DM603 S2 tweeter repair or cosmetic issue?

[Tim Eagles]

I have just had my eyes opened to the fact that removing my tweeters from a DM603 case would not be as hard as I thought, but from users experiences with bonked tweeters, or in this case, a childs delightfully directed poke on both tweeter domes, would you recommend disassembly and repair of what I have pictured here:




I'm not sure if powering the units up after pulling the dented portions out is even feasible, or if I would do more damage than good. I have been looking at possible replacements and the local retailer apprised me of the fact that replacements were in the order of < $100 CDN per side, and labour would be a couple of hours. Estimate is $25 CDN if not used for repair. I'm sure as an automotive technician with some electrical background and some obvious love for audio, I can surely replace a tweeter pack.

Now, would the tweeters be clipped in or soldered?

My speakers are boxed in the basement, along with a nice selection of Rotel gear to power up behind them. The 603 S2's are 2001 era if that makes a difference, assuming any changes were made during their model run.

If anyone had a link to what a new tweeter looks like for this particular model, that would be great. I found something on the local for sale forum and was curious if this would be the correct part or not?

DM600 S3 as advertised:


Seems other people have had similar experiences, and claim no reasonable change in sound quality (subjective of course).




My speakers tweeters have not seen the light of day, nor a system power up since they were pushed in, so I just wanted to put that information forward in case anyone was curious. I know diagnosis without something in your hands is a black art, but if anyone has similar experience with this, just chime in and tell us your story.


Sincerely,

Tim Eagles

[PewterTA]

All you need to do is remove the mid range driver. Reach in and the tweeter should turn by grasping the magnet. Once that happens it will basically fall out. Then you can take the screws out and remove the aluminum dust cover from the voice coil (back part with the magnet). Once you do that you can flip over the dust cover and with something like a Qtip, smooth it back into a roundish shape.

Once you do that you will still "see" the creases as those are perminent, but it'll be in the same shape as before and you're all set.

Using it while it's dented in is perfectly fine, it just might not sound exactly correct, but there will be no damage.

If you have any questions, just let me know (or us) know!

-Dan

[Tim Eagles]

Aha, this is the sort of insight I was hoping for! Thank you very much.

It was your set of pictures and rather thorough process for ultimately getting a "sound" improvement from your sets of B&W speakers, that set of the bells inside my head.

Of the DM6XX series speakers you have taken apart Dan, do the dust covers all look similar or can the covers be replaced with minimal effort if some chose to replace them because they can't stand how they look behind the screen? :B

I guess I'll have to pull my speakers out ASAP and go to town. Thank goodness I'm on temporary layoff with expected return due to school for Automotive Apprenticeship through the GM ASEP program, I can now have a more normal set of hours and probably make some quick progress on this. If I hadn't dropped my camera on a recent trip to vegas, I would use it for pictures. I may have a cell phone at my disposal, but I can't promise those pictures would look all that great.

Again, thanks for the help, I'll make an effort to post back when I get further into this. :T

[PewterTA]

From what I've seen, they are all similar. Not exact, but similar enough. You shouldn't have any problems with at least attempting a repair, but replacing, all you should need is the dust cover, not the whole tweeter, unless they did something with perminently fixing the dust cover to the tweeter...which I doubt.

[Audio_ElF]

Warning I've not tried this ... but I've heard of people using a small amount of vaccine from a Hoover or similar to pull out speaker domes that have been pushed in.

I'm not necessarily recommending this course as I've no fort hand experience of tryig it, but from recolection it was published in a reputable magazine.

Eloise

[PewterTA]

I've heard people try that, but for how bad his tweeter is pushed in, it doesn't really work well.

You are better to take the aluminum dome off and try gently rubbing it out to re-form the domed shape.

[bleeding ears]

If using a vacuum to suck out the dome, try putting a straw onto the end of the vacuum and place the straw onto the dome. More accurate and controlled.

It worked for me, on a different brand of speaker, however the creases in the dome were still there and will push back in again very easily if pressed again just lightly.

Sound is fine as far as I can tell.

Pete

[Tim Eagles]

Well, without having seen the last few replies past Pewter's posts in time for this repair, I had went ahead and pulled the first tower apart.
My tweeters had been condemned to replacement base upon the analysis of my dealer, without even knowing how severe the damage was, and assuming perfect musical clarity was my/his goal in the conversation. He mused that there was not much you could do to repair the tweeter and I now know why.
If you are reading this thread, realise that I did not accomplish what I set out to do, but because I knew I had to replace the tweeter's front portion, or maybe the whole magnet assembly with covers intact, factory fitted, I was not setback any further than I was when I started.

I was surprised at how little torque was needed to make the initial loosening of the allen head bolts, but at least they were all evenly torqued. I proceeded to remove the second speaker from the top, or I assume it would be called the midrange speaker. I saw no need to remove the wiring from the speaker terminals and risk doing more damage than good, as there was plenty of wiring still left to work with, and allow the speaker to come out far enough from the tower, to permit hands on access to the tweeter assembly.

Next step was the removal of the tweeter assembly. I carefully placed my hands inside to feel around for the locking tab locations and to find out where the connector/leads were attached so as to not stress them unnecessarily. One simple twist about a 1/4-1/2" and the assembly can be removed. I noticed that there is a wide but extremely thin foam layer or spacer attached between the tweeter assembly and the outer casing where the tweeter pokes through; be forwarned that this must be reinstalled properly upon installation of the tweeter assembly back into the casing as it provides the pressure needed to keep the assemby locked in place - sandwich effect.

There are a total of three phillips head screws that keep the dome in place (and all of it's pieces), attached to the magnet and cone portion of the assembly, and these must be removed to do any work on the tweeter portion.

BE FOREWARNED, THIS IS WHERE IT CAN ALL GO WRONG DEPENDING UPON THE TECHNIQUE BEING USED TO REMOVE THE CREASING or DENTING IN THE DOME PIECE.

The dome is held in place with a tiny, skinny plastic cylinder, and this wedges the foam surround (glued to the dome) and the plastic face of the dome surround. It is simply a friction fit that keeps this surrounding retainer in place, so be careful. If the dome comes loose because the surrounding retainer did not hold in place, you are seconds away from disaster.

I would not recommend putting any sort of pressure on the unit, such that it would cause the dome to move in and/or out just a couple of millimeters in relation to the outer surfaces, because the speaker leads are the smallest pieces of wire that I have ever seen used in electronics, and they will snap as mine did.
This will render the domes useless, and therefore consequently also render the tweeter units useless because this is the speaker that you are working with. The silver dome has the coils wound in place on the back side lip of the dome. Two minute leads run out the the surround retainer and into two channels of the retainer and ultimately up into the connector for electrical connectivity to the crossovers via cables leading down into the back midsection of the tower.

The little foam pad can now be carefully removed to expose the 3 phillips head screws.

In hindsight, I should have probably used the straw and vacuum technique with carefull pressure to keep the dome from moving mainly out too far, because it can only travel so far when the unit is installed and in place with the magnetic housing behind it. I supposed tape might work if you achieve the a similar effect by localizing the pulling pressure to just the pushed in areas, while keeping the whole dome from being pulled out as a consequence. The little piece of foam you see from the outside, will only keep the dome from moving so far and would appear to serve mainly as a dust shield, probably not doing anything musical for the tweeter assembly. The coils and magnet should be the ones doing the magnetic work and there keeping the dome suspended when activated electrically.

I used a ear swab (or Q-tip type brand) to apply gentle pressure the dome while holding it from the front side to equalize the pressure being applied, but after a couple of minutes, I realise that something could go very wrong here. I was noticing how small the coil leads really are, and therefore started to calculate how much pressure it would take to snap them. Before I knew it, the dome retaining ring had come loose and while I was repositioning the dome in place, I realised I had indeed snapped the coils!

A few curse words later, I came to realise that there was not a single thing I could do for those tweeters. IT MAY STAND TO REASON THAT I SHOULD NOT HAVE DONE ANYTHING TO THE TWEETERS AND SHOULD HAVE JUST RUN THEM AS THEY WERE. Physically the dome was not going to contact the innerds behind it, but I cannot say for sure, so you would be assuming all the risk yourself depending upon how far the dome was poked in. This may cause the tweeter to act irratically if it does indeed contact pieces behind it. I cannot say for sure if this is the case, as I did not check to see how much distance back it would take for contact with the dome in place. I am now reserved to replacing the domes, no questions asked, but may be looking to do it myself and not pay someone 2 hours labour, to do it. Parts again, were estimate at < $100 CDN per side.

Here are the pictures to illustrate what I have written here today, and I hope this will help people to see what is really inside their units in service today.

I apologize for the picture quality as they are from a cell phone.




No putty in place for the wiring going between chambers as was used in the DM604s2's in Pewters speaker removal thread.

Twist to remove this unit as a whole.

Here are the 3 phillips screw locations as indicated by the circular holes. The other 3 holes are ovalled or elongated circles and they mate to similarily size bumps on the magnetic portion of the tweeter assembly. Maybe a good idea would be to mark the orientation of the top to bottom pieces before removal, to preserve the speaker connector alignment and such when connected in the box.

This is the dust surround I refer to above, the retainer that holds the dome in place is not visible here, only from the other side can you see it. The magnetic portion holds the dome retainer in place, a sort of sandwich effect once again.

Back side photos of the magnet portion of the tweeter assembly.

The domes base, the part the coils are wound around, fit like a glove between the aluminum looking portion and the bevelled edge in brown.

You can just make out the two traces where the coil connects to the base, on the left side of the dome, closest in the picture. They attach to the wire set in the two channels in the next photo.


If your tweeter assemby ever looks like this, you have gone too far. ops:
The coil leads are irrepairably separated.
The dome would sit inside the main black plastic surround, and would have to be centered as best as possible, before the small circular ring is put back into place. I can't remember if the coil is under the retainer when in place or on top, but upon seeing one tweeter unit removed, it would then become apparent.




This is what an unsuccessful project will look like.




It does make you wonder how close the DM600s3 tweeters really are to the tweeters in my DM603s2's:

DM600s3 below:


DM603s2 below:


I saw the picture of a DM600s3 unit on an Ebay advert, and it was going for $4.99 US, the auction ended at $39.00 US. This is the product # listed with it, as it was posted so I cannot 100% say this is accurate: B&W BOWERS WILKINS zc13137 tweeter diaphragm dm600 s3

[sanj]

Hi
I am not able to see any image of speakers here.whats wrong.

[Kevin P]

Hi
I am not able to see any image of speakers here.whats wrong.

This is a very old thread, the pictures are no longer available.