# I want to clone the Von Schweikert Unifield 3 Loudspeaker



## briansz

I auditioned the Von Schweikert Unifield 3's at the recent Rocky Mountain Audio Fest. They're $16K a pair, and were being driven by an Oracle CD Transport, Channel Islands VDA2 DAC, a CI PLC1 Mk2 preamp and a pair of CI D200 Mk2 Class D monoblocks. The room and listening position at the show were much like mine at home, and the experience was one of the best at the show. It was scary how these speakers rendered a single lead vocal and then opened to a large choir with a tremendous sense of space. Truly holographic staging/imaging - goosebump material.

My budget is such that a system like the one above is a pipe dream, even used. But I've been analyzing what it would take to clone the loudspeaker and amp end of things. By piecing together the raw drive units and producing the cabinets myself, I think I can hold the out-of-pocket to $1500 or less for speakers and materials. VS had a helpful prop at the show showing their cabinet wall cross section of MDF, stone, and damping material. I've been able to discern through much Googling and synthesis of info that the VS tweeter is a 3" Raven ribbon, the 5" fullrange is a Fostex FX120, and that the 7" woofer is a Seas Excel piece. All are 'suspended' in a synthetic clay gasket that interfaces to the cabinets.

My goals are to come within striking distance of the Unifield 3 performance, but using a less costly ribbon tweeter and possibly a less exotic woofer cabinet (VS is supposedly using a 4-chambered aperiodically loaded TL that terminates in a flared vent). 

If what I've read is correct, in the Unifield 3 the woofer is crossed over at 100Hz and the Fostex does not hand off to the ribbon until 8KHz! Leaves a lot of room for bass cabinet experimentation, maybe even a sub/sat system. In any case I should be able to easily build the mid/tweet enclosures and then experiment with the woofer end of things. I'm thinking I'd enjoy putting together a 4 or 6 channel amp from Class D modules and then using a DCX or other DSP for crossover and EQ duties so I can bi or even tri amp.

Anybody have some input as to a fast/musical 7" or 8" TL woofer design and/or a good ribbon tweet for under $125 each?

Thoughts? This seems to be a great DIY candidate for me as the design is excellent and the crossover network/premise is simple.


----------



## Se7en

I'm a fan of VSA myself but this project seems pretty ambitious to me.

Well beyond they cost of the actual drivers is building and tuning the crossover, which is where Von Schweikert (like many manufactures) specializes and gets his house sound. My understanding is that VSA takes a pretty special approach to it's crossover design, something along the lines of trying to emulate the inverse response to of a recording mic (I'm probably getting that wrong) but that is what defines the VSA "tune".

Although not VSA, I have become quite fond of the new GR Research V1 & V2 designs. There designed as DYI, have a fantastic sound, are very cheap. The V1 in particular has the OB servo subs that play cleanly to 18hz. The mid-compression driver is efficient enough to play to concert levels off of 10watts of power.

I'm not sure if you got to check out these designs at RMAF or not, but they sound great to my ears. You can buy the smaller V2 (non-servo) for a grand and the V1 including the servo subs and amps for closer to two.

V1


----------



## ccdoggy

one other thing to think about... many times speaker designers will modifiy speakers for use in their system or place a requirement on the supplier for something just a little different then what the normal unit will do. so they can get the most/best out of the setup.

then there is the tuning and uniqueness of the crossover and its interaction with the drivers. 

I would consider this very ambitious. there is some great ideas applied in their design but i am sure its not as easy as throwing it all together.

but if you really want to give it a try, go for it. personally i would go with a DIY proven project and improving on it with say that type of dampened enclosure.


----------



## soundevolutionaudio

briansz,

I dont know if this well help or not but, Frank Derrigo use to work for VS years ago, and is a personal friend of mine. He has desinged several things for me in the past and also is a very nice guy, when he left VS he started up Auvia loudspeakers.. Auvia Loudspeakers 
Hes a busy guy you can pick his head for ideas if you like.. You can email him from his website and if longer then todays pm me and I well call him and see if its ok to give you his personal email address.....
Hope this helps some..

JOHN
Soundevolution


----------



## Silver Supra

I agree, the VR speakers I heard at the show sounded very good. 

I have tried to convince Michael Kelly of Aerial Acoustics to release some components to the car world - hopefully including the ribbon from the 20Ts. He use to work at A/D/S and said he really liked tinkering with car audio.


----------



## briansz

Thanks for all the replies, I have a few thoughts.

I didn't enjoy the VS room with the very large speakers at the 2008 RMAF. For $90K plus electronics, they just did nothing for me. This is why I was surprised that I liked the Unifield 3's so much.

I have a room that is quite wide and shallow (with regard to speaker vs. listening position). The UF3's seem to excel with this placement, and many other speakers (including the very good GR Research speakers referenced in Se7en's reply) just don't. I can't locate speakers more than 18" from the back wall (and that's pushing it).

Soundwise, I tend to prefer electrostats, ribbon tweeters, dipoles, or horns. The Analysis Audio room and Classic Audio rooms were favorites of mine. I always like Emerald Physics too. WAF is a very large deal in this project and the UF3 form factor is something I can 'sell'.

I understand that the possibility exists that VS is using modified rather than off-the-shelf drivers, and that's a risk for sure, although it doesn't alter the premise of the design. Crossover-wise, I am not all that worried. I may be way off base, but the UF3 seems like it would have the simplest dividing network in the VS lineup - the marketing literature for the UF3 touts the fact that it's a 'One-Way plus bass' design with the supertweeter to augment only 8,000 Hz and up.

I thought the bass from the Seas Excels in the UF3 was quite good, but nowhere near world-class. For the driver, true, the result is pretty amazing. Could it be bettered? Likely. The challenge will be getting 25Hz at the bottom with a 100-110Hz top end.

As much engineering as VS might have put into this design, I'm planning on doing listening room measurements and DSP correction that most 2-channel customers may not do. I'm willing to bet that within reason, that is going to take me places that the unoptimized system in the RMAF room went. For the last two years, most of my favorite rooms at the AudioFest are all using DSPs, electronic crossovers, and Class D amplification.

Ambitious, maybe. But I have access to a CNC router to do stacked cabinet buildups, a source of 2cm stone falloff, 2D/3D CAD skills, more than 10 years of professional cabinetmaking experience, and full shop of tools at my disposal.

Put it this way: I'm on the tail end of a truck restoration in which I've stripped the entire pickup (except under the hood) to bare metal, learned to MIG weld replacement panels in, did the bodywork, and have shot it with acrylic lacquer. I'm installing a 2.3 Turbo from a Ford Turbo Coupe next. I've never done any of those things before, and it's taken four months and a couple grand so far. I'm not the average hobbyist or a stranger to ambitious projects <lol>.


----------



## Rob K

I've seen a DIY set called the "Statements" over on HTGiude.com. There are three variations that I've noticed. They use the RS180 a Tangband mid and a ribbon tweeter.


----------



## briansz

Interesting. Those are fairly similar to another cheaper design I liked a lot in the SB Acoustics room. It was a small 2.5-way floorstander with dual 6.5's in 16L each and their ring radiator soft dome tweet per cabinet. It is only worth about $350-$400 in parts for the pair, and they did a lot of things pretty well. The Unifield 3's did certain things astonishingly well, and I am not necessarily referring to the bass. More like absence of resonance/coloration and that amazing soundstage.

I'm going to rough out a basic design for the Fostex 5" mid and a ribbon/planar/air motion tweet to be determined. Tang Band has a ribbon with a neo motor out now for $130 a pop that looks very interesting. I'm going to stick with the 8,000Hz crossover point for the tweeter hi-pass and investigate baffle step correction and a zobel network for the mid. If I can do the mids and tweets well for under $600, I have the rest of my life to play with/integrate subs. 

I'm thinking that bi-amping the minimonitors with the Hifonics Olympus on my test bench will let me investigate relative driver levels and experiment with additional crossover points and sub integration without buying a load of crossover parts by the seat of my pants. Not afraid to use the car gear in the house to confirm the project is giving me what I want before spending any more $$ on home amplification or passive networks, I've got a pair of 45-amp 12VDC PSU's here to play with and hook things to.


----------



## soundevolutionaudio

I would test with a cleaner amp if you have access to one.........


----------



## briansz

114dB s/n, 0.02% THD, 10Hz-32Khz -.01dB is substandard?  This is old school Zed.

I mean, I know the Levinsons are out there with fourth decimal place THD and 135dB s/n, but my sources aren't even close to the Olympus in bandwidth/noise floor. 

Hear 0.02% THD?

I'm with Richard Clark on the amp challenge (at the very real risk of igniting a flame war).


----------



## the other hated guy

Go for it.. Translam is easy to do.. and the shape of these cabinets are very straight forward.. I wouldn't get caught up with trying to mimic 100% Von's damping approach.. just be creative yourself.. 

The xover will always be the hard part which is why you should go active


----------



## briansz

I agree 100% on going active. I want to be sure of what works best before I devote any cash to passive components. I may end up just sticking with active once I'm done and just buying or assembling a multiple-channel home amp.

The top cabinet should be pretty trivial to build. Stack laminated MDF with curved outer sides and flat (although angled) inner sides. Glue/mastic 2cm stone to the inner sides and then apply damping material to that. 

Most of the 'exotic' design of the UF3 speaker is in the lower cabinet. I'm not wed to the Seas Excel woofer or the VS bass tower configuration at all. There's a lot of options to do 20-100Hz that aren't really exotic or costly. If I get the minimonitors right, I'm probably 80% of the way there on the project. 

It's easy enough to weld together some hollow metal stands to fill with shot and get the ribbon at the right height if I use a different bass cabinet configuration.


----------



## AVIDEDTR

I miss my Vonschweikert VR-2100s and the Tower of Power sub. Anyways - can anyone tell me what are these layers: 
Best guess would be (left to right) 
*MDF/butyl compound/?????/Cotton acoustic Mat/Dacron*


----------



## the other hated guy

my thoughts on active vs passive is the same for home and car.. passive is designed for best case performance and environment.. but once you toss them into a less then perfect area they become less then ideal..

so.. you tune the loudspeaker to your listening area.. IMO, this makes much more sence...

just my .02




briansz said:


> I agree 100% on going active. I want to be sure of what works best before I devote any cash to passive components. I may end up just sticking with active once I'm done and just buying or assembling a multiple-channel home amp.
> 
> The top cabinet should be pretty trivial to build. Stack laminated MDF with curved outer sides and flat (although angled) inner sides. Glue/mastic 2cm stone to the inner sides and then apply damping material to that.
> 
> Most of the 'exotic' design of the UF3 speaker is in the lower cabinet. I'm not wed to the Seas Excel woofer or the VS bass tower configuration at all. There's a lot of options to do 20-100Hz that aren't really exotic or costly. If I get the minimonitors right, I'm probably 80% of the way there on the project.
> 
> It's easy enough to weld together some hollow metal stands to fill with shot and get the ribbon at the right height if I use a different bass cabinet configuration.


----------



## thehatedguy

Granite or marble it looks like.



AVIDEDTR said:


> I miss my Vonschweikert VR-2100s and the Tower of Power sub. Anyways - can anyone tell me what are these layers:
> Best guess would be (left to right)
> *MDF/butyl compound/?????/Cotton acoustic Mat/Dacron*


----------



## AVIDEDTR

thehatedguy said:


> Granite or marble it looks like.


No wonder they weight a f'n TON


----------



## zorronj

I love VS, my system is VR4 Jr MK II front, LCR 15 CENTER AND VR2 SURROUNDS
Krell TAS,Onkyo 886 Home theater
Balanced Audio VK 150SE's VK 51 SE
Second system 4 VR1 and 1 LCR 15
Bedroom system 2 VR1's with a Mcintosh MA6500, Mcintosh MVP 861 and Sansui TU 717 tuner all powered with PS Audio P600, Acoustic Zen Satori's cables


----------



## briansz

A little progress on the design. I've scaled the cabinet dims based on the known size of the Fostex mid and roughed out the cabinet parts. Still to add is stone/damping, 3D approximations of the drivers, binding posts/plate, brackets to affix the front panel (I want it removable for testing purposes or configuration changes and so I can chamfer the back side of the hole for the Fostex driver). Drawn with the TB neo ribbon tweeter.


----------



## backwoods

To me, the weakest link in that design is the fostex driver. I love using the excel driver but not for that low end of an extension. 

Changes I would make if I was to replicate it myself and try to cut cost, I would use a fountek cd2 instead of the raven, which will save some serious dough and still have very good performance.

For the mid, that's really gonna be personal choice, but for a wide band midrange, I lean towards the jordan drivers over the fostex.

But, on the bottom end, there is a slew of choices. 

As far as tuning, if you are going active, the behringer combo will only do a part. To stay cheap, I would do a room analysis/phase correction with a pc then apply it to your media library. Saves the money of buying high end dsp with still solid performance.

If you love tuning, then give it a shot. But don't be surprised if after a month of evenings playing/tuning you still just aren't there...


----------



## Asdonk

hello

I am new to this forum because off this project
a few months back I was able to listen to the Unifield 3 speakers in the Netherlands
since then I bought a pair Fostex FX120 and build a simple 10 litre
cabinet to go with a tubeamp
now I will also build a cloned version of the Unifield 3
using a Fountek Neo CD3.0 crossing at 8 khz
and the Fostex FX120 in full range , with a Seas 18w001 crossed at
100 hz
I am following this project with great interest and at the moment I have ordered cabinets at Parts Epress in Gloss black with a curved shape


----------



## Asdonk

my resons why to go with this project

-the Fountek cd3.0 will do 40 khz, great with SACD 
=the Fostex will not have any crossover between 100 and 9 khz
and are great with voices
-the Seas 18w001 excel woofer in the small cabinet is better for
smaller rooms, I will use the 18wnx001, papercone with nextel coating
-I like the design of the Unifields 3
you can always use an active subwoofer


----------



## Deton Nation

Looks like fun GL with the project... And cant wait to hear your final listening impressions.
Mike


----------



## briansz

backwoods said:


> As far as tuning, if you are going active, the behringer combo will only do a part. To stay cheap, I would do a room analysis/phase correction with a pc then apply it to your media library. Saves the money of buying high end dsp with still solid performance.
> 
> If you love tuning, then give it a shot. But don't be surprised if after a month of evenings playing/tuning you still just aren't there...


I've been enamored with this idea for some time. How is everybody accomplishing it as a batch process with an entire music collection? I got some great info off the carputer sites as far as real-time DSP using things like kx and ufx, but have never found a good source of info on how to just create a correction filter and run all my files through it.



backwoods said:


> Changes I would make if I was to replicate it myself and try to cut cost, I would use a fountek cd2 instead of the raven, which will save some serious dough and still have very good performance.
> 
> For the mid, that's really gonna be personal choice, but for a wide band midrange, I lean towards the jordan drivers over the fostex.


Several folks have now suggeted the Fountek ribbons. Here's the short list of interesting drivers that I think could be made to work in a fullrange-plus-supertweeter system like this one:

Mid/Fullrange:

MarkAudio Alpair 6 - $70 each
MarkAudio Alpair 10 - $129 each
Fostex FX120 - $113 each 
Jordan JX92S - $205 each
Jordan JX125NG - $241 each
CSS FR125SR - $50 each

Ribbon Tweeter:

Tang Band RT-1516SA - $129 each
Fountek NeoCd3.0 - $89 each
Raven R1 - $250 each
LCY-130 Split Ribbon - $176 each


So many possibilities. With the exception of the MarkAudio Alpair 10, I think that all of the drivers above might be useable in my cabinet design. Once I draw in the stone panels and damping material, I'll start computing net internal volume and looking at predicted response/power handling. My gut is that I'll end up going with the FX120's and the TB ribbon, but I'll evaluate all of the above before deciding on the initial configuration.

The MarkAudio drivers are really interesting.


----------



## Asdonk

with the Fostex fx120 and the fountek cd3.0 you stay close to the original
design , being called a 

Dynamic-driver “augmented one-way” system utilizing a full range driver for “image lock” supported by a subwoofer and ribbon super tweeter


----------



## briansz

As I was hunting around for ribbons, I'd originally looked at the Fountek, but then got interested in the Tang Band unit instead as it seems to have flatter response within the frequency range I'd be using it - the graph is like a ruler from 9,000-22,000 Hz.

Fountek seems to show a large (5dB or so) peak centered around 16,000 HZ and a lot more variance from 9K to 20K. True, they cost $40 less each, but I can burn up $80 pretty quickly building a compensating network or having to deal with the frequency response gremlins via DSP (the value of my time).

Not denying that the Fountek is likely a very good tweeter, it just appears the TB unit measures flatter.

I'm not concerned about relative sensitivity or the like as I am planning on going active/bi-amping.


----------



## xxx_busa

I built these using nearly the same drivers amazing quality and sound the cabinets are a real pain in the ass

Acapella SEasThe non-


----------



## rexxxlo

briansz said:


> A little progress on the design. I've scaled the cabinet dims based on the known size of the Fostex mid and roughed out the cabinet parts. Still to add is stone/damping, 3D approximations of the drivers, binding posts/plate, brackets to affix the front panel (I want it removable for testing purposes or configuration changes and so I can chamfer the back side of the hole for the Fostex driver). Drawn with the TB neo ribbon tweeter.


sorry to steer the topic off but is this google sketch?

ive wondered how to do this sort of thing before can you explain?


----------



## briansz

It's just garden-variety AutoCAD 2008. You can input any image files and scale them, rotate them in 3-space, draw over them, etc. I just inserted various pix into the drawing and scaled them based on a known distance between points - the size of the Fostex driver. I then ended up with approximate cabinet dims that I used to draw 2D cross sections. I extruded those into 3D parts and assembled them into stack-laminated cabinets. I draw hardware this way at work all the time when I can't get a CAD file for it.

I still have to draw the individual drivers in 3D and come up with an approximate net cabinet volume. Then I can model the driver's behavior and decide if I want to modify the enclosure dims in any fashion.

Sketchup is something I've only done a little with. One of the architects I am working with now is sending me design concept drawings in Sketchup. It's very handy when trying to understand complex interactions, but you can do the same things in Acad. But Sketchup is a good deal cheaper (or free!)


----------



## backwoods

I do most all my cabinet designs in Cad as well. Rubber sheeting images is a great tool but accuracy sucks when you can only scale one of the smallest objects. Still should get you in the ball park though.

As far as converting media files, I need to take time and do a write up on how I handle it. I'm sure there are better methods out there then I use but it works.

I'm not online very often anymore, so I can't tell you when I will have it posted.


----------



## xxx_busa

My guess something like corrian like wilson uses on their product, I think they call it material X or something like that, I have done some small builds using corrian, I have a friend whom used to mfg the stuff so it was really easy to get nice size scraps. To bad the **** economy killed his business. I used my corrian on the outside of the cabinet though, I may have to try with the inside, I do have a bunch of odd colors, now I'm thinking............



AVIDEDTR said:


> I miss my Vonschweikert VR-2100s and the Tower of Power sub. Anyways - can anyone tell me what are these layers:
> Best guess would be (left to right)
> *MDF/butyl compound/?????/Cotton acoustic Mat/Dacron*


----------



## briansz

It's interesting, VS called that material 'synthetic stone' but it felt like natural stone as far as texture and damping properties. 

I'm familiar with and have fabricated ctops from Corian/Swanstone/Gibraltar/Livingstone, etc. and after touching it I don't think that layer in the sample is polyester based. it might be something like Quartzstone, but I've never fabricated it or other engineered stone materials so I'm not sure. I was just going to get some 2cm granite or other stone offal and cut it up with my angle grinder and a diamond blade.


----------



## Ga foo 88

Maybe you should check over on diyaudio, there are designs with a ff85k en + sdx7 and a fe167e + sdx7. Both designs feature an aperiodic loaded TL on the fullrange, and a sealed/ (ML?)TL for the sdx7. The fx120 is an interesting choice, not many fr diy'ers use them to my knowledge. But, it may be perfect as a midrange speaker.

search on diyaudio = Tysen FAST


----------



## Silver Supra

My Aerial 10Ts have a head made of a syth. stone type material called Novalith. 1" of Novalith has the same energy absorption as 3" of MDF!!

Here is a cool interview with Michael Kelly of Aerial about it. He mentions his A/D/S 300i/320i designs. I have called him and asked him to get back into the auto hi-fi world... very nice guy.

Stereophile: Home-Grown: Michael Kelly of Aerial Acoustics


----------

