Hi! Well, I know the theory about it, but I'd like to put it in numbers... I have heard that Magnat speakers are not flat at all, and I decided to see some measurements. Without details about the measurement, between 60 Hz and 20 kHz the variation was 3 dB maximum, specially given by peaks in the 100 Hz and 15 kHz range. Good. They are not "flat"... Now then, what is flat? I know there are always variations, but what is the limit? I hope you can help, greetings.