[stehno]

Stenho,

Glad to hear it was the L-Pad as I thought.  I have seen this quite often, and learned the lesson 1st hand myself with my first pair of RM-40.

"1812 Overture Cannons" at high volume was the issue with mine.

The L-Pad being a resistance device heats up, and if sustained High Power is applied they will burn.

Sometimes they can even burn the cabinet.

In any event, I would change them out on BOTH speakers, as the burned windings will reduce sound quality.

Brian bought them from Parts Express often, and they are very inexpensive.  Best plan is to see if you can get the part number from yours, and take a picture on your phone to sent to Parts Express. 

Remember, they have been "hot glued" into position, so be VERY CAREFUL to slowly pry them lose.  Take your time, or you may damage the cabinet.  When you Glue the new L-PAD in place, take GREAT CARE to position it so that 12:00 is at the top.

Also be very careful to mark the wires and what each was soldered to.  Again, a phone photo can be helpful.

Also as a resistance device, the more "wide open" you run them, the lower the resistance and heat created.  I always ran mine hot (like 1:00 or 2:00)  Brian generally ran lower than that, but seldom blasted.

Thanks for the notes, John.  As soon as I read your note I changed the midrange L-pads from 10:30 to 1:00 o'clock and the trebles from 9:30 to 11.

I hate being on borrowed time but the RM-40's really are quite a musical speaker. 

All your points are duly noted and I will move forward toward a sufficient replacement for the midrange L-pads.  Thanks for taking your time with me.

Warm regards,

[stehno]

Hey John S.,

We had a couple long talks 4-5 years ago.   I still have my pair of RM40 BCSE with the MLS cabinets.  My bottom plate of the speakers had the 3" side MDF supports glued into it.  There was no removing the bottom plate on mine.  Just thought you should know as it could also be true of yours.

Good luck,
Bob

Hi, Bob.  Hope you're doing well.  Thanks for the note on the base plates and I'll have to check out how mine are fastened. 

Much appreciated.

[stehno]

Thanks for the notes, John.  As soon as I read your note I changed the midrange L-pads from 10:30 to 1:00 o'clock and the trebles from 9:30 to 11.

I hate being on borrowed time but the RM-40's really are quite a musical speaker. 

All your points are duly noted and I will move forward toward a sufficient replacement for the midrange L-pads.  Thanks for taking your time with me.

Warm regards,

BTW, I forgot to mention.  Besides the questionable L-pad having seemingly less friction while turning than the others, the second night when I turned it gently left and right to full extents and then settled at 10:30 for testing there was indeed a little catch or snag during a turn and then almost as quickly the catch or snag released.  Not a major catch or snag.  Just a minor one as I was doing my best to be gentle.

[stehno]

Stehno, Really glad there working.

There really not that difficult to tilt down on there side, and they out weight  me by 65lbs.  I think bases are actually two pieces, but you have to remove the 4 large Phillip screws (approx. 4”) first. That removes the base from speaker. Then you can remove 8 screws (1.5 -2 “) that hold the bottom to the side of the base.  Good luck Zak

I tilted one speaker and had my wife felt for drilled holes on the underside of the base plate along and beneath one of the vertical supports and she counted 3 holes.  That doesn't necessarily imply the base plates are screwed in (could still be glued) but it does imply hope.  That's a good thing.  So I'll have to get a better look.

[stehno]

Stenho,

Glad to hear it was the L-Pad as I thought.  I have seen this quite often, and learned the lesson 1st hand myself with my first pair of RM-40.

"1812 Overture Cannons" at high volume was the issue with mine.

The L-Pad being a resistance device heats up, and if sustained High Power is applied they will burn.

Sometimes they can even burn the cabinet.

In any event, I would change them out on BOTH speakers, as the burned windings will reduce sound quality.

Brian bought them from Parts Express often, and they are very inexpensive.  Best plan is to see if you can get the part number from yours, and take a picture on your phone to sent to Parts Express. 

Remember, they have been "hot glued" into position, so be VERY CAREFUL to slowly pry them lose.  Take your time, or you may damage the cabinet.  When you Glue the new L-PAD in place, take GREAT CARE to position it so that 12:00 is at the top.

Also be very careful to mark the wires and what each was soldered to.  Again, a phone photo can be helpful.

Also as a resistance device, the more "wide open" you run them, the lower the resistance and heat created.  I always ran mine hot (like 1:00 or 2:00)  Brian generally ran lower than that, but seldom blasted.

John, while I have your attention, I'd like to ask a few unrelated questions if I may based on the label above.

1.  At the very top of the label it looks like Brian is listing the RM-40 model as 8 ohm whereas I always thought these were 4 ohm.  Can you confirm?

2.  I used to bi-wire these speakers but no longer.  My speaker cable runs are routed from the amp to the lower terminals (mid/treble) and the jumpers carry the signal to the upper (bass) terminals.  From a sonics or overall best musicality potential would you consider this the proper config?

Thanks,

[T3GTerry]

I just joined this group recently as a result of acquiring a set of non working ST IIIs. After a tear down I have a 15 inch white woofer that has an open voice coil and a 12 inch woofer with an open voice coil. Anyone have any of these available for sale as I need them? Thanks in advance.

[John Casler]

John, while I have your attention, I'd like to ask a few unrelated questions if I may based on the label above.

1.  At the very top of the label it looks like Brian is listing the RM-40 model as 8 ohm whereas I always thought these were 4 ohm.  Can you confirm?

2.  I used to bi-wire these speakers but no longer.  My speaker cable runs are routed from the amp to the lower terminals (mid/treble) and the jumpers carry the signal to the upper (bass) terminals.  From a sonics or overall best musicality potential would you consider this the proper config?

Thanks,

It says 4 ohms nominal, 3.6 ohms minimal for the RM-40 if you look closely.  It is the RM1 and 626R that are 8 ohms.

That connection pattern is fine.

[stehno]

Hope everybody had a very pleasant Christmas.

Thanks, John.  Much appreciated.  The RM-40's are sounding as good as ever thanks to you guys who've been most helpful.

Somebody had informed me that once part of an L-pad fries, it's only a matter of time before it completely fails.  Don't know if there's any truth to that but just in case I've dialed down my guilty pleasure listening a few db. 

BTW, can anyone confirm for me the exact thread and length of the 4 phillips head screws that fasten the base plate to the vertical columns?  Might they be 1/4"-20 or 3/8"-16?   

Exact length would be very good to know as well. 

Thank you.

[tj309]

I have a 30+ year old pair of VMPS Large subs that I finally got out of storage only to find the down-firing 15" passive radiators were rotted out.  The front mounted active drivers are fine but the speakers only go down to about 30hz in their present condition - certainly not the room shaking like they used to.  Does anyone know where I can find a pair of passive radiators?  I'm assuming to replace them I have to remove the 15" active speaker and will the passive fit through the hole?

Or should I just upgrade to a pair of JBL 18" per side?

BTW new member here.  I've been into audio/stereo equipment for over 50 years and love to build speakers.  My current system was started 40 years ago and consists of SAE, 4 Onkyo power amps, lots of processors, and 306 knobs, switches, buttons, and sliders.

[Jstower]

The passive is easily removed from the bottom. As far as fixing

1. Re-foam the current 15” passive radiators

2.  Purchase new 15” passive radiator from Part Express 
           https://www.parts-express.com/dayton-audio-rss390-pr-15-aluminum-cone-passive-radiator--295-504

           Good luck

[tj309]

Thanks Js.  I don't see how I can fit the new 15" passive radiator thru the bottom slot as its 4.75" tall and the slot is around 3".  Does the bottom of the enclosure come off?

[GeorgeAb]

Thanks Js.  I don't see how I can fit the new 15" passive radiator thru the bottom slot as its 4.75" tall and the slot is around 3".  Does the bottom of the enclosure come off?

Maybe a picture of your subwoofer is in order to assist?  This is a picture of the Larger Subwoofer's from VMPS legacy site:  http://pointillistic.com/vmps-audio/subwoofers.htm and what mine looks like.   

Maybe you have a tallboy Sub?  Which looks like this:  https://www.audiocircle.com/index.php?topic=122314.msg1832169#msg1832169 If so, the base should come out by removing screws to access the passive speaker.   

[Jstower]

tj309 , so you have the older tallboy ( larger ) there should be 4 screws to remove the base, so you can access the passive. I have the smaller version, and mine is screwed together.

[tj309]

yes that is the one I have (in the above pic).  I've never seen the bottom of them but will tonight.  Thanks!

[tj309]

Since I need to replace the passive radiators maybe I should replace the 30+ year old active drivers too.  I'm partial to JBL professional series and a 2206H 12" and a 2226H 15" would be ideal.

I'm itching for a pair of double 18" JBL 2241's or 2242's per side but the rated low frequency response is 30hz/25hz respectively.  The VMPS's go down to 17hz.  I'm not sure I can still hear that low but I can certainly feel it!

Thoughts?  And thanks

[tj309]

The bottom easily came off with the removal of 8 fairly hefty screws.  Easy replacement thanks to the link a couple of posts above.  Thanks! 

[tj309]

I got a pair of 15" passive radiators from Parts Express and to get them in I had to cut a bit only to find that they don't fit the hole.  I need to enlarge the hole by about 1/8" all around.  That is going to be very difficult even for an accomplished woodworker such as myself as one cannot get power tools into the box to do the surgery.  It may have to be a total sanding job with a drum sander on my drill ...  what a pain!

[John Casler]

Did you try "surface" mounting? 

The CSS PR could be surface mounted and the basket fit the hole fine.

But instead of the woofer rim fitting inside the set down it simply sat on the baffle and we used a good gasket or liquid gasket to seal.

Just an idea, since it is not visible and the small off-set does not affect the sound.

[Avoosl]

   I can confirm John's surface mount idea. That is just what I did when changing the passive radiator on my old Super Tower IIIs about 15 years ago. Originally I had an accomplished woodworker take a look at at. He told me he thought he could do it, and would get back to me. Despite reminders I never saw him again. As John said, applying good gasket will provide a sufficient seal. No worry - you'll be fine.

[davidc1]

Just use clear silicone. It cleans off easily if you need to change anything and will fill all holes and gaps. I started using it with my Speakerlab kits (remember them? Based in Seattle), and continued with it for my kit Super Towers and even the LRC I just got.