Buddy of mine recently aquired two infinity 1042w DVC 4 ohm subs...Originally, the subs were hooked up to a memphis monoblock in a ported box...worked fine. Well, he brings it over to my house, and we hook up one sub to my alpine 300 watt monoblock...and nothing. Wired it @ 2 ohms, and when I hook my other subs up, they work fine...amp isnt going into protect, and is receiving audio input from the deck...but getting no cone movement or response from the infinity's...any ideas other than a blown sub? The only thing tripping me up on this one is the fact that, I hook it up to the memphis amp, and it works like rims at a p diddy concert.
---Good to be back.
Tink
Replies (21)
swez on 06/22/2008 07:34:23
Hey Tink, welcome back to CK!
It seems like he has one blown sub here, based on your test. The best way to confirm that is with an Ohm meter.
Each coil should read about 3.4 ohms each. (Both coils OK)
If the meter reads below 1 ohm, that coil is shorting out.
If the meter shows no value, the coil is open. (Wire separated, no flow)
A less common issue that can also happen, while feeding the sub power, manually manipulate the cone in and out with your fingers and thumb. If it suddenly comes back to life and thumps along normally, this indicates loose tinsel lead connections. (Most often under the dust cap)
This is a very delicate repair job at best,
Swez
Tinker18 on 06/22/2008 08:13:58
Well, I have a ohm meter, but not exactly sure how to test it...the oddity of it all is that with the other amp, the system works fine...both subs hooked up by themselves to my alpine, either in a dual set up or single, neither work.
Tinker18 on 06/22/2008 08:35:32
ok, so just bench tested the subs again, hooked up in a single configurations, wired 2 ohms, my ohm meter reads 4.5 ohms roughly, at the leads goign in, and the leads at the bottom of the cone going to voice coil...still no response from the cone...what does it mean?
swez on 06/22/2008 10:10:14
This is a real puzzler Tink!
If your meter is reading 4.5 ohms when both subs are wired into the box, that suggests they are wired in a series/parallel configuration together. (Net 4 ohm load expected) That's a safe load for most any amp on the market. Your reading of 4.5 ohms may indicate this meter has a weak battery or slightly out of calibration. In the series/parallel configuration, I would expect a meter reading slightly below 4.0 ohms
But what I don't get... why the subs work fine on his Memphis amp and not on your Alpine is a mystery to me??? (Scratching our heads huh?) I could see your Alpine putting out less power to a 4 ohm load, but for the subs not to work at all, makes little sense here.
The only thing that makes any sense in this scenario, would be if you hooked up his subs to your amp using 2 Positive lugs or 2 Negative lugs.
The proper way would be one wire to the Pos lug and the other to the Neg lug on your Alpine. If the subs are wired properly, that should produce the desired results.
Comments?
Swez
Tinker18 on 06/22/2008 10:33:54
pos on one coil to pos on other, neg on one to neg on other, neg and pos to amp....shoud net a 2 ohm load correct??? now, what else could prevent cone movement, power not making it from the posts to where the coil is at in the magnet?
Tinker18 on 06/22/2008 10:46:54
also, only wired one sub when i tested it, not both
swez on 06/22/2008 11:02:09
Yep, net 2 ohms here as noted. Even if one coil was bad, the other one would give some output. Are your wires good and tight?
Consider trying one coil at a time to your amp at very low power. That's 4 ohms and will be safe to amp and sub at 10-20 watts power from the amp. It may not sound full, but if you get bass on both coil sets, the sub is OK. If not, there's a reason and more digging is needed to find out why.
Swez
Tinker18 on 06/22/2008 12:06:03
Tried that already, even wiring one coil independently the sub does not respond...is there anyway to test to see if the power is getting down to the electromagnet? This really doesn make sense to me, if the sub is getting power, it should be responding. Yeah, the wires are good and tight, otherwise my ohm meter wouldnt be responding, honestly at a loss here...
ttocs on 06/22/2008 13:31:13
start simple - is there any chance that you have the coils on the subs wired backwards from one another? It is easy to do as often the pos is reversed on the other side of the coil and if you were to wire the coils backward on a DVC sub this is what would happen. The signal would be driving the coils exactly opposite one another with the exact same amount of energy so the sub would not move while the amp would still be under load.
I have done it once and the I double checked every time after.
Tinker18 on 06/22/2008 15:19:11
Absolutely no chance. The reason being...well, each one has caps that are not removable, they are color coded...double triple and quadruple checked...its wired right..and like i said, even wiring only one coil, does not get a response from the subs...
swez on 06/22/2008 15:24:53
Ttocs' suggestion hit me later tonight while fishing as well. It would be very easy to wire up sub Coil A Pos and sub Coil B Neg and get no results.
The other scenario is mis-wiring the polarity of each coil and the net results would cancel each other out and hense, no sound.
The only electromagnet phenom in these subs would be the voice coils. The main magnet structure is a permanent magnet on the back cage of the basket. To motivate the sub cone, we apply AC voltage to the voice coils. This AC voltage is what makes the cone move air and reproduce sound. The change in voltage polarity is what "motivates" the cone into action. (Pulling in or pushing out of the cone is dictated by the shifts in AC voltage and frequency) That's how speakers work.
Take a closer look at your wiring on the bench. If the subs worked before, that's the most logical explanation for this scenario.
Swez
Tinker18 on 06/22/2008 15:48:50
No, the wiring is right...double checked, again. everything is wired right...my question about the voice coils, is this...I know it getting power to the leads at the base of the cone, but after that, who knows??!?! is there anyway to test and see if the actual voice coil is recieving power???!?!? I know iHave not miswired it...
Tinker18 on 06/22/2008 15:50:28
afternote..
I have switched the wires, and tried every configuration possible,
so I know for a fact its not the wiring.
swez on 06/23/2008 01:24:06
This has got to be one of the most unusual "head scratchers" I've seen on this site Tink. Am sure you know what to do and tested this sub 6-ways til Sunday, but still no solid conclusions?
"is there anyway to test and see if the actual voice coil is recieving power???!?!?"
There is, but it's invasive surgery to do so. The dust cap has to be removed and use a meter to monitor AC voltage where the coils meet the tinsel leads.
One trick that sometimes shows where the root problem lies, is to power up the sub and manipulate the cone in and out with our fingers. If this gets the sub working, the connections at the cone, coils and tinsel lead junction have been damaged and need to be reworked with a delicate hand and a low wattage soldering pen.
Finally, had a quick look at the manual for this sub and noted it has the tradition opposing lugs on either side of the basket. This makes things a lot easier to test each coil set. Here's a link that explains the guts of a speaker and how they work:
http://www.bcae1.com/speaker.htm
Swez
The only other conclusion I can offer here, test the other sub too. If his enclosure is ported and has no dividers, if one sub does work, it will motivate a dead sub to move as well. (Passive radiator effect)
Tinker18 on 06/27/2008 13:17:54
I am familiar with the "passive radiator effect" and I have tested both subs individually and by themselves..not a response from either, but both show voltage to the furthest point....The finger thumb thing...no response tried that already...I am at a loss on this one unless the leads from the cone to the voice coil have been severed and arent conducting..
here is a thought swez...with the way a speaker is built it should create a closed loop aka closed circuit if everything is in good working order correct? Maybe I could wire up a low voltage scenario involving an led to see if the power is passing through the speaker and closing the loop right?
swez on 06/27/2008 13:36:39
Yes Tink, the voice coils are a closed loop system. There're actually AC driven electromagnets, set in a permanent magnet fixture. If there is AC power flowing through the coil(s), it will move the coil and cone to produce sound.
LED's work on DC voltage only. Audio signals are AC voltage. So the LED plan won't work w/o and AC/DC converter.
A common failure mode in subs is too much low bass power that makes the cones move beyond normal limits. (past X-max limits) This often pulls the tinsel leads from the binding post or tears them under the dust cap. This is a common mechanical failure.
A thermal failure often melts the tiny coil wires until they burn through and creates an open circuit. This is often noted within the first inch of coil wires as they attach to the coil windings. Why there? No heat sink from the coil to help cool it.
Get the picture?
Swez
Tinker18 on 06/27/2008 13:48:38
Well, let me boggle you some more. Curiosity finally killed the cat, or in this case, the subwoofer...disturbing the results they are... lol..
anyway,
took one sub, and not so delicately ripped the cone off with a razor knife, and cut away the spider....surely to find some tinsel leads burnt or broken right??
wrong...
all the lead are intact and when i test them with a 9v...current flows relegiously....sooo....what pray tell could ever be going on i wonder..
the sub demons are at work once again.
swez on 06/27/2008 14:56:59
As my Mom used to shriek out when she thought I did something naughty... "What in theee Worrldddd are you doing over there child?"
Now that the sub is toast, remove the dust cap and have a good look at the lead attachments under the cap and see how they look.
Think Tink is right... these subs are possessed? In 9 years on this board, this has got to be one of the most baffling, simple, stubborn snigglets I have yet to encounter. I just don't get this either.
Can you take pics and load them to say photobucket.com or similar?
Swez
Tinker18 on 06/27/2008 15:29:03
Yeah, I'll get right on getting some pics in...odd thing is, they ar attached alll the way to the coils...
Victor on 06/27/2008 16:20:57
This definitely is a mechanical failure ....
if the VC shows integrity and your meter reads well, yet the cone doesn't move... then i would believe there is something wrong between the VC and the cone and no where else..
Check if the VC former is attached to the cone>>>>????
the VC is wound on a former, and this former glued to the cone ...
ported enclosure, over excursion, improper SSF setting, common chamber for both subs and high temperatures could have caused the cone to separate from the former, and above all poor quality of glue ,improper bonding surface and weak former material contributes heavily to such failures..
although such failures are very very rare with reputed manufacturers ...
before coming to a final verdict for the cause and reason, just have a look at the integrity on the bonding of cone and the VC former....
Let us first find out WHAT is wrong, before we come to a conclusion on WHY it happened.....
Victor...
PS: I hope u have not torn apart a sub thats under warranty... casue then you would surely get no replacement or repair done for free or nominal amounts....
swez on 06/28/2008 13:28:02
After noodling this over a bit, if the coils are passing current, but the cone does not move, that may suggest a seized VC.
As Victor pointed out, if the coil/former separates from the cone/spider and the coils are still free to move, this will make some terrible noises when the coils are powered up.
However, if the coil has seized in the gap, the cone will not move, even if the VC's are electrically charged. Since you cut this sub apart already, you can check to see if the VC can easily be removed from the pole piece or not. If it's stuck or hard to remove, the former may have been damaged or the pole piece has shifted. (dropped sub)
When the former is properly aligned on the pole piece and the gap is normal, this assy move easily.
Check it out and see,
Swez
---Good to be back.
Tink
Replies (21)
swez on 06/22/2008 07:34:23
Hey Tink, welcome back to CK!
It seems like he has one blown sub here, based on your test. The best way to confirm that is with an Ohm meter.
Each coil should read about 3.4 ohms each. (Both coils OK)
If the meter reads below 1 ohm, that coil is shorting out.
If the meter shows no value, the coil is open. (Wire separated, no flow)
A less common issue that can also happen, while feeding the sub power, manually manipulate the cone in and out with your fingers and thumb. If it suddenly comes back to life and thumps along normally, this indicates loose tinsel lead connections. (Most often under the dust cap)
This is a very delicate repair job at best,
Swez
Tinker18 on 06/22/2008 08:13:58
Well, I have a ohm meter, but not exactly sure how to test it...the oddity of it all is that with the other amp, the system works fine...both subs hooked up by themselves to my alpine, either in a dual set up or single, neither work.
Tinker18 on 06/22/2008 08:35:32
ok, so just bench tested the subs again, hooked up in a single configurations, wired 2 ohms, my ohm meter reads 4.5 ohms roughly, at the leads goign in, and the leads at the bottom of the cone going to voice coil...still no response from the cone...what does it mean?
swez on 06/22/2008 10:10:14
This is a real puzzler Tink!
If your meter is reading 4.5 ohms when both subs are wired into the box, that suggests they are wired in a series/parallel configuration together. (Net 4 ohm load expected) That's a safe load for most any amp on the market. Your reading of 4.5 ohms may indicate this meter has a weak battery or slightly out of calibration. In the series/parallel configuration, I would expect a meter reading slightly below 4.0 ohms
But what I don't get... why the subs work fine on his Memphis amp and not on your Alpine is a mystery to me??? (Scratching our heads huh?) I could see your Alpine putting out less power to a 4 ohm load, but for the subs not to work at all, makes little sense here.
The only thing that makes any sense in this scenario, would be if you hooked up his subs to your amp using 2 Positive lugs or 2 Negative lugs.
The proper way would be one wire to the Pos lug and the other to the Neg lug on your Alpine. If the subs are wired properly, that should produce the desired results.
Comments?
Swez
Tinker18 on 06/22/2008 10:33:54
pos on one coil to pos on other, neg on one to neg on other, neg and pos to amp....shoud net a 2 ohm load correct??? now, what else could prevent cone movement, power not making it from the posts to where the coil is at in the magnet?
Tinker18 on 06/22/2008 10:46:54
also, only wired one sub when i tested it, not both
swez on 06/22/2008 11:02:09
Yep, net 2 ohms here as noted. Even if one coil was bad, the other one would give some output. Are your wires good and tight?
Consider trying one coil at a time to your amp at very low power. That's 4 ohms and will be safe to amp and sub at 10-20 watts power from the amp. It may not sound full, but if you get bass on both coil sets, the sub is OK. If not, there's a reason and more digging is needed to find out why.
Swez
Tinker18 on 06/22/2008 12:06:03
Tried that already, even wiring one coil independently the sub does not respond...is there anyway to test to see if the power is getting down to the electromagnet? This really doesn make sense to me, if the sub is getting power, it should be responding. Yeah, the wires are good and tight, otherwise my ohm meter wouldnt be responding, honestly at a loss here...
ttocs on 06/22/2008 13:31:13
start simple - is there any chance that you have the coils on the subs wired backwards from one another? It is easy to do as often the pos is reversed on the other side of the coil and if you were to wire the coils backward on a DVC sub this is what would happen. The signal would be driving the coils exactly opposite one another with the exact same amount of energy so the sub would not move while the amp would still be under load.
I have done it once and the I double checked every time after.
Tinker18 on 06/22/2008 15:19:11
Absolutely no chance. The reason being...well, each one has caps that are not removable, they are color coded...double triple and quadruple checked...its wired right..and like i said, even wiring only one coil, does not get a response from the subs...
swez on 06/22/2008 15:24:53
Ttocs' suggestion hit me later tonight while fishing as well. It would be very easy to wire up sub Coil A Pos and sub Coil B Neg and get no results.
The other scenario is mis-wiring the polarity of each coil and the net results would cancel each other out and hense, no sound.
The only electromagnet phenom in these subs would be the voice coils. The main magnet structure is a permanent magnet on the back cage of the basket. To motivate the sub cone, we apply AC voltage to the voice coils. This AC voltage is what makes the cone move air and reproduce sound. The change in voltage polarity is what "motivates" the cone into action. (Pulling in or pushing out of the cone is dictated by the shifts in AC voltage and frequency) That's how speakers work.
Take a closer look at your wiring on the bench. If the subs worked before, that's the most logical explanation for this scenario.
Swez
Tinker18 on 06/22/2008 15:48:50
No, the wiring is right...double checked, again. everything is wired right...my question about the voice coils, is this...I know it getting power to the leads at the base of the cone, but after that, who knows??!?! is there anyway to test and see if the actual voice coil is recieving power???!?!? I know iHave not miswired it...
Tinker18 on 06/22/2008 15:50:28
afternote..
I have switched the wires, and tried every configuration possible,
so I know for a fact its not the wiring.
swez on 06/23/2008 01:24:06
This has got to be one of the most unusual "head scratchers" I've seen on this site Tink. Am sure you know what to do and tested this sub 6-ways til Sunday, but still no solid conclusions?
"is there anyway to test and see if the actual voice coil is recieving power???!?!?"
There is, but it's invasive surgery to do so. The dust cap has to be removed and use a meter to monitor AC voltage where the coils meet the tinsel leads.
One trick that sometimes shows where the root problem lies, is to power up the sub and manipulate the cone in and out with our fingers. If this gets the sub working, the connections at the cone, coils and tinsel lead junction have been damaged and need to be reworked with a delicate hand and a low wattage soldering pen.
Finally, had a quick look at the manual for this sub and noted it has the tradition opposing lugs on either side of the basket. This makes things a lot easier to test each coil set. Here's a link that explains the guts of a speaker and how they work:
http://www.bcae1.com/speaker.htm
Swez
The only other conclusion I can offer here, test the other sub too. If his enclosure is ported and has no dividers, if one sub does work, it will motivate a dead sub to move as well. (Passive radiator effect)
Tinker18 on 06/27/2008 13:17:54
I am familiar with the "passive radiator effect" and I have tested both subs individually and by themselves..not a response from either, but both show voltage to the furthest point....The finger thumb thing...no response tried that already...I am at a loss on this one unless the leads from the cone to the voice coil have been severed and arent conducting..
here is a thought swez...with the way a speaker is built it should create a closed loop aka closed circuit if everything is in good working order correct? Maybe I could wire up a low voltage scenario involving an led to see if the power is passing through the speaker and closing the loop right?
swez on 06/27/2008 13:36:39
Yes Tink, the voice coils are a closed loop system. There're actually AC driven electromagnets, set in a permanent magnet fixture. If there is AC power flowing through the coil(s), it will move the coil and cone to produce sound.
LED's work on DC voltage only. Audio signals are AC voltage. So the LED plan won't work w/o and AC/DC converter.
A common failure mode in subs is too much low bass power that makes the cones move beyond normal limits. (past X-max limits) This often pulls the tinsel leads from the binding post or tears them under the dust cap. This is a common mechanical failure.
A thermal failure often melts the tiny coil wires until they burn through and creates an open circuit. This is often noted within the first inch of coil wires as they attach to the coil windings. Why there? No heat sink from the coil to help cool it.
Get the picture?
Swez
Tinker18 on 06/27/2008 13:48:38
Well, let me boggle you some more. Curiosity finally killed the cat, or in this case, the subwoofer...disturbing the results they are... lol..
anyway,
took one sub, and not so delicately ripped the cone off with a razor knife, and cut away the spider....surely to find some tinsel leads burnt or broken right??
wrong...
all the lead are intact and when i test them with a 9v...current flows relegiously....sooo....what pray tell could ever be going on i wonder..
the sub demons are at work once again.
swez on 06/27/2008 14:56:59
As my Mom used to shriek out when she thought I did something naughty... "What in theee Worrldddd are you doing over there child?"
Now that the sub is toast, remove the dust cap and have a good look at the lead attachments under the cap and see how they look.
Think Tink is right... these subs are possessed? In 9 years on this board, this has got to be one of the most baffling, simple, stubborn snigglets I have yet to encounter. I just don't get this either.
Can you take pics and load them to say photobucket.com or similar?
Swez
Tinker18 on 06/27/2008 15:29:03
Yeah, I'll get right on getting some pics in...odd thing is, they ar attached alll the way to the coils...
Victor on 06/27/2008 16:20:57
This definitely is a mechanical failure ....
if the VC shows integrity and your meter reads well, yet the cone doesn't move... then i would believe there is something wrong between the VC and the cone and no where else..
Check if the VC former is attached to the cone>>>>????
the VC is wound on a former, and this former glued to the cone ...
ported enclosure, over excursion, improper SSF setting, common chamber for both subs and high temperatures could have caused the cone to separate from the former, and above all poor quality of glue ,improper bonding surface and weak former material contributes heavily to such failures..
although such failures are very very rare with reputed manufacturers ...
before coming to a final verdict for the cause and reason, just have a look at the integrity on the bonding of cone and the VC former....
Let us first find out WHAT is wrong, before we come to a conclusion on WHY it happened.....
Victor...
PS: I hope u have not torn apart a sub thats under warranty... casue then you would surely get no replacement or repair done for free or nominal amounts....
swez on 06/28/2008 13:28:02
After noodling this over a bit, if the coils are passing current, but the cone does not move, that may suggest a seized VC.
As Victor pointed out, if the coil/former separates from the cone/spider and the coils are still free to move, this will make some terrible noises when the coils are powered up.
However, if the coil has seized in the gap, the cone will not move, even if the VC's are electrically charged. Since you cut this sub apart already, you can check to see if the VC can easily be removed from the pole piece or not. If it's stuck or hard to remove, the former may have been damaged or the pole piece has shifted. (dropped sub)
When the former is properly aligned on the pole piece and the gap is normal, this assy move easily.
Check it out and see,
Swez
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