VMPS SuperTower/R Question

baco99 · « **on:** 2 Jun 2016, 09:17 pm »

Hello! This is only my second post and I am happy to have found this site. I've been working on speakers for over 25 years as a hobbyist.

I'm working on a "light restoration" of a pair of VMPS SuperTower/R speakers that a friend of mine picked up. They need 6 new foams, which is no big deal. One of the bottom-mounted PRs also needs a new rope caulk mass added to it. The prior rope caulk install seems to have peeled off and been lost. All of the other drivers seem in tact and operational.

I have 3 questions, however.

1) When I looked in the box, the sides are coated with the optional VMPS white ceramic "Soundcoat" material. There's very little internal bracing which is shocking for a speaker this size, and there's no polyfill, fiberglass, or Roxul insulation in the cabinet at all.
a) Does the Soundcoat need to be reapplied at all, or is it a material that holds its value forever?
b) Has anyone added bracing to the inside of the cabinet to stiffen it? If so, where? If not, why not?
c) Is there any reason not to line the cabinet with polyfill or fiberglass as additional acoustic damping?

2) Has anyone experimented with using a different added-mass method than rope caulk and hot glue for the bottom PRs? This seems like a rather clumsy solution to me. I was thinking of doing what Snell did for the Type A and adding some kind of epoxy to the cone, or gluing a more solid mass made from wood or plastic. Any thoughts here?

3) The super tweeters on these were apparently upgraded by the owner of VMPS before his passing. They are ribbons but they look different from ones I have seen online. Does anyone have any info on the upgrade paths that were provided well after these speakers went out of production. The tweeters are Morel MDT28 with a rear chamber and ferrofluid. Are these the upgraded tweeters? Were the MDT29 the standard?

(Also, if anyone needs NOS voice coils for Morel tweeters, I have a bunch. )

THANKS!

Under the knife...

RSorak · « **Reply #1 on:** 2 Jun 2016, 11:05 pm »

The soundcoat is a ceramic based coating and should last forever with no care.

My SuperTowers were built from a kit and the instructions said to fill the cabinets with insulation. I did and they are.

I have also upgraded the super tweeters in mine over 15 yrs ago and have no recall of what I used ot what the stock ones were.

The PR's have a tremendous amount of the putty added. There are upgraded PR's available that have a much better tuning system and increase the bass output. Contact John Casler. they are very similiar to these http://www.creativesound.ca/details.php?model=APR15

Holt Hill Audio · « **Reply #2 on:** 3 Jun 2016, 02:47 am »

Sorry, logged in under the wrong alias!

Carry on!

baco99 · « **Reply #3 on:** 3 Jun 2016, 02:49 am »

Thanks RSorak for the reply

That's better...

You know what's funny, I have had a 15" CSS PR with adjustable weights/washers in my workshop for 2 years without a purpose. Just set it aside for a rainy day. Maybe I'll restore one old one and try the new on and run some measurements for fun.

Interesting that your kit said to fill the cabinets. That's uncommon for a PR design. Usually you'd see *some* fill, like in a Polk SDA tower where it's used mostly to mitigate midrange leakage. But the PR is largely open.

Was the ceramic coating intended to replace the fill?

Also, confirmed that these use the MDT28, ferrofluid cooled 200w tweeters.
Can anyone tell if the wiring is also upgraded by looking?

revg1952 · « **Reply #4 on:** 3 Jun 2016, 10:29 am »

That PR has enough Mortite on it to choke a horse

. All VMPS speakers were filled fiberglass with a vent pass to the PR.

Shear Bliss VMPS · « **Reply #5 on:** 3 Jun 2016, 12:33 pm »

On my ST/R which I had re-foamed by Millersound, PA. the putty loading varied from Brian, according to James Romlyn who worked side by side building VMPS, Brian changed loading first with a 1 oz lead fishing sinker, then added 4-8" of putty to dial in the passives, worked great for me.

I bought the line thru type 1 oz sinker, hammered into a circle, then hot-glued it in three places, adding the rest of the putty loading directly onto the lead weights, clean and simple.

Your passives are a mess! Any weight or putty should be centered anyways, not on the cone itself. Once you get both passives re-foamed, vitrify them with yellow Elmers wood glue to stiffen the cones, then do your lead and putty loading ... good luck!!

PS: If James responds to this, listen to him ..... this was his VMPS era working with Brian and he has a wealth of info from back then.
DW

RSorak · « **Reply #6 on:** 3 Jun 2016, 01:21 pm »

Just to add another detail on the fill. My speakers also have the soundcoat and more specifically the instructions said to fill most of the cabinets but leave space at the bottom empty of fill by the woofer/PR.

baco99 · « **Reply #7 on:** 3 Jun 2016, 01:23 pm »

Quote from: revg1952 on 3 Jun 2016, 10:29 am

with a vent pass to the PR.

What do you mean by this?

baco99 · « **Reply #8 on:** 3 Jun 2016, 01:23 pm »

Quote from: RSorak on 3 Jun 2016, 01:21 pm

Just to add another detail on the fill. My speakers also have the soundcoat and more specifically the instructions said to fill most of the cabinets but leave space at the bottom empty of fill by the woofer/PR.

Got it, I think this just answered my other question, above.

baco99 · « **Reply #9 on:** 3 Jun 2016, 01:29 pm »

also, any thoughts on adding bracing? That one piece of pine doesn't seem sufficient to me...

ZAKski288 · « **Reply #10 on:** 3 Jun 2016, 06:01 pm »

This is how I braced my cabinets, right above the 15" woofer, also I raised the base by 3/4" so I could get my hand to the putty on the PR. Good Luck Zak

baco99 · « **Reply #11 on:** 3 Jun 2016, 06:45 pm »

Looks great Zak!
I see you recapped them. The pair I am working on seem to also have the wiring and crossover upgrade. The Monster "Powerlink Low Loss" wire is in the cabinet for the two woofers. I'm tempted to check the values and leave them if they are within spec.

ZAKski288 · « **Reply #12 on:** 3 Jun 2016, 07:29 pm »

Baco99, Also I took out the toggle switch and will use an external jumper wire , or bi wire Zak

oliverbubbles · « **Reply #13 on:** 3 Jun 2016, 08:44 pm »

I have read in several locations where Brian referred to these designs as aperiodic designs and not passive. But an aperiodic uses a tuned vent so i imagine this to be some sort of hybrid due to the amount of stuffing inside the cabinets being coupled to the passive radiator. This is only my guess from reading where he described many of these older models as aperiodic.

baco99 · « **Reply #14 on:** 3 Jun 2016, 10:47 pm »

FYI, the moretite on the PR measured 5.6 oz.

Shear Bliss VMPS · « **Reply #15 on:** 3 Jun 2016, 11:05 pm »

baco99,

Yes way too much! Applied wrong also, but you will get there, killer loudspeakers.
DW

ZAKski288 · « **Reply #16 on:** 3 Jun 2016, 11:12 pm »

Here is what my Supertower/R passive looks like

Yes, Shear Bliss is correct there is a one ounce fishing weight hot glued in the bottom of cone.

I believe this is all original, factory built speakers. I measured the putty for my records.

I added the VMPS logo to the center cap

baco99 · « **Reply #17 on:** 4 Jun 2016, 12:02 am »

There is also a weight on the back.

baco99 · « **Reply #18 on:** 7 Jun 2016, 04:15 pm »

can anyone tell if these speakers also have the Wondercap upgrade? the caps look to be mylar or poly film (not electrolytic).

ZAKski288 · « **Reply #19 on:** 7 Jun 2016, 05:11 pm »

They should be marked if they are Wonder caps. they look like this.