Boo to Boxes, Hurray for Art!

Unfortunately, the subwoofers require boxes, a construct to which I am both allergic, from an audio point of view, and challenged by, from a constructional point of view. The audio side of things is probably ok, they are just subwoofers, so the boxiness isn't going to be problem, I hope. The construction thing is much harder, because boxes require sawing, right angles, joints, all that kind of stuff. Once Upon A Time, I blithely built boxes for all sorts of speakers, but now I seem to be incapable of getting anything to meet squarely with anything else. I suspect this was always true, but maybe I'm just more critical now!

Anyway, I've knocked up the required 1ft cubes with open backs, as specified by SL. I deviated slightly from the Master Plans in that I've used 18mm MDF instead of plywood for the top/bottom/front, because that's what I had, but that shouldn't matter. However, I want to spray them the same flocked grey that I've used for the main speakers... and there's the problem. Unfortunately, I held the panels together with tape while I was lining things up (all part of the patented GoukBuild © method), and the dratted tape has picked up the surface of the crappy 6mm MDF I used for the sides. So now it has rough and smooth bits, which stand out a mile when sprayed. Farts. Yeah, I know, the boxes are utterly cack and completely utilitarian, with screws standing out and all sorts of horror, but I'm drawing the line here, ok?

What to do? My mate G suggested molten plastic, conceptually, which is a great idea but infeasible. Then I thought of gesso - a high-build, water-soluble paint-like material used by painters to smooth out canvas and stuff, with which I'm familiar via my wife's artistic endeavours. She happened to have an used bottle of grey gesso she'd been keeping on the off-chance of ever needing grey... And a foam applicator!

Bottle of instant gesso and applicator

Here's a shot of the boxes, showing one of the bits where the tape has lifted the surface of the MDF, highlighted by the raw gesso application. I'm never using MDF for anything ever again... Am I being fussy?? Hey, it's my project!

Box close-up showing lifted surface

And here are the boxes in all their glory, after two coats of gesso. More to come I suspect, although it goes on very easily, and dries really quickly. I started out using a brush, but the gesso is quite gloopy, and the foam applicator is much quicker and smoother. I'm going to slap lots of gesso on to build up a layer that I can sand back to smooth off the fluffy bits - hopefully! They're looking quite cool, in a "Rebel Alliance spaceship" kind of way... With the awesome ally-coned woofers, they're going to look amazing! Nobody will notice the uneven edges, variously-countersunk screws etc. etc. right?

Subwoofers with 2 coats gesso applied

Input Selection (part 2)

I've chosen to use 2x 2x4 miniDSP units for the 6 channels of DSP required for LXMini+2. Initially they will be used with purely analogue inputs...

All Analogue LXMini+2 Configuration, with RPi/CD sources

But there are other options...

The 2x4 with the miniDIGI input permits an interesting option. The miniDIGI is providing a set of digital inputs across the miniDSP units, but doesn't disable the ADC section of the miniDSPs, merely bypasses it. So it's possible to use s simple switch to select the digital source for the DSP section of the miniDSPs... which could be the miniDSP or ADC!

And then there's using the miniDSP 4x10HD unit, which provides 8 DSP channels in one box, with much more processing power than the 2x4. Because that uses a DIGI-FP for input, and a VOL-FP for volume control, you get multiple digital and one analogue input, with switching from the VOL-FP multifunction controller. And remote! That's available as a complete solution from audio phonics at £547 or you can buy the components (2x8 kit, VOL-FP, DIGI-FP and a suitable enclosure) for £450, with all the fun of building it ;-).

To Be Continued...

Input Selection (part 1)

It's been a while since I posted anything, largely because things have been parked for quite a bit. However, I've started up the subwoofer build again, of which more on another post, and also looked at the critical problem of Input Selection.

Basically, the miniDSP has a single set of stereo inputs, and it's quite likely that we need more than one source. Right now, switching sources (mostly between the RPi/DAC and the CD player) is performed in the analogue domain by (simply?! no...) unplugging/plugging the appropriate set of cables, whilst keeping the right stereo L/R relationships, not getting confused about the right sockets to use etc. Dull. So...

Here's the current situation, and a possible super-simple solution...

Current vs. Proposed Analogue Input Selection Mechanisms 

To that end, I've ordered a well-reviewed analogue 3-1 switch box and a few 1m RCA-RCA cables. Let's start with this...