Poor impedance matching between your receiver or amplifier and your speakers can result in excessive clipping and damage your entire audio system.
Sometimes if you want quality sound, you may need to keep the volume extremely low. however, in some cases, you just don’t have the perfect team.
for example, what should you do if you have an 8 ohm amp or receiver but only 6 ohm speakers? is it safe to run an 8 ohm amp/receiver on 6 ohm speakers?
Usually it is fine to use 6 ohm speakers in series with 8 ohm amplifiers or receivers, as 8 ohms is not far from 6 ohms. however, you should be careful not to run your system too hard (don’t run it at high volume and don’t run the speakers in parallel).
Also, you should check the amplifier or receiver ratings as some receivers and amplifiers will output more power with lower speaker ohm ratings. Some receivers and amplifiers allow a range of impedance, for example they may be rated at 8 ohms but allow a minimum of 6 ohms.
quick introduction to impedance
Impedance is the degree to which an electronic device, such as a speaker, amplifier, or receiver, resists the flow of current. it is measured in ohms and is symbolized by the Greek letter omega (Ω).
In simpler terms, impedance means that the lower the impedance of your speaker, the more power it will draw from your amplifier/receiver. at the same time, the higher the impedance of the receiver/amplifier, the less power it can deliver to your speakers. that’s why it’s ok to use 8 ohm speakers in 4 ohm amps. however, this does not mean that 4-ohm speakers are better than 8-ohm speakers.
With this information, it is now much easier to see what happens when running an 8 ohm amp/receiver into 6 ohm speakers.
hopefully you can see from the explanation above that an 8 ohm amp or receiver will typically supply a little less power than a 6 ohm speaker would normally require. Is inadequate power supply harmful?
Not necessarily, but you should take precautions. let’s see more about nominal impedance to answer this in detail.
The term “nominal impedance” refers to the fact that the stated impedance on your speaker, receiver, or amplifier is an average.
When your audio system is running, its impedance changes based on factors such as the frequencies it produces. other reasons for impedance variation are:
- Each speaker driver has a unique resonant frequency: the driver moves freely at its resonant frequency. as it moves, it creates the counter emf, resulting in a significant increase in impedance.
- variation in voice coil inductance: at higher frequencies , the inductance increases and can cause the impedance to increase. the opposite is true at lower frequencies.
These are the main factors, but there are many others that sound engineers take into account before arriving at the nominal impedance you see in your electronic devices. since the impedance is an average, the actual figure keeps fluctuating.
so when we say our speaker impedance is 6 ohms, what do we mean? we mean that the speaker impedance may drop below 6 ohms at some point. it can also go up to 8 ohms or more, depending on frequencies occurring and other factors.
This means you can use your 8 ohm amp/receiver on 6 ohm speakers. Although the impedance difference is not ideal, it is within an acceptable range. this doesn’t necessarily mean that 8 ohm speakers are better than 6 ohm speakers, it’s about the ratings of your equipment.
It is important to note that we are dealing with a high impedance amplifier/receiver. this means that it supplies less power than your speakers require.
Assuming the impedance fluctuation is minimal, the argument that the current resistance difference is small may not be valid. this means you should not use your 8 ohm amp/receiver on these speakers. that may not be true if you can properly connect the speakers to the receiver/amplifier.
top tips for connecting 6 ohm speakers to an 8 ohm amp/receiver
To connect your speakers as needed and get quality sound, you need to do the following.
1. safe modern speakers
You need modern speakers to help you reduce the risk of using a speaker that draws more power than you need.
Modern speakers are designed to do this because their frequency fluctuations are tighter.
so if you choose the right speaker, you’ll get quality sound. plus, they have higher speaker sensitivity than previous versions. remember, we can increase the impedance of the speakers, as we will see next.
2. connect your speakers in series
Remember that the speaker wiring method you choose can increase or decrease impedance.
with series wiring, you add the impedance of your speakers. this means if you have two 6 ohm speakers you increase the impedance to 12 ohms. in other words, it cuts the power requirement in half.
There are instances where you can opt for parallel wiring. however, it would be better if you didn’t try this here. By connecting two speakers in parallel, you cut the overall impedance in half. this means it doubles the power requirement of the speakers.
In our case, if we do the wiring in parallel, we reduce the impedance to 3 ohms. here is the calculation:
total impedance = product of impedances / sum of impedances
= 36 / 12 = 3
This means that your two speakers will likely draw more power than your receiver or amplifier can supply. can be dangerous, especially if you keep the volume up. the energy demand increases as the volume increases.
You can also connect different speakers of different impedance. just make sure the total impedance is not less than 6 ohms in this case. so you can run 8 ohm speakers and say 12 ohms, but it will be risky to run 6 ohm vs. 8 ohm speakers and even more risky to run 8 ohm vs. 4 ohm speakers in parallel.
just make sure you do the calculation as shown above to see exactly what you’re working with.
Parallel wiring should be avoided, especially if you want quality sound at high volume.
Otherwise, heat can build up and cause the speakers and receiver/amplifier to explode. sometimes you may experience excessive clipping before that happens.
check and adjust the impedance setting of your receiver
many receivers have settings you can use to match their impedance to your 6 ohm speakers.
all you need to do is reduce the impedance to 6 ohms. other receivers have an allowable range of impedance, for example a receiver may be rated at 8 ohms but allow a minimum of 6 ohms.
see this below:
This option may not be helpful in some cases. Considering that the figures we are talking about here are nominal values, changing your receiver settings manually can reduce overall system performance. this usually happens if you choose a lower impedance setting.
where applicable, you can choose a higher impedance setting and get better sound quality.
Use of impedance settings generally limits the receiver’s ability to assign the most appropriate impedance at different times.
what is the difference between 6 ohm and 8 ohm speakers?
The main difference between 6 and 8 ohm speakers is resistance. the lower the resistance, the easier it is for the electrical signal to pass through the speaker. most speakers produced today have impedance ratings of 4, 6, or 8 ohms. 8 ohms is an easier load for an amp when compared to 6 ohms.
can a 4 ohm amp drive 6 ohm speakers?
4 ohm speakers are another story, they can put more demands on 6 or 8 ohm receivers and amp power reserves, but even those receivers/amps will have no problem with 4 ohm speakers as as long as you’re not playing music or movies at a very high volume.
are 6 ohm speakers better?
The lower the resistance, the more efficiently it will allow the electrical signal from the music input to pass through the speaker. 6 ohm speakers are definitely better compared to 4 ohm as they put a lighter load on the amps.
Are 6 ohm speakers better than 8 ohm speakers?
8 ohms is an easier load for an amp when compared to 6 ohms. here’s a simple example: an 8 ohm speaker using 50 watts of power will require double that at 4 ohms.
what amp do i need for 6 ohm speakers?
6 ohm speakers would require something powerful for that level of power, you should look for a high end receiver or integrated amplifier. can also drive 6-ohm speakers with 8-ohm amplifiers.
Why does power capacity matter?
When we talk about impedance, we cannot forget about current and power. matters.
A proper understanding of current will help you avoid wasting a lot of time trying to understand the complex impedance specifications that others present.
Current is the most important thing your amplifier/receiver provides and what your speakers need. If your amplifier/receiver is a high-current design that delivers at least 100 watts per channel without distorting the sound, you don’t have to worry about overloading your 6-ohm speakers.
If you have a high-quality amplifier/receiver, it will draw the required voltage from the wall outlet and power your speakers with the necessary current. By doing this consistently, you are guaranteed to get high-quality sound every time.
When using an 8 ohm amplifier or receiver on 6 ohm speakers, you should opt for series wiring. increases the overall impedance of the speaker.
More importantly, if you don’t want to get lost in the impedance weeds, remember to choose high-quality speakers and a receiver or amplifier capable of delivering the current your speakers require.