[ka7niq]

I bought my RM 40's used, so I was never sure I had all the putty.
So, I decided to "start over"
I finally found some rope caulk, and took 8 inches of a 3/16 strand, and applied it to each speakers passive radiator.

I removed a pea sized amount, just like Brian says to do, and tuned one speaker at a time, one fingernail full at a time.

I tried EVERY level between the factory setting, and 12 oclock.

Finally, out of sheer frustration, and desperation, I turned BOTH controls all the way off.
Next, I  had a friend bring up the mids slowly, as I listened .
I told him to stop, when it sounded right.

To make a long story short, My mids are almost a  quarter turn below 12 o'clock.
That means, they are a little over 1/4 of the way on!

I am running the mids somewhere between 9 and 10 o'clock.

I like the tweeters a LITTLE higher in "level", and have them at about 10 o'clock.

This is where the RM 40's "want to be" in my room, w/o running my subs.

I always tune a speaker to sound it's best w/o subs first, then I add them.

I am currently using a Luxman M 117 amp, capable of 700 watt peaks into 2 ohms, supposedly ....

Runing the ribbons this low sure effects the efficiency of the speakers, and my amps clip lights flicker if I push it really hard.

I just wonder if anyone has had a  similar experience ?

In MY room, with 3 different, well known powerful amps, there just is no way I can run my ribbons anywhere near factory setting.

Oh, I COULD .....

But I do not care for the sound.

Even at 12 o'clock, the ribbons are MUCH more efficient then the woofers, at least mine are.

I even tried removing ALL the putty, to see if I could get some more efficiency out of the woofers, and no luck.

I haven't had the Luxman M 117 amp on a bench, but my modified Ashly was measured at 450 watts into a 4 ohm load.

I cannot imagine all 3 of my big amps will not drive these speakers ...

BTW, I am getting a beautiful sound at the moment.
The only "gripe" I have is I now need just a TAD more power ...

I used male voice, specifically Cat Stevens and Bob Seeger, to tune with.

Down at 9 o'clock, I could hear the woofers seperate sound, and it's cone coloration.

I simply had my friend slowly, one click at a time, increase the midrange level while I listened, until this coloration disappeared.

I HONESTLY wish the factory levels were not on a tag on the back of my speakers.

It would have saved me lots of time.

With all due respect to the putty, and it's effects, it is NOT going to overcome a huge level mismatch between the woofers and the midrange ribbons.

My "problems" were a level mismatch, pure and simple.

Perhaps my room is causing this, I do not know ?

Any comments ??

IMPORTANT IMPORTANT IMPORTANT
I "found" my problem!
BOTH of my amps were plugged in to a PowerVar Line Filter.
I cannot see real well anymore, and asked my friend to plug the amps in, and hook up the wires because I could not find my glasses.

He innocently plugged both the Luxman, and the Ashly into the PowerVar.
The PowerVar "choked" both of my amps, and deprived them of the power they need to drive the woofers!

I noticed severe harshness on Jewell's female voice, no matter what the ribbons level was.

I just happened to look, and sure enough, the amps were plugged into the PowerVar!

While the amp was playing, I jerked the cord out of the PowerVar, and plugged it straight into the wall.
The Ashly never mised a beat.

I sat back down to listen again, and the harshness was gone.

But, it became obvious I needed to completely retune everything.

I ran the ribbons level up considerably, and no more "level mismatch"

After the Football game tomorrow, I will completely retune, plus my SVS Ultra sub will be here, and some 1978 Alnico Magnet Klipsch Cornwalls ...
Yep, I just couldn't say no to a deal .
Like I need more speakers ....

The Cornwalls and the SVS sub can sit and wait for me to play with them, I will get around to it, someday ...

I think I will call my friend Mike and get my other modified Ashly FET 500 amp back from him, and passively bi amp my RM 40's with two Ashly FET 500's

I want to try bigger diameter wire on the woofers, and solid core wire on the ribbons.
I want to believe the signal will be happier traveling on the skin of a solid core wire.
All those strands in stranded wire don't make a lot of sense to me.
It seems like a "rough ride" for a musical signal ?

And Casler is right, more convergence allows higher ribbon levels, and more efficiency.

But honestly, the Ashly FET 500 is a powerful amp, and even with the ribbons turned down to 11 O'clock, the RM 40's will play so loud you will want to turn it down before you hurt your ears.
And, I have a pretty large room.

[John Casler]

Hi Chris,

It is not unusual for a "system" to deliver the sound that way, as well as the "setup".

It could be anything from your 14 guage wiring, to being too much "on axis".

Or it could just be that you like a "softer" sonic and your ears are sensitive to the more detailed sound.

I know Tyson likes his RM40's run around 10:00.

When I had a pair like yours (circa Spiral tweeter, pre-midwoofer upgrade, etc) I liked to run them in the same neighborhood.

But you are correct and running them more closed, does show the amp a higher resitance, and can gobble power.  I used 600wpc on mine so was able to get the SPL's I wanted.

First two things I would try is converging for less "on axis" response, and getting a heavier guage speaker wire.

And for edification.  Pinching putty will have very little effect on the SPL of the bass system.  Its primary affect is in reducing/adjusting the distortion levels, not the loudness.  The active woofs will still receive the same current and anp produce the same SPL's.  Look at it as "synching" the PR to the active woofers.

And the third thing I would try is moving the speakers and or listening position to get a better bass response that would then require a "larger" MR and treble response.  Ususally this will entail moving the speakers closer to the front wall, and moving the seating position back.

But, if, as you say, your enjoying the sound, you might want to simply enjoy it.

[John Casler]

Also you may want to "GENTLY" turn the L-Pad shaft back and forth 15-20 times to "wipe" the contacts, and remove oxidatitive residue.

But make sure and do this "GENTLY" or you could damage the shaft itself.

Good contact is very important here.

[ka7niq]

Hi Chris,

It is not unusual for a "system" to deliver the sound that way, as well as the "setup".

It could be anything from your 14 guage wiring, to being too much "on axis".

Or it could just be that you like a "softer" sonic and your ears are sensitive to the more detailed sound.

I know Tyson likes his RM40's run around 10:00.

When I had a pair like yours (circa Spiral tweeter, pre-midwoofer upgrade, etc) I liked to run them in the same neighborhood.

But you are correct and running them more closed, does show the amp a higher resitance, and can gobble power.  I used 600wpc on mine so was able to get the SPL's I wanted.

First two things I would try is converging for less "on axis" response, and getting a heavier guage speaker wire.

And for edification.  Pinching putty will have very little effect on the SPL of the bass system.  Its primary affect is in reducing/adjusting the distortion levels, not the loudness.  The active woofs will still receive the same current and anp produce the same SPL's.  Look at it as "synching" the PR to the active woofers.

And the third thing I would try is moving the speakers and or listening position to get a better bass response that would then require a "larger" MR and treble response.  Ususally this will entail moving the speakers closer to the front wall, and moving the seating position back.

But, if, as you say, your enjoying the sound, you might want to simply enjoy it.

It may be the wire, and I do plan to go up to 10 or 12 guage.
Where I have the RM 40's placed is not a good bass position.
Even B&W 801's have had problems pressurizing my room in this position.

The Big Von Schweikert Vortex Screens, with 15 inch woofers in a refrigerator sized cabinet do the trick in this same position, as do the Klipsch CF 3's, AND believe it or not, the little Magnepan SMGA's.

I have a wide screen rear projection TV, so I can't go real close to back wall, and if I come out from back wall any further, it looks stupid.

Maybe I should feel "guilty" for running my ribbons so low, but I do not.
I am shamelessy enjoying them.

Now, I just need some more power ....


I have did the pot cleaning routine, but thanks for mentioning it!

The speakers are converged in front of me, but that is a good idea !
Maybe I will try more convergence, and run the levels up a bit ?

Regarding the putty, it should have some effect on woofer efficiency ?
Usually, a woofer tuned higher in frequerncy should be a bit more efficient.

So, removing some putty might have a slight efficiency increase, at the expense of low bass.

As good as these ribbons are, they need help from their woofer to "fill in" the lower range of the ribbons.

I like a warm, rich sound, not a thin, super detailed one.

I can get this from the RM 40, and w/o any tubes either, by adjusting the ribbons to their lowest possible settings.

Lowest possible setting is defined as the setting just slightly above the setting that colors lower male voices, like Bob Seeger, Neil Diamond, and Cat Stevens.

My friend Mike has my other Ashly amp at his house.

I think I will go get it, and bridge them for  about 1000watts into 4 ohms, and see what happens, and get some bigger wire.

I shall play more today.

[audiochef]

My 40s sounded right with mid pots at about 10:45. But bass quantity was never an issue in my smallish 17.5 by 13 room.

The plus side of the all more efficient mids and tweats is that I'm able to bi-amp using only 30 watts, triode mode on mids and tweats ss on bottom. Mid pots opened all the way up.

I believe Chris, you have access to numerous amps.

This will add a hole new level of sophistication and muscle to the 40s.


Stan

[ka7niq]

My 40s sounded right with mid pots at about 10:45. But bass quantity was never an issue in my smallish 17.5 by 13 room.

The plus side of the all more efficient mids and tweats is that I'm able to bi-amp using only 30 watts, triode mode on mids and tweats ss on bottom. Mid pots opened all the way up.

I believe Chris, you have access to numerous amps.

This will add a hole new level of sophistication and muscle to the 40s.


Stan

Yes, two of my big amps, a Moscode 600, and an Adcom 585 have been modified, and are repaired.
I am just waiting on mt Tube Preamp to be done.
It's volume pot went bad, and it should be done shortly.

I will pick all 3 up at the same time.
My tech is also an audiophile, a good thing!

IF my ribbon level has to stay low, so be it.
I will just get more power.

But I am going to try some of John Caslers suggestions, and different amps too.

But right now, it is time to play some more with the RM 40's.

[ka7niq]

My 40s sounded right with mid pots at about 10:45. But bass quantity was never an issue in my smallish 17.5 by 13 room.

The plus side of the all more efficient mids and tweats is that I'm able to bi-amp using only 30 watts, triode mode on mids and tweats ss on bottom. Mid pots opened all the way up.

I believe Chris, you have access to numerous amps.

This will add a hole new level of sophistication and muscle to the 40s.


Stan

I honestly wish those "Factory" settings were never on my speakers.
There is just NO way, in my room, these things will tune with the mids and tweeters set way up there.

I even "felt bad" trying to tune "down" at 12 O'Clock.

Now, I have found the "secret" to the RM 40's.
It's all about level between the Mids and Woofers.

Yes, the putty does make a difference, but not nearly as much as mismatched levels.

I hooked the big Ashly "Pro Sound" amp up, and re tuned to it.

I now have the BEST sound this room has EVER had.

These things just EAT every speaker I own, and lookout AudioGon, because there are a whole bunch of speakers fixin to be for sale!

I have a big SVS Ultra sub coming tomorrow, after the Buccanneers Football Game.
Guy is bringing it over to Tampa from St. Pete, and got a real deal on it too.

I really wanted an all VMPS system, with 2 larger VMPS subs.

Perhaps when these other 9 pairs of speakers go, I will get a pair.

I am getting the SVS cheap enough to actually make 100 bucks or so when I sell it.

But I can see for myself right now my future lies with the RM 40.

The big Ashly FET 500 drives the heck out of them, and has a bigger image then the Luxman M 117 too.

I have another Ashly at my friend Mikes house.
Maybe I will go get it, and passively bi amp ?
Both Ashly's have level controls, but the one at my house has been really tricked out with bias increase, better caps in feedback loop, bigger power supply caps, and lower feedback.

Maybe I will use it on top, and the other one on bottom ?

I will just crank the pots wide open, and use the amp pots to reduce level on the mids.


I just retuned again, JUST a bit.

Had to touch Stevie Nicks voice up a bit, found a good compromise with the putty now for both male and female voices, and bass.

Believe it or not, I am using the RM 40's in a very large room, and not missing my subs all THAT much.

To each his own, but I like to make the speaker sound as good as it can, W/O subs first, then bring the subs in.

I am glad Brian had the foresight to make these speakers so adjustable.

If he voiced them to work in my room, they would be bass heavy everywhere else.

BTW, I have tuned two other pairs of RM 40's, in two different rooms.

My ears always told me the midrange level needed to be lower then factory on both of them.

But I met with objections from one of the owners, because he said "no one else runs them that low"

Me, I could care less where "everyone" runs them, or how much putty, or if there are equal amounts on each speaker.

I actually wound up with slightly different amounts of putty on each speaker too, and the pots are not EXACTLY the same on each speaker.

I suppose they are within a click or two, but I do not care.

I tuned both speakers to sound as CLOSE to each other as possible with my ears, not my eyes.

[fredgarvin]

Glad to hear its sounding good Chris! I used to have RM1's and now use 626r's. On both models I have the tweeters set a click or two apart because of reflection differences from the two walls, I suppose. The bass I am getting from those small megawoofers is impressive! I am going to throw in a sub however, because I need full-range sound to be happy.

[ka7niq]

Glad to hear its sounding good Chris! I used to have RM1's and now use 626r's. On both models I have the tweeters set a click or two apart because of reflection differences from the two walls, I suppose. The bass I am getting from those small megawoofers is impressive! I am going to throw in a sub however, because I need full-range sound to be happy.

You know what Fred ?
I think Brian was very wise to give us VMPS owners such tuneability.
Tweeters/midranges, and woofers all vary, as do the pots.
Some woofers may have a TAD less glue on them for instance, and may require slightly different putty amounts.

Not to mention room placement effects ?
Thats why I now tune for my ears, not my eyes.

My objective is to make one speaker sound as good as I can, and then to make it's partner sound as close as possible to it.

Subwoofers will make a BIG difference, especially with 626's.

What kind are you getting ?

[James Romeyn]

Cleaning/treating the L-pads contacts with Caig Pro Gold transforms the sound.  You must open one of the cooling slots on the L-pad rear cover w/ a screwdriver then insert the spray tube in the enlarged slot, then rotate the shaft back & forth.  Also soldering a 10k resistor from input to output is good.   

One of the many benefits of the OXO is easy access to the L-pads to clean them regularly.  I'd recommend every 6 months, at least annually.

One of the many benefits of biamping is cranking the mid L-pad to maximum clockwise, effectively eliminating it from the circuit.  One amp (preferably the bass) must have an input level control to blend the bass & ribbon output.  This is easily accomplished even if the bass amp has no controls.   

[ka7niq]

Cleaning/treating the L-pads contacts with Caig Pro Gold transforms the sound.  You must open one of the cooling slots on the L-pad rear cover w/ a screwdriver then insert the spray tube in the enlarged slot, then rotate the shaft back & forth.  Also soldering a 10k resistor from input to output is good.   

One of the many benefits of the OXO is easy access to the L-pads to clean them regularly.  I'd recommend every 6 months, at least annually.

One of the many benefits of biamping is cranking the mid L-pad to maximum clockwise, effectively eliminating it from the circuit.  One amp (preferably the bass) must have an input level control to blend the bass & ribbon output.  This is easily accomplished even if the bass amp has no controls.   

Thanks Jim!
I was just going to use Cramolin contact cleaner, but I will take your advice.

[Berndt]

Cleaning/treating the L-pads contacts with Caig Pro Gold transforms the sound.  

[woodsyi]

One of the many benefits of biamping is cranking the mid L-pad to maximum clockwise, effectively eliminating it from the circuit.  One amp (preferably the bass) must have an input level control to blend the bass & ribbon output.  This is easily accomplished even if the bass amp has no controls.   

Jim,

Why not remove the midpot?  With CDWG, treble pot setting is always going to be lower (edit ) than the midpot.  I am thinking of just bypassing the midpot.  What do you think?  I agree that the ribbons really come alive when opened all the way but you can only do this if you biamp.  From my experience with potentiometers on integrated amps and from just fooling with various pot settings while biamping my RM40s  both passively and actively, I can unequivocally state that the ribbons improve as pots open up.  Right now I have the mid pot all out and treble pot at 2:00. 

[James Romeyn]

When the pads are full clockwise, they are effectively gone except for the input to wiper contact point.  The circuit to ground lifts & disconnects internally at full clockwise rotation.  Unsoldering the input terminal wire & soldering it to the wiper terminal will bypass even the one contact above.   

My mids are full open & the treble is slightly attenuated.

My system is analog from the output of the one-box CDP, so digital xo is out for now.  I'm convinced adding any outboard DAC for the purpose of using a digital xo would be a step down. 

It would be interesting to hear the passive xo's replaced by a SOTA analog active xo: bandpass 6 dB for the 6.5s (to blend w/ a sub), staggered dual-pole high-pass only for the mids (unless the mid still has a low-pass pole, in which case bandpass mid), & the high-pass tweeter pole.  I'd guess there is no commercial active xo that exceeds the passive TRT performance.

[ka7niq]

  I'd guess there is no commercial active xo that exceeds the passive TRT performance.
[/quote]

I don't know about that ?
I would think an active crossover would always out perform a passive one.
As good as TRT's are, they are still a capacitor "in the way" of the amplifier/tweeter interface.
They hinder the amplifiers ability to control the tweeter.

I think an active tri amped RM 40 with NO passive crossover, would be superior to any passive crossover equipped one, as long as slopes are equal, etc.

THe "BEST" VMPS speaker is YET to come ..

It will probably be a VMPS Elixir, shipped w/o ANY passive crossover, only input terminals to hook up the amplifiers.

In a seperate wooden box, on casters, it will have all Bongiorno designed amps, and a Bongiorno/Cheyney designed active electronic crossover.

The crossover might even have remote controlled level controls, allowing a direct CD feed, w/o needing a preamp ?

The crosover might even have some built in time delay to compensate for driver mounting.

I might add that I bought my RM 40's used, and TRT caps came along for the ride.

But, If I were buying new, and had a choice, i would MUCH rather spend 1500.00 for a crossoverless RM 40 w/dedicated active electronic crossover, then spend 1500.00 on ANY capacitor.

I think the RM 40 customer is a savvy veteran audiophile, and a tri amplified system is not beyond the realm of possibility.

I know John Casler has requested that Brian offer the no crossover option, and personally, I think it is a good idea.

Of course, Brian can not be expected to warranty fried ribbons because of incorrect crossover applications either!

Brian is a very resourseful guy, and perhaps he can find someone to make dedicated electronic crossovers for his speakers, or adapt existing commercial designs ?

Or, perhaps he and Jim Bongiorno can do one together.

Newform, Orion, Magnepan, ADS, Meridian, and many other high end manufacturers provide, or have provided active crossovers for their customers.

Another option is "amp modules" with crossovers designed to "bolt in" to the speaker itself, perhaps using tomorrows chip amps ?

I have heard about a prototype chip amp my tech told me about.

These chips are getting better, as this technology matures.

I am just babbling now about the chip amps, but I would seriously like to see Brian address the active crossover option for future VMPS speakers.

 

[James Romeyn]

An active xo that fully replaced the TRT's would add about $10k to $15k to the financial commitment.  First is an active SOTA 3-way xo w/ a very complex sequence of poles, constructed so well that it beats maybe the best capacitor currently for sale.  That's at least $10k right there.  There's a reason there's really no such xo commercially available now, & it's not because people are too stupid to miss the chance to make money.  No one except a few diehards could care less.  The company would open & close its doors w/i a few months. 

You must remember that every distortion in the active xo is multiplied in quantity by the upstream power amps.  So distortions in the active xo are in some ways even worse than passive.  Active may distort less than passive (again remember you are comparing to TRT passive), but whatever distortion is created by the active is multiplied, a problem not occuring w/ passive. 

Then two EXTRA amps are required.  That means three amps & input wires & output wires are now the minimum for a speaker that was previously able (w/ passive xo) to utilize anywhere from one to three amps.

That is an absolutely ridiculously huge committment in space, money, clutter, & potential downtime.  If you had the passive xo to begin with at least you'd have the option of going back.  But a dedicated triamped active system would be in many cases virtually impossible to sell.  That's why they are virtually non-existent in commercial domestic applications.  Think about it.

I had old vmps' w/active bass xo.  I never warmed to the clutter & misery.  Don't hold your breath for it.

[woodsyi]

It is a lot of clutter and I don't even mess with the FST/Neos.  But when was the last time you tried a 8 watt 300b set amp on VMPS ribbons?   I tried last night and with some fiddling got them reasonably level matched.  The amp clips at 90 dB but did some cool things with voices when not pushed....  Bet you can't do that without an active crossover. 

[James Romeyn]

Don't even start about that 300B!!!!!!!!!!!!

Yes, a friend who, before his latest marriage, was building a tube amp every week, brought over a moderately priced 300B, maybe 8W or so.  Looked very plain, a surplus chassis, maybe $400-$600 in parts, Elliano output transformers....

Ohhhhh, the haunting, melodic treble.  I have never heard such a realisitc timbre & body to cymbals & piano & violin overtones, like you became one w/ the sound.  Chilling, spine tingling quality.

I'm glad I only was exposed to that sound for a brief period.

[ka7niq]

An active xo that fully replaced the TRT's would add about $10k to $15k to the financial commitment.  First is an active SOTA 3-way xo w/ a very complex sequence of poles, constructed so well that it beats maybe the best capacitor currently for sale.  That's at least $10k right there.  There's a reason there's really no such xo commercially available now, & it's not because people are too stupid to miss the chance to make money.  No one except a few diehards could care less.  The company would open & close its doors w/i a few months. 

You must remember that every distortion in the active xo is multiplied in quantity by the upstream power amps.  So distortions in the active xo are in some ways even worse than passive.  Active may distort less than passive (again remember you are comparing to TRT passive), but whatever distortion is created by the active is multiplied, a problem not occuring w/ passive. 

Then two EXTRA amps are required.  That means three amps & input wires & output wires are now the minimum for a speaker that was previously able (w/ passive xo) to utilize anywhere from one to three amps.

That is an absolutely ridiculously huge committment in space, money, clutter, & potential downtime.  If you had the passive xo to begin with at least you'd have the option of going back.  But a dedicated triamped active system would be in many cases virtually impossible to sell.  That's why they are virtually non-existent in commercial domestic applications.  Think about it.

I had old vmps' w/active bass xo.  I never warmed to the clutter & misery.  Don't hold your breath for it.

Orion manages to pull it off reasonably, and it uses a complex crossover compared to the simple first order of the VMPS.
I am aware Brian uses a quasi second order to give his woofers an extra 'shove" to control their roll off.

This could be done passively on the RM 40 with either a cap, or a series inductor.

The rest of the crossover is a simple first order, and that could be done actively.

The distortion is always an issue between passive and actives, but my opinion is that an active crossover is always better because of better driver control, and lower distortion between amps.

And remember Jim, every passive component has it's own "signature" too, including the excellent TRT caps.

As for the expense and complexity, I think that might be overcome by having Jim Bongiorno build a dedicated 6 channel amp for the speakers, in one case.

Orion uses the ATI amps ....

[James Romeyn]

I assembled speakers for Brian for some time & quite a few of my suggestions have found their way into people's speakers/homes.  I also designed speakers for people as interesting as a first cellist for the SF Ballet. 

The only ribbon w/ QSO is the 626R (Special biwire/biamp models sold in the past on my special orders had no QSO.  B discontinued biamp 626R because of limited internal space.  I suppose he'd make them w/ OXO but I'm unsure if there's enough space behind the speaker for three pairs binding post inputs.)

The only 1st order is the bass low-pass.  An active xo should have a high-pass for the bass to aid in integrating w/ a sub.  The mid & tweeter high-pass are staggered dual-pole 1st order, equal to a sum total four normal 1st order poles of high-pass only per channel, five if you account for the bass high-pass.

The mid previously had a low-pass pole, but it might have been eliminated w/ the CDW eq.

I don't even want to add the number of stereo poles/channels the above non-existent active xo would require, maybe around 20 or so.  SOTA stereo preamps with a sum total of two channels cost $3k to $4k.  Do some basic math.  I get the definite idea you have not correctly calculated the cost of the non-existent active xo that is required. 

When a currently commercially available active xo w/ the above features is identified, that also beats the TRTs, there's a legitmate point.  Till then it's pure unadulterated & idealized conjecture, hypothesis, daydreaming &/or wishmaking.  Nothing wrong w/ that, but it's nice to know what we're talking about.