[russellberg]

Well this is my fourth GR Research project and the first time that I have used a flat pack.  The precision of the work and the care that is invested in the packaging was immediately apparent.  This is very precise and careful work.  I had bought a Wagner Flexio 3000 sprayer because I wanted to have that smoother sprayed on finish.  I started by taping the dadoes and the edges of the braces.  This would maintain a raw edge where the glue was going to come into contact. 


It turns out that if you centre a piece of ¾" painters tape over the edge of the brace the overlap is almost exactly the depth of the dado so you don't end up with unpainted gaps on the edge of the braces.  I then painted everything with Zinsser primer.  I have found that a good primer is essential for painting MDF.  I hand painted an extra coat into the exposed edges of the MDF so that I could sand it down before I sprayed on the first coat.


I really didn't want to be painting inside that tight cabinet and this left me with a pretty good finish inside with out drips or runs.  After I had put on two coats of primer I hand sanded and then began painting the flat black.







After everything was dry I pulled off all the tape.



Then it was time for dry fit and glue up.



The precision of the parts from Jay means that you don't need a lot of glue, or even that many clamps considering the complexity of the glue up.





I then painted the exposed edges with primer and then sanded them to get a nice smooth finish.  Been messy with the paint brush didn't matter too much because this was all going to get another coat of paint with the sprayer.

[Early B.]

Impressive work, sir.

[kickngas]

Great job! Thanks for the tips.  I will be doing the same for my Otica's soon.  Are you going to veneer the sides and front baffle?

[russellberg]

Great job! Thanks for the tips.  I will be doing the same for my Otica's soon.  Are you going to veneer the sides and front baffle?

Nope, I am going all black.

[sortner]

Great job- Speakers look great, man you are in for a treat! I built these with the tripples,  blown away every time I fire them up.

Jay's flat packs are top shelve, would love to see them (pictures) on the web sight!

Cheers,

Steve

[kickngas]

Can you please share which specific primer and paint you are using? Thanks! I am looking at the Wagner Flexio's now 😉

[Endo2112]

Great job indeed!! I love/miss those speakers, they do so many things, so well, like a desert island speaker

Enjoy,

Don

[Captainhemo]

Hey Russell,  nice to see them coming together, as Don mentioned,  you're  going to love  these  guys.

Great job- Speakers look great, man you are in for a treat! I built these with the tripples,  blown away every time I fire them up.

Jay's flat packs are top shelve, would love to see them (pictures) on the web sight!

Cheers,

Steve

Steve,  thanks for the feedback on the  flat packs   Yeah,  would be nice     to once  again be on the  GR Research website....  We've been supplying these cabinet since their introduction along with the  rest of the NX  series,  the Super Series  when it  was previously available, and ofourse ,  our beefed-up version of the  OB servo sub towers from   duals to  6  stacks in both solid and modular  desings for over  6 years.....
Anyhow, looking forward to seeing more progress Russell  !

jay

[russellberg]

Can you please share which specific primer and paint you are using? Thanks! I am looking at the Wagner Flexio's now 😉

The primer I used was Zinnser Bullseye 123.  The paint was Home Depot Behr Ultra Scuff Defence matte black.   I watered the primer down about 10%, it is pretty thick.  See the post below, I did run into some odd issues.

[russellberg]

I painted everything in my garage that is heated only periodically by space heaters.  I left the heaters on to allow the pain to cure but then they sat in the unheated and damp (Pacific Northwest), garage for about a week.  When I next went to check on them they had these weird discolourations.  I almost looked like milldew but not quite.


These markings where all over the speakers in different places.  Anyone seen this before?  I rubbed them down with a dry cotton rag and it almost completely came off.



I am going to let them sit for a few days inside and see what happens.  If it comes back I will assume its milldew and sand it down and repaint.  They are stored inside the house now.  Aside from the weird stuff on them I am happy with how the pain job turned out. 


Now I'm just waiting on parts    

[kickngas]

Thanks for the paint/primer call outs. Yeah, that looks like mildew, hope you get that sorted. Like you, I am also awaiting parts, I ordered early November. When did you place your order and when are you expecting delivery? Good thing I am in no hurry!

[Peter J]

Under humid conditions water-based home paint can leach ingredients to the surface. This describes it better, methinks:

https://www.benjaminmoore.com/en-us/contractors/job-solutions/troubleshooting/surfactant-leaching

Mildew is mold. It's not mold.

[russellberg]

Under humid conditions water-based home paint can leach ingredients to the surface. This describes it better, methinks:

https://www.benjaminmoore.com/en-us/contractors/job-solutions/troubleshooting/surfactant-leaching

Mildew is mold. It's not mold.

Thanks so much for the info.  Im sure that's what it was as it wiped off so easy.  Milldew does not come off this easy.

[russellberg]

Thanks for the paint/primer call outs. Yeah, that looks like mildew, hope you get that sorted. Like you, I am also awaiting parts, I ordered early November. When did you place your order and when are you expecting delivery? Good thing I am in no hurry!

I ordered second week of December, (My Christmas present ,  they haven't given me a date just, "when the inductors and tweeters arrive."  I get it, they can't ship what they don't have.
-Russell

[russellberg]

Well the parts finally got here last week and they are now finished!  I started with mounting all the drivers then I set up some padded blocking so I could lay them down on their fronts without damaging the drivers.


These diagrams from Rock Ball where so helpful.  I couldn't read a schematic to save my life.

Check out his build post for the rest of them  https://www.audiocircle.com/index.php?topic=169168.0

Keeping everything straight with masking tape labels was essential for me.


Now it was time to face my fears and start wiring the crossover.  This was my first attempt.


I got some wonderful advice from the community https://www.audiocircle.com/index.php?topic=182643.0 here and I made some changes to end up with this.  I didn't follow their advice exactly so any mistakes are mine.  I am still open to advice to changing it.




I plugged it in and to my immense relief everything worked!!  (If at first you do succeed try not to look too surprised.
Wiring the first speaker took me almost two full days of going back and forth over the diagrams, other folks' pictures and reading AudioCircle threads but I got it done.
The next speaker went much faster and last night I got to llsten to something amazing that I built.  That is so satisfying.  I played pink noise through them all night and even those 10 hours of burn in has already made a big difference.

I am really happy with the flat black of the finish.


I know that my room setup is far from ideal but I didn't really understand what sound stage was until I heard these.


This tweeter is unbelievable.


The only thing I haven't done yet is put the NoRes in.  Any thoughts on how much of a difference it makes?  I don't really like the way it looks but I am prepared to install it for a significant increase in sound quality.


For those who have been concerned about using NX-Otica's in a smaller room mine are in a 13x13 basement room.  As you can see in the pictures there is another room behind that perhaps gives the Oticas room to breathe.  I will give a fuller description of my impressions of how they sound a little later once they have had time to burn in properly. 

[corndog71]

Nice job!  Yeah, don’t skimp on the NoRez.  It makes a big difference.

[russellberg]

The big wings are intended to be on the inside, right?

[Tyson]

I know that my room setup is far from ideal but I didn't really understand what sound stage was until I heard these.

Haha, I know exactly what you mean.   

The only thing I haven't done yet is put the NoRes in.  Any thoughts on how much of a difference it makes?  I don't really like the way it looks but I am prepared to install it for a significant increase in sound quality.

I didn't think Norez would make much of a difference in my Super 7's, after all, it was just the bass section, how much difference could it possibly make down there?  Well, a lot, actually.  Definitely put in the Norez on your speakers.

The big wings are intended to be on the inside, right?

Correct.

[russellberg]

Thanks Corndog and Tyson, I think Im going to install it.

[russellberg]

Well I am finally finished.  I did put on the no-res and it is very effective.  At first I was very happy, having never heard anything near as good as these Oticas.  I was attributing a softness in the upper range to break in but then I measured my room and there was a significant drop off above 2K Hz so I knew I was having trouble somewhere.  I suspected that I had made a mistake with the crossover as my understanding of electronics and schematics is elementary at best.  Danny and I went back and forth on email but I just couldn't get it so I called him and he patiently explained to me what I had done wrong.  I made the changes and wow!  They just came alive!  It was such a revelation and a relief. 


I also turned my room around as the previous orientation with one speaker having a wall 3 feet behind it and the other 12 feet in front of the wall was not working well for sound stage.  This setup is by far giving me a coherent and focused sound stage.  I have them 40" off the front wall and 36" off the side walls.


I also made myself a new component rack that I am very happy with.  Each shelf is two pieces of 3/4" Baltic Birch laminated together and edged with bird's eye maple.  It is very solid and resistant to vibration.  I use a seismograph app to measure vibrations and this design is very inert. 


The fact that it weighs pretty close to 130lbs helps as well.  I used gas pipe flanges and pipe for the second shelf for a little visual variation.  The wooden vertical supports on the bottom shelf are attached with dowels and glue.  I'm very happy with how it all turned out. 


I finally fell like I have reached a bit of stopping point.  I am so happy with this system and the sound that it is giving me.  It is alive and full with a level of detail that I have never experienced before.  It is something so remarkable that Danny gives us the tools to be able to build these remarkable speakers that open us to a whole new experience of music.   To say nothing of how cool it is to be able to listen to something you built yourself.  I want to thank Danny, Jay, Hobbs and so many others who have posted thoughts or suggestions in my many GR Research journeys.  This is a special place.  Thank you all.