There is much to discuss regarding car speakers as there are many essential factors to consider for the best results. The most important factors are whether you should opt for 2-ohm or 3-ohm speakers, as ohm rating defines the electrical resistance of the speaker while wattage determines the power dealing capacity.
So what is the main difference between 2-ohm and 3-ohm car speakers? The main difference between the two lies in efficiency and power. 2-ohm car speakers can handle more power and are more efficient than 3-ohm speakers.
The Comparison Between 2-Ohm and 4-Ohm Speakers
Sound Quality
The difference in sound quality is only noticeable with extremely powerful amplifiers. Some people are able to notice the difference while others are not.
2-ohm speakers use less power from an amplifier, but they can’t handle very low frequencies as well. For example, most car audio amplifiers will produce the most power at the frequency range of 20-200 hertz. As you go lower in frequency, there’s more current demanded by an amp. If you have a 2-ohm subwoofer instead of 4 ohms, then that same amplifier under deep bass conditions would be working harder which could reduce its lifespan.
That is why it’s generally preferred to have 4 ohms or higher impedance speakers because this requires less work by your amps.
Some speakers feature a switching impedance system where they change the impedance of the speaker based on volume. For example, as volume goes up, it changes from 4 to 2 Ohms. This is done to protect your equipment and not over-stress them.
Amp Compatibility
Most mid-grade and better car amplifiers will work fine with either a 2-ohm or 4-ohm speaker. But it is recommended to always use a 4 Ohms or greater impedance. Low-wattage amps may sometimes not produce enough power for some 2 Ohm speakers.
Some higher-powered amps can damage some lower-powered amps when used with them because of the extra voltage being put out by the power amp which would overwhelm the small-wattage amplifier. This could be seen as dangerous because if you have a low-powered amp, it could overheat or burn out faster than usual.
Sometimes an amplifier has what’s known as “Bridgeable Output” which allows you to connect multiple woofers together in parallel, in order to increase the wattage output or “SVC” which allows you to connect multiple woofers together in series (positive coming from one speaker going into the positive of another speaker, and negative connecting to negative). If you are using 2-ohm speakers with your amplifier the best practice is to use either a 4 channel amplifier bridged at 3-4 Ohms or a 2-channel amplifier bridged at 4 Ohms.
You can solve this problem by buying an additional amp that has enough power for your subs and hooking them up properly. This is known as “Amplifier Bridging.”
Cost Differences
2-ohm subwoofers are usually less expensive than 4 Ohms subwoofers, but both are equally effective. The prices can be compared to the equivalent wattage of each speaker.
1-ohm difference between 2 and 4-ohm speakers is not significant for manufacturers or retailers because it would have almost no effect on the sale price. It’s also rarely an issue for consumers other than those with already botched stereos who don’t realize it before buying new speakers.
However, the impedance is important for matching speakers with appropriately powered amplifiers which must always match up to a pair of speakers that have equal impedances (usually 4Ω). If each speaker has a different impedance then their power ratings must be correctly combined into the proper total impedance.
If you don’t want to connect tweeters through crossovers, it’s best to choose ones that already come with them installed (since sometimes the price/ ratio gets much worse).
Sensitivity
Most speaker manufacturers list the sensitivity of their speakers in decibels (dB). This is a measure of loudness and tells you how much sound pressure the speaker can produce when it’s fed 1 watt of power. A difference in sensitivity means that one speaker will play louder than another when given the same amount of power from your amplifier.
Since most car audio equipment was made to work with 2 Ohm speakers, some 4 Ohm speakers may not be as efficient due to less cone area for moving air and lower sensitivity ratings.
However, many modern amplifiers feature built-in impedance protection circuitry which can compensate for low-powered or high-impedance speakers by “seeing” them as a different load. Sensitivity comparisons should only be made within the same manufacturer’s product line.
Durability
Most speaker manufacturers list the sensitivity of their speakers in decibels (dB). This is a measure of loudness and tells you how much sound pressure the speaker can produce when it’s fed 1 watt of power. A difference in sensitivity means that one speaker will play louder than another when given the same amount of power from your amplifier.
Since most car audio equipment was made to work with 2 Ohm speakers, some 4 Ohm speakers may not be as efficient due to less cone area for moving air and lower sensitivity ratings.
However, many modern amplifiers feature built-in impedance protection circuitry which can compensate for low-powered or high-impedance speakers by “seeing” them as a different load. Sensitivity comparisons should only be made within the same manufacturer’s product line.
Car Speakers
In general, 4-ohm speakers are more durable than 2-ohm speakers. One of the most significant issues facing car audio drivers is heat buildup from hard use over time. Especially in the summer when it’s hot out and windows aren’t rolled down.
The coil of a speaker works by taking a voltage and turning it into a magnetic field which causes a voice coil suspended in that magnetic field to move forward or backwards. As this happens tiny “microscopic” dust particles get caught between the stationary wire and moving voice coil causing friction which leads to “Heat”.
More power = more magnetism = more resistance = heat
Higher impedance pulls more power from the source so there’s higher resistance there too. That means they have a higher risk of being damaged or even permanently ruined by a long session of high power.
What Damage Can Occur if Speakers Are Not Impedance Matched?
Failure to match your equipment’s impedance with that of speakers can damage or destroy your equipment. Leading you to have to buy expensive replacements for speakers or amplifiers. If everything is properly matched, you will experience perfect sound without distortion.
Can you use 4-ohm speakers with a 2-ohm amp?
In reality, if you connect a 4-ohm speaker load to a 2-ohm amplifier, you’ll wreak havoc on your equipment. If your impedance isn’t identical, it will cause a substantial power drain and your amp will overheat, resulting in failure.
In reality, if you connect a 4-ohm speaker load to a 2-ohm amplifier, you’ll wreak havoc on your equipment. If your impedance isn’t identical, it will cause a substantial power drain and your amp will overheat, resulting in failure.
FAQs
What is the best Ohm for a car speaker?
In a car stereo system, 4 Ohm speakers are best to consider because of more power because car audio amps are made to use for low–impedance speakers.
Is two way or three-way car speaker better?
Three-way speakers are best for car audio systems compared to 2 way speakers due to their extra mid-range.
Is higher or lower Ohm better for car speakers?
Low ohmic power in the speaker offers more efficiency because it offers electric signals to car speakers. So the speakers with low Ohm resistance are best to consider.
