First Refoam Problem

[pauvro]

No way of telling. Try doing a battery test to see if the noise is present. Using your fingers to push the cone puts uneven pressure on the cone so you may be masking the problem by using that method. Also, agree you may have dried in some contaminants into the gap or if there is ferrofluid, it may have dried up somewhat and it is moving the vc. Another possibility, though unlikely, is whether the leads from the vc to terminals are in some way interfering.

There is only so much that can go wrong as the speaker is a relatively simple,easy device.

I have never done a battery test so I'll have to figure out how to do that. You are right, I may have got some contaminant into the gap. What is ferrofluid?

If the battery test generates the rubbing noise, what would be your next step?

I don't suppose it's simply loosely mounted in the baffle is it?

Excuse my ignorance, newbie here, is the baffle the actual cabniet itself? I screwed it in pretty tight so I'm not positive but I think it's mounted correctly, how would I tell for sure? Sorry to sound so inexperienced!

Before doing your surround again, try this. Unscrew the speaker and rotate it 180 degrees and re-install it. In other words if the connectors were at the top before they will now be facing the bottom. The suspension tends to sag with age toward wherever bottom was. Sometimes this will give you just enough clearance to fix the rattle. May work, worth a try.

There are a few different ways to center the coil when refoaming. Without removing the dustcap you could try the 1.5V battery method or the 30 Hz tone method. I've done both with success. Search AK for details.

Good luck and don't give up.

I forgot to mention that I actually did rotate the driver before mounting it again, however I am not sure if it was actually 180 deg or if I just shifted it slightly. I'll have to try moving it around to another spot. The problem is my workspace for this endeavor is down two flights of stairs and these speakers are heavy, looks like I need to start working on them near the amp and speaker wire so I can test and make adjustments easier. I wish I knew I didn't have to remove the dust cap. Honestly I feel like the instructions I got left a lot to be desired and caused me to destroy my original dust cap when I had no need to do so.

Your encouragement to keep up with this repair is not taken lightly, thanks, I'm sure you know how frusterating it can be. Honestly it had made me quite depressed at first because I love these speakers, and the repair kit was bought for me as a gift, so I wallowed in the idea of wasting it I'll keep on with the repair until it's fixed though! Will report back after attempting to rotate the speaker again!

Sounds like you did everything correctly. Sometimes you just have a problem speaker. Oddly enough, my first refoam problem was with a CV woofer as well - which is odd because they are one of the more forgiving ones to refoam.

It turned out that I did nothing wrong and the popping noise I was hearing at volume was because the glue holding the front baffle in place was not doing it's job and was allowing the baffle to move slightly when the volume was high. The result was a popping sound.

By process of elimination you can swap the woofers and see if the problem stays in the cabinet or goes with the woofer. Likely it will travel with the woofer but you never know.

If you used white glue like Aileens, you may can roll up a paper towel and get it slightly damp. Lay it around the edge of the woofer where the foam glues to the basket (may take 2 towels depending on how big the woofer is). Let it sit for a while and the glue will loosen-up. GENTLY! Lift the foam away from the basket being careful not to stretch or tear it. If you can get it removed from the basket, you can reuse the foam and save yourself a few nickles. Personally, I use a tone instead of shimming. Not saying that's wrong or right, it's just how I have always done my refoams.

Main thing is don't get discouraged. It's not a hard process but sometimes little snags happen.

Good luck!

I feel like I'm not 100% on what a baffle is and how to check if it's lose. I would attempt to move the woofer into the other cabinet but I could never figure out how to remove the speaker's connections in the back of the driver. They looked like they slipped over two prongs but I tried pulling and they wouldn't' come off. I did the entire repair with the cabinet on it's side and the driver, still connected, sitting on the table. Was frustrating but I didn't really feel comfortable detaching the wire then having to resoder it onto the back.

When you say to place the paper towels around the basket do you mean under the gasket on the rim, around the inside ring attached to the cone, or both? Thanks by the way for offering aid on reusing the surrounds, just got them so would hate for them to be trashed.

I need to figure out how to easily perform this tone test and also what I should be adjusting while listening to the tone and what I am looking to hear to mean it's centered properly. I'm sure someone mentioned more details on this procedure but I'll have to look through the replies and some info on AK for that.

Thanks for your support, before connecting with the gracious members on this website I was quite bummed and 100% believed I had ruined my repair kit, at least now I have hope and the benefit of more experienced people.

I'm not familiar with the C-V drivers, but is it possible the spider is weak and the cone has become too loose at the spider support, and the VC is rubbing from a weakened spider?? Rotating the driver for mounting may help determine if the spider is weak.

Nonetheless, good advise from previous posts regarding attempting to carefully loosen the surround and attempting to re-center the voice coil.

Try to stay with it using patience and some care. You can fix the driver. :yes:

I am not sure, but I did briefly take a look at the spider last time I had it open. It didn't seem to be disconnected from the cone, but then again, perhaps I missed something. I did try to rotate the speaker but just to make absolute sure that rotation won't fix it, I'm going to try to rotate it again a bit more than last time, not sure if I did a full 180 deg last time.

Thanks for your support here!

i scrape the frames with an xacto flat scrape blade. i also do not use shims. i use either a low hertz test disc or audio with a lot of bass at low volume. using a sound source has given me 0 failures. i have refoamed over 500 woofers and haven't looked back

Any refoam I do in the future I will also utilize low hz samples in order to center, just for peace of mind at least, to insure it is centered. Wish they would have suggested that in the instructions I received initially. Do you have a link to a good guide on how to do this, something detailed? I'm going to search regardless but figured I'd ask.

Well, if it didn't rub before than chances are it's something you did. That's a good thing in this case because all you have to do is refoam and this time do it right. First buy good surrounds. Personally I use Rick Cobb. Usually I don't need glue and the cd so I get a little break. I use the 30Hz tone. I use 91% alchohol to remove the surround from almost all cones easily. I cut the hairs on an acid brush to about 1/4" long so they will flow the alchohol and also allow me to scrub the old surround area. Keep it wet (about 2 times around without stopping. You can then take a dull single edged blade and carefully scrape what's left. On the frame you just have to scrape. You will have an area on the cone that makes it easy to see where to apply the glue. Attach the surround to the cone again using this darker area this time to align the surround on the cone. Let it dry. Then play the tone through the speaker and glue the outside to the frame. You will have to attend to both gluings until the glue sets.

After you shimmed your voice coils you must clean the gap. Business card strips with tape. All it takes is one little piece of dirt. That's why I never remove the dust cap. Also if you do pull the surround in one direction to get it to properly attach to the frame when you remove the shims you will have voice coil rub. You can download a tone on the internet.

I think you'll get it right.

While playing the tone through the speaker, am I just listening for disturbances in the sound? If I hear them while refoaming, what do I adjust to make sure it sounds better? Also when you mention "cleaning the gap" where exactly is the gap? Is that where I stuck the shims? I think I MAY have pulled the surround a bit but I'm not entirely sure if that's the culprit...could be though. So you're saying never pull on the surround and just attempt to glue it where ever it lays once gluing it properly around the inner ring? Thanks for your support it means a lot, I didn't expect so many people to offer assistance so soon...I'm sure we'll get this working!

 

[pauvro]

i've found that when working with older drivers that the spiders tend to sag over time
and the method that works for me is to glue the surround to the cone and after it is set-up/ dry them apply the glue to the basket and lift the cone/ surround and let it find
its center, regardless of whether the surrounds outside edges appear centered around the circumference of the basket.
then with a "centered" hand or hands press the cone through the voice coils stroke to check for scrapping.
make slight adjustments to the cone/surround, recheck.
check again in 5 minutes. this method is when using Aleenes

Is the basket the rim that the screw holes are in? or is that the metal outside edge that I'm gluing the surround onto? Wish I had some diagrams this seems like a good way to check.

Please try the '' rotate the woofer 180 degrees '' first.

I'm pretty shure it'll work!

As previously mentioned, I did rotate a bit, but am going to try rotating and resetting in the cabinet again, just in case, so I'll update you ASAP on the results.

I would advise AGAINST using a battery if you are new to this.

Did you take any pictures of the process? Sounds like something went wrong with the shims.

I took no pictures. I don't know how to use the battery method really, and yeah all I did was place the shims in at the 3 spots the instructions told me. Possible I could have messed that up but unsure how.

 

[pauvro]

Update: I just rotated the driver and remounted, after running bass tests I notice a slight buzzing (as if I was listening to a sports bike from far away) persistently through most of the test.

Will rotate once more and try again, JUST in case! Would hate to refoam if I don't have to. What do you guys make of this, is this strengthening the case for a refoam?

 

[pauvro]

Okay so I just removed the driver from the cabinet and played the audio tone over that, and also mounted the speaker back to the original way it was (which means I've had it in multiple positions mounted and unmounted and the vibration is still occurring. I looked at the spider and it seems okay, I'm not exactly sure what else I should try before attempting a refoam...I would much prefer not to refoam so are there any other ideas given my recent tests or should I just go for it?

 

[-reverb-]

This animation may help with some of the terms.

http://animagraffs.com/loudspeaker/

The baffle is the front of the speaker (the "face" if you will) where all of the individual drivers are mounted.

Each one of the devices that create sound is referred to as a driver. Your CV VS-100's speakers has 3 drivers per cabinet; a woofer, a midrange and a tweeter.

To try and loosen the glue, roll-up a paper towel and get it moist. You want the towel to cover the outermost portion of the foam - the area from the end of the roll to the edge of the foam. What you are trying to do is get the glue under the foam where it connects to the basket to release. See attached photo. The area between the black lines all the way around the foam is where you want to lay the moist paper towels. Do NOT put towels on the inside of the roll. You do not want to get the cone wet!

 

[pauvro]

This animation may help with some of the terms.

http://animagraffs.com/loudspeaker/

The baffle is the front of the speaker (the "face" if you will) where all of the individual drivers are mounted.

Each one of the devices that create sound is referred to as a driver. Your CV VS-100's speakers has 3 drivers per cabinet; a woofer, a midrange and a tweeter.

To try and loosen the glue, roll-up a paper towel and get it moist. You want the towel to cover the outermost portion of the foam - the area from the end of the roll to the edge of the foam. What you are trying to do is get the glue under the foam where it connects to the basket to release. See attached photo. The area between the black lines all the way around the foam is where you want to lay the moist paper towels. Do NOT put towels on the inside of the roll. You do not want to get the cone wet!

Your illustration is appreciated. Someone mentioned that perhaps it wasn't mounted to the baffle correctly...do you think this could be it and if so how would I tell?

Also, you're saying I should damp the outside edge where you marked, all the way around, and if I can peel off the outer edge and just reapply glue to that, without stretching it, it should work? How do I make sure it stays glued down because the reason I had pulled it some before is because some of it wouldn't stay glued down. Sorry for all the questions I just want to make DAMN sure I do exactly what you're envisioning, you guys seem to know what you're talking about ;-)

 

[-reverb-]

Some people use clothespins to hold the surround edge down while they dry.

Here is a good description of how to use a tone to attach the surround to the basket.

http://www.audiokarma.org/forums/showthread.php?t=244046

You will need to disconnect the woofer to use a tone. The clips connecting the wires to your woofer will release - they are a friction-fit. Carefully work them from side to side and they should slip off. Note what color wire goes to which terminal. You will need to reattach them in the same orientation.

If using a tone or removing the attached wire is beyond your comfort zone, you can always try to center the cone by hand and hope for the best.

 

[pauvro]

Some people use clothespins to hold the surround edge down while they dry.

Here is a good description of how to use a tone to attach the surround to the basket.

http://www.audiokarma.org/forums/showthread.php?t=244046

You will need to disconnect the woofer to use a tone. The clips connecting the wires to your woofer will release - they are a friction-fit. Carefully work them from side to side and they should slip off. Note what color wire goes to which terminal. You will need to reattach them in the same orientation.

If using a tone or removing the attached wire is beyond your comfort zone, you can always try to center the cone by hand and hope for the best.

I don't mind trying to remove the wires, but why do I need to do that in order to use the tone? I have the driver laying flat down on a table what do I gain by unplugging it? Also, I have the surround completely detached from the outer edge, do I also have to remove the dustcap at this time? Am I simply regluing the surround edge? Or am I taking the dustcap off in an attempt to recenter?

Could you list the steps I should be taking at this point so I don't mess up. Sorry to keep bugging you guys, you've all been so helpful I just want to make sure I don't misunderstand something.

 

[mars_volta]

I would use shims whatever you do. Even if that means cutting the dust cap again or getting if off. I usually place shims all the way around the coil until there is no gap. usually about 4 strips. They should be pretty tight.. Enough to hold the cone 'up' if you lift it. Also, make sure they are all the way to the bottom.

I don't like the clothes pin idea. Just apply the glue, lower the cone until the surround is flat with the rim and then I use the back of an exacto knife to tap it down as it dries. You have to baby sit it and make sure its good and sealed. Just keep going round and round. Have a beer in between.

What kind of glue are you using?

 

[pauvro]

Update: I just got all the glue to release the outside ring, then I applied glue to it again and went to reattach it. As it was drying move the cone up and down from the middle making sure I didn't hear any VC rub, pressed down the sides to adhere it to the edge...few minutes later started playing 30hz over the speaker and it's vibrating no matter what I do.

I have no idea what to do now, I feel stupid because I don't know what troubleshooting I should be doing next, or what it even means that it's still doing it.



So I just lifted the outside edge all the way up again so it's completely detached...I am tempted to use heat to loosen the glue on the inside edge too and take the entire surround off, then take the dustcap off and completely start from scratch/ check everything I can...I don't know exactly what to do...I don't know why it's rattling...

 

[mars_volta]

You either have to play a 30 Hz tone while you glue it or use tight shims.

 

[jhtstone]

It didn't take long before the original foam started to crack and come apart,causing the sound to get worse and worse until I just couldn't use them anymore.

Hopefully, you did not play them with bad surrounds and possibly damage the voice coil or motor structure. If you did play them at normal levels, the bad surrounds can allow the cone to fluctuate side to side and damage the components that have little sideways tolerance.

Fingers crossed that the folks here can help you get this straightened out and all ends well.

 

[pauvro]

Okay so I got extremely fed up with this entire thing and perhaps did something I shouldn't have. Either way I have an update. I removed the entire surround and the dustcap utilizing heat to weaken the glue. I also tore up the cone a little but it's only surface damage (hopefully that doesn't matter). Believe it or not I found a little pebble or something stuck in the voice coil! Jesus! Anyway, consult the pictures and let me know if removing the debris in the voice coil and trying to refoam this beast is a good idea. Did I cause too much damage? Do I need to do any more prep before the refoam? Here are the pics

 

[jhtstone]

I don't know the interchangeability of CV woofers and how easy it would be to find a replacement, but I certainly would look into it. This one is damaged...it may be superficial but you still would have to purchase a new surround and do a new re-foam job. I doubt that you would be happy to spend the hours and labor to work with what you have knowing that it is compromised. You also still don't know if the speaker was damaged before. Having the level of frustration that you do already, do what is necessary to make it right and make you happy in the end. When you have a replacement woofer re-foamed and installed and are enjoying having them done, you can place this in the "experience" folder and file it away.

 

[pauvro]

I don't know the interchangeability of CV woofers and how easy it would be to find a replacement, but I certainly would look into it. This one is damaged...it may be superficial but you still would have to purchase a new surround and do a new re-foam job. I doubt that you would be happy to spend the hours and labor to work with what you have knowing that it is compromised. You also still don't know if the speaker was damaged before. Having the level of frustration that you do already, do what is necessary to make it right and make you happy in the end. When you have a replacement woofer re-foamed and installed and are enjoying having them done, you can place this in the "experience" folder and file it away.

I damaged it beyond repair doing what I did?

...I want to die

 

[jhtstone]

That is not what I said.

What I did say was that it has obviously frustrated you. Consider walking away from it for a bit. Life is too short to stress over any audio or other material things to this degree.

The sun will still rise in the east tomorrow.

 

[Danvee]

Agreed. Good advice.

 

[pauvro]

That is not what I said.

What I did say was that it has obviously frustrated you. Consider walking away from it for a bit. Life is too short to stress over any audio or other material things to this degree.

The sun will still rise in the east tomorrow.

You are right, of course, that I shouldn't stress about something so insignificant.

I'm trying to accomplish a task, however, and that task is the restoration of these speakers. That is something I have set out to do, and while I am currently frustrated with the outcome, my frustration shall pass. I yearn to complete this task successfully and so I push forward.

Unfortunately I experience frustration when trying to comprehend and accomplish something I have little experience with. It's all worth it though, in pursuit of accomplishing something.

I've cleaned up the cone a bit and cleaned out the voice coil. I'm letting the glue bond ATM on the inside and then will finish it up and hopefully it will work. If not, yeah, oh well, life certainly goes on, however I want to make sure I try everything I can before I move on.

 

[cablephil212]

Okay so I got extremely fed up with this entire thing and perhaps did something I shouldn't have. Either way I have an update. I removed the entire surround and the dustcap utilizing heat to weaken the glue. I also tore up the cone a little but it's only surface damage (hopefully that doesn't matter). Believe it or not I found a little pebble or something stuck in the voice coil! Jesus! Anyway, consult the pictures and let me know if removing the debris in the voice coil and trying to refoam this beast is a good idea. Did I cause too much damage? Do I need to do any more prep before the refoam? Here are the pics

OK. I'm throwing my .02 cents in here, because it looks like you're REALLY getting frustrated.

I would not worry too much about the missing paper right now. It's not through the cone, so it might look ugly, but won't affect the cone much, if at all.

Before you proceed to do ANYTHING, get a vac (shop or household), and vac out the inside of the VC (voicecoil). Next, get a business card, and cut it into 1/4" strips lengthwise. Use them to clean out the gap between the VC and the magnet pole (the metal piece inside the VC). Do this at least 3 or 4 times, in a circle around the inside of the VC. Use one, and discard.

Now, before you go gluing the NEW surround on (the one in your pic cannot be re-used), take the speaker wire (either channel will do) from the amp, and connect it to the driver terminal. Place the driver on its magnet (facing up). LOWER the volume on the amp to "0", and turn the amp on. Put a CD on, and SLOWLY increase the volume, but not too much. Just enough to get the cone moving.

Do you hear the "rattle? Does it sound like it's scraping now?

The missing cone paper can be strengthen by brushing some surround glue on it. This has happened to me when removing a surround from a driver also. After I used some glue, I really couldn't tell the difference between a good one, and the one with the damage sound wise.

Post back when you get a chance with the results.

Calm down, and take your time. It'll work out.

 

[mech986]

I damaged it beyond repair doing what I did?

...I want to die

Stop, step back and take a few deep breaths. This is not the end of the world, and not the end of your speakers. If you're young (less than 30 y/o) impatience and wanting things now tend to make everything seem devastating.

Most all of us who have had the chance to do refoams have had a few (or more than a few) go bad. Its a learning experience. Ultimately, you have now found a legitimate reason for the noise - a small pebble, possibly part metallic, in the voice coil gap, rubbing between the voice coil bobbin or cylinder and the inner pole piece (the inner part of the gap). Clear that out by picking it out with a pair of tweezers, careful if your tweezers are metal as they will be attracted to the gap by magnetism.

To clean the gap, get some masking tape about 1/2 to 1 inch wide, pull off a strip and fold it over so that the sticky side is facing out on both sides. Then carefully slip the thin sticky strip into the gap between the inner gap metal and the inside of the voice coil. Holding the cone-voice coil, then slip the tape around the circumference of the voice coil. Repeat at least 3 times with new tape each time or until there is nothing coming out on the tape. This cleans the inner part of the gap. To clean the rest would require removing the cone and voice coil entirely, something that at this point you should not do and may not need to do.

As for "damage", yes, there is cosmetic and some slight physical damage to the cone. The front of the cone has some slight tears towards the area or edge where the dustcap was glued - I don't think that is a problem. On the inside circumference of the old red surround seems to be some shiny material - was that there before, or is it excess glue that got on the cone during your refoam? This isn't a big performance problem but more of a cosmetic issue. There appears to be some areas of cone paper loss in gaps near the old red surround - is that correct?

Now, if you feel you want to salvage this project you have to ask yourself can I live with the cosmetic imperfections? If you can, then proceed on. If you cannot, see below.

The steps I would suggest are this if you're continuing with this woofer - gently clean off all the old dustcap but do not disturb the cone to voice coil area - but any projection of old dust cap above 1/8" should be carefully trimmed off with a sharp exact-o type knife - careful here.

Then, if possible, rub or gently lift off the old red foam if possible IF it comes off without taking much of the paper cone below it. If there is thick glue there and it just won't rub or lift off, then leave it. Now check by pushing the cone up and down to be sure there is no rubbing in the gap. If clear then to next point.

Clean off the surround you used of any paper or glue bits from the underside. Test fit the surround to be sure it will generally cover all of the old surround and looks reasonable centered on the frame. Then glue the inner edge of the surround to the outer front edge of the cone over the old surround. Use a very thin bead of glue on the old surround or cone edge and smooth it out with a thin popsicle stick or similar, and do not allow excess glue to get on the cone if possible. Some will put a super thin coating of glue on the underside of the inner edge of the new surround and then let them both sit for about 2 minutes. Then arrange the new surround and cone to overlap correctly and press the glued parts together, working your way around the cone edge till it all is down with even contact.

Then let this dry overnight (at least 6-12 hours!) This is important so the surround cannot shift. Once dried, then either shim the voice coil evenly around the magnet center pole piece or get the 30hz test tone and feed it into your amp at low level while the amp is hooked up to your speaker - be careful that any speaker wire to your woofer is securely hooked to the terminals. Don't want to short the wires, you could damage your amp.

This will provide centering of the voice coil. IF you play the tone at just an audible level and there is no rubbing noise, the coil is centered. While doing so, I use either medium-large binder clip or clothes pins that can reach over the frame and secure the outer edge of the surround to the frame. You then would secure at least 4 opposite points, checking then for rubbing noise with the tone - if noisy, re-position till no noise - then when clear sound, hold down with 8 clips/clothespins around the frame. Test one more time with the tone. If satisfactory, then remove one quadrant of clips, and glue down a 45 degree angle of the surround to the frame using a thin bead of your glue - press down evenly, then reattach with the clips. Test again, and repeat until the whole surround is glued, then test again. Should sound fine at this point.

Then let dry for 24 hours - you want the glue joints to be solid before using again. After 12 hours, you can take off the clips and glue on the outer gasket that covers the outer edge of the surround on top of the frame, assuming you saved that. If not, you can use generic paper/cardboard gaskets that sometimes comes with surround kits.

If you want to, you can order a dustcap of appropriate size with the CV logo on it or you can use the one that came with your kit.

Once the glue has dried for at least 24 hours, remove all clips if needed and test again with the test tone to assure yourself it works well.