Amp / Ohm load / speaker question

I've always run separate amps for separate components of my system - 1 amp for tower speakers, 1 for sub and 1 for interior.

If a 4 channel amp (Kicker 850.4) is split to run both tower speakers @ 2 ohms (on the front channels) and interior speakers @ 8 ohms (on the rear channels), will that cause any problems with the amp?

2 Tower speakers @ 2 ohms? Are you paralleling 2-4 ohm speakers to get a 2 ohm load? Im not really sure how you got that load but, to try to answer your question the amp responds just link 2-2 channel amps. I work at an audio/video store and in a few cars we've ran door speakers off the front channel and a couple subs off the rear channel. The main disadvantage I see with having one amp run everything is that if it goes bad you'll be outta tunes till you get it fixed. Verses having the interior amp or the tower amp still working. Hope I made since outta that.

(Message edited by lowbowtie on April 16, 2007)

You don't want to run that amp into 8 ohms, wire them in parallel instead then you will have a 2 ohm load on the front and a 2 ohm load on the rear channels.

Do you have the 2 ohm deafcons?

Ah - Mike, I was hoping you might jump in on this one... Yes, the 2ohm deafcons on the tower.

This is actually a question for a buddy, who is already running in this setup. The interior speakers (3 per channel, 6 total) are run in series. Can you tell me why to not run the amp at 8 ohms? Can it damage it?

Thanks for the responses...

the 8 ohms certainly won't damage the amp in any way. The main disadvantage to running a high impedance is that you are unlikely to get the full output of the amplifier.

There are some very simple relationships that define how the Power, current, voltage and impedance of a circuit all relate. The bottom line is that when the imedance goes up, the voltae required to obtain a certain amount of power also goes up. When dealing with stereo equipment you encounter a problem that to drive high power into an 8 ohm load requires too high of a voltage: too high in the sense that it is harder to create the voltage off a 12 volt source and also too high to be safe from electrical shock.

If you look at the specification sheet for a given amplifier you will probably find that they will only deliver the rated power into a 2 ohm load. At 4 ohms they will only deliver 1/2 the rated power, and at 8 ohms only 1/4 the rated power.

Rod

How will you be able to seperate the vlolume between the boat and the tower? 3 amps one eq total control.

Rod,

I disagree, from personal experience I have blown amplifiers running them at 8 ohms because you don't realize that you quickly push their input power supply into overvoltage-overload which killed the a few of the transistors before any of the amplifier's protection circuitry kicked in.

Jerram,

Three 4 ohm speakers in series is actually 12 ohms, not 8 ohms. Don't do it.

1. If you must run the boat speakers on two channels you can series the four boat speakers in parallel with the bow speakers which will yield a 2.67 ohm load. The downside is that the bow speakers will get twice the power and play 3db louder than the interior speakers (although they won't really sound twice as loud).

2. I run my six interior speakers off a four channel amp. The four boat speakers in parallel off the rear channels and the two bow speakers off the front channel (with a PAC-LC1 on the front inputs so the ladies can go chat up in the bow with low music levels). Add a big two channel amp for the tower, use an EQ to fade between the tower and boat.

3. (crappy option) Run the bow speaks off the deck power, parallel the rear boat speaks. Deck fader might even work to balance levels?

Yeah - that makes sense... I'd have to look at his deck to see if it could fade between the pre-amps and the speaker levels.

You're comments about protection circuitry raise my eyebrow's, too as it won't come out of protection mode at this point.

Do you know off the top of your head the rating of those deafcon pods? I'm not finding much online.

Mikeski:

I don't understand how you can damage the input power supply. If the amp was properly designed there should be no way you could cause the input power supply to go over voltage.

Rod

that's what I thought too until the smoke arrived...

I have wired hundreds of amps at 8 ohm loads and never had any issues that were related to the load. I have had issues with amps that were wired below the impedance levels considered stable or crossovers wired backwards. The new amps I have been using do not have any issue with 8,4 or 2 ohm loads.

Mikeski, can you explain the experience you had with this?