How To Wire Tweeters With A Built In Crossover To An Amp

Tweeters – even budget ones – can make a huge difference in your system. However, you may need to know a bit more before getting started. I’d love to help!

In this article, I’ll show you how to wire tweeters with built-in crossovers to an amp. I’ve spent hours creating clear & detailed diagrams to help, too.

I’ll cover a lot of topics that really matter:

  • How to wire tweeters with built-in crossovers to an amp
  • Using tweeters with an amp’s built-in crossovers
  • Using your tweeters with a 2-way component speaker crossover
  • Whether or not you can use tweeters with an amp driving subwoofers

How to wire tweeters with a built in crossover to an amp

how to wire tweeters with built in crossovers to car amp diagram

The great news is that generally, car tweeters with crossovers are fairly easy to connect to amp in your current (or new) mobile audio system.

Note: I’ll use both the words Ohms and its symbol (“Ω”), used often in electronics, when talking about speaker impedance & resistance.

There are a few things to know first:

  • Most of today’s 2 and 4 channel car amp products can handle both a 4 ohm full-range speaker and a 4Ω tweeter connected in parallel at the same time.
  • It’s possible to keep the tweeter’s crossover and use an amp’s built-in crossover later (See related section below for more details).
  • Not only should you never use a tweeter without a crossover, but you also shouldn’t connect a tweeter to subwoofer outputs under normal circumstances. I’ll cover that in more detail later also.
  • You can replace the original tweeter crossover with a better one or use it with a 2-way component speaker crossover if you like.

How to connect tweeters with crossovers to an amp

To connect tweeters with crossovers to an amp, you’ll want to use one of the following setups as they’re the most common situations you’ll come across:

  1. Connect them to unused amp channels with a full-range output option: Follow the positive and negative wiring connections on the amp, being sure to match the same speaker polarity at the tweeter (either on the tweeter or marked on the external crossover for those that use an inline one).
  2. “Tapping off” of full-range speakers already connected to the amp: Don’t mix the polarity – for correct sound, be sure to connect the tweeter’s positive & negative speaker wiring to the same as the speakers already connected to the amp. To save time, effort, and speaker wire, if it’s convenient you can connect them in parallel at the speakers themselves. You’ll get the same audio signal there as at the amp as long as they’re full-range speakers.
  3. Connect them to unused amp channels: Using a full range RCA output pair from your head unit or use a pair of RCA Y-splitters at the amp to connect the 2nd pair of signal inputs to unused full-range amp channels. You’ll probably need to adjust the amp gain to a good level to match your speakers already in use.

Connecting tweeter wiring

While it’s true that a lot of tweeters come with connectors already on the wire, sometimes it’s just easier (and gives better results) if you use another way to connect the wire. Crimp connectors, for example, give professional results and won’t let you down.

In my experience, some of the connectors (usually slide tab or “spade” type) included with car tweeters are a pain in the behind to deal with. In fact, I rarely use them at all myself.

Keep reading to find out how to connect tweeter speaker wiring with professional results.

Where to install your tweeters

Car tweeter factory installation locations examples

Car tweeters work best when installed where they have a good direction toward your ears. That’s because high-frequency sounds are more directional than bass, for example. As a rule, try to avoid installing them lower in your car or truck. This is one reason you see factory-installed tweeters mounted in vehicle doors or side pillars near the windshield.

It’s not always an option, but when possible it’s best to mount tweeters:

  1. High up near the level of your ears
  2. Pointing towards you

That’s because unlike subwoofers which create huge 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 towards you and unobstructed.

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.

It’s one reason that factory-installed tweeters are placed high in the doors or side windshield pillars from the factory. In fact, high-end home stereo speakers are designed the same way…just that both the tweeter and woofer are placed on the same “plane” or at the same level for best results.

This is also one reason why car component speakers include tweeters designed to be mounted separately – to get the best possible sound by putting them in the best position you can find.

How to connect tweeter wires like a pro installer

Man with sign for how to strip & connect speaker wire properly

For excellent installation quality, I recommend using better connectors when possible. There are really only a few steps needed and before you know it, you’ll be great at it!

The steps are:

  1. Strip the speaker wire and prepare it for the connector
  2. Insert firmly into the (correct size) crimp connector
  3. Properly and firmly use a crimp tool to permanently connect the wire

Then repeat for the other wires as needed.

How to strip speaker wire

How to strip wire example

To strip speaker wire you can use a number of tools. My recommendation (and preference) is to use an affordable tool called a crimp tool. Most of these not only crimp connectors but can also cut and strip wire.

Stripping speaker wire can touchy at first and take a little bit of practice, but you’ll pick it up quickly after a few tries. The trick is to pinch only the wire’s insulation and not the wire strands themselves.

If you catch the wire inside by squeezing a stripper too hard you’ll likely break the wire and have to start over.

To strip tweeter speaker wire:

  1. Insert the wire in the stripper and close it carefully on the insulation. Use enough force to hold the wire in place and slightly pinch the insulation, but not enough to put force on the wire inside.
  2. Hold the tool & pressure in place firmly so it cannot move.
  3. Pull the wire. The insulation could break off and the exposed wire should remain.

What to know before stripping speaker wire the first time

Some wire types (especially smaller gauges like 20AWG, 24AWG, etc) can be harder to strip without breaking. For your first few tries, practice on some surplus wire that won’t cause you to use up what you need for your tweeter installation.

Image showing ruler next to 1/2 inch stripped wire

I recommend stripping enough to leave about 3/8″ to 1/2″ of bare wire exposed. For crimp connectors, 3/8″ or more should be fine. 

Don’t leave an excessive amount of length because it can stick out of the connector once it’s inserted.

How to use crimp connectors with speaker wire

How to use crimp connectors with wire instruction steps image

Shown: Step-by-step pictures of how to strip & connect speaker wire using crimp (“butt”) connectors. After stripping the wire, it’s time to use a crimp connector on each one and a tool to crimp them for a long-lasting connection.

Using crimp connectors with speaker wire isn’t very hard – I promise! You’ll get the hang of it after doing a handful of times.

How to crimp speaker wire properly:

  1. Strip the wire leaving 3/8″ to 1/2″ bare wire exposed.
  2. Tightly twist the wire so it can be pushed into the connector properly.
  3. Insert the wire into one end firmly, pushing it into the metal contact inside. Be sure to insert it fully.
  4. Place the connector into the crimp tool in the appropriate position in the tool, near the end of the connector.
  5. Crimp very hard with the tool to make an indentation in the outside of the connector. The internal metal connector should bend inward and make a permanent hold on the wire.
  6. Repeat the same for the other side & speaker wire.
Tip: For best results, once you’re done pull gently on the wire while holding the connector. The wire shouldn’t come out. If it does, you’ve crimped it poorly and will need to do it over again.

What should it look like when you correctly connect speaker wire together?

Closeup example of properly crimped speaker wire

Crimp connectors, also sometimes called butt connectors, are sold in standard colors for the wire gauge sizes they can be used with. Although red is listed as fitting 18 AWG wire, I’ve been using blue butt connectors with 18 AWG speaker wire for years without problems.

You should be able to find a very small package of blue connectors (or an assortment of several sizes) for just a few dollars in general merchandise stores or auto parts stores.

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

Hooking up tweeters to same amp as subwoofer diagram

Here’s the short answer:

  1. You cannot use tweeters on a monoblock (bass-only) amp or a subwoofer output channel using a low-pass crossover.
  2. You can use tweeters with unused amplifier outputs (channels) that are full-range.

Why can’t you use tweeters on a monoblock sub amp or bass output?

You might not have known it, but nearly all monoblock (single-channel) subwoofer amps are designed only to produce bass. They’re designed just to create a lot of power and drive subwoofers with high volume. There’s no treble (highs) to drive tweeters with at all.

Additionally, using an amplifier’s channel/channels with the built-in low pass crossover means you’re doing the same there as well. For that reason you’ll have just a few options:

  • For multi-channel amps, connect the tweeters to unused full-range amp channels.
  • Connect the tweeters in parallel to the main speakers.

If you only have a single amp for driving the subwoofers and no unused full-range speaker outputs on your amp, there’s no way around it – you’ll have to buy another amp for the tweeters or use your head unit.

Note that head units produce a very small amount of power (about 15W or so per channel) so your tweeters won’t get anywhere near the volume or power your amplified speakers will have.

Can you use the built-in crossovers on an amp with tweeters?

How to use car amp built in crossover with tweeters diagram

Yes, in many cases you can use an amp’s built-in crossovers with your tweeters. In some circumstances, you can even completely replace the tweeter’s crossovers this way!

Additionally, it’s one way to take advantage of your amp’s features and improve the sound.

A few examples are:

  • Using the amp’s 12d/octave crossover improves (or replaces) the cheaper 6dB/octave crossover some tweeters use.
  • Remove the hardwire tweeter crossover, making installation simpler.
  • Improve tweeter bass blocking without the need for extra parts or work.

How to use tweezers with built-in crossovers with a 2-way crossover

How to use tweeters with built in crossovers with 2-way speaker crossover diagram

I’ve actually run into this situation myself! Let’s say you have some extra tweeters lying around or you’ve got a cool idea for your own 2-way component speaker setup.

Or maybe you’ve got a component speaker system and one of the tweeters is blown, damaged, or broken. What if you could make good use of those extra tweeters or a pair you got a great deal on?

The good news is that in most cases if the tweeter impedance matches that of the 2-way crossover this can work.

However, the most important thing here (the “showstopper” if you will) is that you don’t use the built-in tweeter crossovers. You’ll have to remove and/or bypass those.

What can’t I connect my tweeter crossovers to a 2-way component speaker crossover?

The problem here is that a speaker crossover is designed to connect directly to the speaker “load” (to the speaker impedance, or resistance if you will) directly.

Speaker and tweeter crossovers contain capacitors and inductors. No problem there, but when one crossover is connected to another it changes how they behave. This means (1) the sound will be wrong, and (2) the crossover frequencies will be very wrong.

There’s no way to “fix” that. You’ll have to be sure and remove or bypass a tweeter’s crossover before using it with a speaker crossover it wasn’t originally used with.


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 »

Your comments are welcome.
  1. Hi Marty,
    I am currently doing my own audio upgrade and running into a problem which I need help with.

    I have an Isuzu Dmax 2021 and I am replacing the 6×9 speakers at the front and the factory tweeters with a set I bought.
    When I look behind the head unit and test for which is my speaker wire there are 2 wires in the pos and 2 in the neg. I’m guessing that a pair is for the tweeters and the woofer in the door.

    I have connected both positive wires to audio wire (so 3 wires) and both negative wires to my audio wire which is running to my LOC and then onto my amplifier. However this does not seem to work. Do I have to only splice my audio wire in between the door woofers and leave the tweeter wire on its own behind the head unit?

    Any tips would be appreciated

    • Hi Joe it was a little but unclear what you did but it sounds like you have ONLY two positive wires from the head unit from the front speakers is that correct?

      The line out converter won’t work with two positive wires connected together; rather, you would connect each speaker + and – wire to the corresponding wires on the line out converter. Don’t connect the positive wires to each other.

      If the speaker outputs from the factory head unit are full range (only one pair of wires for each speaker set, usually) you can tap off those for the line out converter. Howevever, if the head unit has separate tweeter outputs and woofer outputs, you’ll need a summing integration adapter like the AudioControl LC6i to “recombine” them back into a full-range signal.

      Hopefully that helps!

  2. Hey Marty, First thanks for taking the time and effort for explaining all this in great detail. My question. I have a 2009 toyota camry (no JBL) and im going to replace all 6 speakers (tweeters in dash, front doors and rear deck plus im going to be adding a pair of subwoofers. I already have a 4 channel alpine amp and a old school JBL bp1200.1 for the subs. So if I wanted to run all those speakers to there own channel then I would need a total of 6 channels if im not mistaken. The thing is I dont really want to get a third amp just to have them power the tweeters so i was debating on just running the tweeters off the head unit and the front doors/rear deck off the 4 channel and subs off the mono. Would that be ok or should I either replace the 4 channel amp with a 5 channel or get a small 2 channel just for the tweeters. The head unit is going to be Alpine iLX-W650 and the front and tweeters are going to be part of a component system which is alpine as well with a inline crossover . rears will be alpine as well to try to match everything up. What are your suggestions for the best way to hook all these speakers up?



    • Hello there, Chris.

      > So if I wanted to run all those speakers to there own channel then I would need a total of 6 channels if im not mistaken.

      Yes that’s true, but there’s not any reason to do that unless you’re bi-amp, using EQ/DSP/time correction functions which need separate channels, and so on. Just keep the 4 channel amp and use the front speakers in parallel.

      If you’re using a component setup there should be a 2-way crossover used anyhow for the best results. It will also maintain a total of 4Ω at the amp. Best regards!

      • Thanks Marty. I didn’t even think about the time correction aspect of it since that is one thing I want to do and a major factor on choosing the HU I did. I think I will run the front in parallel like you stated and since those speakers are pretty much close to the same distance then I wouldnt think it would effect the time correction to much and keep the rear speakers on there own channel. The front component speakers are seperate and the tweeters have a inline crossover and it appears the woofers have a resistor hooked up to them as well. I’ll know more when they arrive.

        Thanks again

        • Hi Chris yes I agree – it’s probably fine having them on the same channel and using time correction (TCR). If the woofer doesn’t already have a crossover on it (it sounds like it may) you can do it yourself pretty easily and acheive the same thing as a pre-made 2-way crossover.

          If you decide to do that, you can use my speaker crossover calculator (see top menu) and pick one with a low-pass option. Best regards!

          • Marty, I’ve been thinking about the wiring configuration and trying to plan it out. What do you think about the tweeters being powered by the HU and the rest (front/rear/subs) powered by amps? In my mind Im trying to keep all the speakers separated so I can tune there crossover points different and really utilize the Time alignment which Ive never done or had before but hear good things about it. Example: have the tweeters with a hp around 3500hz, the 6x9s in the doors and rear deck with a hp around 80hz and subs with a LP at 80hz. with this configuration my main worry is the tweeters would be under-powered with only having around 16w x channel rms ( thats whats stated on the data sheet for the HU. Your Thoughts?

          • Hi Chris. It wouldn’t be a good idea to power them from a head unit. The power will be mistmatched versus an amplifier but also the sound quality won’t be as good as a decent (or better amp).

            By all means I’d definitely use all amplified channels – maybe just add a small 2-channel amp for the rear speakers.

  3. Marty, I’ve been thinking about the wiring configuration and trying to plan it out. What do you think about the tweeters being powered by the HU and the rest (front/rear/subs) powered by amps? In my mind Im trying to keep all the speakers separated so I can tune there crossover points different and really utilize the Time alignment which Ive never done or had before but hear good things about it. Example: have the tweeters with a hp around 3500hz, the 6x9s in the doors and rear deck with a hp around 80hz and subs with a LP at 80hz. with this configuration my main worry is the tweeters would be under-powered with only having around 16w x channel rms ( thats whats stated on the data sheet for the HU. Your Thoughts?

  4. Thanks Marty. I was thinking the same thing about not giving the tweeters enough power and was also thinking of getting a small 2 ch. amp for on of the sets of speakers but I realized I only have 3 sets of pre amp outputs but I believe on of the other amps I have has a output to be able to hook into another amp. Im thinking instead of spending the extra money on the amp ill just wire the front speakers and tweeters together like you mentioned on the 1/2 channel and the rear speakers on the 3/4 channel and wire it so it will be easy to hook up another amp. I ordered some 9 conductor speaker wire so i guess I’ll just run another set of speaker wire with it for the tweeters. I wasn’t really thinking that out when I ordered it not realizing I have 6 channels of speakers and the 9 conduct is only 4 channels. oh well haha. Anyways thanks for all your help and advice. Im sure something will come up and you’ll see another comment sometime.

    • Sounds good, Chris. Sure, I understand. If you change your mind later you can make it work using an external electronic crossover to provide the extra channels along with the crossover (high and low-pass) outputs you need. They’re pretty affordable.

      Best regards!

  5. Hey Marty I have another question for you. My 4 channel amp I’ll be hooking up my 6 speakers too is 2 ohm stable so this is my thoughts on wiring all the speakers. Let me know what you think.
    Channel 1: Left Dash and Left Front door. Which I assume will make that a 2 ohm load
    Channel 2: Right Dash and Right front door. “”
    Channel 3 and 4: hook the 2 rear speakers up in parallel then bridge those two channels to make it a 2ohm load.

    Going for a 2ohm load across the board since that will give me 100w RMS X 4 at 2ohms

    bonus question: Looking at different wiring configuring on SVC and DVC doing parallel/series etc. I notice that one set of wires goes directly from one speaker to another then one set of wires goes directly to the amp. is there any difference in impedance or anything else if you just directly wired them to the amp (2 sets up wires to amp instead of 1) and not hooking one speaker directly to another then to the amp?

    And thanks again for taking the time to respond always and give advice/recommendations

    • Hi Chris. You need at least 4Ω when bridging amp channels. Also, there’s no advantage bridging two speakers that are wired in parallel – they’ll still get the same amount of power except you’ll lose the stereo sound, so it’s actually worse.

      Regarding your second question – I think you mean parallel vs series-parallel wiring? Parallel is ideal because each speaker will receiver the same voltage out of the amp’s speaker channel(s), bearing in mind they’ll still share the available power the amp can provide.

      Series-parllel typically isn’t ideal but is the “safe” way since it lets up meet the minimum Ohms requirement. However, typically the *total* Ohms load is higher, which reduces the total power the amp can provide. The speakers will then get a portion of that, which would be less than if they were wired in parallel.

      Hopefully that’s clear! Best regards.

      • Hey Marty thanks for the info. I reread what I wrote and it sounded a little confusing. So to make it more simple. If you don’t mind. How would you wire 6 speakers up to a 4 channel amp to get the maximum amount of wattage to those speakers.
        speaker locations:
        2 dash, 2 door, 2 rear.
        The amp is Alpine MRP-F450: 70 watts RMS x 4 at 4 ohms (100 watts RMS x 4 at 2 ohms)

        dash speakers will be part of a component set from alpine. The tweeters have a inline crossover and it looks like the door speakers (6×9 woofer) have resistors wired in as well, I cant find any info on the web about them.

        The rears will be alpine 6×9 Coaxial 2-Way and they have what looks like resistors wired into them as well. Which like the front door speakers, I cant find any info on the resistors

        Alpine S-S69C S-Series 6×9-inch Component 2-Way Speakers
        Alpine S-S69 S-Series 6×9-inch Coaxial 2-Way Speakers

        I’m also going to have some subwoofers which is why I was asking about the svc/dvc and the wiring. I understand the series doubles the ohms which make its safer but you lose power and parallel is more ideal to get the most about of wattage but can run your amp hot if played at max volume for extended periods. I was just curious because to me wiring a pair of speakers to the same channel seems the same as wiring Speaker Bs wire to Speaker As (parallel) and then run the single set of wires from speaker A to the single Channel terminals..if that made any since haha I guess what im asking is it necessary to wire the speakers together in parallel and run a single speaker wire to the channel or can you just run two sets of wire, one from each speaker to the single channel and achieve the same thing?

        • Hi Chris. My apology, as I thought I had replied to your comment but it seems I hadn’t yet.

          Here’s what I would do in this case to 1) get the most out of your dollar, 2) make it less complicated, and 3) get the most power to everything:

          1. Wire the 6×9″ components to the front amp channels. Fortunately, these are designed to work with a 2-way crossover setup, just that it’s not separate like other component speaker sets. (That’s an inductor on the woofers, not a resistor, to act as a low-pass crossover which is what we want).
          2. Bridge the rear amp channels which will give up to 200W RMS which will be fine for pretty decent bass with a good 4Ω SVC or 2Ω DVC subwoofer wired for 4 Ohms.
          3. Get a small amp for the rear channels. Rear speakers nearly always suffer from bad acoustistics in vehicles but don’t need nearly as much power anyhow. It is better to keep the rear MRP-F450 amp channels for the sub in this case, unless you want a lot more bass/power.

          In #1 above, the front tweeters/woofers will get full access to the rated power for those channels since they’re separated by the crossovers.

          That should get you going well, and then you can use the built-in high pass crossover(s) on the Alpine amp, set to around 50–60Hz, to block subwoofer bass from the front & rear speakers. You can let the subwoofer handle that. You’ll be able to drive the front and rear speakers with more power & volume without them distorting or “bottoming out” that way, too.

          > I guess what im asking is it necessary to wire the speakers together in parallel and run a single speaker wire to the channel or can you just run two sets of wire, one from each speaker to the single channel and achieve the same thing?

          You can do it either way. As long as they’re connected in parallel electrically it’s the same thing. A parallel connection means each load (speaker, in this case) gets the same voltage but the current supplied is split between them.

          Have a good day.

          • Thanks for the breakdown Marty. I failed to mention that I already have a subwoofer amp. A old JBL bp1200.1 that i would use for the subwoofers. I was trying to figure out how to wire the 6 other speakers to the 4 channel amp to get the most out of it. Also I’m not sure if I said this but the tweeters are separate from the 6x9s for the front and the rear 6x9s are 2way coaxial. I believe when we first started chatting you said wire the tweeters and front 6x9s to the front channels (4 speakers/2 channels) and wire the rear speakers to the other 2 channels. My math isnt good and im trying to figure out how to get all of those 6 speakers to run at 2 ohms if possible to maximize the output of the amp.

            >>In #1 above, the front tweeters/woofers will get full access to the rated power for those channels since they’re separated by the crossovers.<<< Im not sure what you mean in this statement. The tweeters have an inline crossover and the 6x9s have what i thought was a resistor but in fact you said an inductor which makes since. Does the inline crossover do something other then keep low frequencies out?

            I'm sorry for all the confusion Marty. Please bare with me.

          • Hi, I understand, but it doesn’t make sense to try and force a 2Ω load wiring setup. There’s nothing to be gained from it in this case – you’re not going to be able to get additional power to those 4Ω speakers without upgrading the amp to a more powerful one.

            Just use the front and rear channels for the front & rear speakers then the JBL amp for the subwoofer. Best regards.

  6. Thanks Marty, so just wire the tweeters and front 6x9s to channels 1&2 and the rear speakers to channels 3&4. Simple enough

  7. Hi Marty, I ran across your blog and it has been the most informative yet. I do have a question, I have a 2010 Camry with JBL system. I bought a kit that said would replace all speakers, however they sent 4 nvx nsp69 coaxial speakers. I put 2 in the door and they work fine, however, the back deck is factory component speakers that sound horrible. My question is, can I hook up the factory amp tweeter wires (which are crossed over in the amp) directly to the tweeter wires coming through the mid range bypassing the inline crossover? So I basically have your last example but wondering if I can turn a coax speaker into a component by removing the capacitor (built in speaker crossover)

    • Hi, yes, you’re lucky that in this case that could be done. Not many coaxial speakers are made in such a way it could be. As long as the factory tweeters didn’t have capacitors on them you can just skip those.

      Just cutt the tweeter wiring from the coaxial speakers’ wiring terminal after the capacitor and then connect the tweeter directly.

      Best regards!

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