B&W CDM 1 Hochtöner (ZZ09989 / ZZ9989)


Reparatur eine B&W CDM1 (ZZ9989 / ZZ09989) Hochtöner

Bitte beachten Sie dass die B&W ZZ03123, ZZ3123 & ZZ10227 in den CDM1, CDM1SE, CDM7, CDM7SE, CDMCSE, P4, P5 und CC6 verwendet eine mehr oder weniger ähnliche Konstruktion haben und ähnlich reparierbar sind.
Hinweis: Einige dieser Hochtöner verwenden eine Aluminium Kalotte anstelle der hier verwendeten "Seiden Kalotte".

Leider ist diese Anleitung noch nicht übersetzt.

How to repair a B&W CDM1 (ZZ9989 / ZZ09989) tweeter

Please note that the B&W ZZ03123, ZZ3123 & ZZ10227 tweeters used in the CDM1, CDM1SE, CDM7, CDM7SE, CDMCSE, P4, P5 and CC6 have a more or less similar construction and are similarly repairable.
Note: Some of these tweeters use an aluminum dome instead of the "silk dome" used here.

The following tools are required for repair, plus a replacement diaphragm. The diaphragm can be found here.
B&W CDM1 (ZZ9989 / ZZ09989) tweeter repair: all parts needed for the repair


Take the diaphragm of the magnet (clamping system, the top is clamped on the magnet). You are going to remove the old ferrofluid. You will use white masking tape. Tear a piece off. Fold the tip of the tape with the sticky side on the outside. Repeat this several times until you have a solid piece of tape with the sticky side on the outside. This tape will remove the old ferrofluid in the air gap in the magnet. Put your piece of masking tape in the air gap of the magnet and move it around circularly. The old, mucky, ferrofluid will stick to the tape.
B&W CDM1 (ZZ9989 / ZZ09989) tweeter repair: remove the old ferrofluid from the magnet gap


The tape is filled with 'dirt', take a new piece. Move the (clean) tape around as long as ferrofluid comes out. If you put in a new piece of tape and it comes out totally clean you're fine.
B&W CDM1 (ZZ9989 / ZZ09989) tweeter repair: old ferrofluid (muck) attached to the masking tape


If you put in a new piece of tape and it comes out totally clean you're fine.
B&W CDM1 (ZZ9989 / ZZ09989) tweeter repair: repeat claeaning of the tweeter gap untin the masking tape comes out clean


Remove the old diaphragm from the plastic cap. Use, for example, tweezers. Please note the cap / tweeter frame will be used again, make sure not to damage it.
B&W CDM1 (ZZ9989 / ZZ09989) tweeter repair: remove the old diaphragm from the plastic tweeter frame


You can throw the diaphragm away, the speaker frame will be used again.
B&W CDM1 (ZZ9989 / ZZ09989) tweeter repair: tweeter frame and broken diaphragm


Carefully remove the glue residue from the tweeter frame. We used a sharp hobby knife for this.
B&W CDM1 (ZZ9989 / ZZ09989) tweeter repair: residue removed from the tweeter frame


Then degrease the tweeter frame with spirits, ammonia or another degreaser.
B&W CDM1 (ZZ9989 / ZZ09989) tweeter repair: decrease the tweeter frame


There are adhesive residues on the solder contacts of the tweeter frame, remove it.
B&W CDM1 (ZZ9989 / ZZ09989) tweeter repair: adhesive residue must be remove from the front of the tweeter frame


Now two small holes are released - these will be used later to direct the diaphragm wires.
B&W CDM1 (ZZ9989 / ZZ09989) tweeter repair: two small holes in the tweeter frame


The wires of the diaphragm are inserted through the released holes. The diaphragm side with the blue dot is the positive pole / wire and its wire has to be dircted through the hole leading to the red coloured connector on the tweeter frame. To hold the very thin wires we secured them with adhesive tape.
B&W CDM1 (ZZ9989 / ZZ09989) tweeter repair: tweeter frame, replacement diaphragm and glue


Detail: The diaphragm wires are guided through the holes in the frame. The wire on the side with the blue dot on the voicecoil extends to the positive connection on the tweeter frame (marked with red).
B&W CDM1 (ZZ9989 / ZZ09989) tweeter repair: diaphragm wires stuck through the holes in the tweeter frame


Apply glue on the inside of the tweeter frame. You can use our speaker glue for this.
B&W CDM1 (ZZ9989 / ZZ09989) tweeter repair: glue applied to the tweeter frame to glue the diaphragm


Now glue the diaphragm on the tweeter frame. Make sure that the diaphragm is glued precisely to the center / middle of the ring. You can apply pressure while gluing with something flat, we used a bamboo stick.
B&W CDM1 (ZZ9989 / ZZ09989) tweeter repair: tweeter diaphragm glued to the frame


Apply new ferrofluid in the air gap. Do not fill the gap completely, leaving about 1-2 millimeters open. This way, the voice-coil will fit the gap later without the air gap 'overflowing'.
B&W CDM1 (ZZ9989 / ZZ09989) tweeter repair: apply new ferrofluid to the magnet gap


Dosage of the ferrofluid may be difficult. If there is too much in the air gap, insert a piece of paper into the ferrofluid. The paper will "suck" some of the ferrofluid. This allows you to remove some ferrofluid from the air gap.
B&W CDM1 (ZZ9989 / ZZ09989) tweeter repair: excess ferrofluid can be taken out using a piece of paper


On the magnet we put a paper gasket, which should prevent the wires of the diaphragm (in the future) to contact the magnet and cause short circuits. The gasket is made of thin cardboard, has the same size as the inside of the tweeter frame, and is glued to the magnet with speaker glue.
B&W CDM1 (ZZ9989 / ZZ09989) tweeter repair: a paper gasket is glued to the tweeter magnet


The tweeter frame connections: The red connector must be connected to the wire leading to the side of the voice coil with the blue dot.
B&W CDM1 (ZZ9989 / ZZ09989) tweeter repair: the connectors of the tweeter


The diaphragm wires run through the holes of the tweeter frame. We secured them with adhesive tape.
B&W CDM1 (ZZ9989 / ZZ09989) tweeter repair: diaphragm wiring attached to the tweeter connectors


Before the wire is soldered, we apply some flux.
B&W CDM1 (ZZ9989 / ZZ09989) tweeter repair: flux applied before soldering diaphragm wiring to the connectors


And the wires are soldered to the tweeter frame .... You can cut of the wires after soldering.
B&W CDM1 (ZZ9989 / ZZ09989) tweeter repair: diaphragm wires soldered to the tweeter connectors


Now place the tweeterframe with the diaphragm carefully on the magnet. You can close the holes in the front of the tweeter frame with some glue, but usually these will sealed with tin after soldering the wires.
B&W CDM1 (ZZ9989 / ZZ09989) tweeter repair: the tweeter frame is carefully attached (clicked) on the magnet


Finished... Now you can mount the tweeter in the speaker cabinet.
B&W CDM1 (ZZ9989 / ZZ09989) tweeter repair: the result after repair

Scary? Afraid to do this yourself? Please contact us, we can provide you with contact details of experienced service personnel for whom this is a piece of cake.

© Good Hifi VOF, 07-09-2017