Wilson Audio Duette / Custom Crossover Upgrade


 

Stereophile review from 2012:
https://www.stereophile.com/content/wilson-audio-specialties-duette-loudspeaker

Specifications: Two-way, reflex-loaded bookshelf loudspeaker with separate crossover enclosure. 
Drive-units: 8" cone woofer, 1" silk-dome tweeter. 
Sensitivity: 90dB/W/m/kHz. (Note: Look at this spec compared to the measurements below from Danny at GR-Research)
Nominal impedance: 4 ohms. Minimum impedance: 3.96 ohms at 3.1kHz. 
Recommended amplifier power: >20W.
Dimensions: 18.4" H by 9.4" W by 13.75" D. Weight: 39 lbs.
Finish: Automotive paints in non-metallic black, Diamond Black, Dark Titanium, Desert Silver, and Argento Silver Twelve.
Price: $13,900/pair plus $1795/pair for matching stands. Approximate number of dealers: 50.
Manufacturer: Wilson Audio Specialties, 2233 Mountain Vista Lane, Provo, UT 84606. Tel: (801) 377-2233. Fax: (801) 377-2282. 
Web: www.wilsonaudio.com

"Overall, however, the Wilson Audio Duettes produced a sound that allowed all the music I listened to during my visit to communicate very effectively.—John Atkinson"

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I own a pair of Wilson Audio Duette speakers. I found a pair after hearing them at a buddy’s home, who also owns a pair of Wilson Audio Alexia. I thought they were different, cool... sounded BIG. I like 2-way speakers... why not?

Living with them... the Duette are extremely "resolving"... so much "resolution" that I found I needed to listen to them way off axis... speakers spread far apart / pointed straight ahead. With it being a 2-way with 8" woofer, it’s unique. It plays BIG, and is well made... except for the crossover, and the fact that it wants to melt my face.

So, what to do? Well, I sent one of them to Danny Richie at GR-Research. I’ve dealt with Danny before and it’s been a pleasure. One thing Danny will do is measure the speaker you send him, tell you what’s wrong with it, and design a new crossover for it - for Free. There’s no fee for that... you just buy the parts from him and you get a schematic. Fair deal, no doubt.

What Danny found with the Duette is eye opening. The reason the speaker sounds so forward is because the crossover was designed with no baffle step compensation. See the measurements below and the big variance between the low end up thru the midrange volume / highs and explains why they sound so FORWARD and IN YOUR FACE.

So, a new crossover was designed... here is how that has turned out, so far. One issue with the front baffle of the speaker is actually the foam on the front, that is meant to "help". The circular cutout for the foam (not the felt around the tweeter) is contributing to some diffraction / unevenness. I’m going to play with building up the area around the tweeter to smooth that "step" on the front baffle. I’ll measure the difference and see if it helps.

New Measurements for the crossover designed by Danny Richie:

Old Vs New Crossover Measurement

 

New Crossover Driver Response

Spectral Decay

 

Issue with the foam around the tweeter...

Another "Interesting" thing... there are 2 different umbilical cords for attaching the external Novel crossover to the Duette. The manual states the following about their use, and threatens warranty coverage if not used properly:

 

Umbilicals in Question... one for use with "Free Space" resistors and the other for use with "Near Wall" resistors. Different resistors are provided to adjust tweeter output.

So, Danny measured the 2 different umbilicals, to see whether there was a difference. Well, at least in terms of sound... there was ZERO difference.

The language in the manual and this measurement was disappointing, to be kind.

So, on to new crossovers. They are currently being built. I am going to make a custom enclosure for them as they will remain external from the Duette enclosure, like the original design. There will be significant differences in how they connect to the Duette, their orientation, etc. Here is the progress:

 

jim2

Yeah good to hear. I have no skin in the game either way but I am a believer in measurements and I am sure the results show that with these speakers. The details can be subtle but it is important to understand those subtleties if you want to apply measurements. 
 

I do wonder if the same thing could be achieved using software like REW to adjust the frequency. I don’t know if changing parts or adding software would result is more signal transparency. 

So, originally I planned to put the crossover board on the base of the stand.  Well, the board is just slightly too big for that, and the wires from the board are just a little too short.  Plus, I didn't like the way it looked.  Then it occurred to me... Where is the Novel crossover going to be?  On a shelf?  In a closet?  "Lost"?  That unit needs to stay right there, in a safe spot.  So, the current plan is to cut some clear acrylic and mount a right angle piece to the backside of the column with double-sided, adhesive velcro, hidden from view and able to support the front of the board.  The back of the board will be supported by another piece of right angle acrylic.  To support that?  Well, we have a ton of fasteners on the back of the Novel crossover to help with that!  It will keep it all as one unit-ish.  

The wires coming out of the crossover to the Duette will have heat shrink, to tidy them up a bit.  The colors will be Tan and White. 

TAN = "T" = TWEETER

WHITE = "W" = WOOFER

The OEM Wilson umbilical has one of the umbilicals in brown, and I think it looks good... different.  So I think this will work out pretty well. 

And everything I'm doing is nothing permanent... so if one day these find a new home, the owner can have the flavor they wish.  At this point, it is highly unlikely they will be leaving my possession, even though other speakers will pass thru. 

Well, that's the plan for mounting the crossover... so far... this evening... This picture has the board spaced up with the books covered so I can see if it looks "right".  

@james633 

I do wonder if the same thing could be achieved using software like REW to adjust the frequency. I don’t know if changing parts or adding software would result is more signal transparency. 

I have a UMIK microphone and miniDSP... have not played with either. I have all Ayre front end... QB-9 Twenty / KX-5 Twenty / VX-5 Twenty.  Balanced / Zero Feedback.  There is a magic to that equipment that I love.  I am skeptical of putting a miniDSP device into the mix to run the entire range.  Playing with a sub?  OK.  Playing with a tweeter... I guess I wouldn't know until I tried it, but this path is working out well, so far.  

As for the idea of "adjusting the frequency" in general, I am all in on a great 2-way supplemented by subs, which can be tuned for the room.  Lower cost, full range sound, with the ability to tune the low end for the room.  It seems to me that when you go up a range in any speaker line, you are buying more low end... a low end you often are stuck with being unable to refine based on the room / placement considerations. 

I think a great 2-way with dual subs resolves that issue... at least it is for me.  And with this special 2-way with an 8" woofer... I've got scale that makes me chuckle at the thought of buying a Wilson sized refrigerator speaker... as if I were willing to devote that much capital to the idea anyway.  

This plan is working well for me, so far. 🏁

I think all speakers needs subs. Even large super speakers do best with subs for room tuning.
 

When I heard the duette the standout was how large and dynamic they were for a small speaker. Wilson is general is good about that. I don’t follow wilson much these days as their prices have just gotten silly imo. My 2 ways use 15” woofers so I guess I am in the two way camp with subs lol.  
 

I don’t have strong options about active solutions for passive ones like the crossover rebuild. I think with software and measurements, things can easily be tuned or corrected these days. I have felt that in a very highend system there is a bit of transparency lost in the digital adjustment domain but the same can be said about adding complicated crossovers. I also don’t have strong feelings about the mini DSP. I question if the output stage is good enough for highend systems (inline with the mains, not just subs). I would love to see more quality crossovers systems on the market. I think people not using a proper highpass system are really missing out on the potential it can bring. 

@james633 

I would love to see more quality crossovers systems on the market. I think people not using a proper highpass system are really missing out on the potential it can bring. 

Ayre Acoustics has high pass crossover input boards for a few models.  I have these for my Ayre VX-5 Twenty.  They are a high pass at 100Hz, and are a common thing for use with Vandersteen speakers.  I don't have them in the amp right now, but will use these with other 2-ways down the road, if needed.  I have a pair of Merlin Music VSM speakers that I'll be playing with soon, blending with subs, etc.  High pass filters can also be built for insertion before the amp that will do the same thing.  The input impedance for the Ayre VX-5 Twenty is 1M Ohms, so the caps can be very small.

 

 

Link: High Pass Filter Construction

http://www.troelsgravesen.dk/High-Pass-Filter.htm