I bought a used Deltalite a year ago and I just now got around to measuring the ohms, i was told it was an 8 ohm speaker, it appears to be a 4 ohms (3.8) speaker. From everything I can find Deltalites 15s only come in 8 ohm. The cone has ridges, could this be a recone with different ohms? I recently purchased another with 8 ohms (5.8) and it has a smooth cone. Im confused.