How to Match Subwoofers and AmplifierUpdated 8 months ago

Are you looking to enhance your car audio system with deep, powerful bass? One of the most critical aspects of achieving great sound is ensuring that your subwoofers and amplifiers are perfectly matched. In this comprehensive guide, we'll walk you through the process of selecting the right amp for your sub or the perfect sub for your amp. Let's dive in and unlock the secrets to achieving audio nirvana on the road.

**Please be advised that it's highly recommended to consult with a professional installer before making any decisions regarding the selection of audio equipment. Their expertise can help ensure optimal compatibility and safety for your setup.**

Understanding the Basics

Power Matching

• Subwoofers are rated in terms of their RMS (Root Mean Square) power handling capabilities.
• Amplifiers deliver power to the subwoofers, and the RMS wattage of the amp should match or slightly exceed the total RMS rating of the subwoofer system.

Impedance

• Impedance, measured in ohms, represents the electrical resistance that the amplifier "sees" at its output terminals.
• Subwoofers can have different impedance ratings, and it's essential to ensure that the amp can handle the impedance load presented by the subs.

Part A: Choosing an Amplifier for Your Subs

If you already have subwoofers and need to find a compatible amplifier, follow these steps:

1. Determine Power Requirements: Calculate the total RMS rating of your subwoofers by multiplying the RMS rating of each sub by the number of subs.
2. Assess Impedance Options:
   Figure out the possible total impedance(s) that the subs can be wired together to form.
   • SVC = A subwoofer with a single voice coil. It has only one pair of terminals.
   • DVC= A subwoofer with a dual voice coil. It has two pairs of terminals.
     • 1 SVC 2-ohm sub can only have 2 ohms of impedance
     • 1 SVC 4-ohm sub can only have 4 ohms of impedance
     • 1 DVC 2-ohm sub can have 1 ohm or 4 ohms of impedance
     • 1 DVC 4-ohm sub can have 2 ohms or 8 ohms of impedance
     • 2 SVC 2-ohm subs can have 1 ohm or 4 ohms of impedance
     • 2 SVC 4-ohm subs can have 2 ohms or 8 ohms of impedance
     • 2 DVC 2-ohm subs can have 1/2 ohm, 2 ohms, or 8 ohms of impedance
     • 2 DVC 4-ohm subs can have 1 ohm, 4 ohms, or 16 ohms of impedance
3. Select an Amp: Look for an amplifier that can deliver the required RMS power at an impedance load compatible with your subwoofers. Consider odd impedance values and choose an amp accordingly.

• 8 ohms: About half the power of 4 ohms.
• 6 ohms: Around three-quarters of 4 ohms' power.
• 3 ohms: Average of 2 ohms and 4 ohms' power.
• 2.7 ohms: Similar to 3 ohms, plus a few watts.
• 1.3 ohms: Utilize the 1-ohm spec, slightly reduce power.

Example Situation:

You have two Black Diamond 10D4 10" subwoofers and you want the right amp for them.

• They are DVC 4-ohm subs rated at 220 watts RMS each.
• Two 220 watts RMS subs together need a combined 600 watts of RMS power.

Using the information above, you can wire two DVC 4-ohm subs together to achieve a 1-ohm, 4-ohm, or 16-ohm load. However, the 16-ohm load isn't practical. Therefore, you're searching for an amp capable of delivering up to 440 watts RMS into either a 4-ohm load or a 1-ohm impedance load. This means you need an amp that can handle:

• Up to 600 watts RMS x 1 at 4 ohms
• Up to 600 watts RMS x 1 at 1 ohm

Among Big Jeff Audio's selection of amplifiers you'll find:

• Marts Digital MXD Series 500-1-V2 - 520 Watts RMS x 1 at 1 ohm
• Black Diamond P1000X1D - 1000 Watts RMS x 1 at 1 ohm

**Considering the typical impedance rise, we advise aiming for an amplifier that exceeds the combined RMS rating of your speakers/subwoofers by 10-20%. This ensures sufficient power delivery and helps mitigate potential performance issues.**

It doesn’t matter which impedance an amp plays through — 300 watts RMS through a 4-ohm load produces the same volume as 300 watts RMS through a 1-ohm load.

Part B: Choosing Subwoofers for Your Amplifier

If you already have an amplifier and need to find compatible subwoofers, follow these steps:

1. Assess Amp Power: Determine the RMS power ratings of your amplifier at different impedance loads.
2. Determine Sub Requirements: Divide the desired power output by the number of subs you plan to use to find the target RMS rating for each sub.
3. Consider Impedance and Voice Coils: Based on the impedance and power requirements, identify suitable subwoofer configurations (single or dual voice coil, impedance rating).

4. Choose Compatible Subs: Select subwoofers that match your calculated RMS power requirements and impedance configurations.

Example Situation:

You have a Black Diamond P2000X1D Amplifier and want it to drive two subwoofers.

• The amp is capable of 2000 watts RMS x 1 at 1 ohm.

If you want to maximize the amp's potential and want the system to put out 2000 watts RMS, you should have your subs wired to form a total impedance of 1 ohm.

Two subs on a 2000 watts RMS amp will want about 1000 watts RMS each. So you'll look for subs each rated for around 800 - 1000 watts RMS.

Using the chart above, for two subwoofers, a final 1-ohm load can be achieved with either two SVC 2-ohms subs or two DVC 4-ohms subs. 

Among Big Jeff Audio's selection of subwoofers you'll find:

• Sundown SA Series 10" Subwoofer - DVC 4-ohm, 750 Watts RMS
• Deaf Bonce Machete 12" Subwoofer - DVC 4-ohm, 800 Watts RMS

Part C: Getting Started from Scratch

If you're starting from scratch without an amp or subs, here's what to do:

• Learn the Basics: Familiarize yourself with the fundamentals of subwoofers and amplifiers using resources from our Help Center.
• Seek Expert Advice: Reach out to a professional installer, and ask our knowledgeable advisors for personalized assistance in building your audio system from the ground up.

By following these steps, you can ensure that your subwoofers and amplifiers are perfectly matched, resulting in exceptional sound quality and bass performance in your vehicle.