note: article incomplete, I need to tidy up the graphs and clarify what the lines are.

I recently purchased a MiniDSP UMIK-1 calibrated USB measurement microphone to help with speaker tuning. I already have a Behinger ECM-8000, but the Behringer isn’t calibrated, while the MiniDSP comes with a calibration file, you just download from their site keyed on the serial number of your unit.
As you can see, the two units come in similar, but not the same packaging, and also look quite similar:

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This is pretty much a “brain dump” of my Audiokarma posts on phase III of the Econowave project (now more likely to be called the big read speakers then “cheapowaves”)… post will get edited down over time, but if the article is disjointed it’s due to being a bunch of seperate posts appended together.

upgrading woofer in my econowaves : adding the Eminence Delta 12LFA and documenting the resultant crossover redesign.. plus some tweaks Continue reading →

I recently got a YuanJing brand low cost TDA8920 based board from ebay. This is a fairly basic low frills build but worth documenting for those interested.

I’d already wired up the case for my second ConnexElectronics TDA8920 board when I managed to fry the board. Out of curiousity I decided to check out this lower cost board that was going cheap cheap ($19USD + $9USD postage), as I could use the transformer I’d already mounted in the case as they are similar units.

This is the board on ebay:
TDA8920 Class D Amplifier board/ audio Power AMP 2X100W – eBay Power Amplifiers, Amplifiers, Home Audio, Electronics. (end time 19-Jul-10 02:14:45 AEST)

It has a smaller heatsink than the connex module, and smaller PSU 4700uF caps.

Initially it sounded OK, but not as good as the Connex module, quite a bit more grainy.. also interestingly it uses 5W power even when silent, and hence (with the smaller heatsink) runs a lot hotter.
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After experimenting with various combos of crossover values, although the MK I cheapowave using the Pyle PDS221 compression driver sounded OK.. the high end was never really impressing me.
Note: this post continues on from cheapowave MK I postwhich documents building the cabinets etc

After reviewing the Econowave thread on Audiokarma yet again I ordered in a  Selenium D220Ti-8 from Parts Express in the USA. The shipping cost almost as much as the drivers themselves.. but although I could probably find a more than acceptable replacement from the P.Audio drivers from Cannon Online, I decided to go with a combination that already has shown so many good results for others, plus the hard yards on the crossover circuit has already been done by people with way more expertise than myself.

The Selenium drivers arrived, and the immediate impression is that they are bigger then the Pyles.

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