Was planning on selling my old Audiobahn 12" 400 watt subs and wanted to make sure they were operating fine before i sold them. Today i put them in my old box that holds 2 12"s and hooked them up and tested them individually. I found that 1 is having problems and i'm pretty sure it's blown out.
It seems to click on and off so to say. With the bass low you can not see any cone movement or hear bass at all and it seems like its not even turned on, but as you turn up the bass knob to max it "kicks" on and you can see cone movement and hear some bass. But even with the bass knob at max at times the cone just stops moving all together and you can hear a rattleing noise. then after about 15 seconds it "kicks" on again.
The times when the bass isn't max and the cone should be moving but it isn't, you can hear the rattle noise and you can start to smell something coming from the speaker until it "kicks" back on.
I was just wondering if anyone has heard of this and if there was a way that i could maybe take the speaker apart and fix it? I'm not to worried about messing it up more if i take it apart since it's already pretty much ruined as it is. If there's no way to fix it i figure i'll just sell the 1 good speaker instead of 2 but figured i'd post on here to see if anyone has experience with blown out speakers and how to take them apart and fix them.
Thanks
Replies (14)
swez on 08/25/2005 17:51:10
This sounds like a bad wire connection between termination posts and voice coils. If the problem is a bad solder joint at the termination lug, you're in luck as this is fixable. If the failure is at the voice coil/tinsle lead point, these are much harder to repair as the dust cap has to come off to get to this junction or the cone, spider and coil(s) have to be removed from the basket to make proper repairs.
BTW, tell me this was a BP or ported box the sub failed in???
Swez
Beau640 on 08/25/2005 19:19:31
Dual Bandpass. Why do you ask?
I have just a regular sealed enclosure i could transfer it to to test it there if it has something to do with the box type.
How would i go about finding out exactly what the problem is and if it's fixable? Is there an online guide that you know of?
Thanks
ttocs on 08/25/2005 22:49:34
when there is nothing hooked up to the speaker, and you push on it, does it move at all? Does it make noise?
Beau640 on 08/26/2005 00:03:06
you mean like when the speaker is out of the box and i just tap on the speaker?
swez on 08/26/2005 10:46:22
This kind of failure is common in BP and ported enclosures which are not properly matched to the subs. Even worse if the sub has a low EBP # (below 50) which is generally best used in sealed boxes. Here are some basic diagnostics you can do to determine where the sub coil is failing:
1. With woofer sitting on its magnet, cone facing upward, no power to sub, use your fingers to gently apply downward pressure on the cone and pump the cone in and out. Do you feel or hear any mechanical "scraping" going on?
If yes, the coil is probably charred from excess heat or out of alignment in the magnetic gap between coil and pole piece magnet. This requires a recone job. (voice coil replacement)
If no, the coil may still be OK, but the tinsel leads between wire lugs and voice coil may be loose. With care and patience, this is something you may be able to repair.
2. Perform these diagnostics with sub out of the enclosure, (free air) and a low power signal (5-10 watts) applied to the sub.
a. Place sub, cone down on a flat surface
b. Apply small audio signal to sub from an amp
c. With your fingers, wiggle the tinsel wires that are connected to the ternination lugs. If you get the sub working by doing this, resoldering the tinsel leads to the lugs, should cure the problem. (60/40 rosin core solder is used here)
d. If the lugs connections are good and tight, but no sound, move your fingers down to the place where the tinsel leads meet the cone. If the sub starts playing normally as you manipulate the wires at this point, the repair is notably more challenging at this location. The tinsel lead is joined to the voice coil at this location and delicate (skilled and patient) hands need to do this repair.
FYI: Bandpass and Ported subs have these sort of issues frequently. It's primarily "over excursion" of the cone, that causes this failure mode. Without proper back pressure or using these boxes w/o a SSF, (Subsonic Filter) the cone can easily go beyond X-max at half their rated power. The cone can jump wildly below tuned frequencies w/o an SSF to block signals below port tuned frequencies. Very common in poorly matched BP enclosures. The hard part is that we cannot even hear the problem as it happens in BP enclosure designs. The first sign of trouble, is often a blown sub. (no output)
Finally, I do not know of any links or sites that offer speaker repair info at this level. Most either send the sub back to Mfg for repair or a reconing service. A complete recone will cost about $70 - 85.00 plus S/H. If the sub is low priced, it may not be worth reconing.
Swez
Beau640 on 08/26/2005 17:07:33
Thanks a lot Swez :)
The subs only cost about 90 a piece so theres no way i'm paying someone else to fix it or sending it back to the manufacturer.
I did have a SSF on my amp but i'm 100% sure it was not set right for those subs cause i remember what it was set at and it was letting way too low of frequencies go through. This with the BP box is probably why these problems started.
I'm going away for the weekend so i don't have time to start repairing them now but on monday i'll for sure run all these tests and figure out what the problem is. Thanks so much for your detailed description on how to diagnosis this and i'll post again on Monday once i find out exactly what the problem is.
Thank You :)
swez on 08/26/2005 21:05:56
Good nuff.... just take your time in the diagnotics phase. With luck, it will be a simple soldering job at the lug/tinsel lead point. Those are easy to repair. The repair at coil/tinsel lead connection is much harder to do, w/o hacking up the cone or removing the dust cap. These are very tricky fixes.
Good Luck!
Swez
PS BP enclosure are notorious for damaging even the strongest subs. Most off the rack BP enclosures are not well matched to a given driver and when you don't know the tuning factors, setting the SSF correctly, makes all the more likely for premature sub failures. The worst part, most cannot observe the cone movements well enough to tell if there is a problem. That's one good reason for a plexiglass/lexan viewing window in BP enclosures.
Beau640 on 08/31/2005 20:38:16
Ok finally ran all the tests and got some unexpected results...
With the sub on its magnet, i push down on the cone in and out and i do not hear any noises what so ever. No scraping of any kind.
So i went on to the next set of steps, playing w/ the tinsel wires. At low wattage with the sub face down out of the enclosure, rather than hearing bass i hear a sort of rattling noise inside the magnet area...kind of like somethign is lose or rattling around in there. Wiggling the tinsel leads does not make this noise go away.
If i turn up the volume, the noise turns violent and the sub puts out a very strong smell. even like this playing w/ the tinsel leads does very little.
Not sure what the rattling noise could be or why the sub starts to smell when you turn it up.
Help! :)
swez on 08/31/2005 22:14:23
Check your spider to cone connection next. The spider is located above the magenet and is used to hold cone and voice coil in place. These joints are epoxied to the coil and help keep the coil in the magnetic gap. (in proper alignment)
To do this, rest the sub in your lap, on its side. Flex the cone with your thumb & fingers and look cloesly at the spider and coil to see if there is a separation of the cone/coil to the spider. If yes, there's your problem.
Can it be fixed? Sometimes it can be. I have done a few w/ success.
HOW TO:
1. Mix up a few cc's of 2 part epoxy on a paper plate
2. Stir/blend together until you see homogenious color
3. Load the mixture into a 3 cc syringe (pull the stopper stem out and load from back of syringe with a popsicle stick, nail or screwdriver tip)
4. With 1.5 - 2.0 cc's of epoxy in syringe, re-insert the plunger and evacuate the air by pressing the plunger in with tip facing up (no needles needed here)
5. Run a 1/8" bead of epoxy around the area where the cone and spider joint have separated
6. Set sub (magnet down) on a flat surface and break out the hair dryer and send warm air into the repair point while rotating the sub
It takes about 5-10 mins for the epoxy to cure. While you are heating the epoxy, make sure the joint is in original position from the factory. You will see a noticable ridge where the original epoxy joint was. Keep that alignment constant until the epoxy has cured.
Allow epoxy to air cure a bit (1 hour) at room air temperature, then test your work at low power to sub. If you got it right, the sub should work fine, as long as the voice coil was not charred too bad.
Here's a pic or 2 on how I did this for a buddy's Eclipse 8710 sub:
http://www.sounddomain.com/ride/171942/3 (Jeff's F-150 install)
Good luck,
Swez
PS Yeah, that's me with my lucky Orange Tide Racing Team cap on. Don't forget the beer as you work. Nothing like a cold beer on a warm day! Only if you are of age however... hehe
Beau640 on 09/5/2005 20:18:13
It's really hard for me to tell if the spider has been separated from the cone/coil. If i posted a few pictures on here of the spider and me pushin on the cone would it be possible for you to see if they are separated or not? I just am not quite sure of exactly what i'm supposed to look for.
Thanks
compvr15s on 09/5/2005 22:24:03
here is a link that explains the speaker
http://www.goodsound.com/howto/2001_06_01.htm
the spider is the yellow thing ruffled material you see when you look inside the back of a sub woofer. the voice coil is loacted in the center of the spider... its round and connected to the spider.... if you press the cone from the front while looking at the woofer, you will se the spider move up and down, if its seperated it wont move... just look you will notice a rip or tare, i think the cone will move a lil bit more freely if its seperated... does this help any. if not sorry. but good luck. yea you can definitly post some pics. will have to use yahoo or picturetrail. since we cant upload pics
swez on 09/6/2005 11:48:24
Yes, you can post a few pics of the sub if you wish. Focus on shots of the rear cone, spider and voice coil junction at rest and when cone is manually lifted outward/forward.
You can easily tell if the spider has separated, as there is little pressure needed to move the cone manually, in and out of the gap. Compare that pressure to your good sub. If there is a notable difference in physical pressure to move either cone, you can rest assured that the spider is not moving or providing resistance to cone manipulation. This is a sure sign of spider/coil joint failure and can easily be sees as you conduct these tests.
If that is what you see, follow the repair notes mentioned earlier. However, if you feel the repair is not within your skills, perhaps we can work out a plan whereby you can ship the sub to me and I will test it, repair if possible and return the sub to you.
If you wish to take that route, you cover the shipping costs both ways and a nominal repair fee.
What say you?
Swez
PS I live in the western burbs of Detroit, MI. (48135 Zip code) Where are you located?
Beau640 on 09/10/2005 01:51:38
Right by you Harper Woods 48225 remember me from a while ago? we had box building plans...
I could probably even just drop the sub off to you if we took that route haha i'm like no more than 15 min from you probably.
swez on 09/10/2005 10:58:00
Actually in Garden City, MI. Harper Woods is a bit of a ride, but yes, we can h ook up on personal e-mails or phone and discuss the options available. I might be able to fix this sub, depending on what's actually wrong with it.
Send me a private message or e-mail and we can discuss this more.
swezdp@juno.com
Swez
It seems to click on and off so to say. With the bass low you can not see any cone movement or hear bass at all and it seems like its not even turned on, but as you turn up the bass knob to max it "kicks" on and you can see cone movement and hear some bass. But even with the bass knob at max at times the cone just stops moving all together and you can hear a rattleing noise. then after about 15 seconds it "kicks" on again.
The times when the bass isn't max and the cone should be moving but it isn't, you can hear the rattle noise and you can start to smell something coming from the speaker until it "kicks" back on.
I was just wondering if anyone has heard of this and if there was a way that i could maybe take the speaker apart and fix it? I'm not to worried about messing it up more if i take it apart since it's already pretty much ruined as it is. If there's no way to fix it i figure i'll just sell the 1 good speaker instead of 2 but figured i'd post on here to see if anyone has experience with blown out speakers and how to take them apart and fix them.
Thanks
Replies (14)
swez on 08/25/2005 17:51:10
This sounds like a bad wire connection between termination posts and voice coils. If the problem is a bad solder joint at the termination lug, you're in luck as this is fixable. If the failure is at the voice coil/tinsle lead point, these are much harder to repair as the dust cap has to come off to get to this junction or the cone, spider and coil(s) have to be removed from the basket to make proper repairs.
BTW, tell me this was a BP or ported box the sub failed in???
Swez
Beau640 on 08/25/2005 19:19:31
Dual Bandpass. Why do you ask?
I have just a regular sealed enclosure i could transfer it to to test it there if it has something to do with the box type.
How would i go about finding out exactly what the problem is and if it's fixable? Is there an online guide that you know of?
Thanks
ttocs on 08/25/2005 22:49:34
when there is nothing hooked up to the speaker, and you push on it, does it move at all? Does it make noise?
Beau640 on 08/26/2005 00:03:06
you mean like when the speaker is out of the box and i just tap on the speaker?
swez on 08/26/2005 10:46:22
This kind of failure is common in BP and ported enclosures which are not properly matched to the subs. Even worse if the sub has a low EBP # (below 50) which is generally best used in sealed boxes. Here are some basic diagnostics you can do to determine where the sub coil is failing:
1. With woofer sitting on its magnet, cone facing upward, no power to sub, use your fingers to gently apply downward pressure on the cone and pump the cone in and out. Do you feel or hear any mechanical "scraping" going on?
If yes, the coil is probably charred from excess heat or out of alignment in the magnetic gap between coil and pole piece magnet. This requires a recone job. (voice coil replacement)
If no, the coil may still be OK, but the tinsel leads between wire lugs and voice coil may be loose. With care and patience, this is something you may be able to repair.
2. Perform these diagnostics with sub out of the enclosure, (free air) and a low power signal (5-10 watts) applied to the sub.
a. Place sub, cone down on a flat surface
b. Apply small audio signal to sub from an amp
c. With your fingers, wiggle the tinsel wires that are connected to the ternination lugs. If you get the sub working by doing this, resoldering the tinsel leads to the lugs, should cure the problem. (60/40 rosin core solder is used here)
d. If the lugs connections are good and tight, but no sound, move your fingers down to the place where the tinsel leads meet the cone. If the sub starts playing normally as you manipulate the wires at this point, the repair is notably more challenging at this location. The tinsel lead is joined to the voice coil at this location and delicate (skilled and patient) hands need to do this repair.
FYI: Bandpass and Ported subs have these sort of issues frequently. It's primarily "over excursion" of the cone, that causes this failure mode. Without proper back pressure or using these boxes w/o a SSF, (Subsonic Filter) the cone can easily go beyond X-max at half their rated power. The cone can jump wildly below tuned frequencies w/o an SSF to block signals below port tuned frequencies. Very common in poorly matched BP enclosures. The hard part is that we cannot even hear the problem as it happens in BP enclosure designs. The first sign of trouble, is often a blown sub. (no output)
Finally, I do not know of any links or sites that offer speaker repair info at this level. Most either send the sub back to Mfg for repair or a reconing service. A complete recone will cost about $70 - 85.00 plus S/H. If the sub is low priced, it may not be worth reconing.
Swez
Beau640 on 08/26/2005 17:07:33
Thanks a lot Swez :)
The subs only cost about 90 a piece so theres no way i'm paying someone else to fix it or sending it back to the manufacturer.
I did have a SSF on my amp but i'm 100% sure it was not set right for those subs cause i remember what it was set at and it was letting way too low of frequencies go through. This with the BP box is probably why these problems started.
I'm going away for the weekend so i don't have time to start repairing them now but on monday i'll for sure run all these tests and figure out what the problem is. Thanks so much for your detailed description on how to diagnosis this and i'll post again on Monday once i find out exactly what the problem is.
Thank You :)
swez on 08/26/2005 21:05:56
Good nuff.... just take your time in the diagnotics phase. With luck, it will be a simple soldering job at the lug/tinsel lead point. Those are easy to repair. The repair at coil/tinsel lead connection is much harder to do, w/o hacking up the cone or removing the dust cap. These are very tricky fixes.
Good Luck!
Swez
PS BP enclosure are notorious for damaging even the strongest subs. Most off the rack BP enclosures are not well matched to a given driver and when you don't know the tuning factors, setting the SSF correctly, makes all the more likely for premature sub failures. The worst part, most cannot observe the cone movements well enough to tell if there is a problem. That's one good reason for a plexiglass/lexan viewing window in BP enclosures.
Beau640 on 08/31/2005 20:38:16
Ok finally ran all the tests and got some unexpected results...
With the sub on its magnet, i push down on the cone in and out and i do not hear any noises what so ever. No scraping of any kind.
So i went on to the next set of steps, playing w/ the tinsel wires. At low wattage with the sub face down out of the enclosure, rather than hearing bass i hear a sort of rattling noise inside the magnet area...kind of like somethign is lose or rattling around in there. Wiggling the tinsel leads does not make this noise go away.
If i turn up the volume, the noise turns violent and the sub puts out a very strong smell. even like this playing w/ the tinsel leads does very little.
Not sure what the rattling noise could be or why the sub starts to smell when you turn it up.
Help! :)
swez on 08/31/2005 22:14:23
Check your spider to cone connection next. The spider is located above the magenet and is used to hold cone and voice coil in place. These joints are epoxied to the coil and help keep the coil in the magnetic gap. (in proper alignment)
To do this, rest the sub in your lap, on its side. Flex the cone with your thumb & fingers and look cloesly at the spider and coil to see if there is a separation of the cone/coil to the spider. If yes, there's your problem.
Can it be fixed? Sometimes it can be. I have done a few w/ success.
HOW TO:
1. Mix up a few cc's of 2 part epoxy on a paper plate
2. Stir/blend together until you see homogenious color
3. Load the mixture into a 3 cc syringe (pull the stopper stem out and load from back of syringe with a popsicle stick, nail or screwdriver tip)
4. With 1.5 - 2.0 cc's of epoxy in syringe, re-insert the plunger and evacuate the air by pressing the plunger in with tip facing up (no needles needed here)
5. Run a 1/8" bead of epoxy around the area where the cone and spider joint have separated
6. Set sub (magnet down) on a flat surface and break out the hair dryer and send warm air into the repair point while rotating the sub
It takes about 5-10 mins for the epoxy to cure. While you are heating the epoxy, make sure the joint is in original position from the factory. You will see a noticable ridge where the original epoxy joint was. Keep that alignment constant until the epoxy has cured.
Allow epoxy to air cure a bit (1 hour) at room air temperature, then test your work at low power to sub. If you got it right, the sub should work fine, as long as the voice coil was not charred too bad.
Here's a pic or 2 on how I did this for a buddy's Eclipse 8710 sub:
http://www.sounddomain.com/ride/171942/3 (Jeff's F-150 install)
Good luck,
Swez
PS Yeah, that's me with my lucky Orange Tide Racing Team cap on. Don't forget the beer as you work. Nothing like a cold beer on a warm day! Only if you are of age however... hehe
Beau640 on 09/5/2005 20:18:13
It's really hard for me to tell if the spider has been separated from the cone/coil. If i posted a few pictures on here of the spider and me pushin on the cone would it be possible for you to see if they are separated or not? I just am not quite sure of exactly what i'm supposed to look for.
Thanks
compvr15s on 09/5/2005 22:24:03
here is a link that explains the speaker
http://www.goodsound.com/howto/2001_06_01.htm
the spider is the yellow thing ruffled material you see when you look inside the back of a sub woofer. the voice coil is loacted in the center of the spider... its round and connected to the spider.... if you press the cone from the front while looking at the woofer, you will se the spider move up and down, if its seperated it wont move... just look you will notice a rip or tare, i think the cone will move a lil bit more freely if its seperated... does this help any. if not sorry. but good luck. yea you can definitly post some pics. will have to use yahoo or picturetrail. since we cant upload pics
swez on 09/6/2005 11:48:24
Yes, you can post a few pics of the sub if you wish. Focus on shots of the rear cone, spider and voice coil junction at rest and when cone is manually lifted outward/forward.
You can easily tell if the spider has separated, as there is little pressure needed to move the cone manually, in and out of the gap. Compare that pressure to your good sub. If there is a notable difference in physical pressure to move either cone, you can rest assured that the spider is not moving or providing resistance to cone manipulation. This is a sure sign of spider/coil joint failure and can easily be sees as you conduct these tests.
If that is what you see, follow the repair notes mentioned earlier. However, if you feel the repair is not within your skills, perhaps we can work out a plan whereby you can ship the sub to me and I will test it, repair if possible and return the sub to you.
If you wish to take that route, you cover the shipping costs both ways and a nominal repair fee.
What say you?
Swez
PS I live in the western burbs of Detroit, MI. (48135 Zip code) Where are you located?
Beau640 on 09/10/2005 01:51:38
Right by you Harper Woods 48225 remember me from a while ago? we had box building plans...
I could probably even just drop the sub off to you if we took that route haha i'm like no more than 15 min from you probably.
swez on 09/10/2005 10:58:00
Actually in Garden City, MI. Harper Woods is a bit of a ride, but yes, we can h ook up on personal e-mails or phone and discuss the options available. I might be able to fix this sub, depending on what's actually wrong with it.
Send me a private message or e-mail and we can discuss this more.
swezdp@juno.com
Swez
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