Norwegian Wood Bookshelf Speakers by Juan Macchiavelli, First Place winner in the “Open Unlimited” and “Fan Favorite” category at the 2026 Open Speaker Design Competition.

“I used to have my own amps and speakers shop for musicians back in Argentina, and right after I arrived in the States, I went to Parts Express and found out about the speaker design competition. I’ve been hooked ever since — it’s letting me channel my speaker freak/musician energy in a positive way.“

Project Level: Advanced

Project Time: 20+ hours

Project Cost: $100 – $500

Project Description: Mid-size 2way with good directivity control.

Design Goals: The idea behind the Norwegian Wood: inspired by the 2 way designs with good directivity control we found at AXPONA 26, I decided I want something like that. I went for the regarded Dayton rs180 because being a 6.5 inches I can repeat the AXPONA recipe and have a reasonable size bookshelf.

Driver Selection: Dayton Audio RS180 4 and Wavecor TW022 (with no faceplate). The design is compatible with the LaVoce TN100 but with higher distortion in the Tweeter lower octave.

Enclosure Design: The RS 180 it’s nice and I was expecting that. The inductance is so low! The aluminum cone gives life to the mid range and can play low enough for my taste. The unexpected surprise is that the impedance goes down to 2.4 ohm (*). That makes my class ab amp run too hot. At this point I thought why not go for it, and DSP her? Those class d amps can handle low impedance and also the DSP thing is in my bucket list.

Since this was meant to be a good looking speaker with promising specs, why not once and for all go all in and make no compromises in the budget? I read reviews about the peerless da25tx corundum. So I gave them a try. They measured flat as they come of the box with a simple filter. I guess this is what you get when you pay more! But that push me to not let my acoustic lens ruin that performance. I couldn’t get rid of that nasty dip around 10 to 13k depending on the throat design… That’s what, in the end, lead to try a couple of 25mm tweeters with no waveguide: lavoce TN 100 and wavecor tw022. The tn131 was the hero behind the hateful eight’s great imagining (PE Speaker Design Comp 2025 edition). Those can go very low for a 30mm tw and with the 8″ eminence cone as a waveguide, worked very well. My goal is again to cross as low as possible to improve imaging and avoid the nasty break up of the aluminum cone. Although both tweeters work very well, this time the wavecor jump at front with a very low distortion at low frequency, so 1.8k is the Xover.

The tuning frequency is 42hz in a 19lts cabinet. Maybe too low, but this set up let me get away with it.

Months before this, The Eggman (Clay) tasked me with getting “the Gypsy speaker” working. And with it came the Dayton 4100. Special thanks to him!

The next challenge is to make it play like this but passive. It’s doable because the design makes things easy. 6.5 + oblate spheroid = success. Of course impossible tasks without a CNC and patience.

*Eventually, thanks to Blaine, Chris and the Tech Support guys, we know than mine were some anomaly and the current stock is fine

Enclosure Assembly: CNC finger joints clamps and glue. The baffle is locked in place by a perimeter recess and polyurethane paint. Everything comes out from 2.5″ and 1″ ash slabs.

Crossover Design: SigmaStudio, 24 dB/octave Bessel filters at 1800Hz

Conclusion: I got the sound I wanted, by controlling directivity.And the process led me to take on new challenges, which feels great. But anyway you could cut some corners and try this same design! There are great waveguides to achieve this here in Parts Express ( like the Visaton WG 148 R Round Waveguide for 1” Dome Tweeters Part # 292-768) so you could build a simple MDF box and reach the same sound. The Dayton RS180 it’s not expensive considering it’s performance.

Tips & Tricks: By using the Omnimic 40K you can know the precise location of the acoustic centers, which is very useful if you want to try your own waveguide design.