What are the difference in ohms

Yes, two 4 ohm speakers wired in series will present an 8 ohm load, though even with matched speakers they are likely to produce different volume levels.

It is probable the receiver will be quite happy using a single 4 ohm speaker if only modest volume levels are used. Many popular hi-fi amps quote power outputs for both 4 and 8 ohm indicating either could be used.

The best thing to do is place a VOM meter to confirm that there are 6 ohm speakers

They are probably trying to tell you that if your amplifier calls for a speaker system of 6 ohms or 8 ohms, then, it is not recommended to use a lower speaker system of 4 ohms or less. Why? Because at a lower impedance, the amplifier might not be able to handle the extra current and it might result in a poorer performance or damage to your amplifier. Hope this helps!!

As far as the speakers are concerned 6 ohm speakers should not have damaged the unit, unless some of the connections wires short circuited. But I think that would have blown the channel not reduced the volume. If you had connected 4 ohm speakers to a 6 ohm amp that would have been a different matter entirely.
The only thing that I can think off that would do this is some kind of circuit that detects the ohm level and adjust it when you put different ohm speakers on. 6 ohm speakers would off course be quieter than 4 ohm ones.
So if you have 6 ohm speakers still on then it will detect that and reduce the volume for them. But at the end of the day it connecting 4 ohm speakers back up should cause it to reset. It might take some time for this to happen!
If the device has a factory reset try that with the old speakers on it. That would reset it back to 4 ohms.
Otherwise get in touch with JVC to see if the unit does indeed have an adjustment ohm setting built in and see what they have to say.

you should use a 6 or 8 ohm speaker. if you use 4 ohms, you could possibly burn the amp out.

the speakers are 6 ohms, and it will be very difficult to find a receiver that is 6 ohm compatible. most home amps are 8 ohm, and will overheat and burn up when used with 6 ohm speakers.

the subowoofer is 4 ohms, but i am unsure as to whether it is self-powered, or if it is powered by the receiver.

4 ohms is the standard for car audio, and 8 ohms for home audio.

Officially this receiver supports only 6 and 8 ohm speakers. But for surround speakers it should not do any harm, because they are not played at full volume. But be sure to set yamaha for 6 ohm speakers.
Using only 4 ohm speakers makes the amplifier work more hard and produce more heat, that's why you can't use it at high volume.

That model of receiver goes into protect mode when there is really
low
resistance or a short on your speakers/wires. It does it to protect the
final drivers in your amp. Does it do the same thing with all of your
speakers disconnected? If it doesn't then you might have a problem with
one of your speakers or wires. Check your wires for shorts in them
first. That may be the only problem. That model is designed for 8 ohm
speakers, but you can go down two 6 ohms safely. I have a STR -D865 that

has been running 6 ohm speakers safely for almost 3 years now. A way to
check your speakers out is to take an ohm-meter across the terminals on
them(with the receiver unhooked). They should read anywhere between 8
and 4 ohms. Check with the manual on your speakers to see if they
correspond. If the resistance is really low, you may have a short in
that speaker. it is also possible that if they are 4 ohm speakers, you
could have damaged the drivers in your receiver. I know the model above
mine, (the 965) has a 4-8 ohm speaker selection switch on the back. The
lower models were not designed to run 4 ohm speakers. Hopefully this has

been of some help.

Brad / Luisa_K - usenet poster

You can plug in higher ohm speakers , the higher the ohm the higher the resistance is, it is a danger when you plug lower ohm speakers into a higer ohm Amp , at a high volume that will cause them to blow , the center speaker would be fine to use a higer ohm speaker , your best choice is to buy a Active Subwoofer, which means the sub has it's own power supply , and u can blast the thing as much as u like , thn u can turn the bass down on all the other speaker's so u can play it louder , and have the sub turned up has high as u like , this is the best way to get great sound with high volume , buy a Active sub woofer , any active subwoofer is ok , a active sub woofer has its own volume and inputs on the speaker ,