Start at the start, Dave. Why did you do this thing?
Bass. Sub bass specifically. This is the story of how building a simple DIY sub blew out of all proportion. Because more bass is better bass, and the best bass is more.
B.A.S.S.
It also serves as an [im]practical guide how to hack together a fully working dub reggae inspired sound system in your attic. With the mere application of a few years, many hundreds of hours effort, and some £s.
To recap; The journey started here. I had almost no tools, knowledge or sense. But I had a shed, an attic and an internet. Which is all you need to build a sound system, it turns out. That, and a lifelong love of dub reggae and bass music. And whisky. Lotta whisky.
So, I had a sub as a starting point. Now I needed a vision. And that vision was B.A.S.S. …with the rest of a sound system attached to it. With scant regard to sanity, wisdom or personal freedom, I started reading everything I could about sound systems and speaker building. And made plans. Many, many plans. Like this:
Interestingly (to me) the system ended up looking and performing pretty much exactly as I planned it. Who knew. WAIT! mind blown… B.A.S.S = Build. A. Sound. System.
I digress…
I needed wood (fnurk). Turns out brand name DIY stores only stock really poor quality plywood. As I found out when building my first MVP sub. Why plywood Dave? Good question. Because MDF dust is carcinogenic. And plywood is prettier. But, as with just about everything in this project, it turned out to be much harder than you might first think (fnurk), to get good wood (gnurk). But I did. And it was glorious (gnargle).
One of the things about being an idiot, is that you learn how to cut unfathomably straight lines with fundamentally inappropriate tools. I built this entire thing using a cheapy jigsaw with some old blades that didn’t fit properly, with no jigs or guides – all freehand. I like to think of it as quintessential British pluck. Or idiocy – your shout.
B.A.S.S. – Yes, bass. I had a sub. It worked. It proved a principle, and it was ace. I knew how to build more subs. Problem was – drivers. I needed drivers. Drivers made from pure unobtainium. I mention this now, as I’ll come back to this story later. Spoiler alert – B.A.S.S.
A dub reggae sound system consists of subs (sub bass), bass (kick bins), mids (vocals) and tops (tweeters). All covering off specific parts of the frequency range.
I figured I’d work from the bottom up (Gnurgk). I wanted to design and build everything from scratch. Because being anything other than a complete masochist would be a cop out. I already had a sub, so I started with bass bins (kick bins). That’s when I realised I had bit off more than I could chew. So I figured I’d add some constraints.
My MVP sub used a little 6.5″ driver that made a BIG sound because of the clever chappies that designed the enclosure. Sealed boxes were simpler to build and more fault tolerant in their design. Perfect for numpties with ideas above their station, just like me. So I searched around for 6.5″drivers that might fit the bill. Using a couple of android apps that matched drivers to box volumes, I found Visaton ws-17e drivers. They were (crucially) cheap as chips, and even more crucially, available from a stockist less than a mile down the road from where I live… sweet serendipity.
Wait – android apps, box volume calculators… the actual f*ck?! What I hadn’t realised (before it was too late) was that to build speakers, you need a basic understanding of carpentry, joinery, maths, physics, sound engineering, acoustics, electronics, amplification and Thiele Small (TS) parameters (don’t @me, even now I couldn’t explain). The beauty of the internet is that you don’t need to know any of this stuff. Just find the right calculator[s] online, mash in the numbers with your pudgy meat sack fingers et voila – instant genius.
I’m not going to dive in to the technical details of the size and shape of these things. Keep it light and breezy, that’s the way (Leave a comment if you want to explore the nerd life). Suffice to say I built 4 kick bins – 2 bigger boxes and 2 smaller boxes, using the same drivers – to see what the differences were like. It was all a massive experiment.
Trivia – speakers are generally stuffed with wadding to stop unwanted frequencies reverberating around the inside of the enclosure and escaping through the driver – muddying the sound. The boxes you see above are all stuffed with polyester wadding. These are very simple, reinforced sealed boxes with a driver at one end, wired to a terminal cup on the other end (where you stick in your speaker wire from an amp).
Issue now was, how the hell do I funnel the correct frequency ranges to these things? I had to start buying hardware. And learn how to use it. And make somewhere to put it. So I stopped building speakers for a bit, and built an amp rack. To put my new amps and crossovers in.
Trivia – A passive crossover is a simple network of capacitors and coils, that allows certain frequencies to pass through a circuit, but not others. An active crossover is a piece of hardware (or software) that allows you to dynamically choose what frequencies are assigned to individual outputs. A passive crossover requires diligent planning, design and a strong knowledge of electronics. An active crossover costs £55 from Amazon.
At this point I had acquired three amps – one for sub, one for bass and one for everything else. I also had two active crossovers, because one went bang and I got a replacement. (you get what you pay for…). Proper sound systems have separate amps for each part of the stack, so I was keeping it real. At least that’s what I kept telling my wallet.
Then I started thinking about mids and tops. The tweeters turned out to be mercifully simple. You don’t even need to put them in a box as the dome is sealed. But I built some funky boxes anyway. Then threw them away and left them open. I used Monacor DT-300s with WG300 wave guides.
Because I had active crossovers and multiple amps, everything was essentially modular, so I could grow and test the system organically. For instance, instead of having the tweeters separate and everything else (vocals and bass) coming out of the kick bins (and sounding really muddy), I could use the smaller two kick bins as dedicated mids instead. With the vocals and mid-bass separated out, it sounded loads better. Separating out the sound so each different section does one thing, and one thing well was a win. Those particular Visaton drivers had a particularly wide, usable frequency response which allowed me loads of options.
Then it happened. Two Exodus Anarchy 6.5″ woofers came in to my possession. The drivers the original MVP sub design used, and pure unobtainium in the UK. Their story on its own is mental. Involving airline pilots, more air miles than Tyler Durden, layovers in Utah, San Francisco, New York, London, Kent and finally Bristol. 9 months I think it took in total to get them after I cheekily asked an American friend of my wife to buy some for me.
By that point I had run out of the juices (hrurk) required to build those bonkers tapped horn sub boxes (gneek). So I figured I’d use the last of my good wood (grurk) to build two more Mid boxes for vocals, and slap the two anarchy woofers in a plank. But hooked up to the amps so they could be broken in a bit. Which I did.
Everything was all getting a bit techno by this point and I was questioning what the f*ck I was doing with my life.
To the point where I damn near sold the lot and jacked it all in. Spoiler alert: I didn’t.
But I did have a long break from building stuff and did something more interesting instead. Though I can’t remember what.
Then it was time. I had come full circle. I had put together a fully functional (albeit rudimentary) sound system, but I was missing the final piece of the puzzle.
B.A.S.S
So I built two more subs. This was one of the most challenging things I’ve ever done. It took months. Blood, sweat, tears, the lot. What a journey. But boy was it worth it. I learnt so much. From building your own tooling and guides, through to sanding and finishing with amazing beeswax. All done with zero screws, all glued – for proper geek points. They are beautiful things, and provided I’m not a dick and blow the drivers, will last a life time.
So that was it, mission accomplished.
Or so I thought.
Turns out that with so many different elements, tuning it is a nightmare. Also, as soon as anything goes wrong, tracking down the issue is bloody hard. And don’t talk to me about wires. Never mention the wires. So. Many. Wires.
And then there’s my attic. Which is acoustically, a twat.
But I did it.
I. bloody. well. did. it.
There’s a couple of minor issues. One – I can’t actually listen to it. I have neighbours, and small children. It’s fecking loud. And one of the things about bass, is that it travels. Like REALLY travels. You know whales… gentle undersea leviathans? They talk to each other over hundreds of miles using sub-sonic low frequencies. Two – I can’t get it out of my attic. It’s too heavy, and too complicated to move. So I’m never going to really hear it at its best. Did I mention the acoustics in my attic are wack?
It IS very pretty to look at though.
And the kids dig an attic rave.
Additional 15th Jan 2020:
A DIY sound system is never ‘finished’. I ended up building a 4th tapped horn sub for a nice round number and putting a bunch of extra effort in to adding extra driver covers and making it properly nice to look at.
Which is nice. Because I rarely get to turn it on.
There’s always the thought “Maybe I should re-build those bass cabs to improve the [excuse to tinker more]…”
Update: Not sure if I mentioned this but I stripped and rebuilt the first MVP sub and built another sub (both with the 8 Ohm Tang Band drivers) so I have 4 x ‘Insubnia’ subs in this rig spread around the attic. It makes sick wubs, bro.
Dave Cropley 