While I do like the hexagonal speakers, they do have in hindsight some odd driver choices. I'd like to make another set of speakers that correct these and other problems.
There are several options available for what to do:
These speakers are an unsymmetrical hexagon (a truncated triangle?). I wanted to reduce the reflections between opposite sides of a typical square box, and also the largely triangular shape allows for the speakers to be angled easily while being against a wall. It also allowed for a neat transmission line cone shape to exist in 3 dimensions, instead of the usual 2-d in most square box designs (often a folded 'cheese wedge'). I naively thought I'd enjoy the woodworking challenge. I did not. These were built circa 2014-2015 in the Nottingham Hackspace in Sneinton.
Unfortunately, they sounded very underwhelming when I tested them out. While sticking with a 2-driver design, I had massively overcompensated for the lack of bass in the red box speakers, and chosen a bass driver meant for PA applications [8]. The tweeters [9] were well reviewed though! While the frequency reponse calculations I did in Excel showed that there would be enough overlap, in practice they sounded pretty dissapointing. I resolved to modify them by adding a mid-range driver [10]. This involved relocating the tweeter to a new cone in order to make space for the midrange. The end result looked much better than the originals! Doubly unfortunately, they still didn't sound great as modified. It was only when I purchased a graphic equaliser [11] that I was really satisfied with the sound they delivered. It only took 8 years!
These were my GCSE design and technology (D&T) project in school year 11. They are based around four midrange Audax ___ that my dad gave me. I bought some tweeters [12], and got drawing!
At the time, these were a huge improvement compared to a little Sony all-in-one stereo [13] I had as a teenager. However, they (predicably) lacked bass response. Eventually I got a subwoofer in the loop , but they still didn't sound anywhere near as good as Dad's speakers. I was still proud to have built something myself, especially with a meaningful crossover. I connected them to my computer and hearing in-game sounds through 'real' speakers instead of little plastic computer speakers was pretty epic. One of the things that highlighted the lack of bass response was this back-to-back comparison to a friend's 5.1 surround sound computer speakers, which had a pretty capable sub.
For a long time I lent these to my brother to use in his flat, however he never set them up. In 2024 I planned to set these up in the kitchen to compliment my hex speakers in the living room, so I could have both on while cooking.
These unique brown obelisks were my earliest memory of hi-fi audio. They towered over me as a child; I fondly remember (very carefully) putting CDs in the player and choosing my favourite Michael Jackson songs. Despite the reverence for records and CDs, curioisity did finally get the better of 8-year-old me as I one day poked-in the dust cap on one of the woofers. Whoops. My dad build these ugly boys circa 19xx, and one at a time. My mum recalls listening to music in mono for quite a while before the second one was completed! Another consequence is that they were significantly different sizes. They had no crossovers, simply a high-pass capacitor to protect the tweeters; the woofers were driven with full range.
Around 2010 one of the KEF bass drive units [15] burnt out, so the cabinets were tossed. I salvaged the remaining good drive units, initially earmarking them for a home cinema centre speaker.
Aghast at the cost of a separate streamer (even a basic decent iFi Audio ZEN Stream is £300!), I thought I'd put together my own using a Raspberry Pi 4 I had spare. Previously I had been using a Google Chromecast Audio to listen to Spotify, but this wasn't capable of playing music locally stored on the phone through the Apple Music app.
I thorught it would be cool to have a small screen on for displaying album art, and ideally a device with optical digital audio-in. This would allow a modern DAC to be used with my existing CD and MiniDisc deck, turning them into a transport rather than a player. As an aside, this means I can use any old CD or MD as long as it has a Toslink output. I bought a 'HiFiBerry DAC+ DSP' hat for £83, which met all these needs. For an OS it runs Moode Audio, a specifically designed package for RPi streamer projects such as this.
It works pretty well, the only issue I have is that sometimes at ~50% volume or below the really quiet parts of a song will be cut off. There is basically a minimum volume limit. Maybe some sort of noise reduction happening, but I've not managed to find any discussion about it online.
Foolishly I also bought a HyperPixel 4.0" Square screen. I knew it connected to the GPIO pins, but I assumed there would be some way of connecting it either to the HDMI or SPI interface, or maybe that the DAC hat and the screen didn't use the whole set of GPIO so that I could still connect both. It turns ot it can't. This RPi 4 was originally set up as a HTPC, but didn't have the grunt to handle high-quality 4k content.
I love minidiscs. I remember a friend-of-a-friend Takenori 'Jack' Kimura having one at school in 1999. I hadn't even properly had a go on a personal CD player at this point yet, so seeing a portable minidisk with in-line remote was a very powerful experience. The 'my first Sony' tape player I'd used since being a child, this was not.
[8] Emminence Gamma 12.
[9] SEAS H 882.
[10] SEAS H1304.
[11] Behringer ULTRAGRAPH PRO FBQ6200HD.
[12] (tweeter model).
[12] Sony CMT-CP2WA
[14] Monitor Audio Radius 360.
[15] Possibly SP1014 B200A?