[mca]

I hope to receive my new RM30's sometime in early March. These will have the new MLS cabinets and waveguides. I'm now wondering if I should upgrade from the stock Solen Caps to the Auricaps? Anyone have any experience between the two? Is this $550 well spent?

Thanks for the correction Josh.

[JoshK]

FYI, the stock caps are Solen, not SoniCaps.   If they were SoniCaps, I'd leave them as is, but the Auricaps are said to be a nice upgrade from the Solens.

[mca]

No one has experience with these?

[JoshK]

Tyson, iirc, upgraded from Solen to Auricaps and thought it was well worth the money and providing a nice setup in clarity. AFAIK he might be one of hte few who has done the upgrade.  Since the cap upgrade came out most VMPS purchasers order the upgrade with the original purchase, so I am not sure if you are going to find a lot of feedback on this upgrade.

I still own the Solen version, so I am not of use.

[Corbin Johnson]

I noticed an improvement in clarity after upgrading my RM40 from Solen to the Auricaps and I my electronics are very good, but far from state of the art.
I felt the money was well worth it.

Corbin

[Q]

I hope to receive my new RM30's sometime in early March. These will have the new MLS cabinets and waveguides. I'm now wondering if I should upgrade from the stock Solen Caps to the Auricaps? Anyone have any experience between the two? Is this $550 well spent?

Thanks for the correction Josh.

Why not put that $550 toward a $3700 DEQX and do away with ALL capacitors, Inductors, resistors, and the associated inherent impedances?  Of course that would mean tri-amplification.  OH...and you could also compensate for that Waveguide-related hi-frequency problem everyone's been try ing to figure out!  Anyone out there using DEQX or TAcT with VMPS speakers successfully in this manner?
Q

[CornellAlum]

So, $3700 for the deqx, minimum $4000 for two more amplifiers...good lord!

[ctviggen]

Somewhere down the road I may try my own home-brew technique like that.  The two things stopping me:  money and time.  Another two two-channel amps is a bit of cash.

[JoshK]

I have the RM40s, the DEQX and the necessary amplification....the time is what I am shy of.  It isn't as trivial as it may first appear.  Lots of GOOD measurements must be made to do it right.

[ctviggen]

I think you're right.  You'd really want to take the speakers outside and position the drivers toward the sky and then take measurements.  You'd have to manipulate the slopes and crossover points for the filters, and determine any speaker-level corrections.  That could take a while.  And then you'd like to keep all that information and add room correction.  You may also want to mess around with amps and try to adjust so that the best amp for bass/midbass is used for bass, the best amp for mids (tube?) is used for mids, etc.  Of course, all that will affect filtering.  I have no doubt it would sound kick-butt, but the time (not to mention money) aspect of it is daunting.  That's why so many people buy a TACT and just use room correction for the entire speaker.

[Q]

Hmmm...I guess I didnt think it would be that complex to at least get started.   I wonder if there isnt a way to electrically connect to the inputs at each driver set, and get a baseline for what the passive crossover is doing, so that the active can then put in place of the passive system, mimicking its behavior.  BUT, I would think that as soon as you place a high slope filter and absolute phase control over any speaker system, you would begin to see sonic improvements....after that, it should be simply tuning out FR anomalies from the room and speaker.  On the other hand, Im sure its MUCH simpler to implement on a speaker with fewer drivers than one with multiples, such as the VMPS's...for so many reasons.

[ctviggen]

It amazes me that people think that all you do is slap on a high slope filter and -- wham! -- you have a much better speaker.  That is simply not true.I think people who think this (with all due respect to you, Q) just don't know how complex speaker design really is.  It's akin to saying "take off that passive radiator and throw on a port and the speaker will be 100 times better".  It's only 100 times better in the mind of someone who doesn't know what they're talking about. Also, remember that "phase control" is something that has to be determined and implemented and is also based on drivers and their locations.  Plus, even though room correction is now becoming ubiquitous, it's very complex.  

"The creation of a correction filter for room acoustic compensation is quite a challenging task. A typical acoustic environment is a non minimum phase system, so in theory it cannot be inverted to get perfect compensation. Furthermore a typical HiFi system in a typical listening room isn't either a single linear system, but it is instead a different linear system for every different listening position available."

http://drc-fir.sourceforge.net/doc/drc.html

What these systems do is an incredible feat of engineering and not possible even 10 years ago because the processing power couldn't keep up.  Moreover, digital room (or speaker) correction is fraught with its own set of problems.  

I challenge anyone to just throw a digital filter with some steep slopes onto any speaker.  I guarantee you'll be there for days to get a reasonably flat response that doesn't sound like crap.  I estimate it would take me at least a month of weekends, working every weekend all weekend, to employ digital filters and room correction.  And the last time I "estimated" something like this, I missed by about a factor of eight.

[skrivis]

Somewhere down the road I may try my own home-brew technique like that.  The two things stopping me:  money and time.  Another two two-channel amps is a bit of cash.

Then you've got to hurry up and buy some modules from amplifierguru.

[James Romeyn]

How much attention have you given to room acoustics?  If little to none, an RM30CDWG with stock caps has such high performance that room  improvements might provide good value.    

OTOH, it's more difficult/costly to upgrade the xo parts later vs. at the time of original purchase.  And the Auricaps do provide better audio performance.  

I have standard caps.  But I might trade speakers more often than average.  I live nearby VMPS.  I visit there often, am very familiar with the sound in their specially treated room, & similarly familiar with the speakers & different crossovers.

Without hearing the speakers in your room, the above facts are more helpful than a third party providing their opinion what you should do.

Either way, you are in for a treat.

[Q]

It amazes me that people think that all you do is slap on a high slope filter and -- wham! -- you have a much better speaker.  That is simply not true.I think people who think this (with all due respect to you, Q) just don't know how complex speaker design really is.  It's akin to saying "take off that passive radiator and throw on a port and the speaker will be 100 times better".  It's only 100 times better in the mind of someone who doesn't know what they're talking about. Also, remember that "phase contr ...

I dont for one minute think that speaker design is simple. However,
I'll make a few assumptions here about speaker design and tell me how im wrong:
1. Give any speaker designer who is designing a 2-way or higher system a tool that would provide high filter slopes, frequency based amplitude correction, and correct phase across all freqs and he(she) would throw all passive parts out the window.
2. A desinger rejects the above methodology for ONE reason...COST...the cost of multiple amps and the associated electronics.
3. Active systems are becoming THE standard.  This is not by accident.
4. A passive crossover designer will try to MINIMIZE the number of parts, not only because of cost...because the more you add, them more it has detrimental effects on the sound.  An active system will be the ultimate in passive minimization.
5. Most people reading this have spent a good amount on nothing but WIRE from their amp to their passive crossovers.  WHY?  To maintain signal integrity.  A passive system counters this goal.
6. A passive system is a series of tradeoffs.  You trade impedance matching for response.  You trade sensitivity for balance and baffle step correction.  You trade phase coherence for filter slope.  

Note that I have not said ONE WORD about room correction.  Thats an added benefit.  The point is, I dont see why anyone wouldnt want to go active.  A littile input from the speaker designer would give you the basis for what resonances to quell, what slopes to use, etc...so you could come very close to the passive system in a hurry.
NO, its not easy, but the advantages are HUGE when done correctly.
Lets ask Brian if things would be better and easier, in the active domain..all else being equal!

[ctviggen]

My main point is that people underestimate how long this takes.  You assume you just buy a filter and toss it on there and in 10 minutes you're up an running with much better sound.  That's BS.  It's going to take you days if not weeks to tune the system to get better sound.

Moreover, I think that passives can be better than actives.  I see no inherent benefit to actives.  The benefit exists solely in the ability to modify the curves to fit the drivers, but that benefit is going to take much, much, much longer than you anticipate.  If you go to DIY Audio.com, there's a hugh thread where many were of the opinion that passives can be better than actives.

[James Romeyn]

Digital vs. passive xo is fun to argue about.  But that's all it has ever has been & continues to be, an academic argument, at least regarding VMPS speakers.

Till someone actually orders a pair of VMPS with the three direct input pairs for all three driver sections (or modifies a stock pair), hooks up the digital xo & three amps, & A-B's it against a stock pair.

Till that happens everything written on this subject (as far as VMPS goes) is purely, 100% theoretical.  This, my friends, is what I like to call dueling BS (with all due respect to all sides).

Because this has been argued about for a few years already, I'm beginning to get the idea that people would rather argue about it than test the theory, because the actual testing is a way too much work, & its potential value is minimized when the speakers sound so good to start with, especialy a totally stock RM30 pair with CDWG (what I have at home).

Hey, I'll toss this "theory" into the ring: Even if one or two digital xo-equipped VMPS ribbons have been A-B'd against a passive xo twin, the feedback will be mixed, both pro & con, while the CDWG will continue on with its universally positive feedback.  How many of the people with the the CDWG disagree with that prediction?

And another bonus theory: A reasonable percentage of owners have so many room &/or equipment deficiencies that they will never even experience the potential quality in a stock pair of original RM30's with the CDWG.  In other words, it is foolish & a waste of time to even consider the potential digital xo advantages without having done significant acoustical upgrades to your room, & to have brought your equipment level up to the highest levels or darn near to them.

Lastly, with all due respect, making the general statement that digital xo advantages are "huge" may be true, but only for the exact speaker model that has been A-B'd against a passive xo equipped twin.  Without question, if someone has not A-B'd a digital xo-equipped model directly against a passive equipped twin (the passive twin absolutely must be passively biamped or triamped same as the digital speaker, driven by the highest grade preamp capable of properly driving the amp loads), this opinion is purely theoretical & is untested in the actual world.  Making statements like this without the above test having been performed is extremely misleading IMO, & is absolutely nothing more than repeating the advertising/marketing/theoretical claims of the manufacturers of the digital xo gear.  It might look great on paper, but you don't know that capsule will survive re-entry till you get it above the atmosphere.  

Now, if you have done the above A-B test 100x with 100 different speaker models, & every time the digital beats passive, there may be some weight behind a statement that one believes the digital xo will be preferred vs. passive, on an untested speaker model.

[mca]

How much attention have you given to room acoustics? If little to none, an RM30CDWG with stock caps has such high performance that room improvements might provide good value.

Right now I have double stacked 2x4x4" GIK panels in all four corners of the room. That made a noticable improvement in bass in my room. I will be placing an order soon for nine each 2x4x2" panels. Two for each side wall, three for the front wall and two for the ceiling.

[ctviggen]

Well, I plan on creating a digital crossover and room correction.  However, my initial plan is for the bass and mids/highs for the RM40s.  The RM40s are not that conducive to digital crossovers in the sense that multiple bass/midbass and mid drivers are harder to examine and determine proper filter coefficients for.  You can figure out slopes and perhaps crossover points relatively easily, but when it comes to using the tools of filters, ie, being able to adjust the frequency response and perhaps phase response of the bass/midbass and mids/highs, this is a much harder proposition.  

I think therefore the easiest step is a lows (bass/midbass) and mids/high split at first. The second step is a mids and highs split.  By the end of the year, I hope to have a digital filter set up using a lows and mids/high split with digital room correction.