4 ohm vs 8 ohm speakers which is better?

Why are 4 ohm speakers used in cars?
Why are 8 ohm speakers used in homes?
Do 8 ohm speakers sound better than 4 ohm speaker?

Let's talk about this!

[AT-wlyq]

When I saw the title of the video I thought it was great because its something that really needs to be addressed. The information in the video, however, came up a little short. And I don't mean that in any negative way. You come across as an honest and genuine person, so I'm not trying to bash you, or the video. If anything, I appreciate the effort on your part to raise the issue. Its not an easy topic. I'll list some basic concepts that may help clarify some things. A lot of what you were saying was going in the right direction. It just needs a little refinement.

When it comes to an amp driving speakers, home or car, the lower the impedance, the harder the amp has to work. When you see a speaker rated for 4 or 8 ohms, it doesn't tell you much. That's just an average. If you look at the specs for the speaker, the most important number to look at is the lowest impedance that the speaker can show the amp. So, the rating would look something like, 8 ohm nominal, 3 ohms minimum. The 3 ohms is the important number. If you have a different 8 ohm speaker that drops down to 5, its a much easier speaker to drive even though they are both rated for 8 ohms.

In the video, it was said that the speakers impedance constantly changes when in use. That's 100% correct, but its not random. The amount of impedance a speaker shows an amp is based on the frequency its asked to produced. To visualize, think of a piano. Since 8ohms is an average, there's only 1 key on a piano that will produce a note that the amp will see as 8 ohms. As you move to the right and the keys get higher and higher, so does impedance. And its the opposite for lower notes. Impedance drops. One thing that confuses people, is they think higher impedance and less wattage means its a more difficult load for the amp, and that's why it makes less power. That's not the case, and here's why. When you look at a big subwoofer moving in and out, it takes a lot of power to get it working. A tweeter only has to move a tiny bit compared to a sub. Most of the time you can't even see it moving. It just doesn't need that kind of power, so its not a negative. Going the other way, if you remove your speaker wires and touch them together, its called a short circuit, or 0 ohms. So, if you are asking your amp to drive a 1 or 2 ohm load, its only 1 or 2 ohms away from a dead short. This is not something you want to do to your amp and speakers, even if the specs show it can be done. Its like driving your car with the motor always pinned at the rev limiter. Technically, its rated for it, but in reality you're beating the crap out of your car. Its no different with your audio system. That's why I thought it was such a good topic to discuss. It seems like with car audio everyone is trying to get to the lowest impedance possible because you get more power. That's really not a good idea. Does a 4 ohm speaker sound better than an 8 ohm speaker? That question can't be answered. There's too many variables in play. Will a power amp sound better if its asked to drive a 4 ohm load over a 1 or 2 ohm load. Yes it will. Its also a lot easier on the speakers.

Beyond that, there are a couple of other issues worth mentioning. I know in car audio its very common to bridge power amps. That's when you combine 2 channels on a stereo amp into 1 channel to get more power. A bridged stereo amp is not a mono amp. Its very different. The important thing to know, is when you bridge an amp, it now sees half the impedance it normally does. A 4 ohm speaker is literally a 2 ohm speaker with a bridged amp. Yes, you get more power, but the quality of power isn't as good because you bear the crap out of your amp to get it. I'm not saying you should never bridge an amp. You just need to be careful. Personally, I prefer not to bridge, but in some situations, it may be an OK option. Just be aware of the downsides.

[jorjor]

Thanks for putting out so much information everyday

[robertholsopple]

I started running Taramps Smart amps to fight impedance rise and im so happy i did. The difference is night and day. Im running a single Resilient Sounds Onyx 12"at ½ ohm and Taramps amps handle it incredibly well. I get the same wattage at .5, 1, or 2 ohms. Gotta love smart amps. They are one of the best things to hit car audio in 30 years. I hope more companies go this way of smart amps.

[larrygaines]

Keep learning, you haven't quite seen the overall to home/ car audio, the 18 turns or the 32 turns moves the voice coil and the air pressure changes in front an rear of cone. Then physics takes over and pressure waves . They all sound different depending on the wave form and the material it rattles, if the rattle resembles the original we say it reproduces the sound. This is very good . The 50 years as a tech, helps, but there is so much more to love and learn . Keep on

[skatebunch]

You rock brother!!! We need somebody like you out here in this basshead world 🦾🦾🦾

[johnnycorn]

I'll put it to you like this I'm happy to spend twice as much on an amp to run it at 4 ohms instead of two, because of the dampening factor improving so much. Sounds better, no doubt.

[boydw]

Given two otherwise identical drivers, the only meaningful difference is the required amplifier output voltage to reach a given power level. Impedance in simple terms determines the current flow for a given voltage.
A lower impedance sees that given power level delivered as less volts & more amps (Volts x Amps = Watts).
Having lower impedance drivers is helpful in car environment, where you only have 12 - 14Vdc of supply voltage to start with, and creating amplifiers with high output voltage swing from a low supply voltage is difficult.

[T_Burd_]

There's other factors involved than just resistance. Any time you have a coil in a circuit you also have inductance and reactance. Inductive reactance increases with frequency and inductance. Capacitive reactance decreases with frequency and capacitance. These factors also affect a driver's ability to reproduce certain frequencies as well as the amplifier's power output. Piezo tweeters are literally disc capacitors, so capacitive reactance is the main factor on those. Also why piezo tweeters usually don't require a capacitor to filter out lower frequencies because that capacitance is built-in.

[sethgt]

I have a definitive technology powered subwoofer that has a 30 ohm subwoofer in it. The built in amplifier is pretty small. I think it's like 650 watts. The amplifier puts out a ton of voltage, but obviously not much current. I hooked up the subwoofer to my Orion HCCA 11000.1, and it pushed the subwoofer pretty good without blowing it right away.

[philipeli]

I have pioneer towers that read 11.5 ohms, unusually high I thought, but I always heard the less impedance the less control.I run 1 ohm subs now because car amps are dialed in to 1 ohm for max power.

[Mark_]

I like how in car audio now, an amp's THD and S/N is rated at 4 ohm, but the power is rated at 1 ohm (or the amp's minimum impedance).
So, the 4ohm and 8ohm speakers may "sound" the same, but the amp might not be as clean, especially at lower ohm load near max power. But honestly, it's probably undetectable.

[CharlesDowiot-qvpp]

4ohm good car Battery 8ohm good for House Electricity Both Good ✨️✨️

[OGJD]

In Watts it doesn't matter what voltage you start with. That's how much power the speaker is getting if it's 12 volts or 120 volts ac. Watts is volts x amps (current). Car speakers need more watts to drive past all the road noise and engine noise, ect. compared to a home. Sometimes watts is called VA or volt amps. In order to make an amp put out more wattage for a given design you can design it more heavy duty to run higher current and lower ohms like car audio. It takes a larger amp to run a higher wattage when you have more resistance. Low ohm loads almost pull power out of the amp. It's why low ohm loads are used in car audio to pull more power. Power is not near as much of a concern in homes with even thousands of dollar speakers running great off of only like 150 watts.

[MobileAudioPro]

IDK what youre talking about because in my living room I have jama surround sound speakers and an 18inch skar subwwofer all in my livign room and being powered all off car amplifiers and that includes mty surround sound speakers and I have been using the same 12v power supply that has a 100amp max and have been using this set up for over a year and aside from some noise troubleshooting I have almost no feedback either or diustortion and I use to have a hifi receiver but have since been happier using the car amplifiers. Its louder and cleaner sounding imo.

[irawardofficial]

Nice explanation !!
This is a real rabbit hole LOL.
I use notch filters to balance the frequencies that get amplified by Ohm fluctuation.
All amplifiers are DC at the output? AC amplifiers are converted to DC by the transformer/power supply.
The car has 12v X 670 amps = 8040watts and the home has 110v X 200amps equals 22000watts.

[Tekatogokuta]

thanks ive also noticed in car amps like taramos with out moving the gains at all just going from one sub to another example rf t2 then to a skar 6.5 sub no movement and at volumes that the t2 is slapping and moving air the 6.5 is moving taking it but way less like the amp knows the sub cant take and gives it less??? its od

[notyobiz]

when it comes to ohms on car vs home higher ohms are used in home maybe also in part due to a heavier coil for lower fs for better sq (more windings more weight more ohms is my logic) also tho, you get higher BL due to more windings. so for the same magnet and the same proportional gap at the same wattage an 8 ohm speaker should be the better ovrall performer due to higher bl and inherit lower fs, higher inherit sensitivity. this is also assuming the suspensions are proportionally adjusted. another up side to higher ohms is if you had a radio that is rated at 4 ohms but you ran it at 8 ohms i'd almost guarantee it runs more efficient. aside from having a heavy coil for lower fs and better sq you could use a heavier cone or looser suspension to achieve similar sq but as is such in cars "no replacement for displacement" (no replacement for more windings) the higher ohm speaker should be the winner when compared to a comparable clone of itself. just wanted to add that to the mix lol - nice vid brother

[tedtan]

The final tweak is always the EARS. It's called subjective listening.

[recordingwhiz]

The 4ohm/8ohm conversation is only 50% without taking amplifier's slew rate and damping factor into account at those specific impedance

[WadeTheWin]

Do you have a video on running tweeters active with a DSP? How to power them using a amp but not blowing them?