what kind of amp to use... confused!

[danyal711]

Ok, so I recently bought a Dual Voice Coil 4Ohm amp (orion cobalt 12"). The manual says that I can run it in parallel at 2Ohms or Serial at 8Ohms. So I most likely would want to run it in parallel since the 2Ohms will give me more wattage however what I take this to mean is that I need an amp that is 1 channel or bridged to 1 channel at 2 ohms that I can then run in parallel to both of the voice coils. Is this correct first of all? Ok aside from that, then I was looking at orion amps, and all of the 2 channel amps after being bridged are 4Ohms at 1 channel. This doesnt help me at all since I need 2Ohms at 1 channel. My understanding is I either need mono 2ohms or 2 X 4Ohms and run a 4Ohm load to each voice coil? The problem with that is I lose tons of wattage and would have to buy an amp that is really powerful. I think it makes more sense to run mono 2 Ohms because the wattage goes way up (I dont need that much wattage only about 300). For example the orion CS150.2 has the stats:
1 x 75 @ 4 Ohm
2 x 150 @ 2 Ohm
1 x 300 @ 4 Ohm

Would this amp also be 2ohm stable at 1 channel or is that not how it works and am I missing something? Basically what kind of amp do I need to run my sub (200rms, 400max).

Thanks

[mlomker]

It sounds to me like you understand just fine--amps that are stable at 2 ohms mono are expensive because they draw a ton of power and need large power regulators (we're talking 4 gauge power connections). What I did on my last system was to buy a normal 2-channel amp and then wired one channel to each voice coil--that maintained the 4 ohm load and provided enough sound for me.

Just because a sub is rated for 200/400 doesn't mean that's the minimum you need to run it. Volume is a logarithmic curve, so you actually have to double the power in wattage to be able to hear much of a difference in volume (3 db increase).

That last 12" sub that I had run (Punch DVC) was at 160 watts and it was loud enough for me--it all depends upon whether or not your are running a sealed box, vented, or bandpass and how much volume you expect. If you just want thump then buy a bandpass box and even a reasonably priced amp will pound. The box that you choose will make a bigger difference than 100 watts of power will.

[danyal711]

Well, I don't neccesarily want it to thump, I ideally just want to use the box/power that makes the sound the cleanest/smoothest with the best quality and range. What box would be the best for this? However this makes me think that I would need to power it with at least 200-300 watts so that it can handle the lows properly etc?

[danyal711]

Also, you mentioned that 2ohm X 1 channel amps require large power supplies and G4 cable, so would it be unwise for me to buy such and amp and put it my car (1992 325is)? Would it kill the battery or something?

[mlomker]

I wasn't saying that you shouldn't install it--I was just trying to explain why the higher power amps can jump in price so much.

Any high-powered system will drain the battery if you listen a lot when the car isn't running. My systems have typically been 500 watts total and that isn't enough to worry about. If you go over 1k watts then you need to give some thought to the power consumption (deep cycle battery, larger alternator, stiffening capacitors).

If you are looking for maximum sound quality then you'll want a sealed box. I just looked over the available Orion amps and I would use the one that you were looking at and wire it for 1x300 at 4 ohms.

[danyal711]

Which amp is that? Do you mean 1X300 at 2 ohms? Because the sub is DVC so how would I wire it if I ran the amp at 1X300 at 4ohms?

[jllphan]

Didn't read the thread, just the question. If you are wishing to power a single sub that has dual 4ohm voicecoils, buy a mono (1 channel) amp, preferably a Class D. Not a 2ch that you bridge, or any other config. Don't need to get into a deep discussion on impedence, phase, etc. just trust me here. Find the best (lowest THD%) you can afford in this config. and your all set.

[wulley1]

I agree with Jllphan, drive it with a mono amp, it's what they are made for.