2 ohm vs. 4 ohm
10-09-2008, 04:57 PM
#1
Member
Thread Starter
2 ohm vs. 4 ohm
I know a little about stereo, and I know that 2ohm is less resistance which means more power. I have always tried to wire everything to get the lowest ohms possible.
But is there a difference in SOUND QUALITY?
I ask because I am shopping around looking at kicker 8's. i'm not looking for big bass just a quality sounding system like those found in a factory top end car (lexus, cadillac, etc.) only a little more bass. as they generally have only 1 sub with 10 being huge, 8's and 6.5's being a little more common (I think).
Anyone know?
But is there a difference in SOUND QUALITY?
I ask because I am shopping around looking at kicker 8's. i'm not looking for big bass just a quality sounding system like those found in a factory top end car (lexus, cadillac, etc.) only a little more bass. as they generally have only 1 sub with 10 being huge, 8's and 6.5's being a little more common (I think).
Anyone know?
10-09-2008, 07:07 PM
#2
Senior Member
Not sure about sound quality. Would think that lower impedence would offer the potential for greater dynamics - louder thumps, cymbal crashes, etc. Speaker power is a function of the square of the current times the impedence (I^2 x R). For a lower impedence, it takes less of a change in voltage to achieve a given change in current - or the other way - the same change in voltage results in more current at lower impedences.
Suggest to go with the lowest resistance speaker that the amp is rated to push. Optimum power transfer occurs when the speaker impedence matches the amp's output impedence. Many times, there is a switch on the amp to select what impedence load is being pushed.
Remember, if speakers are chained - the effective impedence seen by the amp will change.
If the speakers are chained in series (+) to (-), with a (+) from one speaker and a (-) from another speaker connected to the amp, the impedences are summed. For example, if three 2-ohm speakers are connected in series, the effective impedence seen by the amp will be 6 ohms.
If the speakers are paralleled - all (+) connected together, and all (-) connected together, the math gets a little trickier - but if the speakers are all the same impedence - then divide the individual speaker impedence by the number of speakers. For example, if three 2-ohm speakers are paralleled - the effective impedence seen by the amp will be 2/3 ohm - perhaps below the rating of the amp, increasing the chances of popping a fuse or blowing the amp.
If multiple speakers connected to the same output are in your plans - it may be that 4-ohm speakers paralleled could be a better match for the amp than 2-ohm speakers seriesed, with 4-ohm seriesed and 2-ohm paralleled being outside of the amp's range of capabilities.
Speaker efficiencies can play a big part in the size of amp needed. This is usually stated in dB per foot or meter. A difference of 3 dB means that it will take about double the power for the lower efficiency speaker to make the same sound as the higher efficiency one. However (there's always a 'however') - the sound quality of the higher efficiency speaker may not be as desireable as the lower efficiency speaker. Also, pay attention to the distances used in the efficiency rating. They need to be equal for a valid comparison. Each doubling of distance lowers the dB output by about 3dB at that point.
Keep in mind the area of the speaker - remember the formula for a circle - pi times radius squared. Essentially, take the ratio of the diameters and square it, everything else cancels out. Comparing a 10" to an 8" speaker - 10 / 8 = 1.25, squared = 1.56 - meaning that the 10" speaker has 56% more area for sound radiation. All other things being equal - the 10" speaker will thrust around significantly less in order to move the same amount of air - less movement means less opportunity for distortion.
A note about sound quality - unfortunately, much of this is perceived by the listener. The best way is to 'test drive' the potential combinations in your vehicle with your ears - the next best way is to read up on reviews and what others have to say. Sorry to say that I'm not very up-to-date on current offerings - my experience dates back to the days of the Jensen Tri-Axial 6x9s run by a Fosgate Punch (before the days of Rockford, before being manufactured in a foreign country, and back when they only offered one size amp in only 2-channels).
Ahhh, I could go on, but perhaps I've already said too much.... :-)
Suggest to go with the lowest resistance speaker that the amp is rated to push. Optimum power transfer occurs when the speaker impedence matches the amp's output impedence. Many times, there is a switch on the amp to select what impedence load is being pushed.
Remember, if speakers are chained - the effective impedence seen by the amp will change.
If the speakers are chained in series (+) to (-), with a (+) from one speaker and a (-) from another speaker connected to the amp, the impedences are summed. For example, if three 2-ohm speakers are connected in series, the effective impedence seen by the amp will be 6 ohms.
If the speakers are paralleled - all (+) connected together, and all (-) connected together, the math gets a little trickier - but if the speakers are all the same impedence - then divide the individual speaker impedence by the number of speakers. For example, if three 2-ohm speakers are paralleled - the effective impedence seen by the amp will be 2/3 ohm - perhaps below the rating of the amp, increasing the chances of popping a fuse or blowing the amp.
If multiple speakers connected to the same output are in your plans - it may be that 4-ohm speakers paralleled could be a better match for the amp than 2-ohm speakers seriesed, with 4-ohm seriesed and 2-ohm paralleled being outside of the amp's range of capabilities.
Speaker efficiencies can play a big part in the size of amp needed. This is usually stated in dB per foot or meter. A difference of 3 dB means that it will take about double the power for the lower efficiency speaker to make the same sound as the higher efficiency one. However (there's always a 'however') - the sound quality of the higher efficiency speaker may not be as desireable as the lower efficiency speaker. Also, pay attention to the distances used in the efficiency rating. They need to be equal for a valid comparison. Each doubling of distance lowers the dB output by about 3dB at that point.
Keep in mind the area of the speaker - remember the formula for a circle - pi times radius squared. Essentially, take the ratio of the diameters and square it, everything else cancels out. Comparing a 10" to an 8" speaker - 10 / 8 = 1.25, squared = 1.56 - meaning that the 10" speaker has 56% more area for sound radiation. All other things being equal - the 10" speaker will thrust around significantly less in order to move the same amount of air - less movement means less opportunity for distortion.
A note about sound quality - unfortunately, much of this is perceived by the listener. The best way is to 'test drive' the potential combinations in your vehicle with your ears - the next best way is to read up on reviews and what others have to say. Sorry to say that I'm not very up-to-date on current offerings - my experience dates back to the days of the Jensen Tri-Axial 6x9s run by a Fosgate Punch (before the days of Rockford, before being manufactured in a foreign country, and back when they only offered one size amp in only 2-channels).
Ahhh, I could go on, but perhaps I've already said too much.... :-)
Last edited by wde3477; 10-09-2008 at 07:13 PM. Reason: clarification