As of June 2023, the third incarnation of the Rolling Lion Hi-Fi was finished, with an updated Cubo15 (extra extended) subwoofer design, an additional 12″ Paraflex kick, and 2 brand new mid-tops! I’ll begin with the most recent construction and work my way to the initial build towards the bottom.
New mid-top designs (June 2023)
So, after trashing (or should I say crashing?) one of my two tweeters in 2022, and then the other one in April 2023, I began to think about redesigning the mids and tops into one, more efficient cabinet. As I had been using Eighteensound drivers from the beginning, I had a look on their website and found just what I needed – a compact, 2-way point source speaker which could play down to 100hz! So I ordered two new 1″ drivers (ND1030), and using the 8″ drivers (8NMB420) I already had, as well as the XT120 horn flares, I began construction on my new mid-tops! I also added some Visaton damping foam to the insides of the speakers, and some rubber feet to the bottom.
Paraflex G#1 (12″ kick)
In the meantime I had also been looking at some Paraflex designs, and decided to build a G#1 kick to go between my sub and new mid-tops. So I ordered a new Eighteensound 12ND930, went to the construction store to pick up some new sheets of 15mm Baltic birch plywood (which is widely regarded as one of the best materials for speaker construction), and got to work! Admittedly, I built the Paraflex speaker as much for the added functionality to my system, as for the fact that it would raise the height of the mid-tops another 35cm (and because I just like building new stuff!). I was quite happy with the way it turned out! It adds some nice punchiness to the mid-bass, and although it can be a bit much in some of the roots tunes I play, it works really well for drum & bass, jungle, dubstep and UK steppas!
New Cubo15 (extra extended)
With those finished, I decided to overhaul my Cubo15 design as well, as it was the first speaker I had built, and thus not as well constructed as it could have been. When I had built my first one I was using a handheld jigsaw, and screws to hold everything together, and don’t think I initially even used wood glue! Over the past 3 years I feel like I’ve substantially improved my woodworking skills (learning by doing!), and felt it was time to take apart* my old Cubo and rebuild it! With a proper table saw now on hand, I was able to make much more precise cuts, and nearly eliminate the need for excessive sanding and occasional wood filler. I had originally built the Cubo15 “Standard” as I hadn’t seen (or known) then, that the driver I had purchased (basically on a whim), had a Qts * Vas value of less than 50, and was therefore suited for the “Extra Extended” version.The difference was astounding! The lower frequencies were now much warmer and fuller, and most importantly without many unwanted resonances.
All speakers were built using 15mm Baltic birch ply and no screws (wood glue only from now on!), with recessed ports for the speakon plugs, rounded edges and an Osmo high solid wax oil finish! I added protective speaker grills to the mid-tops and Cubo, using perforated steel sheets (hexagonal, 1.5mm) and Adam Hall speaker foam.
The original build… (May / June 2020)
I began by scouring the internet for different plans (“Speakerplans Forum” and “12v Sound Systems” Facebook group have both been great resources!), and eventually settled on the Cubo15 design – a 62cm cube powered by a 15″ driver – which would amplify the lower frequencies between 40-100 hertz. After asking a lot of colleagues about other recommended designs for the mid / top sections (and receiving various responses from everyone I asked!), I decided to just start on the Cubo, and then build the other sections according to my own vision of how I wanted the sound to look! I could have spent months researching different aspects of sound design, frequency response and whatnot, but as a practical learner, I decided to just begin the project. After all, sound systems are a constant learning curve, and there will be plenty of time to learn about the various aspects and make any necessary adjustments to the design!
How did you construct the rest of the sound system?
After I finished building the Cubo15 – using 15mm birch ply, I installed the Eighteensound 15ND930 15″ driver I chose to provide the low-range frequencies. Although the original design calls for 18mm birch ply, I decided to use 15mm to cut down on some of the weight, and used the same wood for all cabinets. Next I built a custom designed mid-cabinet (62*30*30cm) which houses 2x 8″ drivers (Eighteensound 8NMB420), providing the mid-range frequencies between 100 – 2,000 hertz. Then came the top-cabinet (62*20*20cm), which houses 2x 1″ compression drivers (Eighteensound HD1050) attached to “horn flares” (Eighteensound XT120), thus providing more balanced sound coverage. Once everything was built, all drivers and speaker ports installed, all connections glued and screwed, it was time to give the wood a nice finish. I chose an all-natural wood glaze (Deutsch: Holzlasur), with an Oregon Pine tone, which gave the wood a slightly darker, orange hue.
Afterwards I built a simple cabinet to hold all of the various components and cables, battery, amplifier, DSP and capacitor, and also added some hexagonal speaker grilles and protective speaker foam to avoid any dust or damage to the drivers.
A Bass Odyssey 