Converting Infinity Infinitesimal 0.1 speakers to DSP crossover

[HAL]

Found a pair of Infinitesimal 0.1 speakers that someone had changed the 5in Watkins 8 Ohm dual voice coil speaker to a FOCAL 5in dual voice coil replacement.  Sadly one of the FOCAL drivers has one voice coil open and even FOCAL does not know how to repair them. So time for some fun!

Could not find any original 0.1 woofers, but found a pair of 0.3 Watkins 4 Ohm single voice coil drivers.  These do not work with the existing passive crossovers, so time to remove them and convert to direct drive for active speakers.

Made a simple replacement connector panel for two sets of 5-way binding posts.  Added a fuse holder inline with the EMIT planar tweeters for protection.

Ever since hearing a pair of Infinity IRS Reference III's in 1979, the EMIT and EMIM planars have always sounded great, but need a little help.  They extend to at least 30KHz and very short impulse response.  They are easy to EQ flat.

Using Audio Weaver for the DSP crossover and room EQ software to run the dspNexus 2/8.

First measurement was an impulse test for time alignment.  Had to add 13 time sample delay to the tweeter to match the woofer to give a coherent wavefront.  It is easily heard in image stability.

Will be doing more in seat room measurements to flatten out the response.  If it is to bright I have designed a variable Harman EQ process that lets the user adjust the response at their seat.

[Nick B]

Interesting project, Rich. I hadn't heard of that particular model. Did hear the IRS a few times, but that was years ago.

When you did the measurements for time alignment, did you use Audio Weaver? Did the software give you a starting point to make changes and did you finish the settings tuning by ear only or still use more measurements?