Speaker Repairs

Beolab 8000 Damper Reform

Keith Saunders — Tue, 20 Jul 2021 17:50:00 GMT

Current revision posted to Speaker Repairs by Keith Saunders on 20/07/2021 18:50:00

Beolab 8000 Damper Reform

Filed under: Refoam

Beolab 8000

Keith Saunders — Tue, 20 Jul 2021 17:49:03 GMT

Revision 1 posted to Speaker Repairs by Keith Saunders on 20/07/2021 18:49:03

Speaker Surround Repair

Søren Mexico — Mon, 30 Jul 2012 20:18:53 GMT

Current revision posted to Speaker Repairs by Søren Mexico on 30/07/2012 21:18:53

Speaker Surround Repair

Filed under: speaker repair, driver surround, Foam surrounds, Refoam

Here a good video for refoaming http://www.youtube.com/watch?v=lp1kjymypQc&feature=related

Driver foam surrounds gets old and brittle with use and years, so vintage drivers (normally bass drivers) will need new surrounds, if your speaker has distorted sound in the lower tones, take of the speaker grill (USA "frets") and if it looks like this, its time to start working.

To get the right surrounds you will have to measure your driver, some sellers just sells what they think is right, so check the dimensions before buying.

Your dimensions may be 1-2 Mm different, but try to get as close to the original as possible. For an 8" driver glue strip to the cone should be at least 4-5 Mm. To the basket more like 8-10 Mm. May be less for very small drivers and more for bigger ones.

Tools, red arrows are Acetate strips for shimming

The old surround and old glue, will have to come of, the best way to do it is with a hobby knife or razor blade. On the basket you can scrape and cut it of easily, but on the cone (mostly paper cones) you will have to work with care, not to damage the cone, DO NOT USE ANY SOLVENTS HERE. And don't cut of the dust cap, before you finish cleaning and have glued the inner edge of the surround to the cone

Clean

Check your spider, not warped and same look all around, if damaged you will have to get an expert to reconstruct your driver. this will include a new cone and spider, only if you are very skilled and know how drivers are build, you can do it yourself.

With everything clean and looking like new, apply glue to the cone where the inner edge shall go, You may wish to make a pen line all around the cone, marking the inner edge diameter.

Apply glue to the cone and/or surround, according to glue recommendations.

This is too much, less will do

Now place the surround on the cone, carefully press the surround to the cone without pulling or stretching the surround, make sure the surround fits like this all around the cone

Press the surround to the cone with one finger under the cone and one finger over the surround, all around 2-3 times, When properly fitted, find a dish or something circular that fits exactly over the glue strip and put some wight upon it, leave until glue has dried. The pic is just for show, its a finished RL 140 driver.

Glue dry, now cut the dust cap, as close to the cone as possible and nearly all around, leaving a 2-3 Mm bit still attached to the cone

Fix it with tape

DO NOT use cardboard or paper for shimming, like in this photo, its not precise enough and may leave dirt in the voice coil

Green Arrow

Now start shimming, You will need some strips of different thickness, clear plastic film or transparencies, I use 0.05, 0.1 and 0.3 Mm, cut 10 x 80 Mm. strips, and start inserting strips all the way to the bottom, in the gap at "0", 120 and 240 degrees, the same count of strips at all 3 points, moving the cone in and out, adding strips until you feel the cone starts moving harder, the adjustment is right when the cone moves hard if an extra 0.1 Mm. strip is inserted at one of the 3 points.

Red Arrow, paint with a marker, its easier to see them.

DO NOT use cardboard or paper for shimming, its not precise enough and may leave dirt in the voice coil.

Now add glue to the basket and/or surround outer edge, press the surround to the basket, same way as to the cone, two fingers all around, without pulling or pushing.

If your driver has a gasket, Red Arrow, place that over the glued surround , and/or find a circular item that fits over it and add some weight to it, Blue Arrows, leave to dry.

When dry, retract the plastic strips and check, moving the cone in and out, with 3 finger on the cone, if the voice coil moves freely and without "scratching" sound its OK, glue back the dust cap with just a small strip of glue on the cut.

When the glue is dry, you can connect your driver to the crossover and connect the speaker to an amp for testing, or if you are an optimist, build it into your speaker, connect to your amp and test, start at low volume and let it play for an hour or 2, then gradually increase the volume and bass levels until you are satisfied that it works okay, if you at the same time changed your caps or repaired your crossovers, there will be some "playing innin" time before the speaker will reach the correct sound.

Finished

Speaker Surround Repair

Søren Mexico — Sun, 26 Feb 2012 16:46:30 GMT

Revision 7 posted to Speaker Repairs by Søren Mexico on 26/02/2012 16:46:30

Speaker Surround Repair

Filed under: speaker repair, driver surround, Foam surrounds, Refoam

Here a good video for refoaming http://www.youtube.com/watch?v=lp1kjymypQc&feature=related

To get the right surrounds you will have to measure your driver, some sellers just sells what they think is right, so check the dimensions before buying.

With everything clean and looking like new, apply glue to the cone where the inner edge shall go, You may wish to make a pen line all around the cone, marking the inner edge diameter.

Apply glue to the cone and/or surround, according to glue recommendations.

Now place the surround on the cone, carefully press the surround to the cone without pulling or stretching the surround, make sure the surround fits like this all around the cone

Glue dry, now cut the dust cap, as close to the cone as possible and nearly all around, leaving a 2-3 Mm bit still attached to the cone

Fix it with tape

DO NOT use cardboard or paper for shimming, like in this photo, its not precise enough and may leave dirt in the voice coil

Now add glue to the basket and/or surround outer edge, press the surround to the basket, same way as to the cone, two fingers all around, without pulling or pushing. If your driver has a gasket, place that over the glued surround, find a circular item that fits over it and add some weight to it, leave to dry.

When dry, retract the plastic strips and check moving the cone in and out with 3 finger on the cone, if the voice coil moves freely and without "scratching" sound its OK, glue back the dust cap with just a small strip of glue on the cut.

When the glue is dry, you can connect your driver to the crossover and connect the speaker to an amp for testing, or if you are an optimist, build it into your speaker, connect to your amp and test, start at low volume and let it play for an hour or 2, then gradually increase the volume and bass levels until you are satisfied that it works okay, if you at the same time changed your caps or repaired your crossovers, there will be some "playing inn" time before the speaker will reach the correct sound.

Speaker Surround Repair

Søren Mexico — Sat, 25 Feb 2012 21:52:53 GMT

Revision 6 posted to Speaker Repairs by Søren Mexico on 25/02/2012 21:52:53

Surround Speaker Surround Repair

Filed under: speaker repair, driver surround, Foam surrounds, Refoam

To get the right surrounds you will have to measure your driver, some sellers just sells what they think is right, so check the dimensions before buying.

With everything clean and looking like new, apply glue to the cone where the inner edge shall go, You may wish to make a pen line all around the cone, marking the inner edge diameter.

Apply glue to the cone and/or surround, according to glue recommendations.

Now place the surround on the cone, carefully press the surround to the cone without pulling or stretching the surround, make sure the surround fits like this all around the cone

Glue dry, now cut the dust cap, as close to the cone as possible and nearly all around, leaving a 2-3 Mm bit still attached to the cone

Fix it with tape

DO NOT use cardboard or paper for shimming, like in this photo, its not precise enough and may leave dirt in the voice coil

When the glue is dry, you can connect your driver to the crossover and connect the speaker to an amp for testing, or if you are an optimist, build it into your speaker, connect to your amp and test, start at low volume and let it play for an hour or 2, then gradually increase the volume and bass levels until you are satisfied that it works okay, if you at the same time changed your caps or repaired your crossovers, there will be some "playing inn" time before the speaker will reach the correct sound.

Surround Speaker Repair

Søren Mexico — Sat, 25 Feb 2012 21:51:53 GMT

Revision 5 posted to Speaker Repairs by Søren Mexico on 25/02/2012 21:51:53

Surround Speaker Repair

Filed under: speaker repair, driver surround, Foam surrounds, Refoam

To get the right surrounds you will have to measure your driver, some sellers just sells what they think is right, so check the dimensions before buying.

With everything clean and looking like new, apply glue to the cone where the inner edge shall go, You may wish to make a pen line all around the cone, marking the inner edge diameter.

Apply glue to the cone and/or surround, according to glue recommendations.

Now place the surround on the cone, carefully press the surround to the cone without pulling or stretching the surround, make sure the surround fits like this all around the cone

Glue dry, now cut the dust cap, as close to the cone as possible and nearly all around, leaving a 2-3 Mm bit still attached to the cone

Fix it with tape

DO NOT use cardboard or paper for shimming, like in this photo, its not precise enough and may leave dirt in the voice coil

When the glue is dry, you can connect your driver to the crossover and connect the speaker to an amp for testing, or if you are an optimist, build it into your speaker, connect to your amp and test, start at low volume and let it play for an hour or 2, then gradually increase the volume and bass levels until you are satisfied that it works okay, if you at the same time changed your caps or repaired your crossovers, there will be some "playing inn" time before the speaker will reach the correct sound.

Surround Speaker Repair

Søren Mexico — Sat, 25 Feb 2012 21:35:50 GMT

Revision 4 posted to Speaker Repairs by Søren Mexico on 25/02/2012 21:35:50

Surround Speaker Repair

Filed under: speaker repair, driver surround, Foam surrounds, Refoam

To get the right surrounds you will have to measure your driver, some sellers just sells what they think is right, so check the dimensions before buying.

With everything clean and looking like new, apply glue to the cone where the inner edge shall go, You may wish to make a pen line all around the cone, marking the inner edge diameter.

Apply glue to the cone and/or surround, according to glue recommendations.

Now place the surround on the cone, carefully press the surround to the cone without pulling or stretching the surround, make sure the surround fits like this all around the cone

Glue dry, now cut the dust cap, as close to the cone as possible and nearly all around, leaving a 2-3 Mm bit still attached to the cone

Fix it with tape

When the glue is dry, you can connect your driver to the crossover and connect the speaker to an amp for testing, or if you are an optimist, build it into your speaker, connect to your amp and test, start at low volume and let it play for an hour or 2, then gradually increase the volume and bass levels until you are satisfied that it works okay, if you at the same time changed your caps or repaired your crossovers, there will be some "playing inn" time before the speaker will reach the correct sound.

Surround Speaker Repair

Søren Mexico — Sat, 25 Feb 2012 21:35:50 GMT

Revision 3 posted to Speaker Repairs by Søren Mexico on 25/02/2012 21:35:50

Surround Speaker Repair

Filed under: Surround, speaker repair, driver surround, Foam surrounds, Refoam

To get the right surrounds you will have to measure your driver, some sellers just sells what they think is right, so check the dimensions before buying.

With everything clean and looking like new, apply glue to the cone where the inner edge shall go, You may wish to make a pen line all around the cone, marking the inner edge diameter.

Apply glue to the cone and/or surround, according to glue recommendations.

Now place the surround on the cone, carefully press the surround to the cone without pulling or stretching the surround, make sure the surround fits like this all around the cone

Glue dry, now cut the dust cap, as close to the cone as possible and nearly all around, leaving a 2-3 Mm bit still attached to the cone

Fix it with tape

When the glue is dry, you can connect your driver to the crossover and connect the speaker to an amp for testing, or if you are an optimist, build it into your speaker, connect to your amp and test, start at low volume and let it play for an hour or 2, then gradually increase the volume and bass levels until you are satisfied that it works okay, if you at the same time changed your caps or repaired your crossovers, there will be some "playing inn" time before the speaker will reach the correct sound.

Surround Speaker Repair

Søren Mexico — Sat, 25 Feb 2012 21:33:38 GMT

Revision 2 posted to Speaker Repairs by Søren Mexico on 25/02/2012 21:33:38

Surround Speaker Repair

Filed under: Surround, speaker repair, driver surround

To get the right surrounds you will have to measure your driver, some sellers just sells what they think is right, so check the dimensions before buying.

With everything clean and looking like new, apply glue to the cone where the inner edge shall go, You may wish to make a pen line all around the cone, marking the inner edge diameter.

Apply glue to comethe cone and/or surround, according to glue recommendations.

Now place the surround on the cone, carefully press the surround to the cone without pulling or stretching the surround, make sure the surround fits like this all around the cone

Glue dry, now cut the dust cap, as close to the cone as possible and nearly all around, leaving a 2-3 Mm bit still attached to the cone

Fix it with tape

When the glue is dry, you can connect your driver to the crossover and connect the speaker to an amp for testing, or if you are an optimist, build it into your speaker, connect to your amp and test, start at low volume and let it play for an hour or 2, then gradually increase the volume and bass levels until you are satisfied that it works okay, if you at the same time changed your caps or repaired your crossovers, there will be some "playing inn" time before the speaker will reach the correct sound.

Surround Speaker Repair

Søren Mexico — Sat, 25 Feb 2012 14:53:26 GMT

Revision 1 posted to Speaker Repairs by Søren Mexico on 25/02/2012 14:53:26

With everything clean and looking like new, apply glue to the cone where the inner edge shall go, You may wish to make a pen line all around the cone, marking the inner edge diameter.

More to come

Speaker Grill Repair

Søren Mexico — Sun, 04 Mar 2012 06:40:11 GMT

Current revision posted to Speaker Repairs by Søren Mexico on 04/03/2012 06:40:11

Speaker Grill Repair

Filed under: Speaker_Grill repair, Speaker_cloth, Fret_Repair, Grill_Cloth

The speaker front is the first thing people sees when looking the first time at your vintage Beovox speakers, if it looks bad they will think that it also sounds bad. So a 20 to 40 year old speaker deserves a new front.

Speaker cloth or fabric comes in several different types and colors and is advertised in different manners, but what I look for is a kind of open fabric, meaning you can look through it when very near to the eye, not so at 50 Cm distance, and it has a little stretch in it.

A close woven fabric will distort the sound, specially the bass driver needs to move some air and a closed fabric will inhibit that and furthermore dampen the other frequencies. Audiophile Fabric is like the Audiophile cable, Snake oil.

Before starting you will need the Fabric, tools and glue. Most important (of course the Fabric) is the glue, I use a good 3M spray glue, and at times Arleene's Tacky glue, I have tried with double sided tape, but after a week or so the fabric started loosening again, so try it out, there are as many glue types out there as beer in southern Germany

The drink and he cigarets are only for relaxing in between, doing hard work as this turned out to be.

We have to get of the old fabric. I cut the front edges all around, and the just pull of the rest from the back side.

On these Beovox 3702 grills it came of easy, but if someone did a bad job before you, you may have to use a hobby knife to get all old glue and fabric of, clean the base properly before attaching the new fabric.

Now check the base/frame for damages or broken pieces, specially if there are broken pegs, repair these before attaching the new fabric, my frame turned out like this.

So I decided to make new ones, I found a piece of 1/4" plywood, and before starting cutting I had the good idea to check the old frames against the speaker, turned out that the holes for mid range and tweeter was of by some 3 Cm. I corrected that on the new frames. Marked the plywood after the old frames and corrected the holes for tweeter and mid range, cut the surrounding and thereafter the holes with an electric top handle oscillating jig saw, then I took out my router and routed the edge offset and the offsets for screws around the hole for the bass driver, here the front

And here the back

In my secret chamber I found a liquid that will protect wood against termites, woodworms, meal dew, wrinkles and bad breath for 200 years, I will try that on my face some day.

Left it to dry for a couple of days, and then got out all the tools and glues needed for attaching the fabric, I placed a woolen blanket on our dining table (FS not at home) and over that the beautiful colored fabric, as the fabric had some wrinkles, I ironed it with an iron, never ever tell the FS that I can iron, I will have to do my oven shirts for the rest of our relationship.

I placed the frame over the fabric and cut, with the scissors, the fabric about 5 Cm bigger all around the frame. Then I took one frame to the garage and sprayed the front with 3M Super 77, left it for 5 min. and then placed it centered on the fabric, pressed it down and left 5 min. to dry.

Now I took the frame outside again and sprayed the edges with the spray glue, you may want to mask of, or hold a sheet of paper over, the areas where no glue is wanted, the glue is easy to clean of with acetone, but this will also clean of any paint applied, back at the table I started wrapping the fabric from the front to the back, with my 2 big thumps, stretching the fabric a little to get a close fit around the edge.

In the corner I cut the fabric to fit with a little overlap and glued with a drop of Arleene's

Then I grabbed the technically advanced tool, called Rotary cutter, check your FS's sewing chest, they all have one of these, and cut the fabric along the inner edge, be careful the rotary cutter has a mind of its own, you will have to guide it with a strong, clear eyed hand.

Cut all around and peel of the cut of fabric.

As you see, the glue will show if not covering before spraying.

Finished it looks like this, and the fabric color is not red, pink or whatever malicious members will call it, its maroon or magenta, as we call it in the printing business.

Next to come is how to fit these

The old grills was attached to the speaker with glue, I like to be able to take mine of for easy removalcleaning or repairs. As the driver frame is 10 Mm. lower than the grill frame and I wanted the grill flush with the aluminum frame, as originally they were glued I choose to make some bases for Hook and Loop pads, yes, in my secret chamber I found some round plastic pieces some 20 Mm long, I cut them down to 7 Mm, the H and L pads are 3 Mm. so here you go

And the grill with the H and L pads, ahh the pig, my doll made it, she makes dolls I fumble in vintage B&O

Here the grill on the speaker

Don't forget the B&O sign, but will have to shoot drill a couple of pics 2.5 Mm. hole and attach it, before drilling, cut a cross in the fabric, with a sharp knife, where the hole has to do thatbe made.

Here on stand, and I'm absolutely sure, it sounds better with new grill.

And that concludes the grill repair, comment and suggestions welcome

Speaker Grill Repair

Søren Mexico — Sat, 03 Mar 2012 17:46:29 GMT

Revision 2 posted to Speaker Repairs by Søren Mexico on 03/03/2012 17:46:29

Speaker Grill Repair

Filed under: Speaker_Grill repair, Speaker_cloth, Fret_Repair, Grill_Cloth

Before starting you will need the Fabric, tools and glue. Most important (of course the Fabric) is the glue, I use a good 3M spray glue, and at times Arleens Arleene's Tacky glue, I have tried with double sided tape, but after a week or so the fabric started loosening again, so try it out, there are as many glue types out there as beer in southern Germany

The drink and he cigarets are only for relaxing in between, doing hard work as this turned out to be.

We have to get of the old fabric. I cut the front edges all around, and the just pull of the rest from the back side.

Now check the base/frame for damages or broken pieces, specially if there are broken pegs, repair these before attaching the new fabric, my frame turned out like this.

And here the back

In my secret chamber I found a liquid that will protect wood against termites, woodworms, meal dew, wrinkles and bad breath for 200 years, I will try that on my face some day.

Left it to dry for a couple of days, and then got out all the tools and glues need needed for attaching the fabric, I placed a woolen blanket on our dining table (FS not at home) and over that the beautiful colored fabric, as the fabric had some wrinkles, I ironed it with an iron, never ever tell the FS that I can iron, I will have to do my oven shirts for the rest of our relationship.

Now I took the frame outside again and sprayed the edges with the spray glue, you may want to comemask of, or hold a sheet of paper over, the areas where no glue is wanted, the glue is easy to clean of with acetone, but this will also clean of any paint applied, back at the table I started wrapping the fabric from the front to the back, with my 2 big thumps, stretching the fabric a little to get a close fit around the edge.

In the corner I cut the fabric to fit with a little overlap and glued with a drop of Arleene'm tired s

Then I grabbed the technically advanced tool, called Rotary cutter, check your FS's sewing chest, they all have one of these, and cut the fabric along the inner edge, be careful the rotary cutter has a mind of its 4 AM going own, you will have to bedguide it with a strong, clear eyed hand.

Cut all around and peel of the cut of fabric.

As you see, the glue will show if not covering before spraying.

Finished it looks like this, and the fabric color is not red, pink or whatever malicious members will call it, its maroon or magenta, as we call it in the printing business.

Next to come is how to fit these grills to the speaker, for easy removal, as originally they were glued to the speaker, but will have to shoot a couple of pics to do that.

Speaker Grill Repair

Søren Mexico — Sat, 03 Mar 2012 10:00:59 GMT

Revision 1 posted to Speaker Repairs by Søren Mexico on 03/03/2012 10:00:59

The speaker front is the first thing people sees when looking the first time at your vintage Beovox speakers if it looks bad they will think that it also sounds bad. So a 20 to 40 year old speaker deserves a new front.

Before starting you will need the Fabric, tools and glue. Most important (of course the Fabric) is the glue, I use a good 3M spray glue, and at times Arleens Tacky glue, I have tried with double sided tape, but after a week or so the fabric started loosening again, so try it out, there are as many glue types out there as beer in southern Germany

The drink and he cigarets are only for relaxing in between, doing hard work as this turned out to be.

We have to get of the old fabric. I cut the front edges all around, and the just pull of the rest from the back side.

Now check the base/frame for damages or broken pieces, specially if there are broken pegs, repair these before attaching the new fabric, my frame turned out like this.

And here the back

In my secret chamber I found a liquid that will protect wood against termites, woodworms, meal dew, wrinkles and bad breath for 200 years, I will try that on my face some day.

Left it to dry for a couple of days, and then got out all the tools and glues need for attaching the fabric, I placed a woolen blanket on our dining table (FS not at home) and over that the beautiful colored fabric, as the fabric had some wrinkles, I ironed it with an iron, never ever tell the FS that I can iron, I will have to do my oven shirts for the rest of our relationship.

More to come, I'm tired its 4 AM going to bed