[James Romeyn]

How would you guys quantify the change/improvement (if any) from the dual spirals to the FST?

[Pez]

James,
I remember when it used to have the dual tweeters and I would describe the high-end sound as brittle and a bit crunchy. Having lived with the 626 Rs with spiral Tweeter I can tell you firsthand that FST tweeter is vastly superior in every respect. Smoother more musical and a hell of a lot more detail. As far as the woofer configuration I'm pretty sure that the double magnet woofer is still on the top of the cabinet. If I remember correctly there isn't enough space in the bottom cabinet as the woofer is right up against the passive radiator in the bottom of the cabinet in these particular cabinets.

The RM40s in the configuration I have are easily in the top five speakers I've ever heard. In this set up and in this room they are the most passionate speaker I have ever heard. Hands-down.

Here is a link to my amplifier build. Note that the simple SE amplifiers are 5 W single ended triode. They have the option to switch over to pentode mode and that will give them an added 5 W I believe, but the trade-off is significant! the sound quality isn't even near what you get out of triode. http://www.audiocircle.com/index.php?topic=73713.0

[studiotech]

Looks fantastic Pez!  What are the Xover points and slopes on the speakers?  With all of those mods, it's not really fair to call that a DCX anymore is it?  How far away are you from the speakers compared to how far apart they are?

You're in the Denver area, correct?  Next time I'm out there for family visits or RMAF, I may have to ask you for a listen.  Actually I am considering moving out that way.  Know any good leads for commercial A/V designers/installers?

Greg

[Pez]

Greg,
My xover points are 300hz 7khz and I'm using a 1st order BUT slope. The coherency is astounding. On tracks like Roger Waters 'perfect sense' The effects of thunder and voices going all around you is eerie. The DCX is way beyond its original design and is performing its duties very well.

I have said it before and I'll say it again. I have a pretty open invite policy. Send me a PM and is be more than happy to try and accommodate anyone who wants to swing by.

Oh, and sorry I got out of the commercial installation rackets several years back. I'm sure that there is plenty of work out here, I just wouldn't know what direction to point you in.

[Tyson]

High FS woofer is on the top in these 40's.

[abernardi]

Hey Pez, beautiful, exciting system.  For the hum, this is obvious and I'm sure you know about it, but if you're anything like me, I'm constantly missing obvious things!  I'm assuming you probably have an upgraded linear power supply of some sort for the SB and that thing may be giving off a lot of crap.  I had to move mine FAR away from everything else. 

Congratulations from an envious hopeless audio-addict 

[Pez]

Abernadi,
You make a great point! The power supply was built by Wayne at Bolder Cables. The PS itself is very quiet, but it's plausible that it is throwing off EMI/RFI. I have it a good distance from my amps and the dcx. I also have a power conditioner also made by Wayne that the SB and DCX are both plugged into that I know for a fact can cause things to buzz and is therefore also placed quite a ways away from anything that could be problematic. I have virtually eliminated noise as an issue in this setup. Save for a barely perceptible hum from both of my amps. From the listening position it is phenomenally quiet.

[studiotech]

Wow, 300-7KHz for one driver crossed only 6dB/oct.  THOSE panels ARE the speaker.  I have a love affair with planar mids myself.  I have an old set of Monsoon computer speakers, have owned Maggies and AV123 Stata Minis( same basic mid panel as yours I think ) and now use BG Neo10 in my baffles.  Sounds like fun, I will certainly hit you up when in the area.  What general part of town are you located?  My brother is in Cherry Creek up the hill from the mall.

Greg

[Pez]

Ya if I ever DIY up some speakers the Neo10s would probably be at the heart of the system. I love the sound of push pull ribbons. Nothing comes close to the fidelity and soul.

I'm in Aurora. Funny I'm at cherry creek mall right now. 

[James Romeyn]

Wow, 300-7KHz for one driver crossed only 6dB/oct.

Negative.  VMPS models with this planar mid panel employ the following slopes:
All high-pass, whether active or passive, a crossover that can be viewed as either dual-pole 1st order or simple 2nd order electrical (acoustic slopes unknown)
Low-pass: early versions employed no electrical low-pass...starting middle vintage employed passive 2nd order electrical (again, acoustic slopes unknown).

Electrical slope is always misleading.  Acoustic slopes are the sum total of the crossover electrical slope + driver acoustic/electrical slope.  For instance, commonly a 2-way monitor has asymmetrical 2nd order electrical slope which effectively equal asymmetrical 4th order acoustic slopes.  In this case the electrical slope expresses only half the actual acoustic slope. 

Brian last offered Behringer DCX-2496 upgrade to active digital crossover, definitely employed for woofer low pass and mid panel high pass.  IIRC 2496 also employed for mid panel low pass but not sure on this issue.  Brian inaccurately used the moniker "Fully Active."  Brian's version of "Fully Active" still employed passive treble high pass (I realize some users may have switched to fully active, but Brian himself never did).  Brian's preferred amp for about the last twelve years was the late James Bongiorno's Ampzilla mono blocks, about 65 lbs each, current MSRP $8500/pr.  "Fully Active" would require six mono blocks...yikes, that's real money!   

The 2496 parametric EQ flattened the mid panel's narrow 1k Hz resonant peak, that driver's only Achilees heel (for its intended range) after fixing the terminal defect.  One could argue that flattening that peak increased performance even more than upgrading the woofer's passive low pass to active.

[Pez]

No passive xover components in my speakers period. All have been ripped out.

[studiotech]

I'm in Aurora. Funny I'm at cherry creek mall right now. 

Totally off topic, but have you tried the hotdog/sausage joint on the other side of the street from the mall that wraps them in pizza dough and has a million different gourmet toppings?  Damn.....tasty.

http://www.hawtdogsausageeatery.com/

I've been looking online at the medical city they are building in Aurora.  Some internal A/V jobs there too.....

Greg

[James Romeyn]

No passive xover components in my speakers period. All have been ripped out.

Yes, I presumed you were a user who actually meant "Fully Active" when using the term even though Brian the speaker designer used the term but didn't mean it.

In certain rare circumstance in the range from about 1.5kHz to 2.5kHz a passive crossover, in a certain designer's hands, might be the only alternative.  For instance, a designer who does not design with active but one at the top of the passive crossover design ladder.  In such case, one's alternative is a speaker vs. no speaker.  We'd have no option of claiming active was better because such does not exist.  In such case, one could not simply replace passive with active because overall system synergy depends on the sum total of two passive electrical crossovers (LP/HP) + both driver acoustic/electrical motors. 

But we could compare such passive crossover equipped speaker to a completely different active speaker, and such comparisons have been made, and in some rare cases the passive crossover equipped speaker wins independent judging.     

None of this applies to any VMPS with the planar mid because it crosses so far away from the narrow range I specified.  I would love to hear these 40s, probably the best sounding pair extant from what I read here.

If the high 10" has higher FS than the lower 10, I predict better performance inverting them if such would physically fit.  Do you guys notice the image elevating over a certain narrow range where the upper 10 is dominant?  Like the middle range of Mel Torme's voice for instance?         

[Pez]

If the high 10" has higher FS than the lower 10, I predict better performance inverting them if such would physically fit.  Do you guys notice the image elevating over a certain narrow range where the upper 10 is dominant?  Like the middle range of Mel Torme's voice for instance?         

I'm listening to Mel Torme right now just listened to Lady is a Tramp and am currently listening to Fascinating Rhythm.  Rock solid image. Doesn't shift anywhere regardless of frequency. If you look at my pictures the height of the TV is where you hear vocals on Lady is a tramp and because Fascinating Rhythm is a mono recording it is all coming dead center from the approximate position of the TV. This is of course what one would expect from a mono recording. No drift, no frequency specific oddities. Not sure if that answers your question fully... 

[James Romeyn]

My 40s setup was antique compared to your rig.  I'm sure it was an anomaly sharing no resemblance to your sound.  Good on ya!