Troels NOMEX 164 Build

[satx]

Hey everybody, This is my first time posting a build thread so let me know if I've done anything wrong or need to make changes. I started a thread a few weeks ago asking questions about this design.
Troels NOMEX 164: any thoughts - diyAudio

I had already read just about everything I could on this and a lot of other designs and was all set to order the parts to build it, but when the final bill was added up I decided I should get a second opinion. I didn't want to waste my time and money. In the end I decided to build them, but I was able to save a good deal based on the suggestions from the first thread. Thanks to everybody that helped me!

So please take a look at the photos of the build and please feel free to offer suggestions for improvement to these and future builds. Yeah, I think I'm hooked.


First thing I had to do was make a couple jigs because I don't have a table saw. I made a rip jig and a cross cut jig.


AND here's my first mistake. I assembled them with the back, sides and top and then added braces. It's hard to keep a lot of glue on the sides of the braces when it's getting scraped off by the sides as you slide then in. Worst part was I didn't think to do it differently until after the second box was assembled.
View attachment 315095
Could of used more clamps!
View attachment 315096
The braces are .5" birch ply plus I added 1" pine dowels between the braces.

 

[satx]

Sorry, I'm having a lot of problems uploading photos.


These go with the end of the first post.

 

[satx]

So, I guess I'll just post a couple of photos at a time. More that two or three and I get an error saying that a security token is missing.

.75"+.5" MDF for front baffle.

My new router; it was a revelation. I had never used one before.

 

[satx]

I used a maple veneer from parts express. It may not be the best, but I thought it was pretty nice and it's about $30 cheaper per roll than local. I used most of two rolls. I applied veneer then routed. worked great.


Used painters tape to protect the fragile points from the truncated Peerless frames.


Chamfered bass and mid drivers 45*

 

[satx]

I made a few changes to Troels recommendations to save a bit of money. Stuck to his values though to not alter crossover.

I made the bottom removable for access to the crossover. I tried a few different gasket materials; the foam you see here was too thick as was a 1/4" foam. I thought they would compress more than they did. I ended up using a rubberized electrical tape for the gasket. It's about 3/32" thick.

 

[satx]

I originally soldered the speaker wire to the crossover, but I didn't like it. I replaced it with hookup wire to european style blocks. It's much cleaner now and puts less stress on the components when I access the crossover.

Here's a shot with the tape I used. Verdicts still out on the gasket. P.S. I think I would use something other than hot glue next time. Not too strong in the end.

 

[satx]

I use 1.5" acoustical egg crate from foam factory instead of the 10mm foam called for. Didn't realize the discrepancy until I had already bought it. Also, Madisound Acousti-stuff top, bottom and behind each driver. I might try removing the stuffing from behind the mid driver since I used such a thick foam and see if it might give the mid range more energy.

 

[satx]

I cut fillets for the sides and top of the baffle so that I wouldn't have to route the flat edges for the truncated frames. I used Poplar strips stained an espresso. I was planing to use solid maple for the outside fillets, but was told that I would only be able to get rough. I made them out of MDF, put a 45* on them and then veneered them; it was a mighty pain in the a** because they are relatively thin.

The final speaker before finish

 

[satx]

Alright I got it to attach a few more photos.


Here is the mostly finished product. I wiped on a coat of clear de-waxed shellac, then brushed on 3 coats of clear Polycrylic, sanded between coats to 220 and rubbed on a wax. I think I am going to remove the wax and sand to 400 or 600 and re wax. I would like a smoother, deeper finish.

Port is not secured yet; it still needs fine tuning.


I was able to get some body out of the wood, but I'm hoping for more.

 

[satx]

Life could of been a lot easier with a table saw, but at least I have a chop saw for the 45*'s
One other big mistake I made was that I measure down on the baffle for driver holes without including the top fillets in the equation. So everything is moved down about 11/16" They are spaced correctly from each other though. Troels said the effect should be minor though. Sounds good to me, maybe verticle dispersion is affected though. Oh well.

In my rig. I use the Peachtree Nova for two channel with Apple TV and lossless files; MP3's actually sound pretty good through the Nova. Nova in HT bypass with Pioneer 1018 as processor for TV/movies.

And here they are next to the Kef iq5's they replace. They may look huge, but the Kefs are really small. I built the 40L version by the way so they are fairly deep.

And finally after spending almost two days trying to get REW to work, here is an impedance measurement. My port tuning is really low because I was using an online port calculator that seems to give longer than realistic lengths.
Also I am told the ripples around the tuning freq may be from a less that air tight enclosure. The only place that could be leaking is the removable bottom so I'll need to take another look at it.

Just quickly I'll talk about the sound. I know a lot of people don't think you should talk about sound, but when you're trying to decide on a DIY design you can't hear, a couple words on sound would be nice. So here goes.
They are still breaking in and this only refers to the NOMEX 164 in my room and through my system.
Compared A/B to the Kefs through a Sherwood stereo integrated (the only thing I had with A/B speaker outs), they are much fuller sounding than the Kefs. They bass is deeper and meatier, but even nicer is that they are fuller and tuneful through the lower mid range. I can really hear the woody body sound of guitars, stand up bass and violin. Electric guitars sound much nicer too. The highs are smooth and clear and shimmery and vocals and piano are very clear and natural. I have adjusted the L-pad a bit to attenuate the tweeter a bit more and it did make them even smoother and easier to listen to, but I am still deciding if it makes them a bit boring. I'll have to listen to them some more and run some different kinds of music through. Also, I need to adjust port and maybe play with stuffing to get a better idea.
Anyways, they are richer, fuller, clearer and less grainy than the Kefs. They are a lot nicer and easier to listen to. And I like them

Thanks for looking and enjoy!

Evan

 

[satx]

I was typing in a hurry and attaching photos took a lot longer than expected, so please excuse any typos and if I missed anything or glossed over anything please feel free to ask questions. I would also appreciate any suggestions.

Evan

 

[pguerin]

Hi Evan,

I think you have learned a lot from your build and it's a success
Enjoy

 

[satx]

Hey Pascal,

Thanks man! Yeah I learned quite a bit, mostly thanks to people on here like you, but also from some of the mistakes I made. All in all I'm really happy with them.

Thanks again for the thoughts on how to tune them further. I really had no idea about how to adjust L-pad or port. I'm learning.

Evan

 

[marc brown]

Thanks for this build thread. Certainly gives me some inspiration. I'm still deciding which of Troels' designs to build but I'm 90% set on the 164 Nomex.

 

[satx]

Sure thing. Glad you stopped by.

For the money invested they are great and look great too. Very, very smooth sounding and also detailed with great tonal balance. I've since started to like a bit more sparkle in my speakers. I still recommend exploring the lpad adjustment the Pascal helped me with, but this really depends on your front end and room. I like the fact that the 2-10K region is reduced just slightly and then I added a supertweeter around 10K. It really brought excitement with no extra brightness, it also raises the image some and somehow makes the bass more tuneful... or that's in my head.

Anyways, if you decide to build them and have any questions just stop by. Also, take a look at the thread I started before I decided on these; a lot of good advice on there.

Here's a pic of the supertweeters I built.

 

[marc brown]

I like what I hear about Troels' designs having a laid back sound etc. I never enjoyed a Thiel-type sterility. My front end is all solid state so no tubes to tame a harsh top end. I'm running a Technics SU-9070 into a Citation 19 power amp. Analog and digital sources with my laptop streaming FLAC files through a HRT DAC more and more. I've got a nice EQ if I need to do anything drastic with the sound. After spending half a year with the Nomex's I'll decide if I want to play with the two resistors in the tweeter circuit.

 

[satx]

I like what I hear about Troels' designs having a laid back sound etc. I never enjoyed a Thiel-type sterility. My front end is all solid state so no tubes to tame a harsh top end. I'm running a Technics SU-9070 into a Citation 19 power amp. Analog and digital sources with my laptop streaming FLAC files through a HRT DAC more and more. I've got a nice EQ if I need to do anything drastic with the sound. After spending half a year with the Nomex's I'll decide if I want to play with the two resistors in the tweeter circuit.

So you've decided to build them? They shouldn't disappoint. Really nice drivers for the money and Troels definitely knows what he's doing.

Yes, I'd recommend waiting a while to adjust the lpad. I wasn't so patient. After about 40 hours, some female vocals and piano still had more bite than I wanted. I've thought about trying the original values again, but I just haven't gotten around to taking out the crossovers.

BTW, I tuned mine (40L version) to 40Hz instead of the 45Hz that Troels calls for. They have plenty of smooth, strong bass like this, so something you may experiment with. Easy enough to do. It gives it more of an extended bass shelf alignment.