[Ric Schultz]

These speakers were original Emerald Physics 2s.  They already had the baskets of the Alpha woofs damped with EAR SD40AL to great sonic benefit (I was there when we did the first pair) and the baffles were increased from two pieces of three quarter inch MDF with a rubber interface to adding a third three quarter inch thick Birch Plywood piece in the center (2.25 inches thick total).  All layers are glued using Green Glue (damping glue).  The original cheap waveguide was replaced by the Gedes 12 inch waveguide and the compression drives is a Beyma.  The xover is an EVS modified Behringer and the amps are a Yamamoto on top and an EVS modified Hurricane on the woofs.  xover is 900 hz at 48db per octave.  Time aligning and very flat frequency response provided by the Behringer.  Speaker magnets are surrounded by ERS material and EVS ground enhancers are used on one of the woofs and directly on the compression driver.  I have been after him for awhile to add a brace to the woofs and he finally did.  This is his response to me via email:


"Adding the wooden brace to the woofers on these modified Emerald Physics CS 2s adds punch, dimension, delineation and authority to the bass. Very low bass notes--around 30hz and up--are more clearly present and not just as tones, but as identifiable musical notes. Bass instruments have more body and presence in the soundstage. While I would have never said the bass before the mod was wooly and ill-defined, it almost seems it was that way in comparison to how it is now.

There are a host of other positive effects that pretty much run the typical audiophile-cliche gamut: the soundstage is wider, instruments more identifiable on the soundstage with better separation, voices are more natural, etc. All of these positive results are due to a lessening of noise and a greater presence and awareness on my part of recording detail (but not sharpening, bright detail--overall sound is much more natural). I think this is more the result of overall rigidity in the baffle."

So, as you can see, this is just a piece of three quarter inch Birch plywood epoxied to the back of the magnets and screwed to another piece of plywood at the bottom which is glued and screwed to the alluminum base of the speaker.  Imagine if he had made the brace out of multiple layers of plywood and attached them to the drivers via the edges of the plywood and also ran this brace above the woofs and attached it directly to the baffle above the drivers.  Look at Studiotechs feet/stands/brace and imagine a super long version running from the base, glueing to each woof and then going to the baffle above.  A five inch thick brace like this would take the sound to another whole level.  I will "try"and get him to add a second brace at right angles behind this first one and extend it and attach it above the top woof to the baffle......and/or add a super brace from the base to near the top of the panel on each side. 

So, for a few dollars and a couple of hours work, he has a new speaker system.  Differences like this can be worth thousands of dollars at retail.  By the way, I heard his speaker before this mod and it is a seriously transparent system....I did notice then that the bass was not the best I have ever heard in pitch clarity (but still really good in the bass! and deep!).  I cannot wait to hear it again.....and especially if he ups the ante on the bracing.

Well, its obvious I don't know how to upload a picture.  I have the pic in the gallery and I hit save and I get nada.  Help!

The guy took better pics and the only way I can upload is to create a web page and link....below is two better pics:


http://www.tweakaudio.com/EVS-2/speaker_pics.html

[ebag4]

Here you go Ric.

[Ric Schultz]

That's great.  So, I will email you everytime I want to get a picture up.  He he.  Well, what did you do that I did not?  I want to learn!

[Ric Schultz]

I think the open baffle thang is a revolution.  You can now get planar sound for pennies on the dollar.  But, it has to be done right.  Look at those Magicos, etc. that cost tens of thousands of dollars.  Why do they sound so fast and electrostatic?  Because they use fast, clean drivers and super, super dead cabinets with sound absorbing stuff inside.  Almost all super high end speakers use baffles at least 2 inches thick and some way thicker and way more tweak than that!  And they have a whole speaker to brace the front baffle with.  When you go open baffle, you eliminate the sound of the cabinet....all the sound reflecting back to the driver and vibrating a box is gone.  But, if you do not have the baffle rigidly mounted then you cannot get any better sound than a well made box.  They have box sound, you have vibrating baffle sound.  If a box speaker must be at least 2 inches thick and it is braced in all directions with the box, then we need to make the baffle that much thicker and brace it somehow to equal those expensive box speakers in deadness.  When we do this then we win!  We have no baffle sound and no box sound.  Now those electrostats, etc. have serious competion.  Now we are having fun!  Driver baskets, magnets and baffles vibrating do not make good sound!  We want the cone of the driver to be the only thing moving.  Super braced, super thick, super dead....this is our motto.  Amen!

[Russell Dawkins]

So, what is the function of the brace, Ric? Is it to make the driver/baffle assembly more rigid?
Are the 15" drivers still bolted/screwed to the baffle?

[ttan98]

Ric,

You input is most welcome I am in the same situation, can you tell me a little more about, EAR SD40AL, what s it and how you use it?

[Tyson]

Why not just make an H-Frame? 

[Ric Schultz]

Russell: Better sound!!!!!! yes....yes, still bolted to the baffle.  It damps resonances in the magnets and braces the whole speaker and woofs.

EAR SD40AL is a constrained layer damping material sold by Michael Percy.  You can see it on the basket of the Alphas in the pic.  Similar to Dynamat Extreme except this uses a fairly stiff polymer as the base and then the aluminum layer on top where the Dynamat uses some gooey butyl or something and then the aluminum layer.  My sense is that the SD40AL would be more linear.  Gooey stuff tends to sound gooey.  The downside of the EAR stuff is that it is realitively expensive.  You cut it with scissors and peel off the clear layer underneath and apply.  It has adhesive on the back.  Night and day difference in the sound!

Another thing about the Alpha woofs.....and this applies to all big stiff woofs and for that matter all drivers.  They sound terrible until you get at least a few hundred hours of seriously loud music through them.  The spiders and surrounds are really stiff when you get them new.  You can hardly move the cone.  Some people give up on these drivers right away because they sound so dead.  The things are so stiff they hardly make noise (exaggeration).  I use a 30hz sine wave (40hz when I leave the house....40hz I can hear and feel but 30 done this way hardly makes any noise) and put them face to face and run them out of phase.  After about 10 days straight you can actually move the cone.......much looser.  Now they will finally have some transient response.

H frame is fine if you are xing over below 200hz.  If you are running up to 900 hz like in this two way speaker the sound would sound very bad coming out of a tunnel.  A U frame would be better, but an open baffle at 900 hz is probably most natural.  By the way, I have never seen a post by anyone who has A/Bed an H frame with a U frame.   The H frame is closest to a dipole where as the U frame puts out more energy to the front.  I always want to time align and having a U frame or large open baffle lets you time align the drivers easier if you are using physical time alignment (not digital).

[ttan98]

Ric,

I am not familiar with the purveyor of audio equipment, can you tell me which company is Michael Percy from? I will look into the prices of the damping material.

Thanks.

[Russell Dawkins]

Ric in another thread you said this:

"Have you seen that Linkwitz has his cast frame midrange driver on his open baffle speaker mounted by its magnet?  If it makes a midrange better, imagine what it would do for woofers with resonating stamped frames?"

Do you realize that the midrange in question is actually mechanically de-coupled from the baffle board and held entirely by the magnet, so the vibrations from the frame are not amplified by the baffle board.
That was de-coupling, this is something else, I think - stiffening? Have you considered what the effect of actually suspending the woofers by their magnets and not by the edge of their frames might be? the seal to the baffle could easily be self-adhesive foam weatherstrip.

[Ric Schultz]

Percy Audio......he and Parts Connexion are the two largest audiophile parts sellers.

Mounting a midrange by its magnet only makes sense.  However, large woofers would flex in the front, especially ones that have stamped frames like the Emminence Alpha woofs.  In this instance, the hard mounting of the woofers is especially needed as this added brace braces the whole speaker through the woofs.  If the baffle was already at least 5 inches thick and braced and you used cast frame woofers then there might? be some benefit of decoupling the woofs from the baffle.  However, mounting a large woofer with only its magnet would not be easy.  The mounting would have to be absolutely dead.  Remember, the waveguide above the woofs has to be absolutely rigid. 

The original Emerald Physics 1 was shown in 1996 at Rocky Mountain.  It used 4 Alpha 15 inchers per channel.  Two were on one baffle and behind was another baffle with two more.  The two baffles were connected together via large Aluminum rods (see link and pics).  This would make both baffles fairly stiff as they are connected together.  Robert Harley said it was the best bass he ever heard in a hotel room (digitally eqed for flat sound at listening position).  Now just think if he had really made the baffles serious and damped the baskets and hard mounted the magnets as well.  Probably jaw dropping!  4 better woofs per channel done right?  Probably need a jaw remounting!

Below is link to pics of original CS1. Scroll to the bottom of the page.  Crappy stock DBX xover and ordinary amps and wires on floor and not good damping keeping this speaker from being state of the art.  At least the panels were braced some.  Looks like two pieces of three quarter MDF for all baffles.  No damping on baskets, no mounting of magnets.  Because they were so ugly and required a lot of room and triamping, Clayton later went with the one baffle system and biamping.  This original CS1 done right would be killer. 

http://www.audiofederation.com/hifiing/2006/RMAF2006/report/500/part3/index.htm

[Redefy Audio]

Russel,

great job man. I got 2pcs alpha15 and 2pcs beta15. im considering to do alpha&beta per ch, with BEYMA 12CX that i got.

the reason for this is the sens in 12cx is very high around 98db, so i figure by using 2 15" /ch can make up for it. Using 1 /ch i need to -5db for the 12cx.

im interested to use the isodamp, i figure this approach will help, as the stamped frame is ringing if u knock on it.

thanks for sharing man.

cheers
henry

[Ric Schultz]

Just talked to the guy with the speakers and this week he will be adding another brace turned 90 degrees to the speaker.  It will be glued to the existing brace and also fastened to the baffle above the woofs and to the base.  Now, we are getting somewhere!  I will have pics and comments in another thread. 

Please see the original post above for a link to some better pics, showing the constrained damping layer on the speaker baskets and the ERS on the magnets and also the Ground Enhancers in place.  Also notice there are no crappy sounding binding posts or speaker wire connectors.  Less is better!  He will also add more constrained layer damping to the woofs, so they will be entirely covered.

[myaudioking]

cool! more pictures please