How To Wire A 4 Channel Amp To 4 Speakers And A Sub: A Detailed Guide With Diagrams

4 channel amps are great and have a lot of flexibility for the most part. However, they’re intended for use with 4 speakers or 2 speakers and a sub – not both.

However, it is possible to wire a 4 channel amp to 4 speakers and a sub! I’ve put together some really detailed information to help make this as painless (and inexpensive) as possible.

Read on to find out how! There are plenty of detailed diagrams to guide you, too.

What you need to know first

Clip art image of a face thinking - Things to know content image

Let’s get a few things out of the way before we go any further. To drive 4 speakers and a sub with a single 4-channel amp you’ll have to make a few compromises.

I’ll explain here what I mean:

  • You’ll likely have to give up front-rear fader control ability as you’re giving up 2 channels for the rear speakers to drive a sub (2 front/2 rear).
  • Most but not all car amps today can handle speaker loads down to 2 ohms. If yours doesn’t, you’ll need a work-around I’ll show you. You may need a few extra parts.
  • Driving 4 speakers from 2 channels means the speakers are sharing the amp’s power, so you’ll have less power available to each of those.

That being said, don’t worry too much! You can still enjoy the music you love with a nice-sounding 4 speaker + subwoofer system.

What does the minimum impedance (Ohms) rating mean for an amp?

Image showing the minimum speaker Ohms rating for Rockville RXA-F1 4 channel amp as an example

Image showing a typical 4 channel amplifier’s minimum speaker load (Ohms) rating. Most car amps today have a minimum of 2 ohms per channel in standard (stereo) use and 4 ohms minimum when bridged. Never run an amplifier with a speaker load that’s lower than the rating! Your amp will run hot and possibly become damaged.

Today’s 4 channel (and other) car amplifiers have a minimum speaker load they can handle. The speaker impedance or “Ohms” rating of a speaker (also called the speaker load) is the resistance to the flow of electrical current that the amplifier sees at the speaker terminals.

Amplifiers are designed to handle a minimum speaker load. The rating shown on the amp or in the owner’s manual serves as a warning.

If you connect a speaker load below the amp’s minimum rating it can get hot and even become permanently damaged at some point.

I’ve seen this happen when people try to “get more power” by incorrectly wiring speakers to an amp. Don’t do it! Burning out your amp’s output stages is not a nice surprise.

Minimum speaker loads for wiring a 4 channel amp to 4 speakers and a subwoofer

Diagram showing series and parallel speaker Ohms calculation examples

Diagram showing how a car amplifier’s Ohm rating works with speakers. Speakers are usually connected in series or parallel (well, really, most often in parallel) which affects the total resistance an amp will see. That’s important because amps are designed for a certain minimum speaker load (Ohms rating).

As I mentioned above, most car amps today can handle a 2 ohm load per stereo channel (left & right channels) and 4 ohms minimum when bridged to drive an amplifier (called “mono”).

The real answer, however, is that it depends on your amp’s ratings. Always be sure to check to be sure. To keep it simple, I’ll summarize what will work for almost all systems & amplifiers you’ll come across.

The amp wiring systems I’ll cover here

In this post I’ll cover 3 types of systems as that should cover almost all amps you’ll find:

  1. 4 channel amps with a minimum speaker load of 2 ohms in stereo, 4 ohms bridged (for the subwoofer)
  2. 4 channel amps with a minimum speaker load of 2 ohms in either stereo or bridged
  3. 4 channel amps with a minimum speaker load of 4 ohms

#3 is less common but it’s one you’ll run across. Maybe you’ve got an older amp that’s been sitting around unused. If so, you’ll be glad to know there’s a work-around that I’ve come up with that will let you wire your 4 speakers up without damaging your amp.

4 Channel Amp Wiring Examples

Here are the speaker wiring and speaker (Ohms) loads possible for nearly all amps you’ll run across. I’ll describe 3 main system setups which I’ll cover in detail.

System 1: 2 speakers (parallel wiring) to each front channel = 2 Ohms x 2 + 1 subwoofer wired for 4 Ohms on the rear channels bridged for more power. This is the first and best choice for most modern 4 channel amps.

System 2: 2 speakers in parallel to each front channel = 2 Ohms x 2 + 1 subwoofer wired for 4 or 2 Ohms on the rear channels bridged for more power. 4 channel amps that handle 2 ohms bridged are less common but they are out there.

System 3: 2 speakers on each front channel (parallel wiring) wired with extra parts for 4 ohms per channel + 1 subwoofer wired for 4 ohms minimum. Because these kinds of amps can’t handle a 2 ohm load, it’s a bit harder and needs a different approach.

Testing speaker ohms with a multimeter

Image showing an example of how to test speaker ohms with a multimeter

Shown: An example of how to measure speaker impedance (Ohms) with a multimeter. It’s a great way to know for 100% sure what kind of speakers you’re dealing with to avoid problems with your 4 channel amp.

Car stereo and home speaker speakers are very similar except for the impedance rating they use. A speaker’s impedance value, measured in Ohms, is just the total measurement of electrical resistance the amp will see from the speaker’s voice coil.

Partly due to tradition in the electronics world and partly due to various other electrical reasons car stereos are commonly rated at 4 ohms and home stereo speakers around 8 ohms.

The good thing is that all you really need to know is roughly what the resistance of a speaker is. If you can measure that you can tell what Ohms rating to go by!

How to measure speaker Ohms with a multimeter

Example image showing how to use multimeter probes on a speaker

To measure the Ohms (resistance) of a speaker’s voice coil, hold the meter probes to the speaker terminals, making sure to keep firm contact to bare metal Paint, insulation, dirt, and solder flux can mess up your reading otherwise.

For example, we usually have a label on a speaker telling us if it’s 2 ohms, 4 ohms, and so forth. However, as crazy as it sounds, some speakers don’t!

That’s why it’s excellent to have a multimeter handy – you can find out 100% for sure.

Measuring speaker Ohms with a multimeter
  1. Set the multimeter to the Ohms setting. If the meter has an auto-ranging function you should be fine. Otherwise, set it to the lowest setting like the 10 Ohms or 200 Ohms range, etc.
  2. With the speaker disconnected, touch the speaker terminals with the meter probes. Be sure to touch bare metal on the terminals and make good contact.
  3. Read the measured value. The general range will tell you the Ohms rating of the speaker (Example: 3.6 ohms resistance would mean a 4 ohm speaker)

It’s important to be sure you’re not measuring across substances that can interfere with your measurement.

Things like the following can cause problems (I have seen this happen many times!):

  • Leftover solder flux or solder coating from manufacturing
  • Heavy oxidation
  • Heavy dirt, dusty, or other contaminants that build up over time
  • Paint or other coatings that don’t conduct electricity

If in doubt, you can rub them gently with a bit of sandpaper or even scratch the meter probes against the terminals to make better electrical contact.

Note: If a speaker is “blown” or burned out from abuse or physical damage to the voice coil you’ll never get a reading. That’s because for blown speakers the voice coil no longer has a complete electrical path you can measure.

Multimeters show an open circuit condition as “infinite” Ohms, which just means there’s no reading to be made.

Speakers don’t measure exactly 4 or 8 ohms!

Car and home speakers are rated by their general Ohms (impedance) rating. For example, 2, 4, and 8 ohm speakers are never measure exactly with those Ohm measurements.

That’s because each speaker’s design is a bit different from the next. The resistance you measure from a speaker is due to the voice coil’s resistance thanks to the long wire it’s made of.

Here’s an example chart to help you know what to expect when measuring speakers.

Speaker Rating Typical Measurements
2 Ohms 1-1.8 Ohms
4 Ohms 3.2-3.6 Ohms
8 Ohms 6 Ohms or more
16 Ohms 12 Ohms or more

As you can see, you won’t measure exactly 4 ohms for a 4 ohm speaker. It will be in the general range and close to its advertised rating, however.

What is “bridging” an amp? Why is this best for driving a subwoofer?

Diagram showing a 4 channel car amplifier bridged to 2 channels

Shown: Example of a 4-channel amp bridged to 2 channels.

Bridged mode (mono mode) is a built-in amplifier feature in which a “push-pull” set up is created: one channel (normally used for the left speaker) produces a signal that’s the opposite of the second channel (normally used for the right speaker).

When this happens the result is that you’ll get substantially more power with them working together than you would with one channel alone.

Bridged mode is a flexible way to get more power from 2 channels (in this case the rear channels, for example). That’s especially important because subwoofers are big, heavy speakers that need more power than small speakers to produce the bass sound you want.

Diagram – How to wire a 4 channel amp to 4 speakers and a sub

Note: Most standard aftermarket car speakers are 4 ohms each so I’ll use that assumption for my diagram. Always be sure to check your speakers before you wire them to your amp to be sure they’re compatible.

(Or click on the image to enlarge & zoom)

Detailed diagram for how to wire a 4 channel amp to 4 speakers and a subwoofer

Using power resistors for harder installations (4 ohm min. amps)

Image showing examples of higher power resistors (4 ohms) for use with speakers

Shown: High power resistors that can be used with a 4 channel amp when adding more speakers. Using these will allow you to keep the total speaker load (speaker Ohms the amp sees) to a safe level so the amp won’t get damaged. They’re inexpensive and are easy to use.

Power resistors are larger versions of the resistors used in many electronic products. Unlike their smaller siblings, they’re designed to be able to handle a large amount of heat.

Because of this, they’re a great way to deal with more difficult speaker and amp systems. In example #3 I showed you earlier, it’s not possible to use two 4 ohm speakers in parallel with an amp that can’t handle 2 ohm loads.

We can use 1 large resistor for each speaker as a work-around for this.

This workaround won’t be necessary for most modern car amps. However, since a few amps out there can’t handle 2 ohm loads (especially older amps you might have that you’d like to use) I’ve included this just in case.

Diagram showing how to wire speakers with power resistors for 4 ohms total

In the case of a car amplifier that can’t go below 4 ohms per channel, there’s no other way. However, if we add one 4 ohm power resistor in series with each speaker we can use the math to our advantage.

By doing so, we’ll end up with two 8 ohms measurements in parallel which will give us a nice, safe 4 ohms per channel!

However, you’ll want to buy the right kind of resistor. I recommend at least 25 watt (25W) 4 ohm resistors. While you won’t find them in many local stores, the good news is that they’re affordable. I’ve used them many times for speaker problem-solving.

I’ve used some like these over at Amazon.

How to get around the lack of a front/rear fader

As I mentioned at the beginning, if you’re using a 4 channel amp to drive both 4 speakers and a subwoofer, you’re going to have to make compromises. There’s simply no way around it.

The biggest one that comes to mind is losing the front/rear fader control. However, I’ve come up with a sort of solution that helps a bit!

By adding inline resistors to the rear speakers you can drop their volume and it acts as a “fader” already. You can use an L-pad (speaker volume attenuation) site like this one here to calculate resistor values for you.

I’ve already done the work for you, and here’s a great example. If you’re wiring 4 speakers and a subwoofer to a 4 channel amp, by adding 60 ohm resistors to the rear speakers you’ll drop the volume by 24dB (decibels).

The result will be that the sound is “faded” to the front and the rear speakers won’t be too loud.

Image showing to how to create a fader to rear speakers using resistors

Following the example I’ve provided here in the diagram above it’s pretty easy. You’ll need to pick up some 15W-20W (or higher) resistors. I recommend about 60 Ohms as it will give a volume reduction of 24dB.

That should be enough in most cases: Not totally silent in the rear, but most of the volume towards the front speakers.

What crossover settings should I use on my 4 channel amp?

Close up image of a car amp crossover controls

As most modern car amplifiers include very nice optional crossovers, for good sound it’s smart to take advantage of those.

Here are some good recommendations for the 4 main speakers and the subwoofer:

Speaker Crossover Settings
4 main speakers Flat (crossover off) or 56-60Hz high pass
Subwoofer 80Hz low pass

By using a high-pass filter for the 4 main speakers you can crank the volume when you want for more power & sound before distortion happens. When using a subwoofer, it’s really important to block vocals and upper-frequency music from getting to your sub.

The idea is to get “pure” bass sound as that’s what subwoofers are best suited for: Just purely producing great-sounding bass you’ll love.

What if my amp can’t be bridged?

Image with diagram of how to bridge an amplifier

While it’s true that nearly all amps with any “real” power today can be bridged from 2 channels to 1 channel (called “mono”, or bridging) for more power, some can’t. That’s especially the case for some older “old school” amps you might have in your closet but still like to use.

In that case, unfortunately, you’re really limited. Sorry! You have just a few options:

    1. Buy another small amp just for the subwoofer/subwoofers
  1. Run one small subwoofer from each of the rear channels

The problem with option #2 is that subwoofers need a lot more power to drive them well and sound good. There’s just no way around it.

8″ subwoofers are an option or a dual 4 ohm voice coil subwoofer could be used. That way you can safely drive each channel with a 4 ohm load even older amps can handle. These days, though, it’s usually easier just to get a cheap budget amp and avoid the headaches.

How to connect a 2 ch. car stereo to a 4 channel amp

Diagram showing a 2 channel car stereo connected to a 4 channel amp

If your stereo doesn’t have output channels that’s ok! You can still connect a head unit car stereo with only 2 channels (left and right) to a 4 channel amp easily. In most cases, you only need 2 RCA Y adapter cables. The head unit’s left channel RCA jack is connected to the left front and left rear amp inputs. Then the same for the right channels. If using speaker level inputs on the amp, use the connections shown above. NOTE!: Use only ONE of the two connections shown. Never connect both the speaker level and RCA jacks at the same time – speaker level signals can damage your head unit’s RCA outputs.

If you’re wanting to install a 4 channel amp for 4 speakers and a subwoofer but only have 2 stereo channels available, that’s ok.

As shown in my diagram, you can connect 2 channels to a 4 channel amp using either the speaker level inputs wired in parallel or by using RCA “Y” adapter cables.

RCA y adapter cable image

All you need is a decent quality pair (2 total) 1 female to 2 male RCA “Y” adapters like these inexpensive ones from Amazon.

The sound quality will be exactly the same. Modern car amps are designed in a way such that all 4 inputs will get the same signal and there won’t be any problems.

After connecting the stereo to the amp, you’ll need to adjust the gain controls for both the 4 main speakers and the subwoofer output. My advice is to use a high-quality music track you know well already so you can easily tell when music sounds correct.

Additional suggestions & parts you may need

An amp wiring kit like this one will make your life easier! A a great (but affordable) amp wiring kit like this Belva 8-gauge complete kit includes not just the basics but a lot more. You’ll also need to pick up a 2nd pair of RCA cables (if using them) and maybe some extra speaker wire, too.

I can’t stress enough how important it is to be ready to install your 4 channel amp. While there are several ways you can go about it, wasting gas, time, and getting stressed out isn’t worth the headache.

It’s a lot better to start on the right foot and be ready at installation time. My advice is to pick up a good amp wiring kit and the tools you need beforehand.

I’ve also got some great guides ready, too, if you’d like more ideas:

Need advice on finding the right installation wiring? Check out my post with some of the best wiring kits for the money here. You’ll not just save a few dollars but avoid getting ripped off on fake wire gauges.

Comments, questions, or more? Let me know!

I’d love to hear from you and make this post even more helpful. Let me know in the comments below if you have questions or comments.

You can also reach me here via my contact page.

Your comments are welcome!

  1. Please help
    I have a 300w 4 channel home amp.

    I have two 120w speakers and two100w speakers. Can i connect all four and how do i connect them.

    Will appreciate.

    Reply
    • Hello, I need more information: what kind of speakers they are, what impedance they are, and the minimum Ohms rating of your home amp. Those are all important things not to leave off.

      Reply
  2. Any help would be appreciated.. I have an F-150 two 15in Memphis subs on 1500 watt amp, what I would like to do is put a 400watt max Kenwood amp on my high and mids and lows I got after market kappa 60csx 61/2- 300watt peak and matching 6×9 300 watt peak how do I install amp on just my mids and lows? I got factory head unit an ran a loc. Pro lp7 2…. do I have to install an lp7 4 to accommodate my 2nd amp? Thanks for any answer in advance

    Reply
  3. Friend got an install done, alpine deck, morel components upfront and components in the rear, unfortunately the shop wired a cheap morel sub up to the morel 4 channel amp. Now time alignment is impossible and full range audio is going to the sub. This could be a decent mid range system upto the sub, why the shop did not suggest a 5 channel or mono amp is beyond me. I intend to persuade my friend to drop the cheap sub and run the components in regular configuration allowing time alignment and proper crossover. Shady for a high end shop to do this.
    Any suggestions on tuning in sub 4 channel configuration, to me a low rent approach, just curious.
    Appreciate your time.

    Reply
    • Yeah, there’s not much you can do if using a 4 channel amp. Just bridge the rear channels and use the low-pass filter for bass only output. That means the components would have to both be run off of the front channels and there would be no front/rear fader. Unfortunately it won’t be like it should but at least you can get clear bass this way and still use the component speakers. (Or even leave off the rear components for now).

      He either needs to get a 5 channel amp in place of the 4 channel or add a 2nd amp for the subwoofer. That’s odd they didn’t recommend the right thing.

      Reply
  4. I am installing a marine radio on my boat. I was thinking about a 1000watt bridgeable amplifier, pyle marine to be exact, all of it. I read above on how to hook up a sub and 4 speakers I understand the output side of the amp. that is what my goal is, 4- 6.5″ speakers and one 10″ subwoofer. but my head unit or receiver has 4 rca outputs for each of the 4 speakers, and 2 rca outputs for the subwoofer. Do I simply just get the 2-to-1 rca adapters for my head unit rca speaker outputs? run all 4 speakers from the receiver into just 2 channels on the amp? and of course use the other 2 for the subwoofer. is this possible? I understand I will most likely lose ability to control fade or balance, maybe both.

    Reply
    • wait, I think I got it. I would only run either the front or the rear rca speaker cables from the head unit/receiver to the amp. then bridge the 4 speakers coming out of the amplifier as explained above. and then I would lose my ability to fade to the front or rear of course… but if I wired them correctly coming out of the amp, I could wire them so my balance would become my fade maybe?? Its always nicer to have the speakers in the back by the motor a little louder. anyways, let me know if I got it correct this time. any input would be much appreciated, always trying to learn everything I can.

      Reply
      • Well, it depends on the amp which you haven’t specified as different amps have different channels. Basically, if it’s a 4 channel amp you’ll have to run all 4 speakers on the front channel, two each (no fader will be available), and bridge the rear ones for the subwoofer.

        Reply
        • 4 channel- bridgeable… but I think I have to change my approach. the outboard motor on my boat only has a stator, not an alternator. stators only pump out 35 amp hours of charge, the 1000 watt pyle amp has 2x 30 amp fuses, which tells me it could draw up to 60 amps of power. ill be dead in the water after a few hours. I don’t want that. looks like I might have to run 2 smaller amps, or maybe just 1. not sure. most likely going to lose my idea of a subwoofer. I’ve spent more time researching this stuff than it will take for me to install a set up I know that. thanks for your input. I have researched adding a second battery with a VSR switch so the stator will charge both batteries without draining by starting battery. however with this much power in that 1000 watt amp, ill still only be able to listen to it for 5-6 hours. when we boat we spend all day. I want awesome music but not at the expense of problems.

          https://www.amazon.com/Pyle-Hydra-Marine-Amplifier-Configurable/dp/B00068U9Y8/ref=sr_1_14?dchild=1&keywords=marine+amplifier+4+channel&qid=1617818494&sr=8-14

          here is an amazon link to the amp I was referring to. marine pyle 1000 watt bridgeable

          Reply
          • Hi Cory. Ok thanks for the additional info as that helps a lot. First things first, I checked out the Pyle amp and it’s going to be somewhere around 538 watts RMS it can actually provide (it’s ok though, just clarifying). As you mentioned you’re going to have limitations due to the boat’s electrical system etc, I should mention that the Pyle amp being class A/B will draw more amps than a class D amp.

            So if you can, you should consider using a class D amp. They’re around 85% efficient vs the ~65% or so of class A/B amps. One example that can also drive your subwoofer would be this Soundstream class D 4 channel marine amp. There are some other class D marine amps (including with a Bluetooth smartphone connection) but a lot of them don’t have much power to drive a subwoofer when bridged.

            For the connections you asked about, there’s two ways to do it but I’d recommend this:
            – Front RCA outputs -> amp front RCA inputs -> 2 speakers per channel wired in parallel (2Ω load)
            – Subwoofer RCA outputs -> amp rear RCA inputs -> bridged to drive subwoofer

            You can also use the rear RCA outputs instead for the subwoofer amp channel inputs but usually a head unit with subwoofer output has additional controls you can use there instead of having to use the amp’s crossover. That often is more convenient. This should work out well. Hope that helps!

  5. yes it does help out a lot thanks. as I was waiting for your response I started diving into the different classes for ampfliers. It sounded like D was my best bet but A/B seem to be most common, and im not an expert. so that helps a lot. I did check out the amp you suggested. ill have to dive deeper as I don’t want to be consuming too much energy than I can create. I’m limited with only 35 charging amps unfortunately. my receiver takes 10 amps, well it has a 10 amp fuse, not sure how much it draws just being on… the power trim for the motor when used draws some amps as well, even with a new battery I notice a dip in the voltage but it returns quickly. other than that I don’t run any lights or extras.

    Reply
    • Sure thing. Your head unit (if it’s not powering speakers) will not draw much – probably somewhere around 1.5-2A. You could always measure it to be sure using a multimeter that can measure amps if you like.

      Class A/B is older and often very common in budget amps but class D has gone up in quality and down in price, fortunately.

      Reply
      • , thanks again for all your help.. knowing that I’m applying what I learned properly is important… so I am going to install a second battery. I still am all on board for a class D amp. My head unit will not be powering any speakrs, i hope to run everything from the amplifier. so here is what i have for speakers.
        i have 4 marine pyle 6.5″. individually they are 250 watts max. ill link it here.
        [link edited]

        i also have 2- 10″ pyle marine subwoofers, 500 watts max. link here.
        [link edited]

        Now i checked out your suggested amp, and looked for additional ones of course. I found this one, advertised as a class D, but reading into it its actually a class G. it pushes 1600 watts max, RMS 800. your thoughts? ill link it here.
        [link edited]

        Reply
        • Hi, that amp is a class A/B that they call a “class G” for some reason; there’s really no such thing. If an amp isn’t listed specifically as class D 95% of the time it’s A/B. The rest of your setup seems pretty good.

          Best regards.

          Reply
          • ok that’s what I was thinking about the class G amplifier. I think I’m going to go with the amp you suggested then. thanks for all your help.

  6. Hey Marty, I plan to install a KENWOOD KAC-M1824BT 4-CHANNEL BLUETOOTH AMP KACM1824BT in my classic Toyota Land Cruiser. As it will not be connected to any head unit I am thinking about how to get a left/right and front/rear fade. I have found some old stand-alone control units (1970s I think) but it looks like they were only designed to handle 2 speakers, not 4. Can I split their wires, or bridge in some way so I can get control over all 4 speakers?
    Thanks

    Reply
    • Hi, unfortunately, no you’re really limited on what you can do for this setup. Speaker fader controls were a thing back in the day but are hard to find now for 4Ω speakers (you can get them for 8Ω however). Most things available are for RCA signal adjustment/fading.

      You can search a lot and may find something – possibly on eBay, AliExpress.com, or Parts Express. Otherwise you’ll just have to adjust the fader control on the amp and leave it.

      Reply
  7. Hi! Great read btw, I was just wondering since I’m a first time installer doing it on my own. I currently have 2 6.5 Kicker DSC and 2 6×9 Polk DB692 I just finished installing in my car, and I noticed the previous owner already has RCA and looks to be remote wire already running through the back.

    So I ordered a amp wiring kit assuming all I have to install is ground and power, 4 channel 1500 watt amp by blankput and RCA Y cables.

    What’s the best way to hook that up?

    Reply
      • Thanks Marty! I guess my problem is the numbers part that I am sadly all new too lol so I connected just my rear 6x9s for now, and I can hear almost a little static coming from the speakers. There is sound coming out. **front 6.5 are still wired to HU, haven’t ran speaker wires from amp to the 6.5’s yet. To be exact…I have:

        2- 6×9 Polk DB692 (peak 450w / rms 150w) 4ohm
        2- 6.5 Kicker DS650 (peak 240w / rms 60w) 4ohm

        Blaupunkt AMP1504 1500w 4-Channel (4-3-2)
        – RMS output power 2ohms (watts) 300W x 4
        – RMS output power 4ohms (watts) 150W x 4
        – 30a x 2 fuses

        4 AWG Amp kit with 18 gauge speaker wires
        – 100a Fuse

        What is the best way to run my wires for all 4 speakers? Words I’m commonly seeing are bridged, series, parallel and series parallel.

        Oh and HU is Kenwood KDC-452U. And I should mention that there were already a remote and 2 rca cables already running through to the trunk.

        Reply
        • Hi, just wire them normally, one per channel, in this case. Front RCA jacks to amp front inputs, likewise for the rear RCA jacks. You may need to pick up additional RCA cables depending on what you have. Then install the amp wiring kit like you normally would (assuming the remote wire is still near the radio and won’t have to be run again).

          Reply
    • You’ll need to give me more info as it’s important to know the speaker impedance. For 4Ω speakers they can be wired in parallel; ideally using crossovers if using a component speaker style setup.

      Reply
  8. i have a single infinity kappa 8 inch 400w 4 ohm subwoofer and jbl 5501 mono amp. so should i connect it on bridge mode or shall i connect it on single channel mode

    Reply
      • Hey Marty there are L-R input is there and on out put also 4 ports are there +- +- and first + and last – port are mentioned as Sub.. so i am bit confused how to power sub .

        Reply
        • Yes, mono amps still have stereo inputs but have only a single channel but may have more than one set of speaker terminals. Just connect it to one pair of the outputs. In a mono amp two pairs of speaker inputs are connected internally.

          Reply
  9. Hello Marty your info is great. I have an e4300 JL 4 channel amp and I want to wire 4 cl1’s JL coaxials, and 1 10 inch jl audio w0. Will it sound good?

    Reply
    • Hello Carlos. Well that’s very hard to say because it depends on many things. If your head unit is of good quality and everything’s used right, yes it can sound good. However, you’ll have to give up having a front/rear fader which isn’t great.

      You might consider leaving off the 2nd pair of speakers if they’re for the rear. Your amp should have a fair amount of power drive the subwoofer with the rear channels bridged.

      Reply
  10. How to wore 3 pre amp outputs- front, rear, and sub lets and rights for each so 6 sockets to a 4 channel sub 4 sockets 1 for each channel. Bridging chan 3abd 4 for subwoofer on the amp.

    Reply
    • Hello there. If you’re using a 4 channel amp you won’t use all 6 RCA jacks on the head unit. You’ll use the front RCAs for the amp’s main speakers (ch. 1 & 2) and either the rear RCAs or subwoofer RCAs for channels 3 & 4 for your subwoofer.

      Reply
  11. I bought my son his first car the other day. The neighbor came over and gave him an old 10″ kicker comp c10, 4 ohm sub. 150 watts rms and peak power handling 300 watts. I found an old orion cobalt 435 xp 4 channel amp in my closet. I ran the power, remote and one rca. I picked up two rca y splitters today and 100 feet of 18 gauge wire. I’m wanting to run 4 door speakers and a sub. My questions are. When running the 8 wires for the 4 speakers from up behind the dash. I would disconnect the speaker wires from the car to the head unit and hook up the speaker wires from the car factory speaker wires to the 8 i ran? And run them straight back to the amp and hook them up parallel? Front two channels will be the front speakers and back speakers and use the rear two channels to bridge the 4 ohm sub. Stereo speaker wires won’t be being used. Will running wires parallel to the amp and rcas be bad news? I thought I read that it could fry your jacks.

    Reply
    • Hi John:

      • I think you’re thinking about using speaker level inputs and RCAs at the same time. In that case yes you can damage RCAs. But sounds like you’re just referring to running speaker output wiring to the amp which is fine.
      • Yes, you’ll run speaker wire to the factory wiring behind the radio, from the amp, and connect to it there.
      • You can use two speakers in parallel on each channel but only if the amp is 2Ω capable. Some older amps were limited to a min. of 4Ω so it’s important to be sure.

      It sounds like that amp doesn’t have a lot of power so you may want to consider only powering the front speakers. Remember that speakers will share the available power, meaning each will only get up to 1/2 the rated power when used in parallel. I would recommend you consider getting a 4 channel amp with a bit more power since they’re so affordable these days – that’s especially true when powering a subwoofer.

      Best regards!

      Reply

Leave a Comment