Theo Verelst Local Diary Page 70

I've ditched the usual header for the moment, I think it doesn't help much anyhow.
This page is copyrighted by me, and may be read and transferred by any means only as a whole and including the references to me. I guess that's normal, the writer can chose that of course, maybe Ill make some creative commons stuff one day, of course I have made Free and Open Source software and even hardware designs available!

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  24 Mar, 2009

I watched Starsky & Hutch, Enchanted, Jeckyl,  and Across the Universe lately on bluray, which was a good quality expericnce boost.

I slightly cought this rainbow at dusk.

New Pages and my own Wiki on the server!

First: my own wiki (, with small w, if you want to remember the url) !

Isn't Open Source technology wonderful: I worked on it a few hours and presto: the same type of Linux server (apache 3 with mediawiki) is running as powers one of the internets' great resources, the wikipedia.

Another few hours and I knew how to make a Postres sql database backup, now lets hope it indeed works.... The wikimedia software (via yum and webinstall on Fedora 8/64 with Apache 2) runs good it seems, I've tried making pages and editing from various stations on the local network, and from a mobile phone with internet, and page views from all over the world seem no problem.

An example page layout (can be set under Preferences when you take a minute to login, there is no email verification needed):

Another sample page (showing the loged-in maintainer options and another layout, and in this case from Firefox Linux, I've also tested Iexplorer)


That's a sample Upload, which is possible for everyone who creates a login and logs in, and that process seems to work fine, just like on the wikipedia. And I tested it from mobile phone, too, which is fun.

I've also made a new audio page, describing most of my more recent activities in the area.

Oh and my Home Page on this local server has been updated, too, check it out.

The Home Cinema setup in diagrams


Space layout, with indirect, reflecting rear/side sound.

Player to beamer


  Audio setup signal path

A satisfied user of the cinema and audio setup (Jean-Michel Jarre in this case) after the yet more improvements:

HD-DVD versus Blu-Ray?

Well, comparable but not really the same thing in my experience, but not that far apart quality-wise. I guess since HD-Dvd is officially no more, it doesn't really matter, though I like to get cheap sale HDDVDs...

The HD-dvd player I use is the cheapest there was, half the price of the BluRay player I use a lot: the Sony S550 which is close to the best consumer player around.

The inside of a HD-DVD (not bluray) player:

more thana bit of stuff there. A known Analog Devices chip:

A SHARC DSP chip, I suppose for audio processing. Pitty the capacitors of the analog audio outputs might be of the electrolytic kind...

No rolling-speaker: small improvement ?


These are asphalt nails, with broad head, driven through the carpet, the hardboard plate and the softboard damping plate onto the conrete underneath under 4 wooden corners under the sub-woofer now, which let the weight of it and the speaker on top rest directly on the concrete with little room to move or resonate.

Also I filled a little gap between the top and bottom speaker with hard, solid cardboard and closed the slim airgap on the side with some damping.

The result: even more rock-solid sound, no rolling or moving effect means much more punch without sideeffect, which is great, I should now also get the right speaker from it's soft chair resting place and do the same!

Low-Mid speaker replacement

Well, it was broken in some major power event but I don't know when. It was planned to be not up to the power of the main amp and the other speakers, so it was no surprise it broke.

I got this replacement for testing, for a very good price from and electronics store, which I know since I was 8 or so, and it's being tested, hence the duct tape air closing and only two screws.

It's a great success, but I think I must, just like the mid high speaker, make a seperate amplifier channel for it, or maybe combine it with the mid-high channel if those volumes match.

Nice mid low, but as I said a bit less volume is better, and probably it isn't up to the power in the whole mid low range either, so dimmingit would be cool.

A resistor you say? Go somewhere else, inferior audio being, that would destrpy the damping exerted on it by the power amp, so no, that is no option. I don't even have more than a single capacitor as exchange filter for the same reason (the upper frequency limit is electronically filtered) and I even prefer non-bipolars for that.

The result is nice, in fact it can compete with the much softer but more subtle sounding Kenwood which I have on the other side and have no spares of. Well, I don't ever use more than a quarter (1/4th) of the available power amp wattage at any time where this setup currently is used, that'd be too loud. I have in other places, it is up to more! So I suppose the mid low can stay in one piece as it is. A hundred brutal watts on the speaker as a whole may well destroy it though, of course depending on the coupling capacitor and the applied frequency spectrum distribution, including the transients and probably on the time distribution of the power.

Rough guitar

Can those linux plugins, which are all free in fact, meaning even like free beer, they cost nothing, except some of the good ones you'll have to compile yourself, do some real good things ? Like there are hundreds of even quite expensive windows plugins, I've 'evaluated' in the literal sense, and removed from disk at the time, some good Vst plugins a number of years ago, and found them no comparison with for instance the Yamaha S90 build-in (hardware) effects, most of the time. Really, not suitable for serious music making almost.

These linux ones aren't perfect, but certainly can kick *ss! And of course some higher knowledge about how certain things were already done in studios and equipment and shows in the early days of Rock 'n Roll (mid 50s) doesn't hurt...

Above you see the controls of (clock-wise, starting in upper left corner) Jamin, a heavy fft-based multiband compressor/32/1024 band stereo equalizer/analyzer with boost control, jack's connections between the programs shown and the Lexicon AD (with guitar input) and DA converters, jack-rack with a nice plate reverb, stereo compressor, stereo delay and volume control and the guitar input processsing rakarack guitar effect processor suite with eq, compression, overdrive and chorus effects on.

Does that sound cool ? Oh yeah, in spite of the heavy hum from the notebook supply unit (putting on battery makes it quiet), this is the result, judge for yourself:

   .wav guitar rough  (CD stereo quality, 9MB)
   .mp3 idem               (stereo mp3, 128kbps, 1MByte)

Is that a rough minute? Well, I guess on any sound system by any normal musical standard, but it is just something I tried a few hours, no more......

Open Sound World

I think from Berkeley, there's besides my Bwise another Tcl-TK interfaced audio block program: