Some questions about ohms and voltage

[Cole_Guitar]

I hope someone can help.

I understand that ohms are a measurement of resistance, I just don't understand how that affects a speaker system. When it comes to impedance, is better to push a lower ohm rating versus a higher rating (i.e. 2 ohms vs 4 ohms)? I would think that it would be better for the speakers, but harder on the amp. Is that true (and I'm making assumptions)? As far as voltage goes, is it better to push more voltage or less (i.e. 12V vs 14.4V)? I would appreciate any input because I am in the dark. And to let you all know I am asking because I am planning on putting a system in my vehicle, and I am not quite sure about the technicalities. Sorry if this is strictly a Home Audio forum and not a Car Audio forum. I have had many questions answered here, so I thought I would give it another try. Thanks all.

Cole J.

[E-Stat]

I would think that it would be better for the speakers, but harder on the amp. Is that true (and I'm making assumptions)? As far as voltage goes, is it better to push more voltage or less (i.e. 12V vs 14.4V)?
The short answer is that a lower impedance load can provide more watts for the dollar, but frequently trades off sound quality as indeed most amps are not happy driving such loads.

As for voltage, that is determined by the amp's requirements. Overdriving wouldn't help.

rw

[MikeyBC]

In car audio it is normal practice to run amps at lower impedances to achive a greater power output , many car amps are stable at 1 ohm and some even advertise 1/2 an ohm. the idea is to make a 100 watt rated system rated into 4 ohms achieve upwards of 400 watts into 1 ohms so the owner could try to achetive the loudest SPL in the 100 watt class. your best bet would be to bi-amplify, 1 amp for subs with 2 8 ohm woofers parralled and the other for front and rear and avoid using the crappy amplifier sections all powered decks come with. Rockford Fosgate make good sounding, bulletproof amps. Personally I wouldnt run under 2 ohms to maintain sound quality and reliability.

* note...when you bridge a car amp and run it mono into a 4 ohm load each channel of the amp will see 2 ohms.

[risabet]

I hope someone can help.

I understand that ohms are a measurement of resistance, I just don't understand how that affects a speaker system. When it comes to impedance, is better to push a lower ohm rating versus a higher rating (i.e. 2 ohms vs 4 ohms)? I would think that it would be better for the speakers, but harder on the amp. Is that true (and I'm making assumptions)? As far as voltage goes, is it better to push more voltage or less (i.e. 12V vs 14.4V)? I would appreciate any input because I am in the dark. And to let you all know I am asking because I am planning on putting a system in my vehicle, and I am not quite sure about the technicalities. Sorry if this is strictly a Home Audio forum and not a Car Audio forum. I have had many questions answered here, so I thought I would give it another try. Thanks all.

Cole J.

The majority of home audio amps act as voltage sources, the impedance of the speaker cause the amp to draw current, thus a 4 ohm load draws more current than an 8 ohm load. Utilizing a derivation of Ohm's Law I=V/R one can calculate the current drawn at any voltage and resistance. However, resistance and impedance are different. Impedance, as found in a speaker, is the total opposition to the flow of current at any single frequency. Resistance is the property of a conductor which opposes the flow of current, leading to the generation of heat. Any competently designed SS amp should be stable into a 4 ohm load. Car amps, from what I recall, can easily drive 2 ohm loads. Good Luck.