[PMAT]

close-up pictures would be nice 

[James Romeyn]

close-up pictures would be nice 

Pictures of what?  Neo panel input terminals?  I have no Neo panels.  Just going by memory, I will personally mark six months after Brian won the CES award (I forgot the year) as the date after which all Neo panels were repaired prior to leaving the factory.  My offer stands only for original VMPS buyers with proof of purchase.  Other Neo panel owners can contact me personally for a charge quote for service. Neo panels have sum total two input terminals, one positive, one negative, located center of one of two short dimensions.  I wrote:

...look at the panel terminal.  If it's a rivet, if you don't see a screw head (my repair) or nut (Brian's repair), if I was you I'd update the panel ASAP...

It is reasonably easy to discern the physical differences between a rivet, a machine screw head, and a machine screw thread/washer/nut.

If you see a rivet, it needs attention.
If you see a machine screw head, it's already fixed. 
If you see a machine screw thread/washer/nut, it's already fixed.

Readers unsure what is a rivet can post an image and request help.     

[dubravko]

This is the first generation Neo from 2001, made by Sonigistix. This is how it looks originally, no repair done. It was problematic in at least three points as far as I know.
- buzzing when played louder since magnets were quite close to foil and they played quite low in the range
- losing contact on rivets, not always related to how loud it played
- paint peeling off on the inside over the years, small pieces of paint causing more buzzing even when played soft

I had the "luck" to be the first with the rivet problem, before it was even known that rivet is the cause of it. At that time, beginning of 2002, Brian seemed to have none of the problematic Neos. Perhaps mine were a bit hurried up to a problem during a long and probably rough shipping. Anyway, at that time he could not reproduce the problem and therefore help me with useful advice.

I checked a lot of parts before I narrowed it down to rivet. Then it took some time to figure out that any practical soldering method won't solve anything. I finally found small enough Aluminum screws and drilled out the rivets. That worked. If I recall it correctly I placed nuts out because nuts were larger than a screw head or washer. Having nuts on the inside could cause shorts since there is really little space between leads, some 0.5 mm or so. Brian later adopted and improved the method with different washers. I think that all speakers from second half of 2002 and later had repaired Neos.




Second generation, made by Level 9, all speakers from about late 2002 should have those.
Larger gap between magnets and foil (I think gap was doubled), so no buzzing, and I never heard of paint problems either. Also more openings, 13 columns compared to 8 at first version.
Problem with contact rivets still there.




Same panel from the back.





Repaired Level 9 panel.

[Linkwitz Riley]

Yes I think I have answered my questions with this post from Long Ear regarding an email he got from Brian:

http://www.audiocircle.com/index.php?topic=96810.msg971709#msg971709

So to sum it up, the Ultra Megawoofers appear to be:

Dayton Audio RSS390HF-4 15" Reference HF Subwoofer 4 Ohm
Brand: Dayton Audio   |   Model: RSS390HF-4

Dayton Audio RSS315HF-4 12" Reference HF Subwoofer 4 Ohm
Brand: Dayton Audio   |   Model: RSS315HF-4

If using the Dayton Audio HPSA1000-R 1000W Rackmount Subwoofer Amp, wire the two drivers in serial or use another amplifier that is capable of driving a 2 ohm load (like the Crown versions mentioned in the thread).

Surgery is required due to the larger diameter of the aforementioned drivers as John mentions.

gab

Yes, the info provided is correct.  I have 2 larger subs and I purchased the Dayton Audio drivers mentioned along with the Big Bump passive radiators.  The Dayton drivers sound fantastic.  They are better than the megawoofers which I had previously.  The big bump passives were hideous looking and VERY sloppily made, but they seem to be working for now.  I may purchase the alternative PRs that John has discovered in the near future.  My drivers are both 4 ohm & wired in parallel for a 2 ohm total impedance,  but my Crown K2 amp handles that load with no problem.  It is putting 1250 watts into each sub and the drivers are handling it fine.  I've had my VMPS subs for almost 15 years now so I can tell you with confidence that the upgrade is well worth it.  You will have to enlarge the mounting hole for the drivers in the cabinet though.  Some people just put speaker flange gaskets in the existing flange area as spacers so that the new drivers would mount flush to the top of the front baffle.  I didn't like that idea because the driver would stick out and hit the grill cloth. I routed a new wider flange into the cabinet so that the new driver would sit recessed like it was designed to do.  Required a special router bit but well worth it to have everything mounted properly.

[James Romeyn]

...If I recall it correctly I placed nuts out because nuts were larger than a screw head or washer. Having nuts on the inside could cause shorts since there is really little space between leads, some 0.5 mm or so...

Thanks for the images and panel history.  Again, I repaired many panels both with Brian at the Plant and separately at home.  I have no panels now.  IIIRC, it's true there is minimal dielectric between the conductive traces for the terminals.  But the space between the terminal centers clearly (to me) indicates plenty of space for the nuts (at least the fasteners I employed and have here for free for anyone who wants them) for those preferring the cosmetics of a screw head showing vs. threaded stud, washer, and nut.  Also, no reply when I asked Brian the reason for his screw orientation.     

IIRC here is the risk: whatever is on the side of the trace (screw head or nut, terminal side, the panel side facing the sub enclosure), must be held stationary while turning/torquing whatever is on the outside of the panel (screw head or nut).  If whatever contacts the trace turns, the trace will likely break or deform resulting in open or shorted circuit, neither of which will do especially much to improve audio performance.  Again, the minimal dielectric between traces increases risk. 

We have many primeVibe customers throughout Europe including Croatia.  We hope to visit one day, and will request a brief visit at that time if convenient for you. 

[dubravko]

Perhaps a space problem for the nut on the back was present only for 1st generation Neos, or I simply had larger nut than usual.
I never needed to repair 2nd generation.

Your advice for not letting anything scrub the traces is very important, that could destroy panel easily.

If you visit here, just let me know in advance, it would be nice to meet you.

[John Casler]

GOOD NEWS for those of you with Classic VMPS with "DYNA-RIBBONS".

This includes Early FF-1 and FF-3 owners.

We have uncovered 15 of the DYNA-RIBBONS (see photo below)  $99 plus shipping.

I will update the INVENTORY page.

[John Casler]

Here is another pic of the driver itself

[John Casler]

Have 2 additional 15" Passive radiators (old style) non-vitrified for $39 each plus shipping.

[underdawg]

Have 2 additional 15" Passive radiators (old style) non-vitrified for $39 each plus shipping.

are they rubber surrounds or foam?

[James Romeyn]

are they rubber surrounds or foam?

I'm interested to see reply.  While I worked for Brian every PR had exclusively foam surround.

In VMPS lingo, does not "vitrified" indicate PR cone coated with white wood/paper glue?  We're going way back, but that's my recollection...http://dictionary.reference.com/browse/vitrified

I stopped following VMPS' product line prior to Brian replacing the active side-firing 10" (RM30) with 10PR.  The RM30 enclosure volume was better limited to two active 6.5".  For RM30 with 10PR, what occupied the down-firing dual 6.5PR slot? 

Interesting that Brian employed the above change among several others I suggested over the decades.  The last one I suggested 15 years prior was the RM50s side-firing PR.  Side-firing PR smooths bass FR more than the slot filtered unwanted HF hash.  I strongly felt and still feel it would be ideal to side-fire PRs on the same side for two L/R speakers.  IOW, fire both PR on the L or R side (side does not matter, even if the active array was not a straight symmetrical line).

Such PR alignment provides non-symmetrical boundary path length for the two PRs, far better than a symmetrical path length.  The latter damps bass modes, the former excite bass modes.  Plus, the user could audition the speakers with both PRs firing either L or R (I guarantee one would sound much better than the other unless the room was totally symmetrical, which of course is only about 1% of domestic sound rooms). 

Symmetrical L/R speakers below 80 Hz are anathema to ideal performance.   

[John Casler]

are they rubber surrounds or foam?

The surrounds on these are foam.  They appear in quite good condition.

[John Casler]

I'm interested to see reply. 

While I worked for Brian every PR had exclusively foam surround.

In VMPS lingo, does not "vitrified" indicate PR cone coated with white wood/paper glue?  We're going way back, but that's my recollection...http://dictionary.reference.com/browse/vitrified

Hi Jim,

Yes, vitrified is when the cone  has been painted with a stiffening agent, which is usually a commercial grade of Elmer's Glue.

That is a term Brian used, but your linked definition doesn't seem to fit B's.   

[James Romeyn]

I'm quite sure if not positive, the huge changes/improvements Brian found while removing tiny portions of a gram of mass from a PR, was simply the damping/masking of a bass mode.  It is highly unlikely to find ideal performance with matched Q between two speakers in a domestic room (commercial, yes...domestic no). 

If I'm correct (I know I am), then every single ported speaker that prohibits the user from altering one or both port lengths (PR mass in Brian-speak) is improved by allowing the user to alter Q (change port length) between the L and R channel.  In fact, one might posit that a designer should arrive at his chosen ideal Q, then stagger the two L/R channels: one channel +5%Q, the other channel -5%Q.  Such is less likely to excite bass modes than two matched symmetrical Q.       

In most domestic rooms, performance can only audibly improve with non-symmetrical bass tuning per L/R speaker.  The only exception is if some non-symmetrical room boundary effect improved performance with symmetrical bass Q.  But in this rare case, the ability to tune/stagger Q is not a determent, it just is unnecessary.

If I had ported speakers I'd staggering the port lengths.  There are power handling considerations though, and sometimes with a 2-way, effects up to the mid range.  Can't help you there.       

[James Romeyn]

GOOD NEWS for those of you with Classic VMPS with "DYNA-RIBBONS".

This includes Early FF-1 and FF-3 owners.

We have uncovered 15 of the DYNA-RIBBONS (see photo below)  $99 plus shipping.

I will update the INVENTORY page.

Good ole Scan Speak D2800/20006 world-class domes (that attract dust like it's going out of style),  flanking Brian's best-ever planar (not true ribbon) tweeter, the big bad Philips.  Those planar tweeters are killer.

I think one of Brian's best speaker lines ever was the series just prior to this, with Brian's own poly/rubber 5.25" cone mids where you see two so-called "Dynaribbon" mids in the image above.  Brian bought out all the remaining Dynaribbon stock from Just Speakers. 

Oh, the good ole days, driving through San Francisco's Mission District and stopping in at Just Speakers on (24th St?) a couple blocks E of Valencia St.  One of the proprietors was an early victim of AIDS, very sad.

Brian's shared Dunlavy's preference for shallow crossover slopes.  Dunlavy physically offset the drivers for better time signature at closer listening distance.  Brian's worked better with longer listening distance, and probably generally had larger dynamic output to work with longer listening distance.  He did not promote listeners in his huge room to audition sitting up super close, at least with the big towers.  Not much point in a 250# 6' tower at 8-10'!  (Some of his larger towers worked well at close distance, model dependent.)

I auditioned huge Wilson towers up close and at long distances.  Former sounds much better than the latter, same as Brian's.       

[Shear Bliss]

Hello Mr. Romeyn,

I own RM-1s and have been reading for the first time, about needed repairs to the Neo panels. I have two of the curvy style working fine in my RMs and traded for two more on thier way. I"m looking to keep these running as long as is possible, now find they need a fault repair. I would prefer to have all 4 repaired at the same time.

Can you please direct me to the proper address to get these repaired ?? Either you or angel.

Sincerely,
Shear Bliss
dmwest2011@hotmail.com

[James Romeyn]

email sent

[Hipper]

James R, that's very interesting information about the neo-panel alterations - thanks for posting.

I had a problem with these nuts coming loose a couple of years ago - I posted about it here:

http://www.audiocircle.com/index.php?topic=100812.msg1017673#msg1017673

I don't know if that's the reason Brian put the nuts on the outside. I was always a bit nervous as to how tight the nuts should be.

[James Romeyn]

Let me know if interested in:

One only: VMPS 10" steel basket, black graphite impregnated poly cone (rubber surround IIRC...have to check) 40oz magnet, IIRC VMPS model is 4197, definitely made by Gefco, VMPS design, employed in Mini Tower II and possibly other models I can't recall.  $20

One only: 10" WCF cone, 80oz magnet, steel basket, employed in RM40 and possibly other model, Brian apparently removed model stencil on magnet. Phase plug missing.  If I can find phase plug I'll re-install it.  $30.

Make me an offer before someone else scoops them up! 

Also, as mentioned earlier, two Focal T120 fiberglass inverted dome tweeters employed prior to the Scan Speak domes, tested but never installed in working speaker...I still love these domes, some qualities possibly better than the SS D28 such as they go lower.  New replacement voice coils were available years ago for these but they are likely gone now.  Infinitely preferred musicality and overall audio performance vs. the more popular Kevlar domes Dave Wilson and Brian later used.  $75/pr       

[John Casler]

Recently found in the INVENTORY 2 BLACK LARGER SUBS.

We remaining LARGERS are 2 BLACK and 3 OAK

 Will revise INVENTORY 1st page.