Thanks for your kind words. Yes I wanted a "no compromise" loudspeaker just to see what is possible, especially for low frequency capabilities.
I think you are right about dipole / OB woofers, although I'm a bit afraid about sensitivity and maximum output. But maybe I will just give it a try, I think it's nice to not have cabinet coloration.
I added frequency response images (brown line is freq. response) together with distortion graphs. The first picture is measured at listening position (microphone about 3 meters from the loudspeaker), but unfortunately only at about 70 dB output and with an external equalizer.
After that I did several new measurements at 1 meter distance and higher output (picture #2 and #3), without external equalizer. There is some heavy distortion below 200 Hz and I think this is caused by undamped resonance: when I attach a damping screen at the back stator this distortion is much lower. I'm using a UMIK-1 microphone so I have no idea about distortion of this microphone, so these graphs have to be taken with a grain of salt.
Last edited by j.postema; 25-12-2016 at 21:15.
The Umik mic is very good I use one. I assume you applied the correction file for your particular mic before doing the FR tests.
Will PM you in a couple of days or so.
Conned through life.
Hi, good to hear that the microphone is very good Yes I applied the correction file.
I tested Equaliser APO and Peace GUI and I didn't manage to observe any audible sound quality degradation. First I played a record from my Raspberry pi + hifi DAC+ and at the same time I started the same record on the windows pc, Peace GUI turned off, same sound level. There was no audible difference in sound. After that I turned on Peace GUI, still no difference between both systems. Then I measured both fundamental resonant frequencies using REW and added a notch filter for each individual channel. After that still no degradation of sound quality of the Windows + Peace GUI system compared to the Raspberry. So I'm convinced now that these software equalizers are quite good, at least for the low cost!
A cost of zero. The Peace GUI looks dated but it is functional. But the best bit is it isn't application specific - it works with all media player software.
Once you've used a test mic and know what is wrong with your system FR wise, I have found it to be the best method of correction. I vastly prefer it to the likes of DIRAC.
You can do things with it that aren't practical in a passive x-over. That's cool.
Conned through life.