[DR2]

My Dad and I need guidance on replacing the tweeters on VMPS 40's.

Long story short I have temporarily inherited 2 VMPS 40's from my Dad. When they arrived I was looking them over and discovered that a tweeter ribbon is severed on one of the towers.



I was able to reach John Casler about them and he led me in the direction to find the replacements which he said are either Aurum Cantus G2 or G3.

At this point, I really do not want to bother John any more than I have about this and to see if anyone knows what the tweeters are all about in these towers.





Based on what I can see, it looks like its the G2Si.

Now I noticed that the tweeter has no visible fasteners. Upon closer inspection there is clearly a firm yet compressible material adhered over the tweeter. It has a bumpy surface and is cut to the width/height of the tweeter opening. It covers the angle of the opening on the tweeter itself, effectively removing the angle on the opening of the tweeters. Which I am guessing is to narrow the direction of the sound.

Does anyone know what this material is? We also do not know how that material is secured, but I'm guessing some kind of glue or silicon?

Given that, is it confident to say its the G2Si from the picture? Or is it possible that its one of the rectangular G2 or G3?

If we did go ahead and remove the Neo Panel above it would the Aurum Cantus be labeled?

I suppose we could do this now since we will have to anyway. But without any visible fasteners I am a bit hesitant given my lack of expertise and the unknown material.

We are also wondering exactly how everything in regards to the tweeters are fastened so we can properly remove and replace them.

I also came across some information that Brian had fixed a defect in many tweeters. So we are additionally wondering if its these specific Aurum Cantus that Brian modified and what those modifications were.

If anyone can help, please do! It would be greatly appreciated as we would like to get these speakers running and keep them running!

If you know an experienced speaker technician in the South Florida area we would also be open to that so we can be sure its all done properly!

Thank you for reading!

[mgalusha]

Many years ago I did this for AC member Tyson and now Pez owns them, I cannot recall exactly what was required, but I think I had to do some slight modification to the cabinet, perhaps Brian had moved to a different tweeter. If Tyson sees this, he may be able to provide further info.

As for what is covering the driver, I'm not sure what it is, but many self adhesive materials can be removed fairly easily when gently heated.

[Early B.]

At this point, I really do not want to bother John any more than I have about this and to see if anyone knows what the tweeters are all about in these towers.

John is an awesome dude. He'll probably be happy to help you out. 

[GeorgeAb]

Fairly easy DIY, I have done a few. If you can use a screwdriver and solder a wire, you got this. Yes, it is the Aurum Cantus 2si. You can either replace or repair.  Replace is fairly similar to repair, but it costs $136 x 2 for tweeters vice $12 all in for replacement ribbbons.  If you go for new drivers, purchase here:  https://www.parts-express.com/Aurum-Cantus-G2Si-Ribbon-Tweeter-276-400

Remove the four outer screws secured with phillips screws. They may be obscured by acoustic material (that is your case, so you will have to peel off acoustic material that is glued onto driver). The driver will come straight out, you may have to hook something into one of the empty screw holes and gently pull back to get it started moving as sometimes they can be in the cutout fairly tight. The two wires connected are blue and green, green is going to postive lead and blue to negative. + and - are annotated on driver. The wires will be soldered so just cut (see note at bottom if repairing). You may want to tape the wires to the ouside of the speaker so they do not fall back into the speaker. To reinstall you can solder the wire to the drivers terminal using a fairly large solder iron or you can crimp and solder a round eyelet and screw to terminal with supplied hardware that came with driver. Reinstall driver, I would not worry about replacing the acoustic material. If you are stuck on replacing the acoustic material look at my prevous posts as I provided the info on material a few years back. Getting the residual glue from the back of the acoustic material that is still on speaker can be done with goof off. Be easy and do not take long so goof off does not mar finish. If you use on speaker driver it can remove the paint so be quick and gentle.   

Repair is similiar, but instead of buying driver you just buy ribbons and replace. Follow the above steps for replacement, but replace ribbon as follows. I would get two sets so you will have spare or if something goes wrong.  They are under $6 each here:  https://www.parts-express.com/Aurum-Cantus-G2Si-Replacement-Ribbon-276-401 I provided a previous post on how to replace the ribbons here which includes the manufactures instructions along with my tips on performing:  https://www.audiocircle.com/index.php?topic=179843.0

If you repair and do not have a large soldering iron then cut wire farther back to give yourself enough wire to be able to strip and the reattach wire and solder then cover with electrical tape or heat shrink.   

Does anyone know what this material is? We also do not know how that material is secured, but I'm guessing some kind of glue or silicon?

Yes, I provided a adequate replacement material. It was in a post I made a few years ago, you will have to dig it up if you want to know. It is glued, good tip provided by @mgalusha of using heat to gently remove. 

Given that, is it confident to say its the G2Si from the picture? Or is it possible that its one of the rectangular G2 or G3?

G2Si, 100%

If we did go ahead and remove the Neo Panel above it would the Aurum Cantus be labeled?

The neo is the midrange panel, this is the tweeter, but yes it will be marked as Aurum Cantus 2Si.   

I suppose we could do this now since we will have to anyway. But without any visible fasteners I am a bit hesitant given my lack of expertise and the unknown material.

Take a deep breath and jump in, you got this. 

We are also wondering exactly how everything in regards to the tweeters are fastened so we can properly remove and replace them.

Addressed above in provided procedure.

I also came across some information that Brian had fixed a defect in many tweeters. So we are additionally wondering if its these specific Aurum Cantus that Brian modified and what those modifications were.

Brian corrected a neo panel. In a previoius post I provided how to do this and how to find and replace neo panels. Since we are talking the tweeter and not not the neo panel it does not apply. I mention if you have any issues with the neo in future, you can repair and replace. 

Congratulations on your speaker aquistion. 


   

[GeorgeAb]

Delete, pardon I was attempting to modify my above post and posted new response instead.

[Jstower]

Also if you’re ever transporting RM40’s you want to cover the tweeters with masking tape to protect the ribbons which are very fragile. Good luck

[DR2]

Thank you for the advice everyone!

Repair is similiar, but instead of buying driver you just buy ribbons and replace. Follow the above steps for replacement, but replace ribbon as follows. I would get two sets so you will have spare or if something goes wrong.  They are under $6 each here:  https://www.parts-express.com/Aurum-Cantus-G2Si-Replacement-Ribbon-276-401 I provided a previous post on how to replace the ribbons here which includes the manufactures instructions along with my tips on performing:  https://www.audiocircle.com/index.php?topic=179843.0   

We are going to attempt the ribbon repair/replacement first in the coming weeks and go from there. Seems logical to start at what is currently the issue.

I will be sure to update here!

Also if you’re ever transporting RM40’s you want to cover the tweeters with masking tape to protect the ribbons which are very fragile. Good luck

We did transport them without unfortunately! We were completely unaware of how fragile they are. Neither of us recall seeing the issue at my Dad's home before they arrived at mine. We had them running at his place for a short while just to make sure they worked and the parasound equipment still worked. They sounded great, but we did not check them over at all. We should have but we were more occupied with him moving soon and getting other stuff ready. Where they were staged in my Dad's home the lighting was not so good. So we are not sure. It's possible it was fine but got damaged on the way. Lesson learned.

[Stimpy]

As noted, tweeters and replacement diaphragms are available at Parts Express.  Maybe get back-up's too, once everything is running.

https://www.parts-express.com/search?order=relevance:desc&keywords=aurum%20cantus%20diaphragm

Good luck!  And I wish someone would drop a pair of RM-40s on me.   

[Pez]

It’s a fairly straightforward process. Just remember, you’re dealing with incredibly strong magnets. Under no circumstance should you have any tools that are ferromagnetic anywhere near the enclosures.  and when you order ribbon replacements, do yourself a favor and order several.

[DR2]

I finally found the time to give this a shot. All went well except there is no volume from the tweeter. After speaking to my Dad about it and testing, we believe is the crossover.

I have some DCM loudspeakers sitting around and I decided to test the leads from the tweeter. Removed the soldered wire from the tweeter and ran speaker cable from the tweeter leads to the DCM and nothing...

My Dad will be back in town in July and he knows his way around crossovers and what not. He's going to take a look with me then and see what we can find / figure out.

But here is how it went..

I was able to remove the foam material with a heat gun from the tweeters without issue.

I made a make shift shim out of some thin plexi I have laying around and sanded it to a point.

No damage to the tweeters or the foam material.

Was able to fully preserve them. So they will go back on.





Decided to leave the tweeter in place and not desolder at the time.





The philips screws for the fastening blocks for the ribbon are rather shallow. Had to sand down a philips #1 which worked very well.





It took 3 ribbons, I ordered 6. Used plastic tweezers for handling the ribbons.

The first try I thought I had made a mistake, as the ribbon was ever so slightly touching the right magnet. 1/32 or 1/64 off to the right.

2nd try I paid close attention this time and got the alignment perfect on the fastening block, but same thing. I believe there is some kind of manufacturing tolerance maybe.

3rd try I took that very small measurement into account, so basically placing the ribbon on the fastening block just ever so slight left and got it perfect.



And all back together.



With quite the mess afterwards



I'm not sure why the forum is rotating some of the images, so sorry about that.

Will update again when we know more.

[GeorgeAb]

Congrats on getting it done. Have you fired them up?

[DR2]

Congrats on getting it done. Have you fired them up?

I did and unfortunately discovered an issue with the crossover. Hopefully some time in July we will address it.

[GeorgeAb]

I did and unfortunately discovered an issue with the crossover. Hopefully some time in July we will address it.

I have not taken the time to make a schematic of the RM-40. One of these days when I get time, I will reverse engineer the circuit and post. I can tell you for the tweeter it is exactly like the RM-30 and RM-V60 with a capacitor in series, then inductor in parallel going to a divider (L-pad) network. For the RM-30 and RM-V60 the component values are the same (1.37uF and .25mH) and RM-40 likely, but I have not verified RM-40 values. Below is the RM-30 schematic and RM-V60 schematic courtesty of Shaukat @shauk786. The schematic I drew for the RM-30 is harder to follow, but it the same as Shaukat's.




 

[DR2]

I have not taken the time to make a schematic of the RM-40. One of these days when I get time, I will reverse engineer the circuit and post. I can tell you for the tweeter it is exactly like the RM-30 and RM-V60 with a capacitor in series, then inductor in parallel going to a divider (L-pad) network. For the RM-30 and RM-V60 the component values are the same (1.37uF and .25mH) and RM-40 likely, but I have not verified RM-40 values. Below is the RM-30 schematic and RM-V60 schematic courtesty of Shaukat @shauk786. The schematic I drew for the RM-30 is harder to follow, but it the same as Shaukat's.

Thank you very much! This should come in handy