eventually it will mess up...... it will play an all but will get hot an then cause problems..... better call them up an tell then no need in burnin up your amp
what amp do you have, most amps can handle an ohm load a little bit under waht there rated, like most 1ohm amp can handle .75ohms, most subs ohms are lower than what is stated, like my atlas's are svc4ohm but the acutally 3.6ohms, so im pretty sure you'll be fine.
I personally wouldn't wire that sub at 1.5 on that amp. I've never seen anything good come from wiring an Infinity lower than 2, in most cases the older ones didn't handle less than 4 very well.. just a heads up, though.
One last question, In the manual it states its DC-R is dual 3.1 Ohms. Now it is advertised on all the sites as being a dual 4 ohm. So does that mean that it happens to have a resistance of 3.1 ohms when not powered (I took my multimeter to it and got the same number) and that when powered it can/will change to average at 4 Ohms?
The sub is a Eclipse Ti Sw9102. I tryed looking up all the info on it online and the only places i could find refering to it as a 3.1 Ohm was a few that had exact transcripts of the manual.
The Eclipse support phone number was useless as they just discontinued the line and do not have any info on it. Although i dont think they could have helped anyways as they would have just read the manual which i can do.
DC-R is the DC resistance, your amp will not actually see that load...the impedence (AC resistance...kinda) will change as the frequency changes (this is impedence rise). Your amp should be just fine at 1.55ohms DCR.
most "dual 4ohm subs" are infact not truly 4ohms per coil...the DCR is usually a lil lower, in your case 3.1ohm