, as Mike C notes above, you're using a bass exciter, I'd err on the side of caution and use no more than the continuous rated power of the system - so if it's rated 1200W Program, use a 600W per channel (@ the nominal impedance of the speakers) amp.
Also make sure you're using a High Pass Filter in your signal chain before the amp, set to just below the -3dB point of the speakers* to minimise the amount of LF content lower than what the speakers can handle reaching them.
* Or whatever the manufacturer recommends if you can source that.
HTH,
David.
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Okay I bought a replacement basket and now have another question. Are these supposed to be 4ohm? The crossovers say 4ohm but according to the manual from the replacement the 8ohm has a better xmax and is the best choice for subwoofers. So why the 4ohm in these cabs??
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Okay I bought a replacement basket and now have another question. Are these supposed to be 4ohm? The crossovers say 4ohm but according to the manual from the replacement the 8ohm has a better xmax and is the best choice for subwoofers. So why the 4ohm in these cabs??
Did you replace what you already had, or did you have your Peavey dealer order the part number specified by Peavey Service?
Regardless, cabinet tuning will affect impedance as "seen" by the amplifier.
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Did you replace what you already had, or did you have your Peavey dealer order the part number specified by Peavey Service?
Regardless, cabinet tuning will affect impedance as "seen" by the amplifier.
I bought the replacement that the peavey dealer said was in the cab. (1808-4 sps bwx) 4ohm. BUT the manual that it came with says that the better the XMAX the better the driver is for a subwoofer. And according to the manual, the XMAX for the 8ohm (1808-8 sps bwx) is 3 times the amount of the 4ohm. So why would they use the 4ohm instead of the 8ohm when they are the same power and same price??
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the manual that it came with says that the better the XMAX the better the driver is for a subwoofer.
Yes that's right.
And according to the manual, the XMAX for the 8ohm (1808-8 sps bwx) is 3 times the amount of the 4ohm.
No it's only about 2x.. 4.6mm vs 2.0mm.. which is significant but it's still only half of what an 800w driver needs to operate effectively as a subwoofer.
So why would they use the 4ohm instead of the 8ohm
Amplifiers produce more power into a 4ohm load so a smaller(cheaper) amp can be utilized, this is an entry level product after all.
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I bought the replacement that the peavey dealer said was in the cab. (1808-4 sps bwx) 4ohm. BUT the manual that it came with says that the better the XMAX the better the driver is for a subwoofer. And according to the manual, the XMAX for the 8ohm (1808-8 sps bwx) is 3 times the amount of the 4ohm. So why would they use the 4ohm instead of the 8ohm when they are the same power and same price??
I'm guessing that the 4 ohm VC exhibits ~8 ohm impedance when the speaker is in the cab. If that's the case, an 8 ohm VC would exhibit around 16 ohm impedance. See where this is going?
I'm not buying 3x the Xmax, either. That doesn't make sense for 2 versions of the same speaker. I suspect the manual writer was discussion in more general terms, what makes for a better subwoofer compared to what makes a good LF transducer.
Either way, the speaker and cab go together. Why they made a particular decision is a question of Peavey, not us.
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Yes that's right.
No it's only about 2x.. 4.6mm vs 2.0mm.. which is significant but it's still only half of what an 800w driver needs to operate effectively as a subwoofer.
Amplifiers produce more power into a 4ohm load so a smaller(cheaper) amp can be utilized, this is an entry level product after all.
But at the same time, 4ohm makes it so you cant bridge. Brings it down to 2 ohm. Either way, The SP118X Comes in 8ohm or 4ohm versions, and im just curious if the 8ohm actually is a better speaker due to the XMAX. They are the same price tho so I dont see why it would be..
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But at the same time, 4ohm makes it so you cant bridge. Brings it down to 2 ohm. Either way, The SP118X Comes in 8ohm or 4ohm versions, and im just curious if the 8ohm actually is a better speaker due to the XMAX. They are the same price tho so I dont see why it would be..
It is entirely possible that the X max is simply a misprint. There is no reason why the X max would be different for the same driver with a different impedance.
HOWEVER it is also possible that some confusion of terms has happened.
Maybe one is X max and the other is X Mech. Could be somebody either misread or misunderstood the differences.
Or there may be a real difference. But a difference in Xmax (especially that much) should mean a different model number-because that big a difference would be quite a bit different.
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It is entirely possible that the X max is simply a misprint. There is no reason why the X max would be different for the same driver with a different impedance.
HOWEVER it is also possible that some confusion of terms has happened.
Maybe one is X max and the other is X Mech. Could be somebody either misread or misunderstood the differences.
Or there may be a real difference. But a difference in Xmax (especially that much) should mean a different model number-because that big a difference would be quite a bit different.
This is copied directly from the peavey spec sheet which can be found at http://www.peavey.com/assets/literature/specs/116630_13591.pdf
(http://i889.photobucket.com/albums/ac94/djspreewell/PeaveyXMAX.jpg)
So thats why I wondered if the 8ohm is actually a better choice.
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This is copied directly from the peavey spec sheet which can be found at http://www.peavey.com/assets/literature/specs/116630_13591.pdf
(http://i889.photobucket.com/albums/ac94/djspreewell/PeaveyXMAX.jpg)
So thats why I wondered if the 8ohm is actually a better choice.
Since so many of the other parameters are different-it seems all they have in common is the model number. It is strange that the model number would be the same-for such different loudspeakers.
There is more than just X max. That is just one parameter that gives an idea of what the performance may be.
If that is all there was-then why don't PA cabinets use home theatre type drivers? Those drivers have some VERY IMPRESSIVE X Max. And it is quite "interesting" to watch them move around. Of course you gets lots of distortion with that large movement.
And remember that there is a tradeoff for low freq extension. Generally it is loud or low. What is more important.
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Since so many of the other parameters are different-it seems all they have in common is the model number. It is strange that the model number would be the same-for such different loudspeakers.
There is more than just X max. That is just one parameter that gives an idea of what the performance may be.
If that is all there was-then why don't PA cabinets use home theatre type drivers? Those drivers have some VERY IMPRESSIVE X Max. And it is quite "interesting" to watch them move around. Of course you gets lots of distortion with that large movement.
And remember that there is a tradeoff for low freq extension. Generally it is loud or low. What is more important.
You just answered my question. I would much rather have it be loud and be heard through the whole building then have it shake your shirt but only if your right in front of it! The SP118x come in 4ohm or 8ohm and im guessing the driver is the difference, but they claim to be the same thing. thats why I was confused after reading the specs.
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You just answered my question. I would much rather have it be loud and be heard through the whole building then have it shake your shirt but only if your right in front of it! The SP118x come in 4ohm or 8ohm and im guessing the driver is the difference, but they claim to be the same thing. thats why I was confused after reading the specs.
Sounds like a call to the manufacturer would be in order.
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Even with what appears to be very different TS specs it is possible these two drivers would sound quite similar in the same box. And again IMO even 4.6mm xmax is a bit low for a PA sub(just 40hz response here not 15hz home theater rumble) that is supposed to handle 1000w, so if you're looking at buying other drivers I'd suggest the Lowrider 18. You would have to do some testing to see what the final system response would be with that driver/cabinet combo but the Lowrider also works well in 5-9cu/ft enclosures.