So in the device the bottom compartment contains a 12v PSU. Mains voltages here, so it’s fully enclosed. There’s a fan as well, although I doubt it’ll be needed. The middle contains three stereo TA2020 class D amps. The top has an external HD and the sound card.
In situ the PC is on top, so I can access the power button, and you can see the volume controls for bass, midrange and treble. I was going to oil it, but I think I’ll have to paint it white sometime*
The next step is to measure the speakers as they are, with the passive crossover. Then I will bypass the crossover and go digital.
The advantage of deciding to host a few people here is that I pull my finger out of my arse and actually do something.
I have been farting about with servers for a while, and somecunt borrowed the sound card for a month or so, but as things stand this NUC is currently a music server and player. So it actually could work.
I plug stuff in, and naturally there’s no sound. This makes me spend a couple of hours testing the hardware. Life is never easy - who has a source that outputs via 3.5mm socket now? Eventually I found a Nexus 5 from a man drawer, and got it playing my daughter’s awful YouTube feed with two hour videos of teenage girls playing Roblox. After much fucking about I ascertained that it was all working (it may or may not have been working prior to said fucking about).
Naturally there are software problems. I can’t remember how I got this sound card working before, eventually I find a setting that puts it into 8 channel mode so it can be addressed properly. After more swearing it’s working.
I have music! All the channels work, the volume controls are fine and have plenty of gain. How does it sound? Umm, not that great really, it’s a bit spitty and there a hole in the midrange somewhere. There’s definitely something wrong, but I knew that. I’ll measure soon…
Whoa, I have done two things on consecutive days. Here is a frequency resonse, at 20cm in line with the midrange:
I’ve certainly seen better! Next plan is to wire up the amps direct to the drivers and measure the drive units independently. I thought that something in the speakers was broken, but the close enough pair matching would seem to invalidate that, unless both woofers are buggered or something.
The wires are not actually long enough to pull it out any further. After taking a few photos to help me to understand it, I snip the wires, leaving just enough behind to ensure that it can be recreated if necessary. The final crossover when taken out looks like this:
Basically there is a chunky capacitor that affects both bass and mid, this must be what he is referring to in the “dual duty”. I’ve noted down the circuit in case I want to use it. It is effectively second order with inverted polarity on the mids; I’m going to do something a lot steeper, I imagine.
I was planning to rewire them (as much as anything to use longer cables!), but actually there are thin cables to the mid and treble that pass through the separate internal boxes. Looks a palaver, so I’ll use the existing solid-core cables.
Of course what you meant to say was you introduced a physical cue to supplement the visual identifiers for the connectors. (You should have left one end crooked, not the middle one)
