Speaker Ohms Calculator – Series / Parallel / Series-parallel, speaker power, and more!

Welcome! I’ve worked hard to create what I think is the best speaker Ohms calculator on the internet for you.

My speaker Ohms calculator will let you:

  • Find the total speaker Ohms for almost any series, parallel, or series-parallel speaker wiring.
  • Find the total power your amp or stereo will output (or warn you when it can’t produce that amount of power).
  • See the power supplied to each speaker for your wiring configuration.
  • Find out if your speaker setup could cause amp or stereo damage before you try it out.

Note: Javascript must be enabled in your browser to see or use the tool.


speaker Ohms calculator section image


Choose your speaker configuration/wiring:

  1. Series connected speakers
  2. Parallel connected speakers
  3. Series-parallel speakers: up to 4 “strings” of 1-4 series speakers, all series strings in parallel. (*Using 1 speaker in each string will effectively be the same as the Parallel speaker option)
  4. Parallel-series: up to 4 speakers in parallel which are then in series with 1 or more speakers.

Input your speaker Ohms and power values:

  1. Speaker impedance (Ohms): Fill in the speaker Ohms value for as many or as few speakers as you’d like.
  2. OPTIONALAmp/stereo power & min. Ohms rating: Input the amplifier or stereo’s power (RMS or continuous) power rating and the min. specified speaker Ohms. This will allow the calculator to determine power to each speaker in any configuration.

You can use whole numbers (2, 5, etc.) or decimal values (6.3Ω, etc.) for Ohms as needed. If using the power option, use the RMS or continuous power rating in whole Watts for your amplifier or stereo. “Peak” or “maximum” ratings are misleading and will give the wrong results.

The speaker Ohms calculator will output:

  • Total speaker Ohms: This is the total speaker load the amp or radio will see based on the speaker Ohms you’ve entered.
  • [Optional] Total power draw from the amp or stereo: This shows the total amount of power the calculated speaker Ohms load will draw from the amp or stereo.
  • NOTE! If the total speaker load would draw excess current (exceed the power rating you specified), this means an unsafe condition would happen and you’ll see “–” to indicate an error/invalid power amount.
  • [Series-parallel option] String (“Strx“) ohms: The series Ohms value for each string of speakers, 1 to 4 speakers each.
  • Power to each speaker (“Sx“): Power, in Watts, each speaker will receive.

How to calculate series, parallel, or series-parallel speaker Ohms (DIAGRAM and examples)

how to calculate speaker ohms series parallel diagram

Figuring out the total Ohms speaker load for nearly any wiring configuration isn’t as hard as it may seem. As you can see from my diagram above, there are 3 main ways to do this:

  1. Find the total series speaker Ohms.
  2. Find the total parallel speaker Ohms.
  3. Using a combination of #1 & #2 for more complicated speaker systems.

1. How to find the total series speaker Ohms value

These are the simplest to deal with. To find the total speaker resistance (impedance) for series speakers, simply add them all together.

For example, let’s say we have 3 speakers we’d like to use: two 8 ohm and one 16 ohm.

We’d just add these together like so: 8Ω + 8 234 + 16Ω =  32Ω 

When speakers are connected in series, they share the same electrical current. The amplifier, radio, or stereo’s power will be divided among them. Note that if the total speaker load is higher than the maximum power output Ohms rating for your amp or stereo, the total power you can get will be lower.

(I’ll go into more detail about this in another section below)

2. How to calculate the total Ohms load for parallel speakers.

parallel resistance formula diagram

When it come to finding the total speaker impedance for parallel wiring, there are two ways to do this:

  1. If the speaker Ohm ratings are all the same, you can just divide by the number of speakers used.
  2. For parallel speakers of the same or different values, you can use the universal parallel speaker formula below. You can call this the “inverse sum of the reciprocals”, which just means we add up all the inverse (1/x) values then take one final inverse function to get the result. (I’ll explain how to do this.)

Example #1: Let’s say we have three 4 ohms speakers wired in parallel. We can use simple division to find the total speaker load:

Rparallel = 4Ω/3 =  1.33Ω 

Example #2: In this example, we have four speakers of different values: two 8 ohm and two 16 ohm speakers, all wired in parallel. What is the total speaker load?

Rparallel = 1/(1/8 + 1/8 + 1/16 + 1/16)

                   = 1/(.125 + .125 + .0625 + .0625)

                    = 1/(0.375) =  2.67Ω 

3. Series-parallel and other wiring types

For anything other than just series or parallel speaker wiring, we can just break it down into a few of same calculations and then add them all together.

Example #3: We have four “strings” of four 8 ohm speakers each. All four series strings are wired in parallel. We can solve this pretty easily!

(a.) Finding the series speaker Ohms: each string of four speakers is 8Ω + 8Ω + 8Ω + 8Ω or 8Ω x 4. This is 32Ω total for each series string.

(b.) Find the total parallel speaker Ohms: we have four strings, so this is 1/(1/32 + 1/32 + 1/32 1/32) or just 32Ω/4 since they’re all the same value. 

So the total is 32Ω [each series string] / 4 strings =  8Ω total in series-parallel 

How to find parallel speaker ohms (inverse sum of reciprocals) on a calculator

example of the inverse (reciprocal) key on a calculator

Many calculators (especially scientific ones, although that’s not a requirement) have an inverse function.

An inverse key (inverse function, or reciprocal function) is simply dividing one by some number. Having a button handy makes it much faster and less likely you’ll make a mistake, too.

Note: The inverse button is sometimes also be written as a negative power of 1 (“^-1”) as it’s mathematically identical.

Let’s take example #2 from earlier to show how you can easily find any parallel speaker load using a calculator. I’ll show where I’m using the buttons you’d use on a real calculator.

(Example #2: We have four speakers of different values: two 8 ohm and two 16 ohm speakers, all wired in parallel.)

(a.) You would enter on your calculator:

8 1/x 8 1/x 32 1/x 32 1/x

which will give 0.125 + 0.125 + 0.0625 + 0.0625 = 0.375

(b.) Then we’ll take the reciprocal (inverse) of this to get our result:

0.375 1/x = 2.67 Ω (rounded from 2.66666… as we don’t need that much precision).

example of sum of reciprocals in a pretty print scientific calculator

You might find it helpful to use a scientific “pretty print” calculator as they display the math you’re entering just like you’d write it on paper. This helps you be sure of what you’re entering as you go.

Amplifier power vs the speaker Ohms load

diagram showing how power is shared between series or parallel speakers

The total speaker load you end up with can have a very big impact on the power you can use. That’s because home or car stereos, amplifiers, and radios can only produce up to a certain output voltage to deliver power to speakers. If the speaker load (Ohm value) is higher, they can’t deliver as much electrical current, resulting in a lower total power provided.

How to calculate amp and speaker power for different speaker loads

Example #1: How to estimate total amplifier power at different speaker Ohm loads

For example, let’s use an example of a guitar amplifier that can provide 50 watts RMS continuous per channel into a min. of 8 ohms. As power is related to voltage and resistance, we can rearrange the formula for power to help us:

(a.) Power (P) = (Voltage (V))^2 / Resistance (R)

We can rearrange this to find voltage: Voltage (V) = square root(Power x R)

(b.) Doing a little bit of math, that means the output voltage at full power into an 8 ohm speaker would be:

V = square root(50 x 8) = √(400) = 20V(Max. output)

What happens if we connect two 8Ω woofers in series? How much power can we expect?

This would be (20V)^2 / 16Ω = 400/16 =  25 Watts 

This makes sense! After all, the electrical current decreases as the resistance increasesTherefore, the amp can’t deliver as much power at 16Ω as it can at its 8Ω specification. There’s nothing wrong with using a higher impedance speaker load, but you’ll have to live with the compromise and less overall power.

Example #2: Estimating power to each speaker vs the total power delivered

Using example #1 above, we have 25W delivered in total to our 16Ω speaker load. For speakers in series, you can find the power each speaker will get even if they have different Ohm ratings.

In this case, we can use: Pspeaker = Ptotal (total power) x Speaker1/(Speaker1 + Speaker2)

This gives us: P1 (power to speaker one) = 25W*8/(16) = 25W*0.5 =  12.5W 

So each speaker will receive 12.5W in this case which is 1/4 of what a single 8 ohm speaker would receive for this amplifier.

What speaker Ohm load should I use for the best power?

what speaker ohms load is best for power section image

When using multiple speakers the best Ohms load for power is the lowest acceptable total speaker load the stereo or amplifier is rated to handle at maximum power output.

This is because many amplifiers (and some radios and stereos etc.) have their maximum power output possible at the minimum Ohms rating specification. This is sometimes called the Ohm rating they are “stable to.”

For example, a 2Ω stable car subwoofer amplifier may be rated like this:

  • 250W x 1 @ 4 ohms
  • 500 W x 1 @ 2 ohms

The specifications tell us:

  • This amplifier is designed to handle as low as 2 ohms minimum
  • It will produce maximum power output (maximum current) safely at a total speaker load of 2 ohms

This means to get all the power we paid for, we’ll ideally have a total speaker load that adds up to 2Ω. The problem is that when using multiple speakers it can be difficult to get match the min. speaker Ohm rating.

You’ll have to match at least the min. acceptable Ohms rating specified. Too low of a rating (say 1Ω in this case) and the amplifier can shut off, overheat, or suffer permanent damage.

Using dual voice coil speakers may help as they offer multiple speaker ohms configurations. However, it’s very common (especially if you’ve already bought speakers) to not be able to get the “perfect” total speaker Ohms load. 

You’ll have to live with some compromises which may mean less total power available.


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 have a NuTone intercom system and the outdoor speaker in the pool area doesn’t work. The burned out speaker is a 25ohm 5″. Do you think I could install 2 or 3 8ohm speakers off the channel or intercom station? I would guess there are 7 or 8 remote stations each with it’s own channel in the intercom system. There are 2 16v 30 watt transformers in the Master panel. I don’t know if that means The system is 60 watts or 30 watts with 2 channels but runs 8 stations? The outdoor speaker is in a face plate but i was thinking I would buy a remote control unit that has only the control buttons and no speaker then use 2 or three 8 ohm speakers in series. Do you think 2 rather than 3 speakers would be the right direction, because of the lack of wattage, or is matching the ohms more important. The other option is buying 25 ohm speakers but I’m thinking there is not much wattage pushing the single (I’m assuming) channel. My other thought was the 5″ speakers sound tinny (Like an ancient transistor radio) and I would get 8″ 8ohm speakers and hopefully get better sound? Can you lend any insight to intercom speaker problems. The problem has been isolated to the speaker and it looks to me like it was an indoor speaker used outside. Also do all speakers work as a microphone back into the intercom? If not should I look for an 8 ohm 5″ that does then add the additional 2 larger 8ohm speakers for quality sound? I know I’m throwing things at the wall to see what sticks.

    • Hi Dave I’m not sure that I’ll be able to help completely as it seems there are some unknowns in this case. I strongly suspect the system isn’t a direct (standard) type but rather a 70V or other similar system that uses transformers for driving multiple speakers. These are commonly used in buildings & business, both for music speakers or intercom systems as well.

      In principle, I do believe using three 8 Ohms speakers in series would be fine to replace a single 25Ω speaker. However, you’ll definitely want to find out *specifically* what type this system is. 70V (or other systems like it) sometimes uses a transformer at the speaker to convert the amplified signal to one to match that of the speaker used.

      I would find out what you’re working with before going further.

      • No transformers at the satellite stations only the 2 16v 30w transformers at the master station. I could test line voltage but suspect it will be 16vdc. I ordered 2 8 ohm speakers and will look for an 8 ohm 5″ to put into the face plate of the satellite station that can also transmit. I’m hopeful somebody makes a speaker that can transmit in 8 ohms. If not we will still have better sound from the satellite station.

  2. Hi Marty,
    Always enjoy reading ur site. My question is: I have a 400w amp, and have 4 4ohm front speakers connected for 75w per speaker. Can I wire the speakers in parallel to make the speakers 2ohm load so I can get 100w out of them? Thanks

    • Hi Albert. Typically you can on most modern amps. The specifications will tell you the minimum OHms load and the power you can get when wired for 2Ω total.

      Usually (not always, but many cases) the 2Ω power RMS output is 2x that of the 4Ω rating. Best regards!

  3. Hello,I have B&W D302 PRISM speakers with nominally rated at 8 Ohms and dips as low as 3.5 Ohms,will it be safe if I Use the speakers with PHILIPS FW C390 hi-fi stereo with these specifications?
    Output power …………………………….. 2 x 120 W MPO
    ………………………………………………………….. 2 x 60 W RMS(1)
    Signal-to-noise ratio …………………….. ≥ 67 dBA (IEC)
    Frequency response …………………….. 50 – 15000 Hz
    Input sensitivity
    AUX/CDR In …………………………………… 500 mV / 1V
    Speakers …………………………………………………………..≥ 6 Ω

    Kindly advice,thank you

  4. I forgot to mentions this,
    These are the specifications of the B&W D302 SPEAKERS
    Frequency response: 72Hz-20kHz, ±3dB. Sensitivity: 91dB/2.83V/1m. Nominal impedance: 8 ohms (3.2 ohms minimum). Power handling: 25-100W continuous.
    Wil it be safe if I used these speakers with PHILIPS FW C390 with this specifications?

      • Thanks for your response Marty,let me get this clarity please and kindly advice,I’m more worried of that dip of 3.2 ohms,will it not affect the Philips system with a minimum of 6 ohms it requires?can a speaker of 8 Ohms dip that low or it’s a 4 ohms speaker?

        • Hi, so I’ve found more information and revised my original comment. According to Stereophile the impedance plot they measured puts in a majority 4Ω speaker range, not 8Ω. I’m not sure why it’s categorized as an 8 ohm speaker in that case.

          So it would be better to either add 1.5-2Ω series power resistors or (preferably) use speaker impedance adapters. Using resistors will waste some power as heat but is cheap & easy to do. Best regards.

  5. Hey (S)Marty!
    1st timer car audio guy. Stock 88 Suzuki Samurai w/2 speaker. Tell me if I’m weird. I wanted to go space saving instead of big sub box and went with the following.

    I have a double din HU (80rms, 4ohm)
    6 total alpine r-series 6.5 speakers
    4 coaxial (240rms, 4ohm each)
    2 component (240rms, 4ohm each)

    Currently have a MRV-M500 – Alpine Monoblock 500W RMS, but don’t mind changing this issue.

    I also have dual battery power.

    What amp should I get and how should I wire them? Channels? Also any additional accessories you recommend? Please help, thanks a million Marty!

    • Hi Will. I wouldn’t say it’s weird as I’ve seen a few people do similar things. :) Sounds like an interesting project. I remember those Samurais; one or two my friends had one.

      The simplest way would be:
      • Use a 4-channel amp that’s rated for down to 2Ω per channel.
      • Wire two pairs of coaxials per channel on one set and the components on the other set of channels.
      • If you’re able to it’s a great idea to mount the component tweeters higher up (on the dash, door sills, etc.) for the best sound.
      • If you use the high-pass crossover set to ~50-60Hz or so you can help block distorting bass on the smaller speakers and get more volume/power before they start to distort.

      A class D 4-channel amp will be a bit more compact & easier to install in many cases and offers more watts per dollar than older class A/B amps. I wouldn’t recommend below 75W RMS/channel – maybe 100+ if you’d like more volume.

      You might find this compact NVX 4 channel amp to be a great fit and it’s pretty compact too. It fits the description of what I recommended above. Hope that helps!

  6. Alright, I’ll throw this out there cause it’s driving me crazy. Currently have nvx 6.5 components in front doors and alpine type s in rear door with standalone tweeter mounted above. Running off skar rp75.4. Its not enough to keep up with the 3 skar audio 12s running off 1500w skar. If I want to add a TX35 with 30 rms next to the new tx65 with 50 rms, both with single 4 ohm vc…. would the 2 speakers be louder than matching one 6.5 to full RMS? Did that make sense, lol? The door panels have had modifications to have speaker mounted externally and pointed up, I can fit the 3.5 next to it is the reasoning, just not sure how to get louder.

    • Hi, well, if you add even more speakers the power will be divided among them, meaning each one will have a lower top volume available. I suggest skipping adding coaxial speakers and instead bridge the Skar amp to two channels to drive the front component set. You can then add a 2 or 4-channel amp later to power the rear.

      Ideally, the front tweeters will be mounted to point towards you (and near the same height as your head – for example, somewhere around the dashboard or pillars) if possible as well.

  7. I have a new JVM410H, and I don’t know the best way to hook it up to my Marshall JCM9001960 lead (A ? ) cabinet. Is 4 ohm or 16 ohm the safest for my equipment ?
    I have read so many comments on the internet and have found no definitive answer. Just a bunch of guess’ and opinions.
    Does ANYONE REALLY know anything about this ?
    I do not want to damage anything.
    I have had this Amp for almost a year and have never hooked a Guitar to it because I can only find opinions on how to hook it up … and those tend to be contradictory at best.

    Marshall JVM410H Head
    JCM900 1960A Cabinet (Lead) angled cabinet)
    4 Celestion 16 ohm speakers wired in parallel

    I have the full stack, but I am only using the 1960A, for now.

    No opinions please.

    Thank you.
    Joe Satriani Signature series JS240PS-CA

    • Hello there. I looked over the equipment you mentioned. As you mentioned the 1960A cabinet is wired for 4Ω already, then you’d use the 4Ω output on the Marshall amp.

      If the cabinet is still configurable for 16Ω, you could set it up for 16 ohms then use the 1×16Ω output jack on the Marshall. The power should be the same either way, since in both cases the impedance would be matched correctly to the rated outputs.

      If by chance you’re using speaker wire/cabling with a longer distance, the 16Ω option would be best. That allows for smaller gauge speaker wire/cabling since the current will be 4x lower than the 4Ω connection.

      At the minimum, you always want to connect speakers at at least the minimum required Ohms rating the amp supports to avoid problems. I hope this helps somewhat!

      • Thank you.
        I appreciate you taking the time.

        I don’t know if this makes a difference, but I think it might be 8Ω.
        I say this because I hooked a cable to the cabinet and then used a DMM at the end of the cable.
        The Digital Multi-meter gave a reading of 5.xx Ω.
        Therefore I suspect the cabinet is an 8 ohm cabinet ?
        And therefore I should hook to the 8Ω output ?

        Again, Thank you very much for your help.

  8. I’m getting ready to build a pair of speakers using two 8 Ohm woofers and one 8 Ohm Full range driver. What would be the best way to wire them to have a 4 or 8 Ohm load to the Amp.

    • Hi Ronnie. Unfortunately there’s not a good way to do that – it’ll require some compromise if you’re wanting to have them matched to the tweeter (since 4Ω woofers aren’t being used).

      If you wire them as a 4Ω load (parallel), you’ll have to adjust the crossover accordingly. However, it will work out ok and have a +3dB volume increase with both woofers wired that way.

      You won’t be able to get an 8Ω load with both woofers unless you add a series 4Ω power resistor to the 4 Ohm parallel speakers. However, that means 1/2 the power to the woofers would be wasted as heat. So I’d recommend either 1) replacing them with 4Ω woofers you can simply wire in series, or 2) wiring in parallel for 4Ω and change the crossover as needed.

      Best regards!

  9. Hey Dave. I have a 400 watt RMS solid state Power Amp with a 4 ohm min. load. What can I expect if I use a 2.65 total speaker load. I have read that I should be ok if I watch for any distortion.

    • Hi Rick. I assume you got the 2.65 Ohms total speaker load by measuring resistance? That’s too far off from 4Ω, so most amps should be able to handle it ok.

      The speaker load affects the current an amp will try to supply (and hence why they can get hot if the Ohms load is well below expected). If you have an issues you can use a speaker impedance adapter set to 2x to safely use the speaker setup you like.

      Best regards!

  10. Hello Sir,

    Thank you or the detailed write-up. I would like to seek your advice on my below situation.

    AV Receiver: Onkyo RZ50 9.2 Channel (120 W/Ch @8 Ohm, 2 channel driven) 4-14 Ohm
    I already have 7 speakers in the bed layer( bookshelf 4-8 Ohm ~150-240 W) and 2 in the Atmos (Top Middle).
    I am now considering to add two more height speakers for Atmos in the front wall for coverage and spread.
    The speakers are of nature 6 Ohm, 50-120W. I am considering the option of parallel connection of the Front Height Left and Top Middle Left which makes the resistive load 3 Ohms. Connecting them in series may not give me the desired watts to run them and also I have learned to lose out on a few frequencies.

    What gives me hope that parallel might work?
    1. It’s an Atmos Channel and not much serious content with high power is driven there
    2. My total seating distance is only 8 feet in a room size of about 12 feet long. The existing speakers also are running under low volume (calibrated @82dB running at 70-75dB volume)
    3. The total connected load (9 channel) in “All Channel Stereo” from the AVR is between 80-150 W (sub excluded)

    Given the above facts do you suggest if I could still drive the Atmos speakers in parallel, considering the lesser impedance than what the AVR can handle?

    Your inputs will be highly valuable to me and thank you very much in advance.

    Warm Regards

  11. I have 6 outdoor speakers rated at 100 W @ 8 Ohms. 3 on left and 3 on right. I’m using 12/4 gauge wire. Each run is about 100 feet each. I hope to power this with a receiver output of 120 W/Ch 8 ohms, 20 Hz–20 kHz. I had 8 speakers with this configuration and burned up 2 home receivers. Question: Will this be ok and what connection method should I use, series or parallel?

    • Hi Mike. Ideally you’d wire speakers in parallel, but yes like you mentioned that causes the issue with the total Ohms load being too low.

      The best way to do this – and use as much of the available receiver power as possible – is to use a speaker volume control with built-in impedance adapter like this one.

      That way you can connect several pair without any issues and get the best sound. Series can work, but the cost will be reduced *total* power, meaning each one will get even less power.

      An impedance adapter will allow the receiver to see a safe total Ohms load even while mutiple speakers are wired in parallel; They can also receive the full power output unlike series speakers.

      Best regards!

  12. I would like to hook 4 12″ , 2 ohm dvc speakers to a single 2400 watt mono amp that is 1 ohm stable.
    I have found wiring diagram to wire them at 1 ohm however, I’m puzzled when it comes to watts delivered to each sub. Please advise.

    • Hi, my calculator can show you the power to each speaker or voice coil etc. The series-parallel option would work for this case.

      If you wire all four subwoofers in parallel with each voice coil pair wired for 4Ω, that would be 1Ω total. Therefore the power to each speaker would be (RMS amp power @ 1Ω) / 4 = 600W.

      Best regards.

  13. Hi Marty, I’ve been hoping to find an expert to pick their brain about this issue, it looks like I’ve found the right place!

    I have a 2005 Toyota Avalon XLS that’s in great shape and I’d love to keep running as long as I can – especially given the current car market!

    It has the JBL Synthesis factory system, which has 11 speakers and an external factory amp under the driver’s seat helping to power everything. All in all it sounds pretty decent for a factory system. However I’m a big audio guy and used to install aftermarket systems for myself and friends so I’m hoping to get more out of it, but it is very notoriously hard & expensive to upgrade, since the head unit has a hand in the climate controls and both are integrated into the steering wheel controls & dash display. So as soon as I was able to I picked up & installed a Bluetooth adapter from GTA Car Kits that wires directly into the factory system to retain the stock controls and bring it into modern Bluetooth times, and it has been working fantastic for a while now.

    The problem is for a long time now, I’ve been wanting more BASS! And I’d love to do it for cheap. I know one can buy a powered sub that just needs to be wired in for less than a separate system – which as I mentioned I have done plenty of times in other vehicles – but money and time are both a little tight right now as it’s our only vehicle, so I can’t be tearing apart too much, and I really can’t justify spending that much right now. I spend a lot of time in my car for work and driving around my family, so I’d love to have a stereo that at least keeps me/us happy for now! So that brings me to this:

    My folks had an old secondhand Polk PSW10 home audio sub with a blown amp laying around, so I thought what the hell, instead of throwing it out, I’ll run a wire from the Polk sub (still in it’s box) to join it to the factory “sub” and see what happens. Well for zero dollars it really sounded great! Much stronger and deeper bass than stock. However, the audio guy in me can’t help but think I can get more out of it. I’d like to turn the bass down on the factory component speakers a bit (the bass control is universal) and still have some good bass fill from the trunk. The stock sub also had some buzzing at louder volumes so I’m thinking the foam is failing. It’s a huge pain to replace and definitely not worth it, so I decided to just cut one lead to the stock “sub” and now the factory amp is only powering the Polk. Well, the bass is much quieter now. I would really have to turn up the bass to achieve the same volume as previously. Then the components get it too, so not ideal!

    I had the two subs simply wired together, + to + and – to -, so parallel before. Now I cut the one lead from the stock “sub” to remove it from the equation, thinking the Polk will get more wattage by itself, and hence more volume. Unfortunately that’s not the case.

    The problem is I don’t know the impedance of the factory “sub”, and no one else out there seems to either. The other speakers seem to be around 2ohms or less according to various sources, likely to milk all the (low) power output of the factory amp possible, but I can’t get a clear answer on the “sub”. The closest I’ve seen is someone hooking up a multimeter to the bare “sub” and it was showing 9.8ohms, but that basically means nothing as far as I can tell.

    The same goes for the Polk – though a quick Google is returning a majority of answers at ~4ohms. I therefore have no idea what the two ended up being combined. So I don’t know if I need to raise or lower the load the amp sees to get the volume I was previously.

    Can you possibly tell me why it was louder when I had them wired together in parallel, and how I should go about wiring for the best outcome with the Polk for my bass desires??

    Sorry for the long story, but hoping I can get some help to keep my cobbled together system working half decently for a while yet!

    Thanks very much in advance!!!

    • Hi Mark. My “educated guess” regarding why it sounded better with both speakers connected is that likely it’s related to the factory subwoofer being in place (or not in place), affecting the factory amp’s output on that channel.

      However, that’s not the real issue. You’re wanting to use a home subwoofer (likely 8Ω) with a factory amp which is not a good idea. Assuming the factory amp was working, an 8Ω speaker would develop 1/2 the power of a 4Ω one. This means you’d need an aftermarket amp to power it decently.

      One thing you could try is wiring an 8Ω power resistor (say 20-25W ratinged) in parallel with the Polk subwoofer and see if that improves things. Power resistors are cheap. Unfortunately I can’t say for sure if this will help or not.

      As a side note, it may be possible to repair the foam on the factory subwoofer. I’ve heard of those subwoofers having their dry-rotted foam replaced, so you may be able to find a repair kit somewhere.

      Best regards.

  14. Hi Marty, thanks very much for the quick reply!

    I know it might be a dumb setup, but I always say that it’s not dumb if it works! 😄

    I have realized since posting that the combined parallel impedance of the two is much lower than when I remove the stock “sub” (I keep using quotes because it’s basically just a free-air 8″ woofer), and the impedance becomes quite a bit higher when it’s just the Polk wired up – which may be 4 or 8 ohms depending on the source of info, but most sources say 4 ohms – so, the volume decreases substantially in turn, no matter the potential wattage increase. I used to wire dual voice coil subs in series quite often, so I think I was misremebering series vs. parallel.

    I’ve ordered a couple of power resistors to try out (thanks to your suggestion and to stumbling on your page on adding resistors, which is excellent!), and am just waiting for them to arrive to try them out. I can then “trick” the amp into seeing a lower impedance and outputting the volume I’m used to.

    The factory amp seems to have no trouble when the two are wired in parallel, and I’ve been running it this way for at least a year with lots of use. Even when running things pretty loud I’ve never heard distortion or anything of the sort, and the bass honestly thumps my chest, shakes my rear-view mirror, and goes quite deep – so I’m pretty happy with the output when it’s wired in parallel with the stock “sub”, but I’d just rather cut it out of the equation so I don’t potentially hear anything from it. The buzzing/almost chuffing sound I mentioned isn’t loud; I can basically only hear it if I put my head near it in the trunk or back seat, but I’m guessing it’s either bottoming out or the foam is degrading. I know I can repair it if need be, but the pain to get it out isn’t worth it, and I can honestly never go back to it now that I’ve wired in the Polk. I know the Polk is pretty much a piece of junk, but wired this way it is actually pretty impressive considering it was a free upgrade!

    Someday maybe I’ll hook up some separates (I have some good subs and amps stored away), but the interface to tap into the factory setup is pricey given the head unit/amp controls things via databus, so I’d pretty much have to buy an integrated solution from PAC audio or somewhere just to get flat line-level outputs.

    For now I’m pretty happy with this, I’ll see how it goes with the power resistors, and if you’re at all curious I can update here.

    Thanks again for the advice and your incredible trove of information here! I’m so glad I stumbled upon your page to refresh some of my forgotten knowledge and to learn some new things! Cheers :)

    • Thanks for the reply Mark and yes, I would be very interested eventually hearing how it goes. It may help someone else in a similar situation as well.

      I appreciate the kind words & thanks for dropping by. Have a great week. :)

  15. Hey gm team I have a questions to ask
    Is it ok if I use amplifier to play three 8 ohms speaker which is about 2.67 ohms
    Once the that unit minimum load Is 2 ohms

  16. Hi! I have a two 6 ohms speaker and one two channel amplifier that is rated to have 8-16 ohms. would i need to do series wiring or should i just plug in one speaker per channel?

  17. Hi Marty,

    I need to wire 6 8ohm speakers to an 8ohm amplifier (3 left, 3 right).
    How could I best wire them to get equal power on all speakers?

    All the best,


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