I just bought Infnity 62.7i 2-ways 75WRMS and 250W max at 2 ohms resistance. If I use an MTX282 140WRMS x2 @ 2 ohms, which I also already bought, will I be at risk of blowing my speakers?
yes, you will as a matter of fact. But with the volume knob, you control the acutal amount of power that goes to the speakers. If you're careful you could potentially power those speakers with that amp and go years without blowing them but i don't see that happening honestly.
Also, if I install the system as I described it, will there be any warning signs(sounds) before I blow the speakers? Or just the sound of me crying once they blow?
Being careful with gains is definately a good start, but it will still be impossible for you to tell how much power this amp is putting out at certain levels on your volume control unless you test it, which you'd have no way to do. Yes, there will be warning signs, but if you're not careful you may miss them. Do to then nature of cone speakers, at the upper realm of its excursion, it will distort a good amount. Do a goggle search for "BL curves" if your interested in learning more. Basically the steeper the slope, the greater the distortion. But i wouldn't get another amp if I was you. Using the amp you have at far under its rated power will result in a much cleaner signal than the amps rated distortion level.
Thanks scuba I will just set the gains low...I just looked at the print on the back of the MTX amp and it says at 2 ohms the output is only 90WRMSx2, and I don't have the birth sheet. Why do all the internet sites list it at 140RMS @ 2ohm?
because its a scam...everyone does it to fool people...They need a set way of rating and displayed things, (CEA), but not everyone follows it...and then they just throw RMS at the end of the wattage to make it seem like double the power