Last Updated on: October 7, 2022
The subwoofer is a specialized type of speaker that delivers low-frequency sound.
Subwoofers are sizable compared to mid and high-frequency car speakers. However, they have a lower impedance rating, typically 2-Ohm to 1-Ohm loads.
While the audio quality may be hard to differentiate for most listeners, the 2-Ohm subs will deliver better sound due to their higher electrical resistance.
But, the 1-Ohm subwoofers will be louder. Your preference depends on several factors that we’ll discuss below.
Main Differences Between 1 Ohm vs 2 Ohm Subwoofers
The main differences between the 2-Ohm vs 1-Ohm subwoofers are:
- The 2-Ohm subwoofers have better sound quality, whereas the 1-Ohm subs deliver louder sound.
- The 2-Ohm subwoofers use less power to operate, whereas the 1-Ohm requires more power input.
- The 2-Ohm speakers are more readily available to buy, whereas the 1-Ohm subs cost less to buy.
What Is a Subwoofer?
A subwoofer is a speaker that delivers lower frequency bass sound than other speakers, typically between 70-80Hz for car audio systems.
We can categorize car subwoofers in two ways, depending on what kind of audio you aim to get. These include SPL and SQ subwoofers.
SPL subwoofers feature ported enclosures to deliver loud sound. Large car subwoofers, such as the 15 or 18-inch models, are typically SPL subwoofers. The large enclosure produces more air pressure, raising the sound pressure level, and giving you more boom and louder bass.
On the other hand, SQ stands for sound quality, and these subs are ideal for audiophiles targeting tonal accuracy. They are smaller than the SPL models at 10 and 12 inches, and feature sealed cabinets.
Why Speaker Impedance Is Important
Impedance is the electrical resistance that a subwoofer has, measured in Ohms. Car subwoofers typically have impedance values of 4 Ohms, with some having 2 Ohm to 1 Ohm loads.
One thing to note is that the impedance value of a speaker changes with its frequency. Also, the lower electrical resistance in the subwoofers uses more power and delivers more volume than higher impedance models.
Therefore, while the 1 Ohm sub hits harder than the 2 Ohms, it has less audio quality. However, most people cannot tell the difference in the sound produced by the 2 Ohm vs 1 Ohm subwoofers.
The impedance load and the RMS watts measure also determine the amp suitable for your subwoofers. But, before we get to wiring your speakers to an amplifier, let’s discuss another subwoofer classification; single voice coil and dual voice coil subwoofers.
Single vs Dual Voice Coils
A voice coil is a structure inside a speaker that passes electric current from the amp to create sound. It features a wire coil wound over a metallic cylinder enclosed with a permanent magnet.
As the electric current from the amp passes through the coil, it creates an electromagnetic reaction with the speaker’s permanent magnet.
The cylinder is attached to the speaker’s cone, and the force from the magnetic reaction of the coil causes the cone to vibrate, thus producing sound waves. You can learn more about how voice coils work from this video:
A single voice coil subwoofer features a single strip of wire coiled around the cylinder, with a positive terminal on one end and a negative terminal on the other.
A dual voice coil sub features two coils of wire wrapped around the cylinder, creating two positive and two negative terminals on each end. Both voice coils will deliver the same performance under similar conditions.
The difference is that the SVC subwoofer allows only one wiring option. On the other hand, the DVC sub enables wiring in parallel or series formats, and it costs more.
Wiring Your Subwoofers
The main factor determining whether to wire your subwoofers in series or parallel is the impedance load and how much power the setup will present to the amplifier.
As wattage increases, the impedance drops, meaning more power demand from the 1 Ohm vs 2 Ohm subwoofers.
Therefore, the amplifier’s RMS power rating should match the subwoofer’s peak power rating to prevent damage to the electrical system. While you can wire several subwoofers to the same amp, ensure that the Ohm load does not exceed what the amplifiers can handle.
For instance, a 500-watt amp will deliver 500 watts of power when connected to a lower Ohms sub. It uses more watts and produces more heat as it has a low electrical resistance.
On the other hand, the amplifier will provide half its rated power to a 2 Ohm subwoofer as it consumes less power. If you use an SVC subwoofer with a lower resistance, you can opt for a mono sub amplifier with the same Ohms measure as your speaker.
In this combination, you connect the positive terminal of the first sub with the negative terminal of the other subwoofer. We then connect the remaining positive and negative terminals to the amplifier.
Generally, connecting your car speakers in series increases the final impedance load to the amp.
So, if you consider two 2 Ohm SVC voice coils wired in series, you get a 4 Ohm load to the amp. However, while the series circuit lowers the overall audio quality of speakers, it doesn’t affect woofers and subwoofers.
In a parallel combination, we connect the positive terminal of one sub to the positive terminal of the other sub. Similarly, the negative terminals of the two subs are connected together.
This circuit creates two combined positive and negative terminals to connect to the amplifier. The total impedance drops inversely for every speaker you add to a parallel setup.
As a rule, the total speaker load should be equal to or higher than the minimum impedance rating of your amplifier or car stereo to prevent damaging your equipment.
How Wiring Affects Subwoofer Output
When using multiple subwoofer systems, it is necessary to consider the total Ohm load of the voice coils to the amps. As mentioned above, you get a higher impedance value and low power output from the amplifier in the series combination.
In parallel connections, the total impedance drops, making the power demand from the amp higher. Additionally, the damping factor of your circuit is another feature to consider.
The damping factor is the ratio of impedance load to the amplifier’s output resistance. If you have a low damping factor value in your setup, it can affect the clarity of the bass sound.
Generally, all amps can drive a 4 Ohm load, and most can work with a 2-ohm load. However, there are ohm stable amps in the market with the full power for the one Ohm subwoofer because it requires the most power output.
Dual 2 Ohm voice coil subs are flexible to wire in any combination, making them ideal for designing car systems. For instance, you can have a total impedance of 1 Ohm or 4 Ohm from the same sub of 2 Ohms resistance, depending on the wiring.
So, is 1 Ohm impedance better than 2? The answer is not as straightforward as we would want. 1 Ohm subwoofers are loud and are great if you are the kind of person who loves rock music. However, one needs a 1 Ohm stable amp to drive this sub.
On the other hand, if you prefer good audio quality, you could consider the dual 2 Ohm subwoofers. It all depends on what you want to achieve in audio quality and volume.