Can You Hook Up Tweeters To The Same Amp As A Subwoofer?

Want to use tweeters alongside your subwoofers? Can you hook up tweeters to the same amp as a subwoofer? Great question!

I’ve put together this helpful article to answer your question – and provide some other great info, too. Read on to learn what you need to know.

Can you hook up tweeters to the same amp as a subwoofer?

can you hook up tweeters to the same amp as a subwoofer section image

It is possible to hook up tweeters to the same amp as a subwoofer in some cases and not possible in others:

  • Monoblock (bass) amps: You cannot use tweeters with this type, as nearly all have an internal low-pass crossover meaning they produce only bass. There’s no way to do this.
  • 2 or 4-channel amps with a low-pass crossover in use: You cannot use tweeters in this case either, as similar to a mono bass amp they’ll produce only bass as long as the low-pass crossover option is in use.
  • Full-range amp channels powering woofers: This will work for hooking up tweeters, although it’s not your best option. Full-range amp output channels can power woofer alongside tweeters as long as the amp can handle the total Ohms load.
  • Multi-channel amps: This is for sure the best way to connect tweeters with to an amp. By using separate amp channels (full range output) for the tweeters you’ll have better control over your tweeter power and volume. You can also connect them alongside smaller speakers on the same channels in most cases.

example of a car woofer speaker box with tweeters

Example of an older speaker enclosure with tweeters and woofers powered from the same amp channels. This is the same principle as using woofer and tweeters on the same full-range amp channels. (Speaker enclosures like these are uncommon in modern times because they’re not great for clear bass)

While you can connect tweeters to full-range woofer amp channel outputs, it’s not really the best approach for several reasons:

  • The tweeters will be powered at the same or similar level as the subwoofers, meaning you won’t have control over their power & volume levels.
  • Woofers don’t sound good without crossovers. While it might be possible to find some passive (non-powered) low-pass crossovers to use with your woofers, they’re not as good sounding as the ones built into most amps these days.

The best option is to use dedicated amp channels for your tweeters either alone or alongside other small full-range speakers on the same channels. Leave the subwoofers on separate amp channels using a low-pass crossover.

You’ll get better sound (clear, tight bass) and better control over your speakers, too!

Tweeter and subwoofer amp wiring compatibility diagram

tweeter and subwoofer amp wiring compatibility diagram

As you can see from the diagram above, connecting tweeters alongside woofers – if the amp’s output is full-range – is simple. However, it’s absolutely critical that your tweeters include their own crossovers to protect them from bass.

As long as the total Ohms load from wiring tweeters in parallel does not fall below the minimum Ohms rating of the amp you’ll be ok. However, wiring tweeters in parallel with woofers on the same channels also means you could overpower your tweeters when driving woofers hard.

You’re better off with more amp channels or a 2nd amp to drive the tweeters or other speakers too.

Do you need an amp for tweeters?

do you need an amp for tweeters section image

When it comes to tweeters here’s the basic truth:

  • You do not need an amp for tweeters if you simply want better treble (“highs”) and don’t need more clarity, volume, and power. In fact, you can wire them to a standard car stereo, the easiest option, if you don’t care that much about more volume and power.
  • If you want to be able to crank your music sometimes and want the best sound quality possible then you do need an amp for your tweeters.

Powering tweeters from an amp vs a car stereo

While there are a few head units out there these days with extra power, most of the time standard car stereo power is about 15 to 18 watts RMS per channel. That’s a fraction of what a decent amplifier can provide per channel.

Since most people use a head unit to power front and rear speakers, adding tweeters to your head unit means you’ll have even less power than that available because they have to share the available power. This means when you start to crank the volume up you’ll start hearing distortion and the speakers “breaking up” early since there’s not enough power.

Here are some pros and cons to consider for using an amp vs a car stereo to drive tweeters:

Tweeter Power Pros/Cons/Notes
Car stereo PROS: (usually) fairly easy to install + costs less. Decent sound quickly. CONS: Low power output, clarity not as good as from an amp. Can’t crank the volume high. Also, have to be careful with the speaker Ohms load as most head units are 4Ω/channel min.
Car amplifier PROS: Great sound, power, and volume even for budget amps. Easier to hook up alongside main speakers as most amps are 2Ω stable. CONS: Requires installing speaker wire, amp, etc. Best for tweeters with a decent power rating (30W-50W and up).
Table Table

Personally, I recommend using at least a small amplifier for your tweeters. Modern class D mini amps are great for this, very compact, and some can be wired directly to the car radio power wiring since they draw less electrical current.

I’ve used tweeters as part of my custom 2-way component speakers for years now with excellent results! There’s just no comparison in the sound quality and top-end volume you’ll get versus wiring them to a head unit.

How much power do tweeters need?

example image of typical car tweeter RMS power rating

Typical car tweeters don’t need a ton of power. Here’s what to remember when choosing amp power for tweeters:

  • To drive your tweeters at full power you’ll need close to the same (or higher) RMS power rating for your tweeters. If your amplifier has even more power than needed that’s fine – it’ll go unused. (Be aware that driving the tweeters with too much power can burn out the voice coils, damaging them permanently)
  • I recommend at least about 30W power although using an amp with at least 50W RMS/channel is best. Car stereos have only about 15-18W per channel typically which isn’t very much, so an amp with so little power isn’t really worth bothering with usually.

Remember that if you connect tweeters alongside (in parallel with) your other speakers on the same amp channel they’ll both have to share the available power.

Let’s take an example:

  • We’ll use an example amplifier rated for 60W x 4 at 4 ohms per channel, 90W x 4 at 2 ohms per channel.
  • A 4 ohm 6.5″ coaxial speaker in parallel with a 4 ohm tweeter equals a total of 2 ohms seen by an amp channel. Therefore there’s 90W available, divided in half by the speaker and tweeter, providing up to 45W each.

As you can see, if you’re planning on hooking up multiple speakers and tweeters to the same amp you’ll need to take this into consideration. In that case I’d recommend at least a 75W per channel amplifier, although 100W RMS would be better.

Where to put tweeters in a car

examples of car tweeter installation options

Car tweeters work best when mounted in a place that directs sound toward your ears. This is because high-frequency sounds, unlike bass, are more focused and lose volume when not aimed directly at your ears. As a general rule, avoid mounting them lower in your vehicle. This is why factory-installed tweeters in vehicle doors or side pillars near the windshield are popular.

Trust me, I understand how tough it can be to find good mounting locations for tweeters! If you have the option, it’s best to mount tweeters based on two things:

  1. They’re more or less at the same height as your ears
  2. They’re pointing directly towards your head & ears

Unlike subwoofers which create huge bass sound waves that are so big it’s hard to tell where they’re coming from, highs are directional, meaning you’ll get better tweeter performance when the sound is directed at you and at approximately the same height.

Tweeters, like some other types of speakers, produce high-frequency audio waves that drop off in volume badly when they’re at an angle other directly facing directly at you. This is called directivity and their off-axis performance is sometimes specified by speaker manufacturers.

You can use less power when driving tweeters the better they’re mounted (as you won’t need to increase the power and volume to make up for them being used “off axis”, or meaning facing at an angle away from your ears).

Tweeter mounting pods

If you’re out of options, you can pick up a set of tweeter pods that are “universal” in that they can be used in nearly any vehicle – even boats or RVs! Made out of plastic or metal (sometimes available in different colors, too), they’re tweeter mounting cups with a base designed to let you mount them to nearly any flat surface.

Installing tweeters in factory door locations

example of component speakers installed in car door

Example of upgrading factory speakers in a car door with a separate woofer, tweeter, and crossover. Note how the aftermarket tweeter is mounted in the factory bracket, held in with hot glue.

In some cases, factory-installed tweeters are placed high in the doors or side windshield pillars from the factory. When replacing factor speakers or adding your own you can often hot glue new tweeters in place of the original ones or make a mounting plate to install new ones. Door window sill plastic covers are also a good place to mount them.

While it’s still better to mount them high up on the dash, this still usually gives pretty good results. Flush-mounted tweeters are arguably the best looking but not recommended unless you’re comfortable cutting your vehicle’s interior and are confident in your project skills because it’s permanent and can be a bit tough.


About the author

Marty is an experienced electrical, electronics, and embedded firmware design engineer passionate about audio and DIY. He worked professionally as an MECP-certified mobile installer for years before moving into the engineering field. Read more »

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