[John Casler]

Hi All,

While Brian and I feel that the best "intended" sound of the VMPS speaker systems is derived from the "SYSTEM" installed and tuned via Big B's design philosophy, we also recognize that many of you are exploring the new "digital room and speaker correction systems".

In light of this, Brian has agreed to let me "offer" all VMPS Systems with an option to accomadate these new systems.  The initial offerings are listed below:

Option 1 = DIRECT DRIVE VMPS

This system has "NO" crossovers in the system and the binding posts drive direct to the individual drivers.  All binding posts will have the minimum possible wiring direct to drivers.  This can be ordered on all systems.


Option 2 = DIRECT DRIVE and Standard VMPS

This system allows the best of both worlds having both "Direct Drive" and Crossover systems in the speaker.  It will have 2 times the binding posts.

I will have the pricing "firmed up" shortly and will post them both here and in the "price list" sticky.

It is quite evident that "at least part" of digital audio's future is moving in this direction.

VMPS is interested in offering the tools to allow our users to have the options they need to move in the directions they choose and not have to resort to a significant amount of DIY speaker building unless they enjoy that sort of thing.

B, and I had the opportunity to have additional discussion on the future of VMPS and we have some things in store that I think will knock your socks off.

I suggested a couple more VERY EXCITING   "upgrade/options" that will be tested and hopefully added to the VMPS menu soon.

One new upgrade is for the RM40 woofer system.  The upper bass woofer has been significantly improved, and is now available.  

I had the opportunity to hear the improvement in weight, impact and attack over the last few days in Las Vegas.  The improvement is very nice, and could only be done by someone who designs their bass drivers, as Brian does.


I will explain this in more detail in a seperate post shortly.

[zybar]

As one of the guys using a Tact preamp with my RM 40's, I am very happy to hear this John.

Please post the details on the woofer upgrade/changes as soon as possible.

George

[ted_b]

John,
This is the right direction for VMPS to be taking.  Great ideas.

I'm sure my RM/X's cannot be retrofitted, as you described, without significant pain and suffering, but I know Brian supports going in and shorting out the woofer xover.  Is there any possibility that the treble/mid xover can be bypassed in the field?  My DEQX arrived this weekend and I'd love to take full advantage of the flexibility of their crossovers.  
Thx,
Ted_B

[JoshK]

Ted,

May I suggest you take one step in sucession with the next?  Start with the woofers disaggregated with the rest and then move onto the mid/tweet section.   Before attempting the mid/tweet, can you verify for DEQX/VMPS owners that the DEQX xo can simulate a series first order xo, i.e. a quasi second order?  PM me if you need more details.  I think it can but I am not 100% sure.

[John Casler]

John,
This is the right direction for VMPS to be taking.  Great ideas.

I'm sure my RM/X's cannot be retrofitted, as you described, without significant pain and suffering, but I know Brian supports going in and shorting out the woofer xover.  Is there any possibility that the treble/mid xover can be bypassed in the field?  My DEQX arrived this weekend and I'd love to take full advantage of the flexibility of their crossovers.  
Thx,
Ted_B

Hi Ted,

I felt that it was the best way to address the direction some customers and clients were going.  That said, the "magic" that Brian "installs" is the heart of VMPS. but...the exploration of the new technology by you, the users, might allow for additional "growth".

We wish to provide a tool to enjoy your hobby wether it be for the ultimate, analog, digital, audio, or HT system.

To address this, we need to offer a flexibility that will allow us to harvest the maximum performance from many directions.

This is just one of those directions.

As far as "retro-fitting" that is a "technical" conversation you would need to have with Brian.

[John Casler]

As one of the guys using a Tact preamp with my RM 40's, I am very happy to hear this John.

Please post the details on the woofer upgrade/changes as soon as possible.

George

Hi George,

Well you and a few of the others here, were the impetus to me petitioning Brian with this move.

I have also contacted the local DEQX dealer and worked out a deal where I might be able to put together some "VMPS Digital Drive" packages.

I beleive it can be so optioned on all of the line.

I would ask that all of you who have success with the two technologies, share some of the details so new comers can profit from your "early adaptor" status.

As far as the woofer upgrade for the RM40, I will post that in another post soon.

[ekovalsky]

VMPS is interested in offering the tools to allow our users to have the options they need to move in the directions they choose and not have to resort to a significant amount of DIY speaker building unless they enjoy that sort of thing.

Glad to hear it, since I've been contemplating an ultra-ambiltious DIY system to replace the RM/X since going "digital".  

I have taken the first step and already and am using the 2.2X subwoofer outputs to driver the RM/X woofers (with the inductor coil bypassed) and the main outputs to drive the mid/tweeter (through the factory crossover).  The improvement just by actively biamping, with room correction bypassed, is substantial.  Best sound  (supported by measurements) is with the TacT applying a 24db/octave low pass filter to the woofers at 300hz and a 36db/octave high pass filter to the ribbons at 220hz.  A slight delay is also added to time align the bass to the mid/treble.  An audiophile who came for an audition greatly preferred this TacT RCS/S2150 setup, in bypass mode, to the much more expensive JRDG 302/4 used in a passive biamp configuration.

Correction definitely takes the speakers to the next level.  Room correction works predominantly in the bass, but an even bigger improvement results from what essentially is speaker correction of the midrange and treble.   Of course the TacT doesn't offer proper speaker correction, as it corrects the combined room and driver anomalies as measured at the listening position.    In the sweet spot the sound is phenomenal, but the pre-distorted output is very evident elsewhere in the room.  DEQX does not have this limitation and would probably work better than the TacT.

I've pestered Brian about embracing new technology for a few years, dating back to when I requested three extra sets of binding posts for my (currently TDangelo's) RM-40.  There is no doubt in my mind that this is the way of the future.  The best mathematical modelling and parts selection cannot compare with measurements made in the owner's listening room with computer analysis and infinite DSP flexibility.  Full control over group delay, phase, and frequency response will raise any loudspeaker's performance to another level.

It is not surprising that loudspeaker producers are somewhat avoidant of this new technology.  The "secret" crossover circuits each produces and markets is what gives their product personality and prevents it from being easily replicated by the DIY crowd.  Build a big box with an Aurum Cantus G2si tweeter, four Monsoon ribbons sourced from computer speakers bought cheap off Ebay, and some 10" Eminence woofers and a passive radiator.  You've made a ghetto RM-40 that would probably perform very well with a DEQX and some decent amps.

Anyway I am very glad Brian is now willing to head down this path.  I look forward to seeing what new products will come to market, and hopefully existing customers will not be forgotten.

[PLMONROE]

Ekovalsky,  obviously I have been laboring under a misundestanding. I thought that the TacT and DEQX  both worked about the same. You said that the TacT corrects for both speaker and room anomalies (I thought both did) and the DEQX doesn't? Are you saying that  the DEQX can correct for one or the other or maybe both somehow?

Paul

[ekovalsky]

Ekovalsky,  obviously I have been laboring under a misundestanding. I thought that the TacT and DEQX  both worked about the same. You said that the TacT corrects for both speaker and room anomalies (I thought both did) and the DEQX doesn't? Are you saying that  the DEQX can correct for one or the other or maybe both somehow?

Paul

The DEQX offers independent room correction and driver correction.  So you can use it to flatten frequency response of the drivers without room correction.  

The TacT technically offers only room correction.  However, in calculating the correction filter it uses measured response at the mic position which obviously reflects anomalies from the room and drivers combined.  What the TacT cannot do is correct the drivers only.  

So of the two the DEQX is the more flexible, and it seems to overall have a better user interface.  But the TacT integrates very nicely with the S2150 amps and has a reasonable amount of control available from the remote and front panel display, without the computer hooked up.

[mac]

Before attempting the mid/tweet, can you verify for DEQX/VMPS owners that the DEQX xo can simulate a series first order xo, i.e. a quasi second order?  PM me if you need more details.  I think it can but I am not 100% sure.

The PDC 2.6 is capable of implementing Linear-Phase, Linkwitz-Riley and Butterworth filters from 1st to 300th order.  While one could certainly emulate the stock crossover of the speaker using low-order slopes (and that's probably a good place to start), most people who ultimately use the unit will end up using high-order Linear-Phase filters (IMO).

Linear-Phase:


Linkwitz-Riley:


Butterworth:

[ekovalsky]

One thing to add about my previous post...

To get best sound at the listening position (i.e. limited sweet spot) the TacT works great.  The correction filter normalizes room effects and driver aberrations, so the signal at the listening position will equal the target curve.  I have two chairs in the "sweet spot", one just to the left and the other just to the right of the room midline.  I have saved a different correction curve for each chair.  When the appropriate curve is selected imaging is phenomenal with a wide and deep soundstage and precise vocals floating in the center.  Amazing!

However, when listening in a position away from the sweet spot where measurements were made for the correction filter, things get ugly.  Sound is better with room correction turned off, but then the non-flat frequency response of the drivers becomes very noticeable.  After hearing the improvements from room/driver correction it is hard to go back!

The big advantage of the DEQX is that, when away from the sweet spot, room correction can be turned off but driver correction is still applied.  

Main benefit of room correction is in the bass, 300hz and below.  The new Meridian gear only works in this range.  Although I had never realized it, before getting the TacT I was missing lots of bass information either because of room suck outs or strong nodes obscuring adjacent frequencies.  With room correction the bass just sounds right!

Driver correction smooths frequency response of the midrange and tweeters.  I was very surprised how non-flat the measurements were from 500hz on up .  

This new equipment has really changed my thoughts on high end audio.  The changes from different cables, source components, power conditions, etc now seem like a joke.

[ted_b]

Eric,
Is the room correction in the Tact aggresively going after the higher frequencies so as to truly give you a flat target?.  In the DEQX you can manually do it, but Auto EQ only addresses 500hz and down, and realistically 300hz and down, the real gremlins in room response.  When I try to get rid of the treble troughs the system sounds a bit bright.  Realize, though, that I haven't done any speaker correction yet.  That's where a lot of that gets fixed...Anyway, was interested in what your RM/X's sound like with gain filters in the higher regions.

Ted_B

[ekovalsky]

Eric,
Is the room correction in the Tact aggresively going after the higher frequencies so as to truly give you a flat target?.  In the DEQX you can manually do it, but Auto EQ only addresses 500hz and down, and realistically 300hz and down, the real gremlins in room response.  When I try to get rid of the treble troughs the system sounds a bit bright.  Realize, though, that I haven't done any speaker correction yet.  That's where a lot of that gets fixed...Anyway, was interested in what your RM/X's sound like with gain filters in the higher regions.

Ted_B

I think you will be shocked at the improvement that driver correction makes .  As impressive as the room corrections is for the bass, flattening the midrange and treble response made an even greater difference is sound quality.

On your measurements, you will probably notice a broad, strong peak at around 1.2khz with flanking dips.  Neutralizing this greatly improved the midrange, and with correction off the midrange sounds way too heavy and the presentation far too forward.  Never noticed this before the TacT  

You will definitely not want to correct the tweeter output to "flat" -- if you do it will be far too bright.   Instead you want a roll off in the treble.  I have mine -3dB at 10khz and about -dB at 20khz.  All the TacT stock curves show a similar roll off, hopefully the DEQX curves do also.

I also noticed a dramatic improvement in imaging with correction of mid and high frequencies.  A lot of this is related to phase and lobing effects that occur off axis.  With correction on the soundstange is huge front to back, left to right.  On good classical recordings each instrument has its own discernable space.  Vocals float precisely in the dead center.  Speakers totally disappear -- pretty amazing given the imposing size of the RM/X.  When correction is bypassed this wonderful imaging diffuses into a wall of sound clearing coming from two big speakers.  Again, I thought imaging was really good before I got the TacT  

Sadly, I don't think I'll ever be able to enjoy a high end system without correction.  Once you cross this bridge there is no going back.

[angelo]

what if the passive crossover of the speakers CAN"T be bypassed (4-way full range bi-ampable floorstander), I know that because of this I can't implement the full potential of DEQX, but can I still use the active crossover to control what frequencies goes to each pair of binding post?

which frequency band will need a higher quality amp, high frequencies or mids?

thanks,

angelo

[Jose R.]

The TacT technically offers only room correction.  However, in calculating the correction filter it uses measured response at the mic position which obviously reflects anomalies from the room and drivers combined.  What the TacT cannot do is correct the drivers only.  

So of the two the DEQX is the more flexible, and it seems to overall have a b ...

If one uses the Tact 2150 amps together with the room correction, one can perform speaker correction as well.  One would take a measurement of individual speakers and/or drivers, apply crossover and correction, ad then remeasure the integrated system with final room correction being carried out by the RCS.

I have been playing around with this for a while now with my RM30's with good results.  I have just received the megawoofer and Auric Cap upgrade and am busy installing this.  I will add separate binding posts connected directly to the different drivers to permit full digital crossover implementation but am short of one amp which I would need for the tweeter.

As has been mentioned, once one is used to listening to corrected sound, there is no going back...

Regards

Jose

[woodsyi]

Ted and Eric,

Thanks for much information on this issue.  As one who is actively biamping a pair of RM40s with 200Hz ribbon hp and 300Hz woofer lp using 24dB slopeand driven by tubes on top and ss on the bottom, I have a couple of questions for you.   Have you tried an anolog source?  Is the gain in digital crosssover flexibility greater than what may be lost in ADC/DAC cycle?  Have you driven the ribbons with tube amp and how well does either DEQX or DACT work with tubes?  

I ask because I am intrigued by the flexibility of digital crossover but I am concerned about losing the richness of anolog sound from tubes.  The biggest gripe I have with a middle of the road digital source is the lack of harmonic fulness in the mid region.  I am concerned that digitizing of anologue source would rob its soul.  Any comments?

[ted_b]

Woodsyi,
The analog issue was my greatest concern in going this direction (with the DEQX).  As I've only had the pre for 4 days so far, and only done some room correction (no xovers, single amp so far) I don't have an answer yet about analog.  The 24/48 DACS sound good (a 24/96 no cost software upgrade is in development, as per Kim's comments in the 6moons review).  The unbalanced analog ins on my pre are too sensitive (clipping inputs) but DEQX support provided me the instructions to set a couple of jumpers to change the input sensitivity.  DEQX support has been great, and it doesn't hurt at all that their Sydney work schedule meshes nicely with my East Coast nightime listening schedule.  As soon as I find an anti-static strap around here I'm fixing the analog ins.

So, I empathize with you.  I've spent quite a bit of time and money getting a beautiful analog sound out of my Modwright 999ES tubed output, and my tubed pre was a nice match.  SACD's and DVD-A's are essential parts of my collection.  However, early results are telling me that the smoothness of the room response, coupled with upcoming speaker correction (my upcoming, not theirs)  and active crossover flexibility will more than offset a da/ad/da journey.

Haven't tried tube amps.

Ted_B

[woodsyi]

Ted,
I am anxious for you to get your anolog connection fixed and report back on the sound.  I don't suppose DACT would have the same issue since they make attenuators.  I am curious about the bypass mode.  Do you still get digital crossover function while an anolog source (i.e. signal from phono pre) is played through an anolog input?  It would be great if this is true.  I can play my vinyl via bypass (avoiding ADC) but still get digital crossover with its inherent advantage over active anolog or passive crossovers.

[ted_b]

Bypass in DEQX world is still digital, it just bypasses the room correction filters.  Any speaker correction is done before the bypass.  I need to understand more about the diff between their analog volume and digital volume, though.  An analog volume button is new in the 1.4.1 software and I need to understand its relevance.

Ted_B

[woodsyi]

I guess I should know better than that -- digital crossover by definition would require a source music to be digitized.     Doh!