Audio Systems: kenwood kac 8104d troubleshooting, dual voice coils, voice coil impedance

Question
QUESTION: i have a kenwood kac-8104 amp powering 2 infinity 12" ref1252 subs 300 rms. this amp keeps shutting off after i play it loud for a min. i have either 4 or 6 gauge wire running to the amp i am not sure what one and 12 gauge wire running to one sub and 8 gauge amp power power wire running to the other sub.(ran out of speaker wire). i am trying to figure out if i have it wired wrong or what. could you possibly send me a wiring diagram of how to run this system the best. i could make a diagram of how i ran it in paint or something and email it to you if necessary. also sometimes when it shuts off the amp is really hot and a few times it blows a fuse.

ANSWER: You do not have it wired correctly.

But, I cannot help you until I know the impedance ratings of the speakers and whether they are dual or single voice coil.  Impedance matching is the most important thing.

Your Kenwood amp is a mono unit with either 4 ohm or 2 ohm load capability.  If the speakers are 4 ohms single voice coil you can put them in series and drive them with your amp.  If they have dual voice coils you can also parallel the coils in each speaker and then series connect them to the amp.  But, if you parallel all 4 voice coils (if you have the dual voice coil versions) you will be putting a one ohm load on the amplifier which will result in over heating and shut down.

http://www.bcae1.com/spkrmlti.htm

The above page has all the wiring connections you need, but you must determine if your Infinity speakers are single or dual voice coils.  Most models, now days, come in either configuration even though the model number is the same or similar.

If you have the single voice coil versions you just want them in parallel to the amp.  If you have the dual coils you want the to coils paralleled and the speakers in series to the amp.

Off you go!  Hope this solves your problem.

C



---------- FOLLOW-UP ----------

QUESTION: OK i am a little confused still because on the box of my subs they say 4 ohm and on the infinity website they say that they can be 2 or 8 ohm what should i go by. they are dual voice coil subs. also i have seen in some places that this amp is not bridgeable. also what gauge wire would you recommend using for the power and ground wire for the amp, and also going out to the subs.

Answer
For automobile usage the wire gauge is not critical because you are not going great distances.  Speaker wires can be 16 or 18 ga and power or ground lines should be 10 or 12 ga.

You will have to open up the sub box and look inside. If they are dual voice coil each speaker will have 4 terminals and a single voice coil is 2 terminals.

To connect in parallel jumper the two + terminals together and the 2 - terminals together.  This will provide you a 2 ohm load for that speaker.  If you connect the + terminal to the other - terminal that will put them in series for 8 ohms.

Since you have two subs, they must be connected to the amp in parallel.  So, for the case they are both dual voice coils, put the coils in each speaker in series for 8 ohms each; then when they are both connected to the single amplifier that will give you a 4 ohm load.  A nice load for the amp you are using.

Does this resolve it for you?

C