[ekovalsky]

Since I have seen no further announcement regarding the 'Direct Drive' offerings from VMPS, I am hoping to get some advice for a DIY conversion.

My speakers have three sets of binding posts, one of which is already set up for direct drive of the woofer system.  There is of course the normal set of woofer posts, which pass the signal through a coil.  

The other set of posts has the crossovers for the planars and ribbon in parallel.  I have already bypassed the high pass capacitor bank, inductor, and L-pad for the planars which was pretty straightforward.  So I am now wanting to bypass the low pass filter on the planars (just a coil) and also the second order high pass filter and L-pad to the tweeter.

I would want to rewire the speakers so that the planars are directly connected to one set of binding posts and the tweeter to another.  I'd replace the internal wiring to the planars and tweeter in the process.  The Analysis Plus on the woofers can stay.

Doing this will require a DEQX instead of a TacT RCS 2.2X, since tri-amping will be mandatory.  Also the DEQX allows for protection of the tweeter in the testing process which the TacT really does not.  I would anticipate using linear phase, high order crossovers at around 275hz and 3khz although exact values would have to be determined by listening tests.  The tweeter should be safe down to 2750hz with 3rd order filter, should it fry I can replace it with an Aurum Cantus G2si at well under $100.

I'd need either a third TacT stereo amp or a six channel BOZ amp, which is the new high end product from TacT.  It has already won the heart of 'The Stereo Times' Clement Perry.  No way am I going back to separate DACs with analog interconnects and conventional solid state amps!

So here are my questions, hopefully Brian will respond...

1.  How many feet of wire are needed to connect the tweeter to the binding posts ?

2.  How many feet of wire are needed to connect the planars to the binding posts ?

3.  What is the impedance of each planar panel and how are they wired (i.e. series / parallel) ?  I could figure out the latter by opening up the speakers of course.

4.  What is the internal cabinet volume for the woofer system ?  I'd like to look into the option of replacing the 10" and 12" woofers with different units (like the TC Sounds) and seal the system.  Response could be flattened into the mid-30's with digital EQ, then the bottom octave would handed over to separate subs.

[BrunoB]

The tweeter should be safe down to 2750hz with 3rd order filter, should it fry I can replace it with an Aurum Cantus G2si at well under $100. ...

I would start with a higher frequency.  2750 Hz/3rd order might be OK for a 626R but in a RM/X, the tweeter has to compete against 6 mid panels which means that it has to play much louder.

FYI, Aluminium ribbons of the Aurum Cantus can be replaced, not easy to do but inexpensive (see e-speakers.com for the replacement parts http://www.e-speakers.com/products/ac-ribbons.html).

[ekovalsky]

The tweeter should be safe down to 2750hz with 3rd order filter, should it fry I can replace it with an Aurum Cantus G2si at well under $100. ...

I would start with a higher frequency.  2750 Hz/3rd order might be OK for a 626R but in a RM/X, the tweeter has to compete against 6 mid panels which means that it has to play much louder.

FYI, Aluminium ribbons of the Aurum Cantus can be replaced, not easy to do but inexpensive (see e-speakers.com for the replacement parts http://www.e-speakers.com/products/ac-ribbons.html).

I meant that 2750/3rd is the safe operating range of the tweeter.  I expect to be at around 3.5khz with a 96dB/octave or higher crossover (to avoid cancellation between the ribbon and planars around the crossover frequency).

[JoshK]

You might consider doing what I am going to do.... I am installing an 8 pole speakon connector on the back of the speaker near the BPs. Alternatively you could use two 4 pole speakons, one for the MT and one for the Ws.  Then I am removing the passive xo's and going to built a nice box for them and they will connect to the speakers via the speakons.  

This way if I want to upgrade the passives, no problem, its all right there in an external box.  If I want to single amp I can do it without a switch, same with biamping. And if I end up getting a DEQX or similar I can just bypass the external passive all together.  

Well that is what I am doing anyway.  I am going to leave the BPs and Lpads in place so that it can all be easily reversed if I were to ever sell my RM40s and the buyer didn't want external xo's.  

The only question I have would it make a difference if my xo's were on my rack near my amp and the interface cable was long to my speakers, versus the external xo's being near the speakers and the amp cables long? If the prior is kosher then the external xo's can go in my rack and it wouldn't even be like I had external xo's.   Anyone got any idea?

[JoshK]

By the way, if this is something you are considering I can ship you the appropriate forstner bit to use and then you can ship it back to me, assuming you don't already have one.

[ekovalsky]

You might consider doing what I am going to do.... I am installing an 8 pole speakon connector on the back of the speaker near the BPs. Alternatively you could use two 4 pole speakons, one for the MT and one for the Ws.  Then I am removing the passive xo's and going to built a nice box for them and they will connect to the speakers via the speakons.  

This way if I want to upgrade the passives, no problem, its all right there in an external box.  If I want to single amp I can do it without a switch, same ...

Josh,

That is a good idea.   When you do this mod, can you take some pics ?

[JoshK]

My dog ate my digital camera, no joke!  Ok, she didn't eat it but she chewed on it and broke it.  I will see if I can borrow the neighbor's or something and I will take a photo copy of my notes.  I like to draw everything out by hand with measurements before I 'cut'.

[John Casler]

You might consider doing what I am going to do.... I am installing an 8 pole speakon connector on the back of the speaker near the BPs. Alternatively you could use two 4 pole speakons, one for the MT and one for the Ws.  Then I am removing the passive xo's and going to built a nice box for them and they will connect to the speakers via the speakons.  

This way if I want to upgrade the passives, no problem, its all right there in an external box.  If I want to single amp I can do it without a switch, same ...

Hi Josh,

Although it is not "official" I recently spoke with Brian about the same thing, so we will have "external crossover/cap electronics" that can be bolted on.

He has assured me that this can be done and we can take "DIRECT DRIVE" PLUS orders this way.  The Plus however will have an option for "bolt on" plus.  That is, the Speaker will be Direct Drive and the x-over caps will be in a "plug in" module.

We have also been discussing the DEQX OEM modules for the Direct Drive Versions of the Line, and those wheels are turning.

We have a deal with DEQX so we can (even now) offer the DIRECT DRIVE VMPS "with" a DEQX unit as a package.

These are for "early adaptors" and when the "VMPS authorized" configs are available we can likely send the files via the internet, if needed.

Wheels turn slowly, especially when you have "other", day to day business needs, but this "IS" something we recognize as important and valuable to our clients and customers.

I will post an assessment of what we are doing in more detail in another DIRECT DRIVE DEQX thread.

While we will certainly still offer the magical passive x-over systems from the Master   that many know and love, he will soon have a "new pallette" to which to apply his Sonic Designs.

[JoshK]

I'll let you know how my mod goes.  Installing the Speakon 8 pole is going to be a cinch, but taken out the passive xo isn't.  It is screwed and glued.  Then there are the binding posts that basically clamp the passives in as well, so not exactly a simple procedure.  I have made fairly exacting drawings of the xo so that I can reconstruct if I need to take any of it apart to remove.

Right now, I am doing the tweeter upgrade, which also isn't a simple procedure, at least not how I am doing it.  I decided that making the template fit inside where the old tweeters went wasn't going to be an easier than to just make a whole new template for the tweeter and the bottom two mid panels so that the mid panels are moved up and the spacing between the top panels the tweeter and the lower panels is slim.  It isn't going to be too hard but it does take some time and some tools.  I just don't like doing things like this half way.

[shokunin]

Josh,

Easiest way to remvoe the crossover is to remove the screws first and then use a heat gun to help melt/loosen the Hot Melt Glue.  The glue will start to liquify and you should be able to remove the MDF board that houses the x-over parts + binding posts.  Trying to pry off the boards without heating the glue can get ugly..

[Jose R.]

Josh,

Easiest way to remvoe the crossover is to remove the screws first and then use a heat gun to help melt/loosen the Hot Melt Glue.  The glue will start to liquify and you should be able to remove the MDF board that houses the x-over parts + binding posts.  Trying to pry off the boards without heating the glue can get ugly..

From my experience with the RM30C upgrade, the only way to remove the crossover/binding post board is to tap it out with a hammer and piece of wood.  The board will probably need to be replaced and the glue that remains on the edges of the box can be removed piecemeal - a laborious process.  I do not think that a heat gun will get to the glue between the board and box.

Regards

Jose