[Jose R.]

Is there any published info on the planar ribbons and FST tweeter that Brian is using in his speakers, specifically impedence and SPL curves?  I am trying to correlate what I am measuring in my room with the intrinsic properties of the drivers.  Are these drivers propriety to VMPS or are the details available from manufacturer sites?
Like some others in this forum, I am using digital crossovers for the woofers with good results.  I am waiting for the Auric cap and megawoofer upgrade which should be interesting - the sound I am getting is already very good and if these make it better I will be very impressed.

Regards

Jose

[ekovalsky]

Not that I'm aware of.  

I think the measurements we have gotten are fairly similar and probably reflective of the drivers and their crossovers.  In addition to measurements obtained 3-4m away from the speakers at the listening position, I have done close range measurements of the mids and tweeters on and off axis.  The dips and rises I measure stay fairly consistent whether on or off axis, near or far.

For me, flattest response was achieved the the midrange L-pads at about 12:00/12:30 and tweeter L-pads at 1:30/3:00 (L/R channels).   Since I have the RM/X ,the tweeter inclination  was another variable I had to deal with. Best output seems to be with the tweeter angled just above ear level.  A laser pointer attached perpendicular to a straight edge was helpful in getting the pods aligned.

One thing I have not noticed is a big change in measured bass response by removing or adding putty to the passive radiator.  However, I think Zybar did measure some changes after replacing all the putty on his Larger subs and RM40s.  The wrong amount of putty likely does raise distortion levels -- probably there is a correct amount of mass to match the electrical and mechanical characteristics of the active drivers with their crossovers and of course the enclosure volume.  Finding that correct amount is the hard part  

I do not have Brian's golden ear.  Without the measurement capability of the TacT I wouldn't have been able to optimally tweak the speakers.  And once I heard what the room correction can do at the seating position there was no going back...

[Jose R.]

I do not have Brian's golden ear. Without the measurement capability of the TacT I wouldn't have been able to optimally tweak the speakers. And once I heard what the room correction can do at the seating position there was no going back...

I agree.  Having the measurements has helped a lot in tuning the speakers.  I have the RM30 thus the pot settings are a bit different.  I have found that the mids become a bit hard if the pots are much above 12 and I also set the tweeter pot to 12.  
I have also found no measured difference with removing putty - I do not dispute that this may have audible differences but with the Tact equalisation, the changes are not as apparent.
In view of this I have asked Brian whether he felt that removing the PR's and creating a sealed box would be beneficial - his answer was that I should not do this.

Regards

Jose

[ekovalsky]

In view of this I have asked Brian whether he felt that removing the PR's and creating a sealed box would be beneficial - his answer was that I should not do this.
 ...

Probably not a good idea if you want any decent bass from the speaker.  But if you go with external subs it may be something to think about.  You will have more work sealing a passive radiator hole than a port though.

Bad thing about ports and passive radiators is that their output is at least somewhat out of phase with the active woofers, and below the cut off the output falls fast at 18dB/octave or so.  Sealed boxes have a slower drop off which makes them more amenable to equalization.

[Jose R.]

I am using subs and agree that creating a closed box for the woofers would not be a good idea if one was not using subs.
With the RM30, it would be fairly simple to remove the PR's and cover the bottom with the base plate.  At present I do not plan to do this although it would be an interesting experiment to perform at some time in future.

Regards

Jose